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NBSIR 85-3118

7th Joint Panel Meeting of the

UJNR Panel on Fire Research and

Safety

N. H. Jason

K. Davis

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Center for Fire Research

Gaithersburg, MD 20899

March 1985

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7TH JOINT PANEL MEETING OF THE

UJNR PANEL ON FIRE RESEARCH AND

SAFETY

N. H. Jason

K. Davis

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Center for Fire Research

Gaithersburg, MD 20899

March 1985

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler. Director

SEVENTH JOINT PANEL MEETING

OF THE UJNR PANEL ON

FIRE RESEARCH AND SAFETY

Joint with Combustion Toxicity and 2nd Expert Meeting of the

U.S.-Japan-Canada Cooperative Research Group on Toxicity of Combustion

Products from Building Materials and Interior Goods

October 24-28, 1983

National Bureau of Standards

Gaithersburg, Maryland

TABLE OF CONTENTS

Page

Agenda vii

List of Members (Japan) xi

List of Members (U.S.) xiv

List of Combustion Toxicity Participants xvi

Group Photograph xviii

OPENING SESSION 1

FIRE HAZARD/RISK MANAGEMENT METHODS 5 Progress Reports:

Progress Report to 7th UJNR Panel on Fire

The Recent Japanese Progress Report on Fire Risk Analysis Method.. 13

Methods of Designing and Evaluating Facilities for Fire Safety 17

Discussion 29

Development of Design System for Building Fire Safety 31

Discussion 39

Human Reactions During Residential Fires: Establishing a Data Bank.. 41

Discussion 51

A Study on Fire Risk Analysis Method for Multi-Use Buildings 53

Discussion

Fire Safety Evaluation Method 79

Discussion 87

General Discussion 89

FIRE GROWTH PREDICTION 93

Progress Reports:

Fire Spread Research in the United States 95

Recent Progress in Fire Growth Modeling in Japan 109

An Assessment of Fire Induced Flows in Compartments 121

Discussion 151

Pre-Flashover and Flashover Behavior in Compartment Fires 153

Discussion 177

Preliminary Report on a Msdel to Describe the Flow in the Ceiling

Layer of a Two Layer Fire Model 179

Discussion 189

The Models to be Developed in Fire Safety Design Project 191

A Model for the Transport of Fire, Smoke, and Toxic Gases (FAST) 209

Discussion 271

Smoke Movement as a Density Current 273

Discussion 285

General Discussion 287

MATERIALS FIRE PROPERTIES AND TEST METHODS 291

Progress Reports:

Materials Fire Properties and Test Methods 293

Discussion 299

Recent Advances in Materials Fire Properties and Test Methods 301

Discussion 309

iii
Page

Identification of Fire Properties Relevant to the Prediction of

Fire Growth 311

Discussion 323

Concepts on Flame Spread Testing 325

A Methodology of the Sensitivity Analysis of Building Properties on

the Occurrence of Flashover 341

Discussion 367

Fire Engineering Test Development: Bench-Scale Tests to Predict

Full-Scale Behavior 369

Discussion 391

Materials Fire Properties and Test Methods to be Developed 393

Discussion 399

General Discussion. 401

COMBUSTION TOXICITY AND 2ND EXPERT MEETING OF THE COOPERATIVE RESEARCH

GROUP ON TOXICITY OF COMBUSTION PRODUCTS FROM BUILDING MATERIALS AND

INTERIOR GOODS 403

Progress Reports:

Progress Report on Combustion Toxicity Research In the U. S 405

Discussion 411

U. S.A.-Canada-Japan Cooperative Research on Evaluation of

Combustion Gas Toxicity 413

Studies on Determination of Burning Condition for the Toxicity Test.. 419

Discussion 445

Conditions Conducive to the Generation of Hydrogen Cyanide from

Flexible Polyurethane Foam 447

Discussion 469

Development of Laboratory Test Apparatus for Evaluation of Toxicity

of Combustion Products of Materials in Fire 471

Discussion 487

Evaluation of a Method for Acute Toxicity of Smoke from Polymeric

Materials 489

Discussion 503

Support Paper

Closed- type Burning Testing Apparatus for Plastic Materials 505

MEASUREMENT METHODS 521

Progress Reports:

Current U. S. Advances in Fire Research Techniques 523

Discussion 535

Various Measurement Methods on Fire Research 537

Discussion 545

New Developments in Fire Protection - Evolution to the Systems

Approach 547

A Measurement of Doorway Flow Induced by Propane Fire 565

Discussion 583

Flammability Testing: State-of-the-Art 585

Discussion 607

IV
Page

COMBUSTION TOXICITY (CONT.) 609

Discussion After Progress Report on Canadian Activities 611

Study on Evaluation of Toxicity By Gas Using Pure Gas 613

Discussion 623

General Discussion 625

OPEN TECHNICAL SESSION 627

Analysis of the Fire Protection Cost Index 629

Discussion 641

An Example of Human Behavior in a Hotel Fire 643

Discussion 655

Panel Discussion on Capabilities of Fire Growth Prediction 657

CLOSING SESSION 661

Chairmen's Reports on Technical Sessions

Fire Hazard/Risk Management Methods 663

Fire Growth Prediction 665

Materials Fire Properties and Test Methods 667

Combustion Toxicity and 2nd Expert Meeting of the US-Japan-Canada

Cooperative Research Group on Toxicity of Combustion Products from

Building Materials and Interior Goods.. 669

Measurement Methods 671

Resolutions 673

Closing Addresses 675

Participant's Index 677

v

AGENDA

Seventh Joint Meeting

of the

U.S. -Japan Panel on Fire Research and Safety

October 24-28, 1983

at the

National Bureau of Standards

Monday, October 24

8:30

9:00

OPENING SESSION - 10th Floor Conference Room, Administration Bldg.

Bus leaves Sheraton for NBS

Call to order by Dr. Richard G. Gann, Coordinator, 7th Panel Meeting

Remarks by Dr. John W. Lyons, Acting Deputy Director, National

Bureau of Standards

9:40

Remarks by Mr. Hiroto Ishida , Science Counselor, Embassy of Japan

Remarks and Introduction of U.S. Panel members by Dr. Jack E. Snell,

Director, Center for Fire Research

Remarks and Introduction of Japanese Panel members by

Dr. Katsuro Kamimura, Director General, Building Research Institute

Election of Officers

Approval of Proceedings of the 6th Panel Meeting

Approval of Agenda for the 7th Panel Meeting

Election of Session Chairmen

Appointment of Resolution Committee

Other Business

9:50

10:00

Group Photograph - Red Auditorium Steps

Break - Outside Lecture Room D

10:20

FIRE HAZARD/RISK MANAGEMENT METHODS - Lecture Room D

Progress Reports:

Progress Report to 7th UJNR Panel on Fire H. Nelson

The Recent Japanese Progress Report on Fire Risk Analysis Method K. Kishitani/T. Jin

10:50 Methods of Designing and Evaluating

Facilities for Fire Safety L. Cooper

11:40

1:10

Formal Lunch - Employees Lounge

Development of Design System for Building

Fire Safety T. Wakamatsu

2:00 Human Reactions During Residential Fires:

Establishing a Data Bank J. Keating

2:50 A Study on Fire Risk Analysis Method

of Multi-Use Buildings A. Sekizawa/T. Jin

3:40

4:00

Break

Fire Safety Evaluation Method Tokyo Fire Department

(Speaker: T. Jin)

4:50

5:30

5:40

7:00

9:30

General Discussion

Adj ourn

Bus leaves for Sheraton Potomac Inn

Bus leaves hotel for reception at home of Dr. Jack E. Snell

Bus returns to Sheraton

vii
Tuesday, October 25

8:30

9:00

9:30

10:20

11:10

11:30

12:20

12:30

1:30

2:20

3:10

3:40

4:30

5:00

5:10

6:45

FIRE GROWTH PREDICTION - Lecture Room D

Bus leaves Sheraton for NBS

Progress Reports:

Fire Spread Research in the United States

Recent Progress in Fire Growth Modeling

in Japan

An Assessment of Fire Induced Flows in

Compartments

Pre-Flashover and Flashover Behavior

in Compartment Fires

Break

Preliminary Report on a Model to Describe

the Flow in the Ceiling Layer of a Two

Layer Fire Model

Break

Buffet Lunch - Senior Lunch Club

The Models to be Developed in Fire Safety

Design Project

A Model for the Transport of Fire, Smoke,

and Toxic Gases (FAST)

Break

Smoke Movement as a Density Current

General Discussion

Adj ourn

Bus leaves for Sheraton

Bus leaves hotel for Cracked Claw Restaurant

H. Emmons

T. Wakamatsu

J. Quintiere

H. Takeda

E . Zukoski

T . Tanaka

W. Jones

M. Tsujimoto

Wednesday , October 26

MATERIALS FIRE PROPERTIES AND TEST METHODS - Lecture Room D

8:30 Bus leaves Sheraton for NBS

9:00 Progress Reports

:

Materials Fire Properties and Test Methods P . Pagni

Recent Advances in Materials Fire

Properties and Test Methods H. Suzuki

9:30 Identification of Fire Properties Relevant

to the Prediction of Fire Growth A. Tewarson

10:20 Concepts on Flame Spread Testing T. Hirano

11:10 Break

11:30 A Methodology of the Sensitivity Analysis

of Building Properties on the Occurrence

of Flashover Y. Hasemi

12:20 Break

12:30 Buffet Lunch - Senior Lunch Club

1:30 Tour of Building 205

3:00 Break

3:20 Fire Engineering Test Development:

Bench-Scale Tests to Predict Full-Scale

Behavior V. Babrauskas

4:10 Materials Fire Properties and Test

Methods to be Developed H. Suzuki

viii
5:00

5:30

5:40

General Discussion

Adjourn

Bus leaves for Sheraton

Thursday, October 27 Parallel Sessions

1. COMBUSTION TOXICITY and 2ND EXPERT MEETING OF THE U.S

COOPERATIVE RESEARCH GROUP ON TOXICITY OF COMBUSTION

BUILDING MATERIALS AND INTERIOR GOODS - Lecture Room

8:30 Bus leaves Sheraton for NBS

9:00 Progress Reports:

Progress Report on Combustion Toxicity

Research in the U.S. E U. S. A. -Canada-Japan Cooperative Research

on Evaluation of Combustion Gas Toxicity I 9:45 Studies on Determination of Burning

Condition for the Toxicity Test 1 10:35 Break

10:50 Conditions Conducive to the Generation of

Hydrogen Cyanide from Flexible Polyurethane

Foam E 11:40 Development of Laboratory Test Apparatus

for Evaluation of Toxicity of Combustion

Products of Materials in Fire S 12:30 Buffet Lunch - Senior Lunch Club

1:40 Evaluation of a Method for Acute Toxicity

of Smoke from Polymeric Materials "5 2:30 Tour of Building 224

4:30 Bus leaves for Sheraton

6:45 Depart for Blackie's House of Beef, Washington,

2. MEASUREMENT METHODS - Polymer Building, Room B-119

9:00

9:30

10:20

10: 50

1:40

2:30

2:30

4:30

6 : 45

Progress Reports:

Current U.S. Advances in Fire Research

Techniques F Various Measurement Methods on Fire Research 1 New Developments in Fire Protection - Evolution to the Systems Approach J Break

A Measurement of Doorway Flow Induced by

Propane Fire I Flammability Testing State-of- the-Art J Buffet Lunch - Senior Lunch Club

Tour of Building 224

Bus leaves for Sheraton

Depart for Blackie's House of Beef, Washington,

. -JAPAN-CANADA

PRODUCTS FROM

D

. . Gann

. Saito

. Tanaka

. Levin

. Yusa

. Alarie

D.C.

. Friedman

. Jin/S. Yamashika

. Beyreis

. Tanaka

. de Ris

D.C.

IX
Friday, October 28 Parallel Sessions

1. COMBUSTION TOXICITY (Continued) - Lecture Room D

8:30 Bus leaves Sheraton for NBS

9:00 Progress Report on Canadian Activities Y. Tsuchiya

9:50 Study on Evaluation of Toxicity by Gas

Using Pure Gas Y. Nishimaru

10:40 Break

11:00 General Discussion

11:30 Formal Lunch - Employees Lounge

2. OPEN SESSION - Polymer Building, Room B-119

9:00 Analysis of the Fire Protection Cost Index H. Nakamura

9:50 An Example of Human Behavior in a Hotel S. Okishio/T. Handa/

Fire K. Kawagoe

10:40 Break

11:00 Panel Discussion on Capabilities of Fire

Growth Prediction

Panelists: H. Emmons, T. Hirano, P. Pagni

T. Tanaka

Moderator: J. Quintiere

11:30 Formal Lunch - Employees Lounge

CLOSING SESSION - 10th Floor Conference Room

1:45 Closing Session, Chairman

1:50 Chairmen’s Reports on Technical Sessions

2:50 Resolutions

3:30 Closing Addresses: U.S., Japan

3:50 Adj ourn

4:00 Bus leaves for Sheraton

x
LIST OF MEMBERS (JAPAN)

Panel Members

Dr. Katsuro Kamimura (Japanese Chairman)

Director General

Building Research Institute

Ministry of Construction

Dr. Takao Wakamatsu

Director, Environment, Design, & Fire Department

Building Research Institute

Ministry of construction

Dr. Tadahisa Jin

Chief, Life Safety Section, The 3rd Research Division

Fire Research Institute

Fire Defense Agency

Ministry of Home Affairs

Dr. Ai Sekizawa

Research Member, Fire Physics Section

The 1st Research Division

Fire Research Institute

Fire Defense Agency

Ministry of Home Affairs

Dr. Hiroaki Suzuki

Head, Smoke Control Division

Environment, Design, & Fire Department

Building Research Institute

Ministry of Construction

Dr. Takeyoshi Tanaka

Chief Research Member

Testing and Evaluation Department

Building Research Institute

Ministry of Construction

Dr. Shyuitsu Yusa

Research Member, Organic Materials Division

Material Department

Building Research Institute

Ministry of Construction

Mr. Masazo Furuya

Research Institute for Polymer and Textile

Agency of Industrial Science and Technology

Ministry of International Trade and Industry

xi
Dr. Yuji Hasemi

Research Member, Smoke Control Division

Environment, Design, & Fire Department

Building Research Institute

Ministry of Construction

Associate Members

Professor Koichi Kishitani

Department of Architecture

Faculty of Engineering

University of Tokyo

Dr. Fumiharu Saito

Head, Test Division

Testing Laboratory of Center for Better Living

Professor Kunio Kawagoe

Dean of Faculty of Science and Technology

Science University of Tokyo

Professor Makoto Tsujimoto

Department of Architecutre

Faculty of Engineering

University of Nagoya

Professor Yoichi Nishimaru

Dean, School of Medicine

Yokohama City University

Professor Takashi Handa

Department of Applied Chemistry

Faculty of Science

Science University of Tokyo

Professor Toshisuke Hirano

Engineering Research Institute

Faculty of Engineering

University of Tokyo

Observers

Mr. Tomoyuki Mizuno

Department of Architecture

Faculty of Science and Technology

Science University of Tokyo

Mr . Hiroyuki Nakamura

Planning Division

The Research Institute of Shimizu Construction Co., Ltd.

xii
Dr. Hisahiro Takeda

Department of Reaction Chemistry

Faculty of Engineering

University of Tokyo

Dr. Toshimi Hirata

Forestry Research Institute

Ministry of Agriculture, Forestry, and Fishery

Dr. Masahiro Morita

Department of Applied Mathematics

Faculty of Science

Science University of Tokyo

xiii
LIST OF MEMBERS (U.S.)

Panel Members

Dr. Jack Snell (U.S. Chairman)

Director, Center for Fire Research

National Bureau of Standards

Professor John Bryan

Chairman, Department of Fire Protection

University of Maryland

Professor Howard Emmons

Division of Applied Science

Harvard University

Dr. Raymond Friedman

Vice President for Research

Factory Mutual Research Corporation

Mr. Harold Nelson

Chief, Facility Fire Safety Performance

Center for Fire Research

National Bureau of Standards

Professor Patrick Pagni

Mechanical Engineering; Dept.

University of California

Dr. Takashi Kashiwagi (Secretary)

Exploratory Fire Research

Center for Fire Research

National Bureau of Standards

Speakers

Professor Yves Alarie

Chairman, Department of Industrial

Environmental Health Sciences

Graduate School of Public Health

Dr. John de Ris

Factory Mutual Research Corporation

Professor Edward Zukoski

California Institute of Technology

Dr. Archibald Tewarson

Factory Mutual Research Corporation

Professor John P. Keating

Department of Psychology

University of Washington
Dr. Gordon Hartzell

Southwest Research Institute

Mr. Janes Beyreis

Underwriters Laboratories, Inc.

Dr. Leonard Cooper

Facility Fire Safety Performance

Center for Fire Research

National Bureau of Standards

Dr. Walter Jones

Snoke & Toxic Gases

Center for Fire Research

National Bureau of Standards

Dr. Janes Quintiere

Head, Fire Growth Processes

Center for Fire Research

National Bureau of Standards

Dr. Vytenis Babrauskas

Head, Materials Fire Properties

Center for Fire Research

National Bureau of Standards

Dr. Barbara Levin

Head, Fire Toxicology

Center for Fire Research

National Bureau of Standards

Dr . Richard Gann

Chief, Fire Measurement and Research Division

Center for Fire Research

National Bureau of Standards

xv
Combustion Toxicity Participants

Dr. Yoshi Tsuchiya

Division of Building Research

National Research Council of Canada

Dr. K. Sumi

Division of Building Research

National Research Council of Canada

Mr. Yasuo Kuchinomachi

Industrial Products Research Institute

xvi

Names of Participants

(Reading left to right, from the bottom row)

Richard Gann

Jack Snell

Sam Kramer

Hiroto Ishida

Katsuro Kamimura

Kunio Kawagoe

Takashi Kashiwagi

Shyuitsu Yusa

Tadahisa Jin

Howard Emmons

Edward Zukoski

Takeyoshi Tanaka

Takashi Handa

Koichi Kishitani

Toshisuke Hirano

Hiroyuki Nakamura

Masazo Furuya

Takao Wakamatsu

Barbara Levin

Yoichi Nishimaru

Hiroaki Suzuki

Fumiharu Saito

Hisahiro Takeda

Yuji Hasemi

Ai Sekizawa

Tomoyuki Mizuno

Leonard Cooper

Makoto Tsujimoto

James Quintiere

Harold Nelson

Raymond Friedman

John Bryan

xviii
OPENING SESSION

Opening Session

Dr. Richard Gann, Coordinator for the 7th UJNR Panel Meeting, opened the joint

session by welcoming the delegation to the National Bureau of Standards (NBS).

He then introduced Dr. John Lyons, Acting Deputy Director of NBS (and former

Chairman of the UJNR U.S. delegation) and Mr. Hiroto Ishida, Science Counselor,

Embassy of Japan. Opening remarks were made both by Dr. Lyons and Mr. Ishida.

Dr. Jack Snell, Director, Center for Fire Research, and Dr. Katsuro Kamimura,

Director General, Building Research Institute, introduced the United States and

Japanese panel members.

The Combustion Toxicity and 2nd Expert Meeting of the U. S. -Japan-Canad

a

Cooperative Research Group on Toxicity of Combustion Products from Building

Materials and Interior Goods was held in conjunction with the 7th UJNR anel

Meeting. The Combustion meeting took place on Thursday and Friday, October 27

and 28, 1983.

Selection of the Chairmen for the sessions was made. The Panel voted

unanimously to make the following individuals session chairmen:

Fire Hazard/Risk Management Methods K. Kawagoe J. Bryan

Fire Growth Prediction R. Friedman T. Hirano

Materials Fire Properties and Test Methods T. Handa H. Nelson

Combustion Toxicity Meeting R. Gann K. Kishitani

F. Saito

Measurement Methods P. Pagni

Open Technical Session T. Wakamatsu

The minutes of the Sixth Joint Panel Meeting in Tokyo were approved and will be

printed in the Proceedings to be published by the Japanese delegation.

The agenda for the week was reviewed and approved. Procedural details for the

sessions were discussed.

The opening session adjourned after the above-mentioned discussions were completed. The group photograph was taken.

3

FTRE HAZARD/RISK MANAGEMENT METHODS

Kunio Kawagoe and John Bryan

Session Chairmen

5

Progress Report to 7th UJNR Panel on Fire

Facility Fire Safety and Risk Analysis Methods

H.E. Nelson, National Bureau of Standards, USA

This report covers progress on the development and delivery of quantitative procedures for fire safety analysis and fire risk analysis in

facilities

.

Fire safety analysis methods concern measurement of facility performance

in a stipulated fire. The stipulated fire may be a "design stress"

(envisioned as a potential method of classifying occupancies) or a specific stipulated fire of particular interest. The object is to

determine the capability of a specific facility or design given a potential fire stress.

Fire risk analysis involves a measurement of the intergrated risk

imposed upon the occupants and/or monitary values in a facility con- sidering the spectrum of potential fire scenarios and the likihood of

occurrence of each scenario.

Fire science and related modeling developments have matured over the

past several decades. It is now possible to make at least primitive

analytical models of many situations from the point of ignition to the

final determination of impact. Current analysis methods build on fire

growth models and empirical data and analyical calculations.

Figure 1 is a schematic outline of this approach. To date this approach

has been applied to fire safety analysis rather than risk analysis. The

fire safety analysis approach starts with emperically derived rates of

heat release and rates of other products produced. This input is

obtained from rate of heat release tests. Given this stress, the

development of threat is modeled as an energy producing process that

evolves an energy bearing fluid (smoke and gases.) The building and the

fire safety systems present react to this stress by absorbing it, removing

it, or undergoing some types of change in response to the stress. The

type, level of intensity, location, and time of occurrence of change are determined. Concurrently the capability of occupants to avoid undesirable

conditions by escape or relocation is modeled.

Currently there exists varying degrees of capability to analytically

model each of the system elements in Figure 1 except for the effectiveness of extinguishing agents and the prediction of the decision made by

individuals receiving an alarm or other fire cue. The level of capability

however varies widely from very primitive estimates to advanced models

with a significant degree of confidence.

7
Verification testing to establish the level confidence to be placed in

these methods is essential. Two large scale verification testing programs

will be initiated in the coming year. One will be conducted entirely at

the National Bureau of Standards. The other will be jointly undertaken

by the National Bureau of Standards and Factory Mutual Research Corporation.

Human Behavior Elements

Modeling efforts related to emergency movement were reported at the 6th

Joint Panel meeting. The development of the Escape and Rescue Model (1)

and the EVACNET+ model (2) are continuing. These models are approaching

useability by the practicing profession. Both, however, suffer from the

parsity of data on specific human performance variables.

Two items relative to the necessary variables can be reported. The work

of J.L. Pauls, National Research Council of Canada, on the effective

width model and the relevance of stairway dimensions (also reported on

at the 6th Joint Panel meeting) is receiving increased recognition and

acceptance. His model and related variables is currently undergoing

public comment review as part of a proposal from the Committee on Safety

to Life of the National Fire Protection Association (3) for inclusion in

the next edition of the Life Safety Code.

In a separate vein Pearson and his colleagues at the University of North

Carolina (4) have completed and issued a report on their studies of the

time involved in the initial actions involved in escaping a residential

fire. Pearson's work involved both young adults (college students) and

elderly persons a number of whom suffer from arthritis. The time differentials found by Pearson appear to be less than expected.

Work on development of the underlining data on human behavior cause relationships continues slowly. The principal investigators in this area are Dr. John Keating, University of Washington and Dr. John Bryan,

University of Maryland. Bryan's most recent work is covered under the

heading of investigations. Keating has been working on the development

of improved interviewing techniques. He is seeking better and more

reliable data on behavior initiating conditions and rationale involved,

and the actual results as related to the expectations. Keating is also

attemping to develop relationships and commonalities that may lead to

future modeling. Currently Keating has trained emergency response

personnel of the New York City chapter of the American Red Cross in his

technique. These persons respond to every significant fire that harms

or displaces persons. It is expected that this project will produce a massive increase in the data base.

Investigations

On the fire investigation front, the future of the National Fire Incident

Reporting System (NFIRS) remains uncertain, due to federal reorganizations

and budget cuts. Decisions regarding NFIRS development and growth are expected to be made shortly. On a more positive note, the NBS Fire

Investigation Handbook (5) continues to be widely used - over 5000

copies have been sold. In addition, several new projects in the investigative area have begun at NBS. One is the analysis of detailed electrical

8
: Ire investigations to determine the sequence of events and failure

modes which led to ignition. Special investigations were conducted for

over one hundred cases in ten cities, and are being studied in this

project. Another ongoing project is the NBS sponsored interlaboratory

evaluation program, involving the recovery and analysis of accelerants.

The purpose of this project is to develop a consensus standard for use

by forensic laboratories in the investigation of suspected arson fires.

Also, two projects are underway which are attempting to develop methods

of detecting the presence of accelerants on soot. One is using gas

chromatography, while the second approach uses a mass spectrometer.

Dr. John Bryan, University of Maryland has continued investigation of

human behavior through questionnaires sent to survivors of fires. He

has provided the following summaries on two such activities.

The questionnaire utilized in the study of participants in the MGM Grand

Hotel Fire, and reported on at the 6th UJNR Panel on Fire Research and

Safety in Tokyo was modified slightly for a human behavior study of the

Westchase Hilton Hotel fire. The fire occurred in Houston, Texas on 6,

March, 1982. The study of the behavior of the participants in this fire

incident was based on 42 written questionnaires, returned from the 130

questionnaires mailed out for a response rate of approximately 32 per

cent. In addition, behavioral data was obtained from the transcripts of

13 interviews conducted by Houston Fire Department personnel. Thus, a total participant population of 55 persons was obtained from the approximately 200 persons believed to be in the hotel at the time of the fire.

This incident occurred on March 6, 1982 at approximately 2:25 a.m. The

questionnaires were initially mailed out 34 days after the fire incident,

with a follow up mailing on June 7, 1982. The last questionnaire used

in the study was received August 7, 1982.

The questionnaire were in a similar format to the MGM Study (6) and

consisted of four pages with a total of 27 check off, completion and

fill in items. The last item contained a diagram of the floor plan of

the twelve story hotel for the guests to indicate their movements within

the building and their egress route from the building. The study elicited

the first five actions of the guests, their means of awareness of the

fire, and their evacuation or refuge actions in the fire incident. The

analysis of the study examined the guest’s age, being alone or with

others, their previous training, previous fire experience, convergence

cluster formation, and reentry of the building.

The questionnaire used in the MGM Grand Hotel fire study (6) and the

Westchase Hilton Hotel fire study (7) was sent to the Fort Worth, Texas

Fire Department, two days after the 14, June, 1983 fire at the Ramada

Inn. The questionnaire was duplicated and mailed out to 65 of the

occupants registered in the hotel at the time of the fire incident. The

questionnaire was mailed out the week after the fire. As of August 12,

1983, 40 questionnaires had been returned. The data is being initially

analyzed by the Fort Worth Fire Department. Copies of the questionnaire

responses will be sent to both the National Fire Protection Association

and the University of Maryland for addition to their data bases and

further analysis.

9
A significant need exists for advancement of fire modeling and similar

capabilities to allow rational recreation of the thermodynamics and

human behavioral actions that occurred in actual fires. The potential

exists using the knowledge of physics of fire to fill the gaps between

data and reconstruct the actual course of a fire event. A prime example

of the potential of such was demonstrated by Emmons in his article, "The

Analysis of a Tragedy" recently published in Fire Technology (8)

.

Smoke Control

To help engineers design smoke control systems, Klote, J.H. and Fothergill,

J.W. , have developed a manual entitled "Design of Smoke Control Systems

for buildings" (9). This manual is being simultaneously published by

both NBS and the American Society of Heating, Refrigerating and Air

Conditioning Engineers.

Automatic Sprinklers

Methods have been developed over the past year by Evans (10) and by

Heskestad and Delichatsios (11) to adapt calculations of sprinkler

response time to fires in single density ambients to the problem of rooms containing two layers. The response time of ceiling pendent

sprinklers can be calculated for room sizes found in residential dwellings.

Computer codes based on two zone room fire models require the user to

specify only the room geometry, properties of the construction materials,

and a heat release rate history for the fire. Quasistudy flow approximations are employed to calculate unsteady fires. Some Validation

studies have been completed in idealized axisymmetric enclosures.

Additional data will be collected in rooms with realistic geometry to assess the accuracy and limitations of the calculation.

10
REFERENCES

(1) Alvord, Daniel M. , "Status Report of Escape and Rescue Model", Washington,

D.C. National Bureau of Standards, 1983, Report No. NBS-GCR-83-432.

(2) Francis, R.L. and Chalmet, L.G., "Network Models for Building Evacuation;

A Prototype Primer, " Washington, D.C. National Bureau of Standards, 1982,

Report No. NBS-GCR-81-316 (Kisko, T.M. and Francis, R.L. "EVACNET+ Users

Guide," Industrial and Systems Engineering Department, University of Florida,

Gainesville, Florida, May 1983)

(3) Report of Committee on Safety to Life, Proposal 101-678; Appendix D

Alternate Calculation for Stair Widths; 1984 Annual Meeting Technical

Committee Reports, pp. 502-506; National Fire Protection Association,

Quincy, Massachusetts, 1984.

(4) Pearson, R.G. , and Joost, M.G., Egress Behavior Response Times of Handicapped

and Elderly Subject to Simulated Residential Fire Situation, Washington D.C.,

National Bureau of Standards, 1983, Report No. NBS-GCR-83-429

.

(5) Fire Investigation Handbook, U.S. Dept, of Commerce, National Bureau of

Standards, Handbook 134, Brannigan, Francis L. , Editor, Univ. of Maryland

Rescue Institute, Adjunct Staff, College Park, Md., 20742, Bright, Richard

G. and Jason, Nora H. , Editors Center for Fire Research, National Engineering

Laboratory, National Bureau of Standards, Washington, D.C., 20234, August, 1980.

(6) Bryan, John L. , An Examination and Analysis of the Dynamics of the Human

Behavior in the MGM Grand Hotel Fire, Clark County, Nevada, November 21,

1980

.

Quincy: National Fire Protection Association, Revised Edition,

August, 1983.

(7) Bryan, John L. , An Examination and Analysis of the Dynamics of the Human

Behavior in the Westchase Hilton Hotel Fire, Houston, Texas on March 6, 1982. Quincy: National Fire Protection Association,

September, 1983.

(8) "The Analysis of a Tragedy", Howard W. Emmons, Fire Technology, Vol. 19,

No. 2 (May 1983) pp. 115-124.

(9) Klote, J.H. and Fothergill, J.W. , Design of Smoke Control Systems for

Buildings, National Bureau of Standards (U.S.), NBS Handbook 141, and

American Society of Heating, Refrigerating and Air-Conditioning Engineers,

Atlanta, Georgia, 1983.

(10) Evans, D.D. , "Plume Flow in a Two-Layer Environment," HTD Vol. 25, Book

No. H00269, Fire Dynamics and Heat Transfer , American Society of Mechancial

Engineers, N.Y. , N.Y1, Proceedings 1983 NHTC held in Seattle, Washington.

(11) Heskestad, G. and Delichatsios , M. , "The Initial Convective Flow in Fire,"

Seventeeth Symposium (International) on Combustion, The Combustion Institute,

Pittsburgh, Pennsylvania, 1978.

11
ADJUSTMENTS

4

12
THE RECENT JAPANESE PROGRESS REPORT

ON FIRE RISK ANALYSIS METHOD

by

Koichi KISHITANI

Faculty of Engineering

Department of Architecture

University of Tokyo

Tadahisa JIN

Fire Research Institute

Fire Defence Agency

Ministry of Home Affairs

Seventh Joint Meeting

U.S. Japan Panel on Fire Research and Safety

UJNR, Washington, D.C. Oct .24-28, 1983

13
THE RECENT JAPANESE PROGRESS REPORT

ON FIRE RISK ANALYSIS METHOD

Koichi KISHITANI and Tacahisa JIN

The research programs relating to "the Fire Risk Analysis Method" have

been conducted under 3 project groups in Japan. One of the projects is

conducted at Tokyo Fire Department and now in the improvement stage for

practical use. The other two studies started simultaneously in April 1982

at Fire Defence Agency, Ministry of Home Affairs and Ministry of Construction.

The main purpose of "the Evaluation Method" developed at Tokyo Fire

Department is to diagnose fire safety of the specified buildings with scoring

system to make the problems clear and to advise building managers or owners

of the adequate methods for improvement of fire safety. To make the long

story short, this method is a systematic methodology for evaluation of human

life safety estimated by summing up scores of 34 fire safety countermeasurement items. These 34 items were selected from 134 fire case study as the

most important influential factors to human life safety. The distinctive

feature of this estimate method is such quantitative scoring system that

rates building fire safety by not only total scores of 34 items which involve

certain categories in each fire stage, but also scores of indispensable items

depending on the occupancies of buildings. Recently in Japan, buildings are

getting higher and/or larger, and furthermore, buildings for mixed various

occupancies are increasing. As a result, different types of problems are

observed in view of fire safety, such as management system or fire separation

by occupancies in a building. Subsequently Fire Defence Agency, Ministry of

Home Affairs has started the study of "the Risk Analysis Method of MultiOccupancy Building Fire Safety" intended to establish the assessment of fire

14
risks of a mul ti -occupancy building.

On the other hand, the study of "the Development of Design System for

Building Fire Safety" has been initiated by Ministry of Construction as a

national project to re-examine the current policies re building fire safety,

then to re-establish fire safety and promote new technology through development of rational fire safety systems.

Although there exist lav/s and regulations for protection of human lives

and properties from fire in Japan, i.e., Building Standard Law or Fire Service

Law, etc., most of them simply touch upon technical specifications. As

mentioned earlier, however, the characteristics of buildings have recently

so changed that the administrative application of these current laws doe s net

always give the rational fire safety system, and new technologies and Knowledge of fire safety system have been developed and accumulated in past

decades. Under these circumstances the study related to such "Fire Risk

Analysis Method" and its surrounding themes has recently become an important

subject of discussions among researchers and administrators. The goal of

this study is taking fire safety of buildings as a system design, to establish an overall safety design method with assessments of initial fire, spread

fire, smoke behavior and escape of human beings.

I myself don't mention the details of above 3 studies now but mention

the current status of these studies. Tokyo Fire Department has a slar. to

distribute 10,000 pamphlets re fire risk evaluation which include self check

lists for building owners to make them diagnose their own buildings.

_ re

studies at Fire Defence Agency, Ministry of Home Affairs and Ministry of

Construction are now proceeding and I am convinced of t

r e concrete notable

results to be obtained and reported in the next UJNR meeting.

15
REFERENCES

1 )

2 )

3)

Tokyo Fire Department, "Fire Safety Evaluation Method", May

Fire Defence Agency, Ministry of Home Affairs, "Risk Analys

of Mul ti -Occupancy Building Fire Safety", March 1983

Ministry of Construction, "The Development of Design System

Building Fire Safety", March 1983

1983

is Method

for

16
METHODS OF DESIGNING AND EVALUATING FACILITIES

FOR FIRE SAFETY

Leonard Y. Cooper

1

.

INTRODUCTION

One paper at the 1982 UJNR Meeting on Fire Research and Safety presented

a broad, long-term framework for research and development with a view toward

the rational design and evaluation of fire safety [1] . The present paper will

outline some of the ongoing types of activities which are consistent with that

framework, and which are being carried out at the National Bureau of Standards’

(NBS) Center for Fire Research (CFR) , and at other fire research institutions

throughout the world.

The focus of attention will be on recent fire-safety-practitioner-oriented

research activities which focus attention on the development of design and

evaluation methods of fire safety. The general and long-term goal of such

activities is to build on past progress in the fire sciences and to develop

a rational, broad-based technology of fire safety. This technology would

be built on the more basic fire research products of CFR and similar institutions. Another paper presented at this meeting [2] provides a report on the overall status of this emerging technology for fire safety.

2.

CATEGORIES OF ACTIVITIES

The activities which directly lead to a technology for fire safety

can be classified into three categories.

The first of these categories has to do with heightening the awareness

of the general fire safety community on the existence, utility, and potential

of methods of rational fire safe design. The second category has to do with

actually carrying out the work of development and verification of design/

evaluation methods. The final category of activities involves the identification and tractable formulation of the most significant problems or barriers

to fire safe design and, when possible, to the generation of practical, nearterm solutions. Having identified these problems, they are referred to basic

fire researchers for indepth study and solution.

3.

HEIGHTENING THE AWARENESS OF THE FIRE SAFETY COMMUNITY

To heighten the awareness of applied fire research products there are three aspects to the message that must be delivered to the fire safety

Numbers in brackets refer to the list of references at the end' of this paper.

17
safety community on a regular basis, and in a convincing manner. The first

part of this message is that it is now beginning to be possible to design

fire safe facilities by means of traditional, rational and reliable engineering methodologies. The second aspect of the message is that there are groups

of scientist/engineers throughout the international fire research community

(such as the Facility Fire Safety Performance group of CFR) which are particularly responsive to the needs of the fire safety community, and which are devoted to the development of such design methodologies. This aspect is

related to a form of confidence building—confidence that a bridging of the

gap between the needs of practitioners of fire safety, on the one hand, and

the capabilities and professional interests of researchers of fire science

and technology, on the other is not only possible, but is actually in place.

The final aspect of the message that must be delivered involves the actual

transfer of technology. Here, reference is made to the delivery of applied

research products in the form of practical design methods which are attractive

and "friendly" enough as to allow the fire safety community to appreciate their

utility.

The message is being delivered to the fire safety community by both talks

and published works. Within the U.S., these include presentations at regular

scheduled conferences of the National Fire Protection Association (NFPA)

,

the American Society for Testing and Materials (ASTM) , and the American

Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE)

.

For example, the 1982 NFPA Winter Conference included a series of talks

which were presented by the Society for Fire Protection Engineers (SFPE) on

the topics "Engineering Tools for the FPE (Fire Protection Engineer)" and

"From Science to Engineering." Besides seminars at NFPA conferences, the

SFPE also sponsors other symposia on a regular basis. The most recent of

these was the 1983 SFPE Symposium entitled "Smoke: Its Chemistry, Physics,

and Control Through Engineering." Another link to the fire safety community

has also been recently established with the appearance of the First Annual

1983 Fire Engineering Conference of the Manhattan College Fire Engineering

Institute. Some of the talks presented at the above-referenced conferences

and symposia were accompanied with full manuscripts which are available, and

which have been or will be published in the open literature.

A comprehensive review of fire science and technology, written for use

as a text in the basic education of the fire protection engineer has recently

appeared [3]. In a similar vein, the text of a series of lectures which were presented at CFR during the summer of 1983 is also available [4]. Reference

[5] presents a qualitative description of the basic gas dynamic phenomena

which occur in developing enclosure fire scenarios, and it should prove to

be useful as an introduction to the subject. Several aspects of fire safety

technology are included in a recent, attractive book on fire safety design

[6]

. As the fire safety technology continues to grow, more of this kind of

fire-science-based material will hopefully be presented in subsequent editions of this latter book and in similar volumes which are written for the use of the fire safety practitioner.

By delivering "the message" to the fire safety community on a regular

basis it will hopefully be ready, indeed anxious to use elements of the

emerging fire safety technology as they become available. This will lead

to the ultimate objective of all fire research, namely enhanced fire safety.

18
4. DEVELOPMENT AND VERIFICATION OF METHODS

OF DESIGN FOR FIRE SAFETY

4.1 Varied Problems—Varied Solutions

Activities of applied fire research groups focus on the actual development and verification of fire safety design tools or methodologies. Taken

together, these tools will make up the emerging fire safety technology.

The character of the problems of the fire safety practitioner are varied,

and it is no surprise that tools for their solution will be similarly diverse.

These tools have ranged and will likely continue to range from simple charts

or graphs, which are suitable for self contained guides and standards, to

comprehensive, user-friendly computer codes.

4.2 Design Guides and Standards

A few recent examples of the self-contained design guide or standard

which is based on advances in fire science and technology include a NFPA

recommended method of calculating smoke levels in a smoke-removal-equipped

prison cell block [8], a Detection Institute guide for spacing of heat

detectors [9], and an ASHRAE guide for designing building smoke control

systems [10], Each of these practical tools for fire safe design are based

on sound engineering practices, and they take into account both analytic

considerations and experimental data.

4.3 Developing Analytic Methods of Analysis for Design

As in the past, self-contained, fire-science-based design guides and

standards of the future are likely to be built on analytic methods (supported

by experimental data) which predict limited aspects of fire-generated environments. Such methods tend to be particularly useful in design when they can

be understood and simply implemented by the fire safety practitioner, while

at the same time holding up to careful scientific scrutiny. Many such analytic

methods, which do not tie the user to a sophisticated computation capability,

have recently appeared. Some examples of these include engineering relations

for fire plumes [11], a method for predicting temperatures in a vented room

fire [12], a method for estimating room flashover potential [13], and a method

for obtaining general quantitative descriptions of dynamic, fire-generated

environments in enclosed spaces under growing, fire-threat conditions [14].

With an eye toward linking the above kind of methodologies together

into somewhat more comprehensive design guides for facility fire safety,

much can be learned from a prototype fire model which was developed to assess complex forest fire situations in the field [15]. This model was

assembled from a series of relatively simple algortums which predict different

aspects of the forest fire scenario. The model with user's guide is designed

to be exercised on a hand-held calculator (with a specially designed Fire

Behavior Chip) [16].

One final, unique example of a self-contained tool for fire safe design

is another method for predicting flashover in certain classes of- single,

vented enclosures [17], In a sense which is different from the aforemen19
tioned method of forest fire analysis, this method can also serve a a prototype for future advances in fire safety technology. The method

allows one to make predictions of flashover with the use of graphs and

tables which are provided in the reference document. The unique aspect

of this work is that the graphs and tables were generated by perhaps the

most sophisticated computer enclosure fire model in existance today,

namely, the Harvard model [18]. Thus, while this kind of prototype design

tool is self-contained, it allows the fire safety practitioner to take

advantage of a tool of analysis which, for a variety of reasons, would

otherwise be totally beyond his reach.

4.4 User-Friendly Computer Aided Design Tools

It is, and will continue to be most effective to determine many aspects

of fire safe facility design by using single or even systems of several

simple algoritums. Yet, if facility designs are to be optimized, fire

safety practitioners will eventually require direct access to relatively

sophisticated computer aided design tools. Moreover, the heart of these

design tools will be detailed, computer-driven, mathematical models which

simulate both fire-generated environments, and the response to these

environments of people and of detection and intervention hardware. Direct

accessibility here refers to well-documented, "user-friendly" computer

software, and to commonly available and relatively inexpensive computer

hardware.

Examples of user-friendly computer programs which have been made

available recently with user's manuals include programs designed to

analyze pressurized stairwells [19], smoke spread in multi-level coal mines

[20], and developing fire environments in fully enclosed spaces [21], The

latter program has been named ASET (Available Safe Egress Time) since it uses the predicted environments to estimate the time available for safe

egress of occupants from the threatened spaces. Except for the apparent

lack of user's manuals and published program listings, it appears that the

recently described programs of references [22] and [23] were also developed

to be user-friendly. These latter programs predict developing fire environments

in a door or window-vented enclosure, and in a fully enclosed or ceiling-vented

space, respectively.

The above referenced computer programs can be considered as prototypes

of the kind of first generation, user-friendly, applied research products

which will likely be developed and made available to the fire safety com- munity in the future. Over the next several years it will be possible to

enhance these programs with a variety of important capabilities. These

would include, for example, the modeling of fusible link response (e.g.

,

for the simulation of sprinkler activation) ; and improved phenomenological

modeling of detector simulation, heat transfer to enclosure surfaces, wall

flow effects, and the onset of hazardous conditions.

One general scheme for the development of future, fire safety, com- puter aided design programs will involve the addition of user-friendly

input and output software to detailed and sophisticated research fire

growth models which have been enhanced with fire detection, fire intervention

20
and human response algorithms. (For now, the "unenhanced" research fire

growth models referred to could include, for example, the above referenced

Harvard model [18], and the two room and multiroom/multilevel models of

references [24] and [25], respectively.) If such a scheme is to be invoked

with maximum efficiency, it is evident that to every possible extent, the

fire modeling activities of applied and basic fire researchers should be

carefully planned to complement one another.

4.5 Verification

Up to now the discussion of this section has concentrated on the development of methods for fire safe design. It is evident that all such development

must be carried out in concert with experimental programs which lead to verification of the validity and limitations of these design methods.

Since successful fire safe design requires some knowledge of the firegenerated environment, one main area of verification must focus on the mathematical models which provide predictions of key parameters of such environments. Reports of several experimental programs which are useful for the

verification of such models have recently appeared. Examples of these include

reports of full scale fire tests in a fully enclosed space with leakage from

below [26] and with forced ventilation [27], in a single space with door vent

[28], and in multi-room enclosures [29, 30, 31].

The verification of models is an important anticipated result of a new

and recently initiated CFR project involving a full-scale, multiroom test

program. The project is entitled "Validation of Fire Models." Verification

of methods of analysis based on fire models is also a major objective of the

full-scale test program of reference [28], which is being continued at CFR

with the support of the National Park Service of the U.S. Department of the

Interior. Another such full-scale test program being planned over the next

three years will involve a joint effort between CFR and the Factory Mutual

Research Corporation (FMRC) , and it will be supported by the U.S. Department

of Health and Human Services.

While this section provided a glimpse of the kind of advances in fire

safe design methodology that can be anticipated over the next several years,

a view of the growth of fire safety technology over the long term is discussed in the reference [1] document.

5. IDENTIFICATION AND FORMULATION OF PROBLEMS

In the course of observing fire tests and constructing compatible,

practical engineering models of hazard development, a variety of important

problems have been identified. Reference here is made to problems which

manifest themselves as apparent barriers to the successful development of

methods of fire safe design. As such, these problems are of particular

and pressing interest. The situation typically involves physical phenomena

which occur during the course of developing enclosure fire environments.

These are phenomena which can have a significant impact on fire safety, and

which are not, as yet, taken account of in either the simpler of the mathematical fire models or, the more sophisticated computer fire models which

are under development in the fire research community.

As the technology for fire safety emerges, a sensitivity to the existance of such problems, which are often masked by conventional wisdom ot

21
f.lic existing fire technology, is required. Having identified them, the

task is to formulate the problems in a concise and tractable manner. As

appropriate, the problems are then referred to the more basic research

groups for indepth study and solution. When possible, practical, nearterm solutions must be developed so that, even during the often lengthy

period of indepth study, the barriers to fire safety which have been identified can be overcome on a rational basis. Brief descriptions of two past

examples, with which the author is most familiar, will illustrate the problem identification and formulation aspects of applied fire research.

The first example has to do with predicting the time-varying temperature of the upper smoke layer and of exposed surfaces in an enclosure

fire environment. Up to and somewhat beyond the onset of a life-threatening

environment (which would, for example, be characterized by only relatively

moderate increases in temperature, the order of a few hundred degrees K) , it would appear that convective heat transfer along with radiative heat

transfer plays a key role in the establishment of these temperatures increases.

Yet, only a few years ago, algorithms for an adequate accounting of the con- vective heat transfer were not available, and even today additional advances

are required in this regard. Since onset of a life- threatening condition

must be predicted with reasonable accuracy by fire-safe-design fire models,

such algorithms are mandatory. In the context of the generic, two-layer,

enclosure fire environment. Figure 1 depicts the plume flow, ceiling jet

flow and ceiling heat transfer phenomena which must be analytically described

if the required algorithms are to be developed.

Over the last few years the above problem was highlighted, and a practical system of solution elements was developed. This work was communicated to the fire safety community and to the applied and basic fire

research community through a series of talks and published papers [32-36],

Hopefully, these communications 1) will heighten the sensitivity of fire

safety practitioners to the problem, 2) lead to the near-term development

of mathematical enclosure fire models capable of reliable temperature predictions,

and 3) stimulate fire researchers to seek the most effective and optimum longterm solutions.

The second example of problem identification has to do with a wall flow

phenomenon which is generic to enclosure-fire-generated environments. In

real fire events, the phenomenon, which is not taken account of in any

existing two-layer zone fire model, can lead to significant deviations in

the environment which would be predicted by such models. The effect to

which reference is made is the wall flow which draws product-of-combustionladen upper layer gases down into the (relatively) uncontaminated lover layer.

The potentially deleterious effect of such wall flows on life safety, for

example, is evident. The phenomenon is illustrated in Figure 2.

The wall flow, which seems to have been observed in numerous experiments

(see, for example, references [19], [26] and [31]), is the result of the

near-wall, elevated temperature, upper-gas layer being cooled (i.e., increased

in density) by the relatively low temperature, upper-wall surfaces. The

significance of the wall effect has been quantified in a study on a relatively

general class of enclosure fire scenarios [37]. The results of the analytic

study have been brought to the attention of the fire technology community.

They indicate that the wall effect will be significant in many practical fires.

22
The results clearly suggest that the wall effect should be studied in

greater depth, and that is should be taken account of when developing

methods for fire safe design.

6. CHALLENGES FOR THE FUTURE

There are three key challenges associated with the task of developing

an effective fire safety technology. First, it is necessary to make judicious

selections of readily available components and systems of components, and to

assemble them into useable and credible working tools and methods for rational

fire safe design. Next, it is necessary to critically evaluate and, where

possible, validate these tools. This must be done with an eye toward both

determining their strengths and revealing their shortcomings. Finally, it

is necessary to initiate research programs which are directed toward the

elimination of these shortcomings.

The kinds of activities described in this paper are designed to meet

these challenges. By continuing to follow the indicated direction it is

hoped that enhanced levels of fire safety, not otherwise likely, will be

attained.

7. REFERENCES

[1] Cooper, L.Y. , and Nelson, H.E., Life Safety Through Designed Safe EgressA Framework for Research Development and Implementation, 6th Meeting of

the UJNR Panel on Fire Research and Safety, Tokyo, JAPAN.

[2] Nelson, H.E. , Facility Fire Safety and Risk Analysis Methods, 7th Meeting

of the UJNR Panel on Fire Research and Safety, Wash., D.C.

[3] Drysdale, D.D., Fire Dynamics: An Introductory Course (Second-Draft,

Jan., 1983), Worcester Polytechnic Inst. Center for Firesafety Studies,

Worcester, MA.

[ 4 ] Kanury, A.M. , Combustion for Fire Scientists , Dept, of Aero, and Mech.

Eng., Univ. of Notre Dame, Notre Dame, IN, 1983.

[5] Cooper, L.Y. , Smoke Movement in Rooms of Fire Involvemtn and Adjacent

Spaces, NBSIR 83-2748, NBS, Wash., D.C., 1983, and to appear in Fire

Safety Journal.

[6] Butcher, E.G., and Parnell, A.C. , Designing for Fire Safety , John Wiley

and Sons, 1983.

[7] Guide for Smoke and Heat Venting, NFPA 204M, NFPA, Quincy, MA, 1982.

[8] A Recommended Method of Calculating Expected Level of Smoke in a Smoke

Removal Equipped Cell Block, Section A-15-3.1.3 of NFPA Life Safety

Code, NFPA, Quincy, MA, 1981.

[ 9 ] Benjamin, I., Heskestad, G. , Bright, and R. , Hayes, T. , An Analysis

of the Report on Environments of Fire Detectors, Fire Detection

Institute, 1979.

23
[10] Klote, J.H., and Fothergill, J.W. , Design of Smoke Control Systems

for Buildings , ASHRAE, Atlanta, GA, 1983.

[11] Heskestad, G. , Engineering Relations for Fire Plumes, Tech. Rpt. 82-8,

SFPE, Boston, MA, 1982.

[12] McCaffrey, B.J., Quintiere, J.G., and Harkleroad, M.F., Estimating

Room Temperatures and the Likelihood of Flashover Using Fire Test

Data Correlations, Fire Technology, 17, p. 98, 1981.

[13] Babrauskas, V. , Estimating Room Flashover Potential, Fire Technology,

16, p. 94, 1980.

[14] Cooper, L.Y., The Development of Hazardous Conditions in Enclosures

with Growing Fires, NBSIR, 82-2622, NBS, Wash., D.C., 1982 and to

appear in Comb. Sci. and Tech.

[15] Rothermel, R.C., Fire Behavior Systems for Fire Management, Proc. Sixth

Conf. on Fire and Forest Meteorology, Seattle, Amer. Soc. of Forestry,

Wash. , D.C. , 1980.

[16] Burgan, R.E., Fire Danger/Fire Behavior Computations with the Texas

Instruments TI-59 Calculator: User's Manual, USDA Forest Service

General Tech. Rpt. INT-61, Intermt. For and Range Exp. Stn., Ogden,

UT, 1979.

[17] Peacock, R.D. , and Breese, J.N. , Computer Fire Modeling for the

Prediction of Flashover, NBSIR 81-2516, NBS, Wash., D.C., 1981.

[18] Mitler, H.E., and Emmons, H.W. , Documentation for CFCV, Home Fire

Proj . Tech. Rpt. 45, Harvard Univ. , Cambridge, MA, 1981.

[19] Klote, J.H. , A Computer Program for Analysis of Smoke Control Systems,

NBSIR 82-2512, NBS, Wash., D.C., 1982.

[20] Edwards, J.C., and Greuer, R.E., Real-Time Calculation of Productof-Combustion Spread in Multilevel Mine, Information Circular 8901,

Pittsburgh, PA, 1982.

[21] Cooper, L.Y. , and Stroup, D.W., Calculating Available Safe Egress

Time (ASET) - A Computer Program and User's Guide, NBSIR 82-2578,

NBS, Wash., D.C., 1982.

[22] Hagglund, B. , A Room Fire Simulation Model, FOA Rpt. C 20501-D6,

Nat. Defense Res. Inst. , Stockholm, SWEDEN, 1983.

[23] Hagglund, B., Simulating the Smoke Filling in Single Enclosures, to

appear as FOA Rpt., Nat. Defense Res. Inst., Stockholm, SWEDEN.

[24] Zukoski, E.E. , and Kubota, T. , Two-Layer Modeling of Smoke Movement

in Building Fires, Fire and Materials, 4, 1, p. 17, 1980.

[25] Tanaka, T. , A Model of Multiroom Fire Spread, NBSIR 83-2718, NBS

Wash. , D.C.

,

1983.

24
[26] Muholland, G. , Handa, T. , Sugawa, 0., Yamamato, H. , Smoke Filling

in an Enclosure, Fire Sci. and Tech., 1, 1, p. 1, 1981.

[27] Alvares, N.J. , Foote, K.L. , and Pagni, P.J. , Characteristics of

Fire in a Forced Ventilation Enclosure, to appear in Comb. Sci.

and Tech.

[28] Lee, B.T. , Effect of Wall and Room Surfaces on the Rates of Heat,

Smoke, and Carbon Monoxide Production in a Park Lodging Bedroom

Fire, to appear as NBSIR, NBS, Wash., D.C.

[29] Handa, T. , Morita, M. , Rockett, J.A. , Sugawa, 0., and Hayashi, K.,

Some Examples of Application of Harvard V Fire Computer Code to Fire

Investigation, Fire Sci. and Tech., 3, 1, p. 63, 1983.

[30] Cooper, L.Y. , Harkelroad, M. , Quintiere, J. , Rinkinen, W. , An

Experimental Study of Upper Hot Layer Stratification in Full-Scale,

Multiroom, Fire Scenarios, Journal of Heat Transfer, 104, p. 741, 1982

131] Smoke Movement in Corridors, BRE News, 60, Building Res. Establishment

Gars ton, ENGLAND, 1983.

[32] Cooper, L.Y. , A Concept for Estimating Available Safe Egress Time

in Fires, Fire Safety Journal, 5, p. 135, 1983.

[33] Cooper, L.Y. , A Mathematical Model for Estimating Available Safe

Egress Time in Fires, Fire and Materials, 6, p. 135, 1982.

[34] Cooper, L.Y. , Heat Transfer from a Buoyant Plume to an Unconfined

Ceiling, Journal of Heat Transfer, 104, 1982.

[35] Cooper, L.Y. , Convective Heat Transfer to Ceilings Above Enclosure

Fires, Proc. of 19th Inter. Symp. on Combustion, Comb. Inst., p. 933,

1982.

[36] Cooper, L.Y. , A Buoyant Source in the Lower of Two, Homogeneous,

Stably Stratified Layers—A Problem of Fire in an Enclosure, paper

83-WA/FE-4 of 1983 Winter Annual Mtg. of ASME, Amer. Soc. Mech. Eng.,

New York, NY, 1983, and to appear in Proc. of 1983 Mtg. of East. Sect,

of Comb. Inst.

[37] Cooper, L.Y. , On the Significance of a Wall Effect in Enclosures with

Growing Fires, 1983 Nat. Heat Trans. Conf., Fire Dynamics and Heat

Transfer, ASME HTD 25, p. 97, Amer. Soc. Mech. Eng., New York, NY and

to appear in Comb. Sci. and Tech.

25
h

(T

at

j—

Ts)

26

Figure

1.

An

illustration

of

the

plume

flow,

ceiling

jet

flow,

and

ceiling

heat

transfer

ina

generic,

two-layer,

enclosure

fire

scenario.
27

Figure

2.

An

illustration

of

wall

flows

which

can

have

significant

effects

on

enclosure

fire

environments.

Discussion After L. Cooper's Report on METHODS OF DESIGNING AND EVALUATING

FACILITIES FOR FIRE SAFETY:

WAKAMATSU: I'm sure it is very important to analyze or to project a phenomena. When we engage in the analysis of ordinary prediction of phenomena,

and if we know the complete factor or element of the phenomena, it's easy to

input those elements in a computer, for example. On the other hand, when we

look at the actual fire, there are many unpredictable elements which influence

the conditions of fire, including how much the windows are opened, or how the

fire started, or the weather at the time. So, my question is, how do you

predict these unpredictable, uncertain elements when you predict fire phenomena?

COOPER: One of the statements I made was that there are various problems

requiring varied solutions and so it is in regard to this question. I'll give

you two examples of real classes of problems and possible solutions. The first

has to do with the question of opened windows or opened doors, or closed windows

or closed doors. One can reasonably argue that for developing fire conditions

in an enclosed space, the completely closed enclosure will yield the most

quickly developing hazardous conditions providing, of course, the fire develops

as it would in open space, which we can assume that it does. So, as a first

approximation, I would recommend evaluating the development of conditions in a state assuming that it was enclosed. With regard to the variation in occupancy

in a building, I would recommend the development of fuel assemblies which are characteristic of a given occupancy. Hospitals would have beds and bureaus as a characteristic of fuel assembly, warehouses would have characteristic fuel

assemblies involving rack storage of special design. One would evaluate the

environment as it developed from one of these characteristic fuel assemblies,

assuming that the fire developed as it would in a free burn situation.

EMMONS: Dr. Wakamatsu asked what seems to me the most critical question that

could be asked relative to fire models. The approach that I think is necessary

is that we will continue through the years to develop better and better models

to be able to answer more and more precise questions. As we use these models,

we will acquire experience with what in a building is critical and what in a building is important but not critical. Each building that is analyzed would be

burned on the computer a number of times. Those items in a building which are critical would have to be given special attention. For example, if a certain

door was essential to be closed to prevent serious fire spread, the law would

have to require that that door be spring loaded, never held open. In other

words, I believe we would learn what features of a building are essential to

control and to control the most important one by legal requirements.

29

Development of Design System for Building Fire Safety

- by Ministry of Construction's Promotion of

Cooperative and Total Development Project -

by Takao Wakamatsu

Yasaburo Morishita

Fire Safety Research Group

Building Research Institute

I. Progress

A Research Project "Development of Design System for Building

Fire Safety" was initiated in Japan from April, 1982 as a five-year

project sponsored by Ministry of Construction's Promotion of

Cooperative Research and Total Development Project. The purpose of

this project is to develop a rational and total design system for

building fire safety by systematizing the knowledges gotten so far

in the field of fire research. By the accomplishment of this

project, such problems as the restriction of flexibility of building

design by fire regulations, the unclearness of the effects and

interactions of various fire countermeasures are solved and the fire

countermeasures are expected to come to be provided logically and

economically from the view point of total fire safety performance of

a building.

In 1982 fiscal year, the following items were studied.

1) Review of the concerned researches conducted so far.

2) Examination of the conditions to be provided in Design System

for Building Fire Safety.

3) Examination of the framework of Design System for Building Fire

Safety

.

4) Preliminary survey on the actual situations of fire

countermeasures and fire damages.

5) Survey on Fire Load taken into buildings.

6) Examination of the fire resistive performance of a steel

structure frame by theoretical thermal strength calculation

with computer model.

7) Examination of the framework of fire safety diagnosis system as

the application of the design system for exist buildings.

II. Framework on Design System for Building Fire Safety

Among these items, the parts concerning the framework on Design

System for Building Fire Safety are considered so important in order

to have a view on the direction of future development of

project, that the details of the examination on the framework

mentioned below.

1) Objectives of the Design System

a) To give logically clear bases and interactions of fire cc • measures

.

b) To evaluate quantitatively the effects of fire countermearr : r- c) To give the alternative countermeasures satisfying a :

31
safety level.

Further, if these objectives are achieved in the Design System, it

will be possible to select an economical countermeasure the effect

of which is highest for a given budget by making the

Cost-Effectiveness Analysis.

2) Items to be examined in the process of making the Design System

a) Controlableness of the elements consisting of the Design System.

b) Possibility of getting objective data on the effects of

elements

.

c) Possibility of estimating the situation of elements from the

gotten data.

d) Clarification of the conditions to be provided in the Design

System ( subject elements and countermeasures to be evaluated,

applicable scope of the Design System, etc. ) e) The goals of the Design System should be described as policies

corresponding to the types of buildings.

f) Expert Judgement should be treated logically and clearly in the

determining process of the evaluation method.

3) Constitution of the Design System

a) The Design System is composed of the goals described as policies

and the evaluation method ( including quantitative standard ) to check if they are satisfied.

b) The goals are plural, and the combination rules would exist.

c) The goals and their combination rule would be determined

corresponding to the types of building.

a) Evaluation method is largely decomposed into 4 subsystems, i)

Outbreak and Growth of Fire, ii) Smoke Control, iii)

Evacuation, iv) Fire Resistance of Structure.

e) Evaluation is conducted on the respective subsystems and the

total system.

f) Economical Performance is desirable possibly to be evaluated in

the last stage of the Design System.

4) Framework of the Design System ( Draft ) Fig.l shows the framework of the Design System for Building Fire

Safety ( Draft ) . The items mentioned above are reflected in the

constitution of this framework.

On this figure, the present situation of fire safety design is

also shown. Many of the buildings designed nowadays are just

checked on the accordances with codes at the last stage of design as

are shown at "conventional type". Concerning large buildings ( ig.

the height of which exceeds 31m ) which may cause large evacuation

risk, the designers of of such buildings are guided to make the

documents on fire safety planning, which are examined and modified

by the experts on fire safety at the evaluation committee instituted

in Building Center of Japan. This evaluation system started in July

1981 by the guidance of Ministry of Construction.

Fig. 2 - Fig. 5 show the design (evaluation) method for respective

subsystems

.

32
III. Current Studies

1) Development of Systematic Design Methods for Total Fire Safety

* Confirm the Framework of Design System for Building Fire Safety.

* Classification of unit spaces composing of a building. - A

building can be considered as a network of various unit spaces

having different qualities. Consequently, buildings should be

classified corresponding to the types of combinations of unit

spaces

.

* Preliminary study on the actual effects of fire countermeasures

estimated as reliability ( by using fire statistics )

.

* Actual state of provision of fire countermeasures and their

costs

.

* Examination of the evaluation framework for residential fire

safety performance.

2) Development of Design Methods for Prevention of Outbreak and

Growth of Fire

* Confirm the Framework of Design Methods for Prevention of

Fire Outbreak and Growth.

* Development of Fire Growth Model in a room of fire origin.

* Trial making of the measuring instrument for combustion

properties of materials.

3) Development of Design Methods for Smoke Control and Escape

Planning

* Confirm the Framework of Design Methods for Smoke Control.

* Confirm the Framework of Design Methods for Evacuation.

* Making of "Menu" of various Smoke Control Methods.

* Survey of air infiltration characterics through crevices of

doors, windows, walls etc. in exist buildings.

* Survey of chracteristics of occupants in buildings ( Hospital,

Department store )

4) Development of Design Methods for Fire Protection of Building

Structures

* Confirm the Framework of Design Methods for Fire Protection of

Building Structures.

* Heating experiment of full scale structure.

* Survey of Fire Load and actual state of structure in exist

buildings

.

* Experiment for characteristics of materials used for fire

protection in high temperature.

5) Development of Methods and Techniques for Diagnosis & Improvement of Fire Safety of Exist Buildings

* Examination of the Framework of Methods for Improvement of Fir-'

Safety Performance of Exist Buildings.

* Survey of actual improvement cases for fire safety in exist

buildings ( Department Store, Theater, etc.).

* Preliminary survey of actual states of maintenances of fire

countermeasures

.

33
34
.£= O CJJ

in — — *j D —. o u — —

<

CT3 *0 Cx_

-*-» o>

. c O

i o —

«

, — X

-*-» o

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35

I)

This

diagram

shows

tho

summary

of

evaluation

systems

for

fire

growth

Ina

compartmont.

and

fire

spread

through

inner

&

outer

parts

of

buildings.

There

ar<’

somo

differences

ho

tween

those

fire

growth

models

in

details.

<ni

erning

the

lain

used

for

evaluating

condition

of

doslgn,

almost

only

the

data

of

the

room

are

concerned

for

the

fire

growth

ina

room

of

fir

thor

hand,

both

the

data

of

tho

room

of

fire

origin

and

the

vicinity

are

to

be

considered

for

the

fire

spread

among

rooms.
FIG. 3

Framework

of

Design

Methods

for

Smoke

Control

36
FIG. 4

Framework

of

Design

Methods

for

Evacuation

3<>* o o

03

—> J3

cu

—<

Ui

CX3

O 3

CJ T3

03 CD

Q.

03 'TZ3 O —

Crt • —

U CD 3 *13 O O

03C

-3

O

CD •— CO -*-> o

CDO <D

O 3 —- O > QC

03 -3 CD

CD Q. CO 03O

CD CO OC CO

sc 0) CD CL CO 03

-•-> o e o

03 DC

Q.3 CD O U o — O Cl.

<3

37
FIG. 5

Framework

of

Design

Methods

for

Fire

Protection

of

Building

Structures

CL.

(-) ooOECO

<D JD

03

03>

03

CO

38

Time

or

prediction

models

for

Stractural

Behaviours

and

Temperatures

of

Stractural

Elements

by

Standard

Fire

Endurance

Test

which

are

specified

in

regulations.
Discussion After T. Wakamatsu's Report on DEVELOPMENT OF DESIGN SYSTEM FOR

BUILDING FIRE SAFETY

NELSON: In Figure 1, you indicated, I believe, that you plan to set a goal for

each of the four subsystems and a total goal. That would seem to be very

constraining. Couldn't you just set a total goal and thereby allow trade offs

between the subsystems?

WAKAMATSU: Yes, we are going to establish a goal for four different subsystems

and also one goal for a total system. The purpose of setting up different goals

will be explained by quoting an example. We are planning to set a goal for a smoke control. In doing so, we will set how much smoke will be allowed from a burning room and how many minutes smoke should be allowed in a certain stairway;

for example, stairway A, and then we might decide that a smoke is not allowed,

for example, in stairway B. Our philosophy is to set up different goals for

smoke control, for example, or for ignition, or for escape, and by combining

these goals, hopefully, we can come up with a complete policy.

If my answer was not very clear, I'm sure that Dr. Tanaka's talk tomorrow will

clarify any questions you may have.

NELSON: Your item 2F on Expert Judgement, have you developed any concept of how

to logically and clearly treat expert judgement?

WAKAMATSU: We have not decided completely how we will treat expert judgement

logically and clearly, but one example is to use the Delphi method. At this

stage we do not know at which point or how we are going to incorporate expert

judgement.

NELSON: Your work plan for this year, III, item 3, is very close to the items

that are on our agenda, and it would be very worthwhile if we coordinated it.

WAKAMATSU: I concur with your comment and hopefully we can pursue our research

together.

a GANN: On Figure 1, you have three diamonds for evaluation of the prediction

models. How do you plan to do the evaluation and what criteria will you use to

determine the accuracy of the prediction methods for specific buildings?

WAKAMATSU: This evaluation is not for the evaluation of accuracy or prediction

methods of a specific building, but this evaluation will be conducted for

established purposes. In other words, this evaluation is to evaluate whether or

not a goal is met.

GANN: Sandy Davis is working with Dr. Jones on prediction of validation of

predictive models for smoke movement and has worked with the American Iron and

Steel Institute on testing prediction methods for steel structures. These

results may be of interest to you, and we can talk about them later.

WAKAMATSU: What part of the smoke prediction model were they engaged in?

GANN: It's smoke filling of a corridor. In our tour on Wednesday, you wiLl se"

the facility and a video tape of one test. Dr. Jones is right here for any

further details.

39
WAKAMATSU: Yes, I would be very much Interested in knowing the results you have

obtained so far.

KAWAGOE: This problem is tackled in the structure of Fire Safety Division which

exists in CIB W14 CIP, and our philosophy is to reduce risks rather than to concern ourselves with safety. In other words, we set up some figures for

ignition, flashover, and failure, and the rate of these, I think, must be below

a certain established figure. I feel that our method is quite an easy one and

quite easy to understand. This subject is mentioned in an article by a workshop

published in "Fire and Materials."

40
Human Reaction During Residential Fires

Establishing a Data Base

John P. Keating, Ph.D.

Department of Psychology Nl-25

University of Washington

Seattle, Washington 98195

U.S. - Japan Panel on Fire

Research and Safety VII

National Bureau of Standards

Caitersburg, Maryland

October 24 , 1 98

J

41
Human Reaction During Residential Fires:

Establishing a Data Base

An opportunity to apply psychological principles to fire

egress problems was provided us in 1974, when we were asked by tin* General Services Administration to design the wording lor the

vocal evacuation system for the Seattle Federal Building. This

building was developed by the federal government to provide a prototype of a high-rise structure which incorporated a total fire

safety system concept. The basic hardware ol the salety system was designed, and several important decisions concerning the personnel

evacuation were made belore our involvement . The most signilicanl

Innovation of the system was the incorporation of a public address

component capable of broadcasting prerecorded directions to communicate with building occupants who might be affected by a fire. While

a vocal alarm was the egress system recommended by several fire

safety conferences for high-rises, systematic development of the

wording to be used in such a system was not attempted until our efforts (Keating and Loftus, 1977)

Our specific work with message development for fire evacuations

demanded that attention he focused on specific answers to immediate

questions within absolute time constraints. As we became familiar

with the whole field of human behavior in fires (e.g. Canter, 1980), we became increasingly aware of how little was documented about human

response during fire emergencies, especially resident ial fires.

Models of human reactions had been developed (e.g., Bickman et al . , 1978 Stahl, 1977), but mainly depended on neeuiuii I a t ed anecdotes

and limited data to define parameters for computerized projections

of damages for specified fire-scenarios. Effective warning systems,

emergency signage, and awareness by architects of principles of

safe design, could all be enhanced If natural responses to fires

could be systematically studied.

Only the survivors really experience how they escape from a fire. Much of what they experienced is forgotten or distorted by

natural psychological processes stimulated by threatening traumatic

memories. Consequently, we developed an interview instrument for

administration to fire victims which relied on the script theory

of cognitive processing (Schank and Abelson, 1977) for its format.

The technique was designed for general use by investigators during

post-fire interviews, and possessed at least five desired charac-

.

teristics. Such a technique should:

42
1) Incorporate pertinent findings from research on the

validity and power of various interview techniques.

2) Be directly relevant to the types of accounts expected

from fire scenarios.

3) Provide data which could be computerized and subjected to

comparative analyses across fires.

4) Be easy to administer and capable of use by fire investigators after minimal training.

5) Have the capability to accommodate data banks large enough

to provide sufficient analytic power for appropriate

statistical probes.

Interview Techniques : Based on a review of research related to

existing interview techniques, an interview approach which could

incorporate both the narrative and interrogatory modes into its

method seemed optimal. In order to provide such incorporation

of both approaches, our procedure involves two phases.

In the first phase of the interview, the witness is invited to

recount his or her story of the fire, free from interference or questions by the interviewer (narrative mode). During the second

phase of the interview, the respondent and interviewer, using a standardized format, cooperatively generate a comprehensive account

of the respondent's behavior during the fire (interrogatory mode).

The narrative account or free recall phase is administered prior

to the more structured mode to capitalize on research findings

(e.g., Whitely and McGeoch, 1927) which demonstrated more accuracy

and completeness when this sequence of methods is employed. Additionally, this sequence of interviewing avoids the bias that can be

created in the interrogatory phase by use of specific questions and

language by the interviewer (cf. Loftus and Palmer, 1974 , Loftus,

1979 ) which may distort accurate recall.

During the initial phase, the interviewer imposes a minimum of

structure on the respondent's narrative account. The respondent is

simply asked to recount all of his or her behaviors during the fire

incident in the sequence they occurred. The interviewer briefly

notes details of the account which seem sketchy or imcomplete and

may need additional probing. Questions are asked only if there

seems to be obvious, unaccountable gaps in the narration.

After the narrative is completed, the interviewer initiates the

second phase. This phase is a cooperative effort between the interviewer and respondent to convert information presented during the

initial narration into a series of statements, each of which

describes a single behaviorial episode. Each of these statements is

designed to include information about what the person did and why,

on response to what cognitive or external cue.

43
Behavioral Episodes . It is obvious that a post-fire interview

technique should be tailored to the types of accounts which could

be expected from survivors of fires. A conceptualization of how

fire events can be sequenced, developed by Lars Lerup (1977), an architect at the University of California at Berkeley, was used to

organize the sequencing of behavior by witnesses in their accounts of

the fire.

During phase two of the interview, the respondent orders, in

the sequence they happened, each of his or her behaviors during the

fire. Each discrete behavior is called a "behavioral episode" which

was defined as Lerup as:

An individual is involved in a continuous stream of behavior,

but this stream has discrete units called episodes , defined at

start and end by decision poin ts. An episode, for example,

could be a nurse rescuing patients, defined at start by

decision point "decision to rescue" and defined at finish by

decision point "decision to stop rescue because of smoke

density." (p. 29)

The respondent and interviewer attempt to include each appropriate element in the statements. In order to facilitate coding the

statements, a form is supplied. A hypothetical example of a sequence

of behavior follows:

Situational

Cue

Behavioral

Response

Reason

Why

I smelled smoke So I ran down To find where

the hall the smoke was coming from

I saw smoke So I opened To see how

pouring under the door serious the

Mr. Jones' door fire was When I saw Mr. I dragged him To remove him

Jones unconscious down the hall from the smoke

by the door to the elevators and flames

I looked back and So I ran back to To shut the saw that I hadn't

shut the door

Mr. Jones' room door

The smoke was so So I ran back down To pull the

intense that I the hall alarm box

couldn't get to next to the

the door elevator

I sounded the So that everyN/A general alarm one in the

building would

be alerted

The resultant data from phase two of the interview is a complete,

sequential account of an individual's behavior during a fire, ordered

44
into discrete behavioral acts, or "episodes." If the interviewer

notices gaps in the sequence, the respondent is encouraged to provide

the missing information. Such gaps, easily recognized, are indicative

of def icienceies in remembering the event, or areas the witness is

unwilling to discuss.

Once the interviewer and respondent have described the episodes

using behavioral statements, the information is in an easily categorized form. The statements can be categorized as units, and the discrete

elements of the statements can be separately categorized as well. The

format presents the information in discrete units, therby avoiding

much of the time-consuming effor required to code narrative accounts.

The system for categorizing and coding the statements and elements

can be derived through analyses of the content itself, or categories

from already existing models of fire behavior can be effectively employed

Once the data is categorized and coded, it can be analyzed to provide

various types of information. Simple frequencies and tables can provide a valuable census of behaviors. Researchers could inquire about

the percentage of fire victims that attempt to extinguish fires in their

homes before calling the fire department, or under what circumstances

nursing personnel deviate from prescribed routines, and with what results

Demographic descriptions can be used to scrutinize the data to determine

similarly occurring patterns of behavior by sub-groups. Further,

elements of the statements can be analyzed separately. Questions could

be answered concerning what cues first alert victims in homes as opposed

to apartments. The "why"element can be examined to reveal the intentions

that underlie selected behaivors suggesting corrective strategies for

fire safety educators.

Results of Interviews . Contingency analyses, where inferences

are based on the concurrence of elements within the same statements can provide a powerful analytic technique to determine commonly recurring

patterns of responses (Breaux, 1977). For example, researchers could

determine what actions victims take when they cannot see through smoke

to a safe escape route. It would be possible to discover the reasons

that victims stay in a room while escape is still possible. Such

analyses and the ensuing generalizations about human behavior provide

potentially valuable information to fire-fighters, building designers,

and fire education specialists in their attempts to eliminate

erroneous human reactions during fires.

Examples of such analyses can be seen in figures 1 and 2. Figure

1 depicts the behavior of 118 victims of 90 residential f i res in

Seattle; figure 2 shows the patterns of behavior reported by 239

victims of New York residential fires.

The numbers linking the behavior in these figures is the q coefficient which is a measure of strength of association between two

variables. If there is no association at all, the q coefficient will

45
equal zero. The higher the positive value of q, the more likely a given

variable is to follow another one. With large samples the q approaches

the chi square distribution.

To compute the q coefficient linking two variables, a transition

frequency matrix was set up, so that both row and column headings were identical and consisted of all the acts which appeared in the behavioral

sequences. Each row corresponded to a specified variable (act), and

each column corresponded to the act which followed a variable in a given

row. The cells of the matrix contain the frequencies with which a variable in a column follows a variable In a row. To use the entire

matrix, all row totals and column totals (marginals) are calculated,

as well as the sum of the rows and columns, to yield t ho total number

of acts which follow another act. The formula for the q is:

fo - f e

fe

where f ° frequency observed In the cell of interest in the transition

matrix, °and f e

= frequency expected by chance in the cell. f e is computed

by multiplying the tow total for the specified variable by the column

total of the variable of interest that followed the specified variable.

This product is then divided by the total number of acts in the matrix.

Thus, form the formula the measure of assiciation is acLually a measure

of the degree of deviation indicated by a given cell in a transition

frequency matrix.

In our case, we used a truncated matrix of the 18 most frequently

occurring acts and computed the q values on the matrix in the manner described above. The entire matrix was orignally thought to be un- wieldy (it was a 30 x 30 matrix, many cells with zero frequencies), but

as sample size increases, this total transition frequency matrix will

become increasingly useful.

Discussion and Future Research . The behavioral episode interview

format satisfies the five criteria listed above as essential to gather

usable data about human responses during fires. It incorporates

pertinent research findings derived from cognitive processing

investigations, tailored to accomodate accounts expected from fire

scenarios. Virtually no victim in the study sample had difficulty re- sponding to the interviewer's directions. It can be used to provide

comparative analyses accross fires as is depicted in figures 1 and 2.

It is easy to administer with minimal training. For example, the New

York sample was interviewed by twelve members of the emergency response

staff of the New York Red Cross, after the staff members were trained

by videotape and instruction during one three-hour period; minimal

training for a major data gathering effort. (We are indebted to the

disaster experts of the Red Cross in NYC for their enthusiastic

cooperation in the project.) Finally, the technique has the capability

to accomodat a large data bank of virtually unlimited size.

46
While it is still premature to provide definitive answers to how

people tend to respond during a fire emergency, some tentative con- clusions can be made from this initial effort. Men are more likely

than women to move toward and fight the fire; women Lend to warn others

and call for help. Similar findings were reported previously by Wood

(1972)’ and Bryan (1977). This is especially true in single dwelling

residences (Seattle), but not as obvious for dwellers in multiple

occupancies (New York). People have difficulty determining whether

a lire is actually present and frequently misinterpret initial cues (signified by the circular start depicted in the figures). Similarly,

people return to the house to recall the fire department, not confident

that the initial call was successful. The above findings have already

proven helpful to fire education specialists.

But the major benefits of this research effort are still to come

and entail the following:

1) Increased expansion of the data-bank by encouraging use

of the interview method by post-fire investigators.

2) Incorporation of accounts by burn victims into the sample

to determine if maladaptive decisions have contributed to their

unsuccessful escape compared to the non-burned sample.

3) The sequential lag analysis technique is able to link up

to four behaviors in sequence, expanding the heuristic power

of the analysis.

4) Development of powerful probability models of human response

based on the contingencies determined by the systematic re- ports and analyses, and

5) Finally, development of an increased data bank will provide

confidence that probabilities of behavior generated from the

interviewed sample will accurately reflect human response

tendencies during fires. Such results should increase the

mundane realism of current computerized fire models.

47
Sequence of behavior during

90 residential fires in Seattle

NS II8

Seattle 1 979 - 1982

Figure i

48
49

Sequence

of

behavior

in

New

York

Residential

Fires

(N=

240)
References

Bickman, L. , Edelman, P. and McDaniel M. A Model of Huamn Behavior

in a Fire Emergency. Center for Fire Research, National Bureau

of Standards (NBS-GRC-78-120) , Washington, D.C., 1977.

Breaux, J.J. Analyzing Complex Data: The Description and Analysis

of Dynamic Behavior in Fire Sitiuations. British Psychological

Society, Exeter, 1977.

Bryan, J . L . Smoke as a Determinant of H u man Behavior in Fire Situations

( Project People ) College Park: Fire Protection Curriculum,

University of Maryland, 1977.

Canter, David (Ed.) Fire and Huamn Behavior . London: John Wiley

and Sons, 1980.

Keating, J.P. and Loftus, E.F. Vocal alarm systems for high-rise

buildings a case study. Mass Emergencies : International

Journal of Theory, Planning and Practices , 1977 , 2_, 25-34

Lerup, L. People in fires: a manual for mapping. Center for Fire

Research National Bureau of Standards (NBS-GCR-7 7-106) , Washington,

D.C., 1977.

Loftus, E.F. Eyewitness Testimony . Cambridge: Harvard University

Press, 1979.

Loftus, E.F., and Palmer, J.C. Reconstruction of automobile destruction:

An example of interaction between language and memory. Journal

of Verbal Learning and Verbal Behavior , 1974, 1

3

, 585-589

Schank, R. and Abelson, R. Scripts, Plans, Coals and Understanding.

Hillsdale, NJ : Lawrence Erlbauin, 1977.

Stahl, F.I. Simulating human behavior in high-rise building, fires:

modeling occupant movement through a fire-floor form initial

alert to safe egress. Center for Fire Research, National

Bureau of Standards (NBS-CCR-77-92) . Washington, D.C., 1977.

Whitely and McGeoch. The effect of one form of report upon another.

American Journal of Psychology , 1927, 38, 280.

Wood, P.G. The Behavior of People in Fires , London: British Joint

Fire Research Organization. Fire Research Note 953, November, 1972.

50
Discussion After J. Keating's Report on HUMAN REACTION DURING RESIDENTIAL

FIRES: ESTABLISHING A DATA BASE

JIN: We also have been conducting studies of fire survivors which involved 40

senior citizens in Japan three years ago. We're trying to define the behavior

of survivors. The survivors are senior citizens; they are old people. It's

very difficult to ask them to answer questions. So, we listen to their stories

of what happened during the course of the fire sequence. We did not interrupt

their stories. Whenever they strayed from the questions, we would interrupt and

ask questions. As a result, because older people did not respond well to our questions, I conducted interviews with my colleague, Dr. Sekizawa. We could

only interview one or two people a day. However, we interviewed twenty

survivors of a fire and, as a result, we could figure out the behaviors of

eighty survivors of the fire. At the most, maybe one or two minutes of

difference in time, we could reproduce the behavior. For the problem areas we

face, we made a scenario. The scenarios were not consistent with each other.

Some of them contradicted each other. We interviewed survivors three times on different days and three times we interviewed the same respondant. Still, we

found some gaps. However, we tried to analyze all of the answers from the

respondants to see why they behaved in a particular manner.

I think you might encounter similar difficulties in interviewing. My question

is: How did you overcome this problem in your interviews?

KEATING: Virtually no member of the sample was not able to respond to the

interviewer's directions; our sample was pre-screened for several important

characteristics.

First of all, the ability to follow directions, which meant that if they were highly intoxicated, they frequently couldn't report and we had instances

pertaining to that. Secondly, we had no instance where the total population

consisted of senior citizens, even though there were several senior citizens in our sample. I understand this method was recently used to interview at least

the personnel in an adult retarded facility in a recent fire in Georgia, by my

colleague Dr. Norman Groner.

51

A STUDY ON FIRE RISK ANALYSIS METHOD

OF MULTI-USE BUILDINGS

by

Ai SEKIZAWA and Tadahisa JIN

Fire Defence Agency

Ministry of Home Affairs

Seventh Joint Meeting

U.S. -Japan Panel on Fire Research and Safety

UJNR, Washington, D.C. Oct. 24-28, 1933

53
1. INTRODUCTION

Recently in Japan, the multi-use buildings have been increased as the

buildings are getting higher and/or larger. In these multi-use buildings,

there are some problems concerning fire safety, i.e., the existence of

plural subjects for building fire safety management and the difference on

the planninq or the structure between different kinds of occupancies.

Against this circumstance, Fire Defence Agency (FDA)

y Ministry of

Home Affairs has started the study of "Fire Risk Analysis Method of Multiuse Buildings". The purpose of this project is to prepare the assessment

manual for fire service which makes it easy for firemen to diagnose the fire

risk of multi-use buildings as well as to advise the building managers or

owners the adequate methods to improve fire safety.

This paper gives an outline of the FDA project which started in 1982

and will continue till 1986.

2. OVERALL PROGRAM OF THE PROJECT

The overall program of the FDA project is as follows: (see Fig. 1)

(1) Fundamental studies on the contents of the fire risk in multi-use

buildings and the purposes of practical application of Fire Risk

Analysis Method.

(2) Studies on other evaluation methods of building fire safety.

(3) Studies on the framework of the total system and subsystems of Fire

Risk Analysis Method.

(4) Studies on the elements and the construction of each system with

theories of fire research and statistical data of actual fires.

(5) Improvement of Fire Risk Analysis Method through its tentative

application to some multi-use buildings.

(6) Preparation of the fire risk assessment manual for fire service.

54
(7) Development of Fire Risk Analysis Method to be used for a new multiuse building design at the stage of planning.

The committee for the FDA project (Chairman: Prof. K. KISHITANI),

which consists of fire researchers, building designers and administrators,

has studied (1) - (3) of the above-mentioned items during 1982. Regarding

the item (4), the committee made out the data-base of building fires and

also conducted some investigations to learn the actual condition in multiuse buildings, (refer to Appendix I, n )

3. STUDIES ON THE PRACTICAL APPLICATION OF FIRE RISK ANALYSIS METHOD BY

FIRE SERVICE

3.1. Purposes for applying the fire risk analysis method

(1) Extracting among many multi-use buildings those which have much fire

risk.

(2) Direction of the improvement for fire safety and/or the suspension of

use in certain case to the building managers or owners.

(3) Presentation of varieties of fire safety countermeasurements and their

effects when the improvement for fire safety is needed.

3.2. Classification of the stage of fire risk analysis

There are so many multi-use buildings in a big city that it is difficult

for fire service to apply the Fire Risk Analysis Method to all of these

buildings. Therefore, it is needed to classify the fire safety evaluation

of multi-use buildings into the following three stages.

(1) 1st stage: Extract by rough data and using a simple method, those

multi-use buildings which have much fire risk.

(2) 2nd stage: Diagnose the fire risk of those buildings extracted in the

1st stage of evaluation by more detailed data and method.

55
(3) 3rd stage: Grasp the factors of fire risk and the grade of their risk

clearly by some necessary investigations of the buildings

which are especially dangerous. And find out adequate

countermeasurements of fire safety.

4. PRELIMINARY STUDIES ON THE FRAMEWORK OF FIRE RISK ANALYSIS METHOD

There are three aspects such as fire outbreak, fire spread and evacuation

difficulty in the evaluation of building fire risk. Therefore, it is

comprehensible and useful that the evaluation method of fire risk is divided

into the following subsystems corresponding to the three aspects.

(1) The evaluation method of the fire outbreak probability

(2) The evaluation method of the fire spread risk

(3) The evaluation method of the evacuation difficulty

Each evaluation method of these three has naturally a respective different

construction and also gives the results of evaluation in a different way. But

the final outputs from these evaluation methods should be a graded value so

that we can compare or integrate them.

On the other hand, life safety and property risk are considered as two

main indexes of the level of building fire safety. The evaluation for these

indexes is achieved by using the results of the three evaluation methods.

The reciprocal relation among the indexes and the methods of fire risk

evaluation is shown in Fig. 2.

56
57
(

Evaluation

Methods)

(Evaluation

Indexes) 4-> u

QJ

•)-> U

cu5-

•r“ -ocAu

CL)

d) 4-> O

CD

s_

•r* -o A

CsJ

cn

•r—

58

The

reciprocal

relative

among

the

indexes

and

the

methods
Appendix I

INVESTIGATION OF ACTUAL CONDITIONS IN MULTI-USE BUILDING

1. Purpose

The purpose of the investigation is to know actual conditions and

characteristics concretely as to planning, various equipments, occupants,

management and etc. in multi-use buildings.

2. Subject building

2 (a) Building with more than 3 stories and besides more than 300 m

as total floor area.

(b) Building for mixed various occupancies.

3. Sampling

In the beginning, we selected main large cities (49 cities) all over

the country. Then we selected 531 buildings totally by extracting about

12 samples from among multi-use buildings in each city above-mentioned.

4. Method of investigation

The firemen of local fire department office reply to the questionnaire

according to documentary data of inspection and their daily impressions.

If necessary, they conduct a supplementary investigation.

5. Items of investigation

See Table 1.

59
Table 1. The Items of the Investigation of Multi-use Buildings

Classification Item

(1) Name of building 1. Name of building

(2) Possessor 2. Classification of possessor

3. Form of possession

(3) Outline of building 2 4. Total floor area (m2)

5. Building area (m^)

6. Lot area (rn ) 7. Number of floors:

a) Surface

b) Basement

8. Structure

9. Occupancy:

a) Main occupancy

b) Other occupancies

(4) History of building 10. Time of application for confirmation

11. Time of completion

12. Frequency of extent ion or reconstruction

13. Initial total floor area

14. Past fires in the building:

a) Frequency

b) Damage of the most damaged fire

(5) Location and form

of building

15. Number of roads facing the lot

16. Width of frontal road

17. Connection with underground arcade

18. Buildings connected:

a) Number of buildings connected

b) Form of connection

c) Floor of connection

19. Characteristics of windows of external wall

facing frontal road

20. Balcony

21. Fire escape floor:

a) Number of fire escape floors

b) Number of entrances on fire escape

floor

60
Table 1. The Items of the Investigation of Multi-use Buildings

(continued)

Classification Item

(6) Setting situation

of fire protection

equipment

22. Extinguishing equipment:

a) Extinguisher

b) Sprinkler

c) Drencher

d) Wall hydrant

e) Outdoor hydrant

f) Halogenated fire extinguisher

g) Fire department connection

h) Fire department water source

23. Fire alarm and information equipment:

a) Automatic fire alarm system

b) Gas-leak alarm system

c) Electric leakage detection

d) Fire information system to fire

station

e) Emergency communication system

24. Escape equipment:

a) Fire escapes

b) Emergency exit lighting and sign

25. Smoke exhaust equipment

(7) Situation of use 26. Use situation of each floor (detailed

investigation by other sheets)

27. Occupant load factor

28. Total number of occupants par day

29. Number of occupants at the peak time

30. Business hours:

a) Main occupancy

b) Other occupancies

31. Situation of use at night

32. Number of tenants:

a) Business offices

b) Residences

(8) Management form of

building

33. Whether management by owner's office or management on commission

34. Contents of management on commission

a) General management

b) Fire prevention management

c) Crime prevention management

(9) Building safety

center

35. Number of building safety centers

36. Location of building safety center

37. Number of workers at building safety center

(10) Fire protection

management system

33. Whether there is a plan of self-protective

fire defense or not

39. Self-protective fire defense organization

a) Number of members in daytime

b) Number of members at night

40. Number of fire protection managers

41. Evacuation drill

61
Appendix II

DATA-BASE OF BUILDING FIRES

1. Purpose of fire data-base

The purpose of fire data-base is to grasp the characteristics and

the factors of fire risk in a multi-use building.

2. Outline of data-base

All of fires in Japan are reported to Fire Defence Agency (FDA),

Ministry of Home Affairs in an unified form. And FDA makes out the database of them every year.

From the data-base, we selected such fires that occur in the buildings

controled by Fire Service Law as fire prevention property, and made a new

data-base.

There are data of 11,150 building fires from 1979 to 1981 in this

data-base.

3. Items of fire report centered at FDA

See Table 2.

62
Table 2. The Items of Fire Report Centered at FDA

Notes; Extracting only the items concerning a building fire

J

Classification Item

1 Entering Form*

(1) Discrimination of 1. Name of munici pal ity code

fire 2. Fire number in the municipality fig.

(2) Out! ine of the 3. Name

building of fire 4. Location

origin 5. Main occupancy code

6. Structure code

2 7. Building area fig. (mf)

8. Total floor area fig. (m ) 9. Number of floors fig.

10. Distance from the nearest fire fig. (100m)

station

(3) Fire origin 11. Position of fire origin in the code

building

12. Business condition of the zone code

of fire origin

(4) Time record 13. The time when the fire broke out fig.

14. The time when the fire was fig.

informed to fire station

15. The time when fire brigades fig.

started water discharge

16. The time when fire brigades fig.

repressed the fire spread

17. The time when fire brigades fig.

-extinguished the fire

(5) Cause of fire 18. Origin of fire code

outbreak 19. Opportunity of fire outbreak code

20. Ignited material code

(6) Weather 21. Weather code

conditions 22. Direction of wind code

23. Velocity of wind fig. (m/sec)

24. Temperature fig. (°c)

25. Relative humidity fig. (S)

26. Snow coverage fig. (cm)

27. Whether there was fire warning yes or no

or not

* Explanatory notes of entering form

code: code value

fig. : figure

(blank): description

63
Table 2. The Items of Fire Report Centered at FDA

(continued)

Classification Item Entering form

(7) Extinguishment 28. Method of fire information to fire

station

code

29. Extinguishing equipment in early

stage

code

30. Number of fire engines which

discharged water

fig.

31. Number of personnel sent out:

a) Total fig.

b) Firemen fig.

c) Volunteer fire corp members fig.

32. Main water supply code

(8) Fire-damage 33. Damage degree of burnt building code ? 34. Burnt building area fig. (nr)

35. Number of burnt buildings fig.

36. Number of suffered households fig.

37. Number of suffered people fig.

38. Number of Fatalities fig.

39. Number of Injuries fig.

40. Fire loss

a) Total fig. (1000 yen)

b) Building loss fig. (1000 yen)

c) Property loss fig. (1000 yen)

64
A STUDY CN FIRE RISK ANALYSIS METHOD

OF MULTI-USE BUILDINGS

( DATA )

by

Ai SEKIZAWA and Tadahisa JIN

Fire Defence Agency

Ministry of Home Affairs

Seventh Joint Meeting

U.S. -Japan Panel on Fire Research and Safety

UJNR, Washington, D.C. Oct . 24-28, 1933

65
150

Fig . 1—1 Number of multi-use buildings

by year of completion

66
Table 1*1 Main occupancies of multi-use buildings

1 . Department stores 108 ( 20.3 %)

2. Hotels 74 ( 13.9 )

3. Apartment houses 72 ( 13.6 )

4. Restaurants 36 ( 6.8 )

5. Theater 34 ( 6.4 )

6. Public hall 32 ( 6.0 )

7. Hospitals 15 ( 2.8 )

8. Others 160 ( 30.1 )

Total 531 (100.0 )

67
Table 1*2 Frequency of past fires in multi-use buildings

0 449 ( 84.5 %)

1 61 ( 11.5 )

2 11 ( 2.0 )

3 5 ( 1.0 )

4 1 ( 0.2 )

5 2 ( 0.4 )

6 ^ 2 ( 0.4 )

Total 531 (100.0 )

68
Tab 1 e 1 *3 Existence of sprinklers

Yes 217 ( 40.9 %)

No 314 ( 59.1 )

Total 531 (100.0 )

Table 1*4 Existence of smoke exhaust equipment

Yes 86 ( 16.2 %)

No 445 ( 83.8 )

Total 531 (100.0 )

Tablel*5 Existence of emergency communication system

Yes 333 ( 62.7 %)

No 198 ( 37.3 )

Total 531 (100.0 )

69
Table 1-6 Frequency of evacuation drills in 1981

0 168 ( 31.6 %)

1 106 ( 20.0 )

2 212 ( 39.9 )

3 16 ( 3.0 )

4 7 ( 1.3 )

5 4 ( 0.8 >

6 2 ( 0.4 )

7 * 16 ( 3.0 )

Total 531 (100.0 )

70
Table 2*1 Number of fires by type of building

1. Apartment houses 4,077 ( 36.6 %)

2. Multi-use buildings 3,655 ( 32.8 )

3. Schools 691 ( 6.2 )

4. Offices 566 ( 5.1 )

5. Factories 565 ( 5.1 )

6. Department stores 346 ( 3.1 )

7. Restaurants 293 ( 2.6 )

8. Hotel

s

240 ( 2.2 )

9. Hospital

s

206 ( 1.8 )

10. Others 511 ( 4.5 )

Total 11 ,150 (100.0 )

71
Table 2*2 Number of arsons by type of building

1. Multi-use buildings 655 ( 36.0 %)

2. Apartment houses 525 ( 28.9 )

3. Schools 242 ( 13.3 )

.*i M-. Department stores 106 ( 5.8 )

5. Offices 89 ( 4.9 )

6. Hospitals 47 ( 2.6 )

7. Hotel

s

33 ( 1.8 )

8. Restaurants 31 ( 1.7 )

S. Factories 16 ( 0.9 )

10. Others 75 ( 4.1 )

Total 1,819 (100.0 )

72
Table2*3 Occupancies of fire origin of multi-use building fire3

1 . Shops 658 ( 18.0 %)

2. Restaurants 504 ( 13.8 )

3. Offices 252 ( 6.9 )

4. Dwel 1 ings 146 ( 4.0 )

5. Factories 116 ( 3.2 )

6. Department stores 78 ( 2.1 )

7. Warehouses 72 ( 2.0 )

8. Others 1 ,829 ( 50.0 )

Total 3,655 (100.0 )

73
Table 2*4 Causes of multi-use building fire-S

1. Arsons 655 ( 17.9 %)

2. Cooking furnaces 627 ( 17.2 )

3. Tabacco 609 ( 16.7 )

4. Electric apparatus 354 ( 9.7 )

5. Playing with a fire 188 ( 5.1 )

6. Stoves 177 ( 4.8 )

7. Bath heaters 95 ( 2.6 )

8. Matches & Lighters 94 ( 2.6 )

9. Others 597 ( 16.3 )

10. Unknown 259 ( 7.1 )

Total 3,655 (100.0 )

74
81.5

Fig. 2*J Frequency of multi-use building fires

by rank of burnt building area

75
h.

Fig. 2*2 Frequency of multi-use building fires

by time of fire outbreak

76
Discussion After A. Sekizawa's Report on A STUDY ON FIRE RISK ANALYSIS METHOD OF

MULTI-USE BUILDINGS

PAGNI: On Table 1, sections 3, 4, and 5, you don't mention smoke detectors. Is

that in the appendix, page 4?

SEKIZAWA: Even though smoke detectors are not included in this table, that

doesn't mean we are not investigating the use of smoke detectors. We do have

data on smoke detectors; it happened to be excluded from this table.

PAGNI: In Table 2, what time period is that 11,000 fires occurring in?.

Secondly, also in Table 2, on arson, you show approximately 35 percent of school

fires as arson and 30 percent of department store fires as arson. Are these

typical figures in other years and would they be representative of world-wide

averages as well?

SEKIZAWA: Where did you get the 35 percent for schools?

PAGNI: 242 divided by 691.

SEKIZAWA: We have not compared this figure with figures from other cities or the typical figures worldwide. So, we do not have the answer to that particular

question. But I'm sure that we can get an answer to your question after we analyze our fire data base.

PAGNI: In Table 2, what time period does that cover? How long did it take to accrue 11,113 fires? Where is that data; is that all in Japan or just Tokyo?

SEKIZAWA: That answer is given in Appendix 2, page 9. In other words, this

figure was collected during a three-year period from '79 to '81, from all over

Japan.

NELSON: On Figure 1, you have two blocks labeled "verification by case study," one of which should occur this year. Have you got an operational

plan? How will you make that verification?

SEKIZAWA: What do you mean by operational plan.

NELSON: Figure 1. Overall program shows a box labeled "Verification by case studies in 1983" and another box "Later in the project in 1984" and I only

wondered if they have a plan on how they are going to make the verification?

SEKIZAWA: Yes, we do have an operational plan for verification of the

subsystem. In here, we mean the verification study of the subsystem. And, in

this case, we are going to use multiple-use buildings from a certain area,

particularly from Tokyo. Typically, we are going to select ten cases.

NELSON: How will you decide that it verifies. . .by judgement, by other models,

or by fire histories?

SEKIZAWA: We have not decided exactly how we are going to do it. Mainly, we are going to depend on judgement. Secondly, if we can obtain a fire data bas^

from the past data case, then we would like to compare our studies with the past

data.

77

FIRE SAFETY EVALUATION METHOD

Tokyo Fire Department

Seventh Joint Meeting

U.S. Japan Panel on Fire Research and Safety

UJNR, Washington, D.C. Oct .24-28, 1983

79
FIRE SAFETY EVALUATION METHOD

Tokyo Fire Department

1. Purpose of the Evaluation Method

I) The main purpose of "the Evaluation Method" is to diagnose fire safety

of the specified building with scoring system to make the problems clear

and to advise building managers or owners of the adequate methods for

improvement of fire safety.

2. Idea of the Evaluation Method

(1) Employ total score system and establish maximum score at each item

and component.

(2) Select indispensable items for each occupancy which must be cleared.

(3) Establish standard score to evaluate the grade of life safety, (see

Fig. 1)

3. Establish 34 items and their score

(1) Establish 34 items and 102 components from case study of 60 small

fires, 41 partially damage fires and of 33 spread fires, (see Table 1)

(2) Weight of each items and indispensable items were gained from matrix

analysis and event tree analysis of 134 fires.

(3) Establish score to each items depending on its grade, i.e., 50, 40,

30, 20 and distribute the score to each component depending on the

percentage contribution.

(4) Classify 34 safety items into following 3 countermeasure categories

and establish their maximum score

80
(categories) (maximum score)

a. fire prevention

fire outbreak control

fire growth control

420

b. fire spread control 365

c. evacuation and escape 535

Select indispensable items depending on the occupancy of building

(occupancy) (items)

Department store and supermarket 15

Hotel and Japanese inn 15

Hospital 15

Multi-use building 16

(6) The evaluation is classified into 5 ranks, i.e., S, A, B, C and D.

The rank is determined by "Total Score" and "Final Evaluation Value"

which consists of countermeasure score and indispensable score.

4. Process to use the Evaluation Method

(1) Total score

Work sheet which consists of 102 components prepare and fill them

out after observation, total score is summing up score of 102

component

.

(2) Final evaluation score

a Classify 34 items into 3 countermeasure categories and establish

their score.

b Select indispensable items and establish their score.

(3) Fire Safety Evaluation

Evaluation is classified into 5 ranks from Table 2.

REFERENCE

1) Tokyo Fire Department, "Fire Safety Evaluation Method", May 1983

81
Table 1. 34 Fire Safety Countermeasurements 1 Items

(I) Consciousness . Organization . Excution of Fire Prevention.

(A) Management of Fire Safety

1. organization . system . competence

2. training . fire safety plan

3. management & inspection of fire protective equipments

4. management of fire control

5. management of general purpose equipments

(B) Empl oyee

6. consciousness of fire prevention

7. excution . behavior

(C) Visitor

8. behavior . the degrees of consciousness

9. visitors' physical states

10. attribute of personnel

(II) Relation between Man and Facilities . Equipments

(A) Location

11. 1 ocation of fire

(B) Alarm & Extinguishment

12. practical use of fire alarm & automatic alarm system

13. practical use of emergency announcement system

14. practical use of extinguishing equipment

(C) Evacuation

15. practical use of evacuation facilities

16. practical use of evacuation equipments

17. operation of smoke control & air conditioning system

(D) Compartmentation

18. opening & closing of fire resistive door

82
(Ill) State of the Fire Prevent Facilities & Equipments

(A) Fire Room

19. fire load

20. equipments using fire

21. interior finishing

(B) Structure

22. principal structural parts

23. characteristics of interior space

24. outside wall & openings

(C) Compartmentation

25. compartmentation of plan

26. compartmentation of stairwell

27. fire resistive door

(D) Evacuation

28. facilities for evacuation

29. equipments for evacuation

30. smoke control system

(E) Extinguishing Equipment

31. fire alarm bell system

32. fire extinguishing equipment

33. facilities for fire fighting

34. sprinkler system

83
Table

2.

FIRE

SAFETY

EVALUATION

DECISION

TABLE

84

The

evaluation

is

classified

into 5

ranks,

ie,

S,

A,

B,C

and

D.

The

rank

is

determined

by

"Total

Score"

and

"Final

Evaluation

Value"

which

consists

of

countermeasure

score

and

indispensable

score.

The

final

evaluation

value

is

determined

by

the

lower

rank

of

them.
Fiji

FLOW

CHART

OF

"FIRE

SAFETY

EVALUATION

METHOD'

85

Discussion After T. Jin's Report on FIRE SAFETY EVALUATION METHOD

GANN: I have two questions. The first is, are there any items in your list of

34 that are weighed so heavily that if a building rates extremely well, that it

get a high rating regardless of how the building rates with the other 33? For

instance, if a building is very well sprinklered, would that give it a high

rating?

JIN: As I showed in the slides, the highest number is 50 points and the worst

is 20 points. So the difference is only 30 points.

GANN: So, there must be several strong features in a building to get a high

rating?

JIN: For example, with the sprinklers, you could get the highest points for

this category. However, you have to take into consideration that if this

sprinkler were out of order. This is more dangerous for the spread of fire.

What kind of counter measures were taken? The sprinkler is but one item; you

have to take it all into consideration. Escape is also an important item.

GANN: My second question is, strictly for clarification, would you redefine

what the indispensible items are?

JIN: I will explain it later.

KEATING: Would you give some examples and explain why you accepted expert

judgement over your empirical generation of the rankings of some of these items?

JIN: The figures we got out of the data is sometimes very far apart from

experience.

PAGNI: What motivation does the building owner have to use your pamphlet? Here

in the United States, I suspect that the only owners who will use the pamphlet

would be the ones that felt their buildings would score well. How do you

motivate those whose buildings they think will score low?

JIN: Our fire department has a lot of authority; no one has reported a problem

to me. Our fire law is very strict, and, if the owner of a building has tried

to cheat, the fire department would know. Another purpose of this brochure is

to get them to evaluate their own building before the fire department does their

inspection.

NELSON: How accurate do you feel the ratings that you get are relative to the

true fire hazard involved?

JIN: We took twenty-one cases and we got twenty-one verifications.

NELSON: Our experience has been that very bad facilities rate very bad and very

good facilities rate very good on any rating system. It's the ones that are in

the middle ground that are difficult to rate.

JIN: I think our results are the same.

87

GENERAL DISCUSSION

GANN: Prof. Keating, I have a question. In the interview works that you've

done, you do that soon after the fire. Some of the survivors have been through

extensive smoke exposure and may, in fact, suffer ill effects much later on. Do

you have any scheme at this point for following up on that?

KEATING: There are several parts in your question, Dr. Gann. The first one is

that the times after the fire that we interview the victims vary widely. We do

not get there as fast as we would like to in all instances. Secondly, the

current sample that I talked about today contains no "victims of fires," anyone

who was hospitalized for any reason. So, we presume that excessive smoke

inhalation during the time of fire is not that prevalent in the sample I talked

about today. Thirdly, in the current grant that the National Bureau of

Standards has funded, we intend, this year, to interview only victims; namely,

hospitalized patients of fires, and obtain during those interviews from the

medical staff the level of smoke intoxication as well as alcohol blood levels

during the time of admission.

GANN: The reason for my question is that if a person involved in a fire is

hospitalized immediately after the fire, that person is counted in the national

statistics for injuries. If the person leaves the fire scene and enters a hospital two days later or a week later, even if the injury is related to the

fire, the hospital has no way to know this. We need data on that.

KEATING: The only indirect answer I can give you is that at the Northwest Burn

Center, we are going to pursue all outpatients of the Burn Unit as well as the

Center. I'm not certain at this time that any even approximations of

percentages, for instance, can speak to your question.

GANN: Is there Japanese experience in this area?

HANDA: Since I've engaged in the evaluation of fire, I have experience of

various stages of people that suffer from fire.

NELSON: Can you tell us anything about it?

HANDA: Most of the records are investigation records by the police of the

district. Sometimes we construct tables and we also take a record of people

whose behavior were unclear. These records also include dead bodies.

NELSON: It's very hard to get interviews from the dead victims. It does leave

a serious void in our data.

EMMONS: Dr. Wakamatsu, in your design you indicate that the occupants of the

building are determined in the statistical data. Clearly the number of people

who are in the building at any one time is a statistical matter, but it is the

best one could do unless you had someone at the door counting. However, in the

design, do we not have to design for the worst case rather than a statistical

measure?

89
WAKAMATSU: There are a great many number of conditions that we have to take

into consideration when we design this type of research. Of these conditions

that we take into consideration, many of them are uncertain conditions. If we

take worst cases for every condition, the outcome would be very unrealistic.

Therefore, I feel that we cannot avoid taking the probability way of thinking.

I don’t think that we should take the worst case for every condition we take

into consideration.

NELSON: What level of probability are you thinking?

WAKAMATSU: Could you elaborate your question a bit?

NELSON: 90 percentile, 95 percentile?

WAKAMATSU: I think the probability percentile will differ depending on the

conditions you are talking about. I think that the answer will differ depending

on the philosophy or way of thinking about the conditions you use in the

design. Let me give you one example. One condition can be the direction of

wind. A certain building will be more severely affected by a certain direction

of the wind and also the behavior of smoke affected by the direction of the

wind. So, we can get the data based on the weather, what the probability was of

a certain direction of wind affecting that building. Then, we can figure out

the percentile of wind direction in this case.

NELSON: It seems to me that what Dr. Wakamatsu is talking about, as we said

earlier, is one of the most serious questions, and there should be efforts in

both of our countries to develop the design stress that will be used for the

design conditions. I expect that while they will not be the true worst case,

they will have to be a pretty severe case if we were going to certify buildings

on the basis of analytical calculations.

WAKAMATSU: It may be necessary to think about the true worst case at the stage

of designing but, if that the true worst case will probably not occur, then I think it is not appropriate to use the true worst case probability in designing

or in diagnosis.

NELSON: Oh, I agree, the true worst case is what has been shutting down nuclear

generating stations in this country. If you design by the true worst case,

you'll never be able to build; it will be too severe. But I would find in this

country in the case that Dr. Emmon's raised, if you design based on a statistical number of persons, our local fire authority would post a sign on that building not allowing any more than that number of persons in the building.

WAKAMATSU: I think that depending on the conditions we are thinking about, we

should depend on the worst possible case, or, in other cases, we should depend

on statistical data. When you talk about the number of people to be admitted

into a building, maybe we should consider the true worst case.

COOPER: Dr. Wakamatsu, are there any specific examples where analytic methods

of predicting fire growth have been used to actually establish Japanese

standards, codes, or regulations?

WAKAMATSU: Standards for individual residences, not the buildings, are made on the basis of analytical methods.

90
COOPER: Is it possible to be more specific?

WAKAMATSU: This particular standard I’m talking about is the one to be applied

to wooden homes.

KISHITANI: I take it that Dr. Jin was not quite satisfied with the answer given

to your question concerning sprinklers, so I would like to elaborate on that

point. One should not be satisfied simply because there are sprinklers attached

to the ceiling, because I know of a complete case in California where sprinkler

heads are attached but there are no pipes. Needless to say, that the sprinklers

will not extinguish fires up above the ceiling, that is the other side of the

ceiling and the sprinkler cannot put out the fire if the fire occurs where

sprinklers cannot reach. This is comon sense but, you know, these have to be

taken into consideration. When the local fire department scores the sprinkler,

we take into consideration three to four subitems for the one item of

sprinkler. In other words, we examine whether or not the sprinklers are being

taken care of or being examined regularly and also whether or not the sprinkler

system is working. In my personal view, concrete walls are 100 percent

fireproof; on the other hand, sprinklers have only 97 percent probability. I feel that this is a very important difference because when we look at a residential fire, the probability of burning the residences is 1/10,000. A 3

percent difference is very important and meaningful when you think about

residential fires.

NELSON: What is the probability that the doors in that concrete wall will be

closed?

KISHITANI: I don't know.

NELSON: I just meant that everything has a failure mode - sprinklers, fire

resistence, compartmentation or any other thing we use.

SEKIZAWA: My question can be answered by either Mr. Nelson or Dr. Cooper. I would like to know how the results of a design system for fire safety research

conducted by the Center for Fire Research will be ultimately used. In other

words, in my presentation I pointed out that our results will be ultimately used

for the development of a manual. I would like to know how the results of your

research will be utilized?

NELSON: The work which Dr. Cooper presented is directed towards practicing

design engineers as you might find working in consort with an architect in the

design of a building. Other work that we’ve done, as presented at previous

meetings, was meant for the plan examiner or other regulatory subprof essionsals

,

such as a fire marshal or fire inspector. We have occasionally done work aimed

at training or educating people on emergency evacuation or similar emergency

actions, but we have not attempted to develop systems whereby a person without

professional qualifications could grade the fire safety of a building.

91

FIRE GROWTH PREDICTION

Raymond Friedman and Toshisuke Hirano

Session Chairmen

93

Fire Spread Research in the United States

H. W. Emmons 1983

The quantitative understanding of the rate of fire spread under

a wide variety of circumstances of geometry, materials, external

radiation, and ambient atmospheric vitiation is necessary for the

successful development of predictive fire models. The energy feedback

by radiation, gas convection, and solid conduction reacting with the

pyrolysis, ignition and combustion of the material is the well established mechanism of fire spread in all cases. The complexity of

these processes has prevented generally valid theoretical solutions

or emperical data correlations.

Some progress is being made with several problems:

Boundary Layer Fire Spread

J. Tien, Case Western Reserve, is studying the flame spread over

a vertical fuel surface both upward (wind assisted) and downward (wind

opposed) . Although both theoretical and experimental work is intended

only theoretical work has been done to date. Laminar flow with finite

rate kinetics are being used. Also a two step chemical process is

considered, carbon to CO then CO to CO^. This prevents the simplification of the Shvab-Zeldovich transformation. This is an extension

of work he did some years ago solving the steady boundary layer flame

with finite kinetics. This work showed the experimentally observed

bulbous flame leading edge and resulted in extinction conditions. Presumably similar results will be forthcoming for the vertical flame

spread problem now under study.

95
Wind Aided Fire Spread

A few years ago G. F. Carrier, Harvard University and F. Fendel

of Thompson, Ramo, Wooldrige Corporation, analytically developed a

solution for the laminar wind aided flame spread along a flat plate.

The formulation assumed constant properties and a Shvab-Zeldovich

transformation with infinite kinetics. The final steps of the solution were numerical but it was otherwise an exact solution. This

solution is now being generalized by including in an equally exact

way both distributed flame radiation by soot production and the charing

of the solid pyrolysing fuel. These solutions when available will be

sufficiently general for detailed comparison with experiments thus

confirming (or refuting) the physical model as it is presently understood .

In the meantime progress is being made with experimental data on

wind aided flame spread. C. Fernandez-Pello , University of California

Berkeley, has obtained PMMA data which shows an excellent correlation

of the rate of spread of the pyrolysis front, S , with the wind

velocity U

Fire Spread on Horizontal Wood Surfaces

A. Atreya, Michigan State University, has just completed his Ph.D.

thesis at Harvard University. He experimentally and theoretically

studied the rate of fire growth on horizontal surfaces of wood with an

external radiant field. The surfaces were 2 feet square and the exter96
2 nal radiation was uniform to 5% but was limited to 1 w/cm maximum.

Uniform grain wood was selected because knots and resinous spots

cause irregular spread. Even without obvious irregularities the

fire does not spread equally fast in all directions. The burning

area is approximately elliptical with one focus at the ignition point.

When boards are made, the saw is approximately parallel to the grain.

When the grain is cut at a small angle, it serves to jet the pyrolysis

gases in the direction of their surface openings thus enhancing or

detracting from the fire spread.

Ten different woods and cellulose were tested. For each wood

data was obtained as illustrated for maple.

Lower AH

Char Combustion

Yield Formula C H 0 kw/ gm

Maple .35 C 1.62

H2.30° .515 .061 .424 18.60

Char C

9.68

H2.53° .752 .034 .214 27.93

Volatiles C

.96

H2.26° .387 .076 .537 13.57

Values for all of the quantities listed in table 3.3 were measured.

A typical surface temperature variation is as shown in Fig. 3.5.

A considerable study was made of pyrolysis and ignition. A new

apparatus was used as shown in Fig. 5.1. This gives quite reproducible

surface temperatures and ignition temperatures, Fig. 4.6.

Theoretical models for pyrolysis and flame spread were developed.

For pyrolysis, rate equations must be used for both moisture desorption

and chemical degradation. For flame spread, pyrolysis must be coupled

97
with the various feedback mechanisms. The results are shown in Figs.

6.6, 6.7, and 6.8.

Flame Spread on Cellular Plastics

Chuan Tan, Singapore, Ph.D. thesis at Harvard University, has

studied the spread of fire on horizontal surfaces of cellular plastics

uisng the same apparatus as for the above study with wood. Cellular

plastics are closed pore if rigid or open pore if flexible. The open

pore material has random openings and does not have the systematic

pore gas ejection properties of wood. Hence the burning in a symmetrical apparatus with uniform external radiation is quite symmetrical.

Cellular plastics burn in three modes, Table VI. Some do not

melt. They char and spread rapidly compared to burning in depth. Thus

the center initially ignited region soon goes out leaving a ring of

fire. Some pyrolyse sufficiently rapidly that the central region does

become deeper, the burn surface taking the shape of a bowl. Finally

some cellular plastics melt below their ignition temperature. On ignition the melt moves downward to the bottom of the sample (the samples

were 3 inches thick) producing a cylindrical hole1 only a few centimeters in diameter. Fig. 30a. The subsequent pyrolysis takes place

from the inside surface of the expanding cylindrical hole while the

flame is attached to the upper rim. A simple theory was developed for

each of these modes of burning. Essentially the theories are for

radiation feedback and check in a general way with the data, Fig. 32b,

which shows considerable scatter.

98
TABLE 3.3a: PHYSICAL VARIABLES

Graph SYMBOL DEFINITION DESCRIPTION

01 R (measured

)

Equivalent radius of the bu

ing area (mm)

02 R dR/dt Radial spread rate (mm/sec)

03 IT," (dm/d t) /-R2 Mass flux (mg/cm sec)

04 IT."

f 1 » i n

05 E

c [see Append . A] Convective energy release

rate (Watts)

06 e r

[ see Append . A] Radiative energy release

rate (Watts)

07 xc V<E

R + V Convective fraction

08

*R V(E

c + V Radiative fraction

09 X,n

(E

r + E

c )/m .AHv Combustion efficiency

10 d

f (measured

)

Final char depth (mm)

(measured at the end of the

test)

11 k. (derived from

rad iaticn

measurement s

)

Grey flame absorption coeff

(1/m;

12 k

£

»! Grey flame absorption

coefficient (optically thir.

(1/m)

13 /m" k^/m" (correlation)

Grey flame absorption coeff

correlation

99
TABLE 3.3b: CHEMICAL VARIABLES

GRAPH /' SYMBOL DEFINITION DESCRIPTION

14 ^ 02 ”02 /A Instantaneous mass

°2

fraction of

13 Vo2 ”'c02

/lr' Instantaneous mass

C0

2

fraction of

16 yH20 “h:) 7” Instantaneous mass

H ? 0

fraction of

17

'co

a

c0

« Instantaneous mass

CO

fraction of

18 'thc *THC /6 Instantaneous mass

THC

f raction of

19 Y sootC

[see Append. D] Instantaneous mass

soot from carbon ba

fraction

ilance

of

20 ^ SOOtP

[see Append. D] Instantaneous mass

soot from physical

fraction of

energy balance

21 x charC [see Append. D] Instantaneous mass fraction

char from, carbon balance

of

22 ^ char? [see Append. Dj Instantaneous mass

char from physical

fraction

energy b; ofal- ance

23 X 02 (derived

from 0^)

Combustion efficiency based

CL consumption

on

24 X C02 , CO (derived

from CO , CO)

Combustion efficiency based

CO^, CO production

on

25 AH [see Append. D] Heat of combustion (KJ/gm)

26 Y

sootM

[see Append. D] Instantaneous mass

soot obtained from

fraction of

conservation

of mass

100
e'-

en

iO

co

OJ

o

co

co

iO

TT

o

P3o

><

o o o o o O o o o o o o o c

lO o in o in o in o in o in o in o

05 05 co co 2> r- CO CO in »n t** co co

(>l) ajn^jsduia^ aoejjnc;

101

FIG.

3.5

[Temperature

Histories

for

MAPLE]

Time

(sec)
L

fg/m

ass

flux]

(K

J/gm

)

1

FIG. 5.1 FLASH POINT-FIRE POINT APPARARATUS

le' 1 is® ie‘ ie 2 ie 35 T I HE ( -- ) APPARENT LATENT HEAT FOR MAPLE

.

102

Fig. 4.6
300

o

CO C\2 — —

(uiui) snip^H aui^y;

wc

V.

103

Fic.

b.fi

[Flame

spread

calculation

for

MAPI,

1C ]

Time
o

o

LC

o

o

o

iO ©

c\i cvi o

(oas/uim) pcsjds

104

FK',.

f>. 7

[Spread

rale

calculation

for

MAPI,

l‘!]

Time
006

c

o C3 o o o o o o o

n o in o in o in o o

CO CO c- CO CO m n

()}) 9jn;Bjadui9x aDejjns

105

FIC.

6

. H

[Surface

Temp.

Calculation.

&

data

MAPI.

ft]

Time

(s
CATEGORY A

rA///>,l

GM3 2

GM4 2

CATEGORY B A

/ \

£ZZ?2

7004

GM22

GM24

CATEGORY C A

mm dm

GM26

GM28

G>!43

TABLE VI Classification of foams tested in study.

106
107

Fig

30A

Sequence

of

photographs

shoving

the

progress

at

the

flame

front

into

GM48

foam

during

the

early

stages

of

fire

spread.
ex t

o

o

o

CO

u. (V

o

o

m

o

o

fCu

c.

ir.

( D3S/IE3 ) 'Si ‘sjey pesids T^TP^X

108

Kate,

K

,

over

(!M4K,

under

the

effect

of

external

radiation.
RECENT PROGRESS IN FIRE GROWTH MODELING IN JAPAN

by

Takao Wakamatsu and Takeyoshi Tanaka

Building Research Institute

Ministry of Construction

Japan

109
RECENT PROGRESS IN FIRE GROWTH MODELING IN JAPAN

INTRODUCTION

In this progress report, we intend to present brief outline of some

of the primary studies associated with fire growth prediction that have

recently been conducted in Japan. The topics here were selected according

to the authors' interest, and consequently there may be some other

important works that we failed to refer to. Also, the scope of this

review is limited to the subjects that directly address building fire

problems, although there seemed to be some more interesting works when we

look at fire research in general.

F IRE SPREAD OVER MATERIALS

Terai(l) created a theoretical model for predicting the burning

propagation over horizontal materials, in an attempt to contribute to

qualitative understanding on how a fire spreads at initial stage, where

enclosure effect is insignificant. In this model, an initial fire source

put on the surface of semi-infinite material, forms a fire column, and

propagates axi- symmetrically over the material surface. The model

incorporates heat conduction within the material, pyrolysis and

gasification of the material, mixing of the gasified fuel with air, and

energy feedback from the flame to the material surface. The conduction of

heat within the material was formulated into an integral equation and

solved using weighting function for the -temperature within the material.

Sample calculations were carried out for PMMA, whose properties are fairly well known. A couple of the calculation results are given in

Figure 1.

Hamada, Sugawara and Kishitani(2) conducted a laboratory experiment

to study the basic nature of flame spread over a vertical material. The

vertically held PMMA boards with 65cm height, 10cm width and a couple of

different thicknesses were ignited at its bottom using nichrome wire, and

from the flame length and the pyrolysis front position that were photographed at a given time interval, the upward flame spreads

velocities were reduced. It was found, as one of the results, that the

110
propagation velocity of

of pyrolysis position (X

pyrolysis front (V cm/s) is given as a function

cm from the bottom) as follows:

V = 0.039 + 0.00126X

P P

BURNING BEHAVIOR IN COMPARTMENT FIRE

Takeda(3) conducted the experiments to investigate the fire behavior

at pre-flashover period using a cubic small scale compartment, whose size

is 50cm x 50cm x 50cm. The PMMA pieces, which were 15cm x 15cm x 6cm of

size and placed on the center of the floor as the fuel, were ignited

along the edge near the opening of the model compartment using alchohol

saturated cotton. It was observed that as the fire grows from fuel

control to ventilation control stage, an oscillatory phenomenon appeared

in the transient period in between. The oscillation was fairly regular

and its interval was a little less than 1.0 second for almost every case. The starting time and the duration of the oscillation varied depending on

the size of the compartment opening.

Another series of reduced scale experiments were carried out by

Nitta(4) using also PMMA as the fuel. These experiments also aim at

investigating the phenomena that lie in the transient region between fuel

control and ventilation control regions. The experiments were conducted

for the different opening widths of the model compartment, whose size is

60cm x 120cm x 60cm. The measurement was made of the hydrocarbon

concentration in the room as well as of other ordinary measurement items,

and it was found that the fires undergo transition from fuel control to

ventilation control where the ventilation factor WH0/ is about 1,000

3/2

cm for this specific setup of the experiments (W and H stand for the

the width and the height of the opening, respectively). In Figure 2, the

maximum values of the various quantities are plotted versus opening

factor, and a sharp peak can be seen on the line of the maximum

3/2 hydrocarbon concentration where WH is around 1,000.

In compartment fire experiments, in particular in case of small

scale ones, there are many evidences that oscillatory phenomena can take

place under some conditions, and they are often attributed to the

oscillation of the combustion in the room due to some unclarified comnl-.-x

interactions among ventilation, heat transfer and fuel pyrolysis. On tin

other hand, Satoh, Matsubara and Kumano(S) challenged this explanation '

conducting some model room experiments in which there is only m 1

>

• t :

111
heater as shown in Figure 3, and the field model computations using code

UNDSAFE (6) . It is revealed, both from the measured room temperature in

the model experiments and the predicted effluent enthalpy through the

opening, that oscillatory phenomena can take place despite there is no combustion at all in the room of origin. It is also found that, both in

the predictions and the experiments, the oscillation frequency was

1/3 proportional to Qq , where Q^is the heat release rate.

DOORWAY FLOW

As we look into compartment fire phenomena more extensively and

closely, it is increasingly important to reasonably estimate the rates of

in- and outflow through the compartment opening, which is driven by the

fire induced buoyancy. And for this purpose, it is almost indispensable

to have some equations to correlate the rate of opening flow with some easily and quickly measurable quantities such as room temperatures and a couple of flow pressures at the opening, since otherwise we have

virtually no practical mean to obtain the rate of flow at our disposal,

especially when we deal with unsteady state fire. BRI felt that it is

very important to get this kind of correlation to carry out the

experiments concerning to the trilateral cooperative toxicity study

project, and conducted a series of experiments for the doorway flow rate

with the consultation by Steckler of NBS, who were invited to Japan

during the period of the experiments. The test data were reduced using

the same procedure given by Steckler (13) . The part of the result will be

presented in the measurement session of this 7th UJNR meeting.

Matsushita and Terai(8), considering hot gas effluent flow as an upside down weir flow and applying the similar technique as that used in

the analysis of weir flow, suggested that there is a possibility that hot

gas effluent flow has hyperbolic velocity profile instead of parabolic

one as is shown in Figure 4.

PREDICTION OF SMOKE MOVEMENT IN BUILDINGS

Tsujimoto, in an attempt to predict stratified smoke layer movement

along corridors and in stair wells in buildings, conducted a series of

experiments for smoke flow behavior under a horizontal and an inclined

ceiling. The experimental results were compared with the predictions by

the theoretical model that were derived based on the theory given by

Ellison and Turner(lO) for liquid. The comparison between the test

112
results and the model predictions in the temperature and the velocity of

the smoke layer shows good agreement. This work has been presented to

this UJNR meeting as a technical paper (9)

Terai and Matsushita (11) predicted the flows throughout an existing

underground building to find out the best method to control smoke for

that building. The calculations were conducted for several conditions, in

each of which one of the candidate smoke control measures to vestibules

was employed. The equations were solved for 103 unknown pressures using

Newton-Raphson method. A sample of the results is shown in Figure 5. The room of origin is located on the 4th basement. It was predicted that any

of the candidate measures will not assure perfect safety for the evacuees

in that building.

SMOKE FILLING MODEL

A smoke filling model was used to estimate the time available for

safe egress of spectators in Shin-Kokugi-kan(New National Smo-wrestling

Arena), which was designed and also is to be constructed by Kajima

Kensetsu, one of the most leading construction companies in Japan(12).

The available egress time thus estimated was compared with the time also

predicted to be necessary for the evacuation of prospected 11,500

spectators. Direct incentive of this prediction was to obtain the

authorization for the fire safety design of the building, which is to be

given by the evaluation committee, but the importance of this is that

this is almost the first time that a smoke filling model is applied to a real problem. Although Shin-Kokugi-kan is somewhat special in its size

and shape, it will be desirable if this example encourages other attempts

to use this kind of engineering means to evaluate the fire safety

performance of buildings. Figure 6 gives the schematic of Shin-Kokugi-Kan

and the predicted results of the smoke filling.

C ONCLUDINGS

Recent works in Japan that are associated with the prediction of

fire in buildings were introduced. Unfortunately, most of the source materials are written in Japanese as can be seen in the reference list,

although a few are available in English. This review is by no means sufficient to describe ongoing works in Japan, we would encourage the

readers to make direct contact with the authors of the paper in which

they are interested.

113
REFERENCES

(1) Terai,T.: On The Axisyminetrical Burning Spread Over Horizontal SemiInfinite Solid, Annual Meeting of The Architectual Institute of Japan,

1982.10 (in Japanese)

(2) Hamada, K. ,Sugawara,S . and Kishitani , K. : Experimental Study on Wall

Fire (Upward Flame Spread Velocity), Annual Meeting of The Architectual

Institute of Japan, 1983.9 (in Japanese)

(3) Takeda,H.: Pre-flashover Behavior in The Small Scale Compartment,

Bulletin of Japanese Association of Fire Science and Engineering, Vol . 33.

No.l, 1983. (in Japanese)

(4) Nitta,K.: Experimental Study on Properties of Outflowing Smoke from A

Small Scale Enclosure in Fire, Annual Meeting of The Architectual

Institute of Japan, 1983.9 (in Japanese)

(5) Satoh, A. ,Matsubara, Y. and Kumano,Y.: A Study on Oscillatory Phenomena

of The Flow in Compartment Fire, Japanese Association of Fire Science and

Engineering, 1983.5 (in Japanese)

(6) Liu, V. K. and Yang,K.T.: UND Report, TR-79002-78-3, 1978.

(7) Nakaya, I . , Tanaka, T. and Yoshida,M.: A Measurement of Doorway Flow

Induced by Propane Fire, to be presented at 7th UJNR meeting, 1983.

(8) Matsushita, T. and Terai,T.: The Flow of Smoke and Air Through Opening

as Two Stratified Layer, Annual Meeting of The Architectual Institute of

Japan, 1981.9 (in Japanese)

(9) Tsuj imoto,M. : Smoke Movement as A Density Flow, to be presented at 7 th UJNR joint panel meeting, 1983.10

(10)

Ellison, T.H. and Turner, J.S.: Turbulent Entrainment in Stratified

Flows, J. Fluid Mech. 6, pp423-448, 1959.

(11) Terai,T. and Matsushita, T. : On The Comparison Among the Various

Methods for Air Supply To and Smoke Exhaustion From The Vestibules of The

Evacuation Stair Wells, Annual Meeting of The Architectual Institute of

Japan, 1982.10 (in Japanese)

(12) Sato,H.: Application of A Total Fire Safety System to Shinkokugikan

Project - Japanese Sumo Wrestling Stadium, Kajima Institute of

Construction Technology, 1983.9.

(13) Steckler,K.D. : Flow Induced by Fire in A Compartment, NBSIR 82-2520,

1982.

114
o d

II II d d

115

Figure

1.

Some

of

the

calculation

results

by

Terai

's

fire

propagation

nodel
Maximum

Hydrocarbon

Concentration

C

]nax

(ppm)

u

- 300

a 200 o

O-i e

<u E-

!/}

o 100 3

<4-1 44

to

-30

c

• r4£

box

C3 20 ^

(D +J

03

10 1

o

0 3

X

Figure 2. Some of the results of Nitta's experiments

Opening height : 450 mm PMMA site : 198x198x20 mm Temperature : relative to 19 °C

116

Maximum

Outflow

Rate

of

Gas

Through

Opening

G

_

(g/min.
Test

and

Calculation

Conditions

CiM

117

qj

/3

(kw'/ 3)

Ql/3

(k,

,1/3)
Effluent Gas Flow Rate Given by The Weir Flow Assumption

Ws = C as b (H2

- X ) 3 / 2

where = k(lcose -} £np/(2gys (ya - ys ))

x = p l/CYa "Ys) + h x k = Uj/uj = 0 . 4685

g ; Angle between the section IJ and average stream

line of the smoke flow. Since generally g<30,

cosg = 1

.

Discontinuity Height at The Section IJ

h? = H? - (1 - (Ya-Ys KH2-hi)

)(1 -k^)(H2

- h x )

Figure 4. The doorway flow seen as an upside down weir flow

118
X. O —

<

X

Figure 5. A result of

(The numbers

. flow prediction for an undeground structure

he branches represent the flow rates in > h.

119
Layer

Thickness

(mi

igure 6

Virtual Point

Heat Source

(a) Schematic of Fire in Shin-Kokugi-Kan

Cb) Predicted Smoke Layer Thickness

The concept and the predicted result of smoke filling in Shin-Kokugi-Kan

120
An Assessment of Fire Induced Flows in Compartments

by

J.G. Quintiere, K. Steckler, and D. Corley

Center for Fire Research

National Bureau of Standards

Department of Commerce

Washington, DC

September 1983

121
NOMENCLATURE

a

A

b

C

P C

E

o

Fm

g

h

H

m

M

Pr

©Q

Ri

T

W

x

y

z

0

A

v

P

5

vertical distance, floor to window

area

constant, Eq. (18)

specific heat at constant pressure

vent flow coefficient

entrainment constants, Eq. (13)

Froude number, Eq. (13)

gravitational acceleration

convective heat transfer coefficient

geometric height, room height

mass

dimensionless mass flow rate, Eq. (17a), or momentum

Prandtl number

energy release rate

Richardson number, Eq. (17)

temperature

width, length of line fire

vertical coordinate measured from lower edge of vent

normalized coordinate, x/H

q

vertical coordinate

coefficient of expansion, 1/T_

difference

kinematic viscosity coefficient

density

(Tv - T )/T g,u a" a dimensionless parameter, Eq. (17c)

122
Subscripts

a ambient air

e vent mixing

f floor

g gas

l lower

p fire plume

o vent

w wall flow or wall

Superscripts

C) per unit time

O’ per unit length

()" per unit area

123
AN ASSESSMENT OF FIRE INDUCED FLOWS IN COMPARTMENTS

INTRODUCTION

The prediction of flow through doors or windows due to compartment fires

is important for two reasons. First, it bears on the accuracy of compartment

fire growth models. Secondly, it is important in order to predict the

effluent rate of combustion products and flames to the surroundings. Since

most mathematical fire growth models are approximate it is necessary to

evaluate their accuracy and consistency with experimental data. Here the

fluid dynamic models and concepts will be examined without concern for the

energy transport models. Thus, an assessment of the fluid dynamics is made

only.

The problem being addressed is the flow due to natural convection through

wall vents and the internal flows associated with a fire within a compartment.

Kawagoe [1] assumed a uniform temperature in the compartment for fully developed fires, and computed the vent flow based stagnant hot and cold gas

reservoirs on either side of the vent. Later Rockett [2] extended this

concept by considering the gas in the room to be composed of a hot upper and

cold (ambient) lower layer. Cold air is entrained by the fire up to this

thermal interface. Only the fire plume mass flux crosses this interface.

Emmons and Mitler [3]

,

Tanaka [4] and others extended these concepts to

include the transient case and a complete range of thermal conditions on

either side of the vent. It is this "simple" model (hot upper layer, ambient

lower layer, plume entrainment) that we wish to assess.

124
It is recognized that entrainment rate predictions for free fire plumes

(e.g., Cetegen, Zukoski, and Kubota [5]) yield good results, but effects of

walls and room drafts disturb fire plumes within rooms. Hence, departures

from the free plume predictions can be expected [6,7]. In the present study,

a line fire along a wall is considered. It is expected that a theoretical

entrainment rate, derived from a line-source turbulent wall plume solution

[8]

, is sufficiently accurate for this analysis. Yet no specific entrainment

rate checks have been made for wall plumes.

Three factors will influence the accuracy of the "simple" flow model

under examination. They include: mixing of hot fluid into the incoming flow

at the vent; transport of fluid along the walls due to local buoyancy forces;

and the resultant increase of the gas temperature in the lower layer due to

these factors and convection from heated surfaces. McCaffrey and Quintiere

[9] have shown that the ratio of vent mixing to inflow rate increases as the

vent size decreases; and the ratio can exceed 1 for very small doors. Zukoski

[10] is attempting to develop a general prediction of vent mixing, and has

suggested a correlation in terms of Richardson number (Ri). The wall flows

present a complicated problem because of their three-dimensional nature and

imprecise free-stream boundary conditions. Nevertheless, Jaluria [11] has

presented methods for estimating these flows. The extent of their net transport across an idealized thermal interface is still somewhat ambiguous.

Therefore, this still will present new data (over 100 steady-state

experiments) of vent flow rates for various vent geometries and wall-line

fires. Those results will then be analyzed to assess the extent of lower

layer heating, vent mixing and wall flows. These all represent departures

125
from our simple concept of fire induced flows in compartments. Finally,

theoretical computations based on the "simple" flow model will be presented

and compared appropriately to the experimental results.

EXPERIMENTAL APPROACH

A schematic of the full-scale flow facility in which the experiments were

conducted is shown in Figure 1. More detailed information on the facility is

described elsewhere [7]. The line burner against the rear wall consists of

four contiguous sand burners to which methane was supplied. The flow rate of

the methane was controlled such that fires of 30 to 120 kW could be specified.

The length of the line burner (W) was varied by supplying gas to one, two,

three or four burners. The vent, centered on the front wall, can be described

in terms of the geometric parameters: WQ , H

Q and a. The distance a+HQ was

kept fixed at 1.8 m, the width W

Q ranged from 0.24 to 0.99 m, and a/HQ ranged

from 0 to 3.

Velocity and temperature measurements were made at the vent and gas

temperatures were measured at the right-front corner of the room on a 11.4 cm

spacing [7]

.

In addition, wall surface temperatures were measured on a

22.9 cm vertical spacing near the right-front corner. Following steady-state

conditions, these measurements were used to compute the vent flow and other

flows of interest. The flow of methane is negligible, so that conservation of

mass requires the in and out mass flow rates at the vent to be equal.

126
A significant feature of this study is the method used to compute the

vent flows. Previously [7] this was done by an extensive velocity and temperature traverse over the vent. Under natural convection conditions it has been

shown that the mass flow rates could be accurately computed from vertical

temperature distributions in the room and vent together with information on

the zero pressure gradient (neutral plane, X£) location. Thus, only centerline velocity and temperature distributions were required at the vent. The

formulae to compute the flows are given elsewhere [7]. The approximate method

used flow coefficients of 0.73 and 0.68 for the out and in flows, respectively. This method serves as the basis of computation for all the experiments of this study.

EXPERIMENTAL ANALYSIS

Accuracy of Vent Flow Computation

Initially eight experiments were conducted to assess the approximate vent

flow rate computational method. Although this had been done for an arbitrarily located circular burner [7], it had not been checked for a line fire.

A comparison (Figure 2) of the results based on velocity data is made with the

approximate results derived primarily from temperature data. Since the agreement was good, the approximate procedure was applied to the remainder of the

experiments. A measure of its overall accuracy is given by Figure 3 in which

the mass inflow rate is compared with the outflow rate. High flow rates

relate to large openings where horizontal temperature differences occurring at

the lower region of the vent are small. Hence, lack of accuracy and precision

in these temperature measurements decrease the accuracy of the inflow rates.

127
In contrast, low flow rates relate to small vents for which these temperature

differences are greater and more accurately measured. These factors explain

the discrepancies between the two flows. For practical purposes in this

study, their arithmetic average was used as the vent mass flow rate (m).

Description of Thermal Layers

Numerous data exist from these experiments describing the vertical

temperature distribution in the room for a variety of fire and vent conditions. A sample of results are shown in Figure 4a, b, c and d. There, the

wall and gas temperatures are shown for two door (a,b) and window (c,d) vent

cases. It is obvious from an examination of these data that they can be

characterized approximately by two thermal layers of uniform temperatures.

Indeed, this representation was done systemmatically . Although somewhat

arbitrary, that process is described as follows:

1. An arithmetic average was used to fit the upper temperatures. The

temperature data included points from the top down until the data

significantly departed from the average fit.

2. Two integral identities were then used to compute the interface height

(x,) and the lower layer temperatures (T 0 and T 0 ). For both the

1 w»* wall and gas temperatures the integrals are

H , / (±-)dx = [H - ( Xl + a)]/T

u + (x

x + a)/T

SL ( 1 )

and

128
( 2 ) H

/ Tdx - [H - (x

x + a)] T

u + ^ + a)

o

Equation (1) constitutes mass equivalency while eq. (2) has no

physical significance.

The results of these curve fits are also shown in the examples of Figure

4. It is interesting to note, that under these steady-state fire conditions,

a significant rise in the lower region gas and wall temperatures occurs. Also

the location of interface (labeled ZD in Figure 4) is nearly coincident with

the position where the buoyancy force at the wall changes sign: positive from

the floor up and negative from the ceiling down in correspondence to the wallgas temperature difference.

Correlations for Layer Temperatures

The temperature is a significant variable controlling the flow rates;

however, it is a dependent variable in these experiments. In contrast, the

fire energy release rate (Q) is an independent variable in these experiments.

Thus a correlation for temperature in terms of Q could be useful. Following

the successful correlation by McCaffrey et al. [12] a dimensionless temperature is given as

T-T

a

,2/3

1.6

h. A

k

v-1/3

p C T /g W H

3/2

a p a o o

p C Sg W H

a p o o3/2

(3)

The heat loss parameter h^ was taken as 0.014 kW/m^-K for these experimental

conditions, and A is the room interior surface area in m . A comparison of

the measured upper layer dimensionless temperature with ip computed from eq

.

129
(3) is shown in Figure 5. The scatter about the line may suggest the lack of

a complete correlation. Indeed, the same correlation applied to the lower

layer temperature is shown in Figure 6. There, most of the data lie below

0.3 i|> as given by eq. (3) and indicated by the straight line. The data above

correspond to the small windows (a/HQ=3) which display a tendency to seek

uniform temperature conditions within the compartment.

Estimation of Wall Flows

The idea here is, within the context of a two layer characterization of

the room, to estimate the boundary layer flows that cross the thermal interface (xj). For this we resort to analyses by Jaluria [11] who made such

estimates based solely on the assumptions of two-dimensional natural convection with the wall and free-stream conditions of the boundary layer described

by the temperature distributions given in Figure 4. The primary issue is how

to decide the net transport rate across the thermal interface ignoring issues

of momentum effects and three-dimensional effects. In all our experiments the

local buoyancy force in the wall boundary layer produces an upward flow from

the floor and a downward flow from the ceiling. These meet and stabilize in a

neutrally buoyant region. A portion of that region may lie on both sides of

the thermal interface as defined in Figure 4. Thus, the very nature of this

flow distorts the concept of a two-layer model.

Jaluria [11] suggests the following procedure to estimate the wall flows

and the net transfer rate (positive to the upper layer):

130

’
1. At the interface (xp, calculate the momentum of the upper and of the

lower wall boundary layer flows. Use the mean of the laminar and

fully turbulent solutions, since this tends to account for transition

effects. Precise transition to turbulent flow can not be accurately

computed. The formula for laminar flow is

M' - pv

2

(Pr + pr-X/2

(^@|T

) 3/4 ,5/4 (4)

\T

and for turbulent flow is

M' 0.04149 pv

2

(l + 0.494 Pr

2/3 )"0,9

pr" 8/15 (£!£I) 0 * 9

Z

1 * 7

(5)

where properties are evaluated at ambient air conditions, AT is the

absolute value of the layer gas to wall temperature difference, and Z

is the distance from the ceiling or floor to the thermal interface.

2. The larger momentum determines the direction of the wall boundary

layer flow across x^. Once the direction is established it is assumed

that all of that boundary layer flow is transported across x^. Again,

the mean of the laminar and turbulent solutions for mass flow rate

(per unit) perimeter constitutes the flow rate. The laminar solution

is

m* = 1.69 pv (Pr §

)' 1/A ,3/4

V

and for turbulent flow.

( 6 )

131
m' - 0.09795 pv (1 + 0.494 Pr

2/3

) 0,4

pr“ 8 / 15 (^I) 0,4

z

1 * 2 (7)

with the same variable definitions in eqns. (4) and (5). The

perimeter is the perimeter of the room minus the burner and vent

widths.

The results of wall flow calculations for all the tests indicate

predominately upward wall flow, so that there is a net exchange from the lower

layer to the upper layer. In about 20 percent of the experiments the flow was

estimated as down. Most of the window cases show this preponderance

essentially due to a decrease in Z and AT in the lower layer. The magnitude

of the total wall flow rate (m ), taken to be positive for up or down, is w

plotted against x in Figure 7. Most of the upward flow rates range from 10 to

50 percent of the vent flow rate, but the net downward wall flow rates nearly

equalled the vent flow rates. This estimation procedure does not track the

wall flows after separation from the wall. Hence the estimates can be high.

Estimation of Vent Mixing

As the cold ambient flow enters the vent and plunges to the floor of the

room, it entrains hot fluid from above. Zukoski [10] has a controlled experiment in which to measure these flows, and a preliminary correlation is given

below:

m

b//Ri (8a)

• • m + m

o e

132
Ri » Ap g(x

t + a)

(8b)

2

u « m /[ p W (x + a)] o a o 1 (8c)

(8d)

The constant b was taken as 0.17 in these computations. Before discussing

those results, an alternative derivation of the vent mixing rates will be

considered.

Case 1. Wall Flow to the Upper Layer:

Consider a control volume including the lower layer (over height x^ + a)

,

but excluding the fire plume and wall boundary layers. For a nonabsorbing gas

with constant Cp, an energy balance can be written as follows:

(9)

where m^ is the firs plume entrainment rate,

hj is the floor heat transfer coefficient

Aj is the floor area,

and is the floor surface temperature

133
From the mass balance.

m + m “ m + m (10)

p w o e

it can be shown that

m m (T o o> gyi - T }/(T

a' v g,u

- t 1 -

g,A J hfA

f

(Tc - T

g,t) / ( T

g,u

- X ) g,* j ( 11 )

This allows us to estimate m

fi from the experimental measurements. It should

be noted that for this case the result is independent of the wall flow rate.

The floor temperature (Tf) was measured for a limited data set and estimated

for the remaining experiments from measured lower room temperatures.

Case 2. Wall Flow to the Lower Layer:

In this case, let m^ be positive to the control volume enclosing the

entire lower layer gas except the flame. A mass and energy balance yield

m - m (T . - T )/(t - T J - m

e o g,i a' v g,u g t l

J w

- (hK f

fA,/c

f

) (T^ - T J/(T - T J

P'

V f gyV v g,u g yl J ( 12)

" ( h

w

A

w,i/cp)( T

w,A

- T

g.*

)/(T

g,u

- Tg.iJ

where A . is the lower wall area, w,A *

and is the convective heat transfer coefficient taken as turbulent natural

convection.

134
The results of these computations are shown in Figure 8 only for Case

1. Eq. (12) gave negative results, suggesting an inconsistency in the

analysis probably due to over-estimates for m^. For Case 1, the energy

balance results are somewhat more than three times those predicted by eq

.

(8). For this range of experimental conditions, this corresponds to 10 to 30

percent of the vent flow rate.

SIMPLE FLOW MODEL

As stated earlier, most of the fire growth models (eq. (3,4)) use a flow

model which is based on the vent flows and fire plume entrainment. This

assumes an ambient lower layer, and no wall or vent mixing effects. As an

exercise in assessing the accuracy of such a model, its predictions will be

compared to the experimental results for m^, x^, and x

2

» The entrainment rate

is taken from Grella and Faeth [8] as follows:

m' = E F

p o m

2/3 4^1/3

(x, + a)

c T

P a (13)

with the entrainment constant, E

Q = 0.067 and the local Froude number,

Fm

= 5.71. Here, m^ is approximated as m

Q

. Hence, the three governing equations in dimensionless form are given below:

m

g = [4>/(i + 40]

1/2

(y2 - y

x

) l/2

(y2 + y/2 ) u*)

M

o “ [*

1/2 /(l + 40] (1 - y2

) a/2(15)

M

q « 5 (y

x + a/HQ

) (16)

135
If yj < 0, then should be set equal to zero in eq. (14).

The dimensionless variables are

M - m /(2/3 Cp Jig w/2

), o o a o o (17a)

(17b)

3

)(

W_

W

1 (17c)

2/2C o p c T Jg W H

3/2

a p a o o -

These equations were solved numerically with given by eq. (3). It

should be noted that the dimensionless variables are a function of the parameters iji and $ which in principle give the flow solution in terms of fire size

and vent geometry. The flow coefficient, C, was taken as 0.70. The experimental and numerical results are compared in Figures 9, 10 and 11 for MQ , y^

and y2

» respectively. As y^ falls below zero, the vent experiences a fairly

uniform compartment temperature. For these cases y£ decreases, dropping below

0.5. These cases yield the best agreement for y£ and MQ

. In contrast, the

entrainment height, (a/HQ + yj), is under-predicted by the model. It might be

noted that in Figure 10, the experimental values of y^ from -1.0 to 0 correspond to a/HQ

= 3; 0 to 0.4, a/HQ = 1; and 0.4 to 0.9, a/HQ =0.3 and 0.

Overall, the theoretical MQ is at most 50 percent less than the experimental

values; y^ is much less than the small window experimental values; and y£ is

over-estimated by 50 percent at most.

136
CONCLUSIONS

The simple flow model consisting of a hot upper layer and ambient cold

lower layer gives vent flow rates and layer positions to within 50 percent

accuracy. Although the vertical temperature distributions within the room can

be approximated well by a two layer thermal model, the lower layer can be

significantly hotter than ambient temperature. For these experiments, this is

predominately due to vent mixing which is estimated for these data to range

from 10 to 30 percent of the vent flow rate. The wall boundary layer flows

are suspected to be over-estimated in this analysis, and for the most part was

indicated as a net transfer from the lower layer to the upper layer.

REFERENCES

1. Kawagoe, K. , "Fire Behavior in Rooms", Rept. No. 27, Building Research

Institute, Japan, Sept. 1958.

2. Rockett, J.A., "Fire Induced Gas Flow in an Enclosure", Comb. Sci. & Techno 1. , J_2, 165, 1976.

3. Mi tier, H.E. and Emmons, H.W. , "Documentation for CFR V, The Fifth

Harvard Computer Code", Home Fire Project Tech. Rept. No. 45, Div. Appl.

Sci, Harvard U. , Oct. 1981.

4. Tanaka, T. , "A Model of Multiroom Fire Spread", NBSIR 83-2718, Nat. Bur.

Stand., Washington, DC, August 1983.

5. Cetegen, B.M., Zukoski, E.E. and Kubota, T. , "Entrainment and Flame

Geometry of Fire Plumes", Dep. Comm. Grant No. G8-9014, Cal. Inst.

Technol. , August 1982.

6. Quintiere, J.G., Rinkinen, W.J. and Jones, W.W. , "The Effect of Room

Openings on Fire Plume Entrainment", Comb. Sci. & Technol., 26, 193,

1981.

7. Steckler, K.D. , Quintiere, J.G. and Rinkinen, W.J. , "Flow Induced by Firp

in a Compartment", 19th Symp. (Int.) on Comb., The Comb. Inst., 913,

1982.

137
8 . Grella, J. and Faeth, G.M., "Measurements in a Two-Dimensional Thermal

Plume Along a Vertical Adiabatic Wall", J. Fluid Mech. , 71 , 701, 1975.

9.

McCaffrey, B.J. and Quintiere, J.G., "Buoyancy Driven Counter-Current

Flows Generated by a Fire Source", In Spalding, D.B. and Afgan, N. (Eds.)

Heat Transfer and Turbulent Buoyant Convection, Hemisphere Pub. Corp.

,

Washington, DC, 1976.

10. Zukoski, E.E., Private Communications, Progress Report, Grant

No. G8-9014, April 1983.

11. Jaluria, Y. , "Buoyancy-Induced Wall Flow Due to Fire in a Room", NBSIR

(to be published), Nat. Bur. Stand., Washington, DC.

12. McCaffrey, B.J., Quintiere, J.G. and Harkleroad, M. , "Estimating Room

Temperatures and the Likelihood of Flashover Using Fir.e Test Data

Correlations", Fire Technol. , 17, 98, May 1981.

138
J 1

Figure 1. Schematic of experiment

139
m

0

FROM

TEMPERATURE

DATA

(kg/s)

Figure 2. Comparison of approximate to direct method for vent flows

140
IN

FLOW

RfVJKIKG/S)

Figure 3. Comparison of inflow and outflow rates by approximate methods

141
A

£

ROOM TEMPERR£yR£S

3QVS. HEIGHT ROOM TEMPERATURES VS . HEIGHT

TG^» TrC.MiS

LEGEND

o - GAS TEMP

» - MALL TEMP

TGU- 113.3 TGL- 42.0 TWU- 96.2

TWL- 66.1 ZD- 1.42

0 0 10 0 20.0 30.0 10.0 50.0 €0.0 70.0 60.0 90.0 100.0 1 10.0 120.0 TEMPERATURE l Cl

LEGENO

o - GAS TEMP

» - WALL TEMP

i a

TGU- 210.3 TGL- 63.5 TRU- 2C9.7 TWL- 115.8 ZD- 1.00

> X.O 40,0 €0.0 60.0 100.0 120.0 110.0 160.0 160. C 200.0 220.0 210.0 TEMPERATURE! C!

.

C d

ROOM TEMPERATURES VS.

TEST TEC113 HEIGHT ROOM TEMPERATURES

$

v 3. HEIGHT

LEGENO

o - GAS TEMP

* - WALL TEMP

*8j

TGU- 95.0

TGL- 1U.9

TWU- 63.9

TWL- 63.

S

zo- 1.09

1.0 10.0 20.0 30.0 10.0 50. C €0.0 70.0 eO.O 90.0 100.0 TEMPERATURE! Cl TEMPERATURE! Cl

Figure 4. Typical room temperature profiles

142
ITBU-TRJ/7R

Figure 5. Dimensionless upper layer temperature correlation

143
Figure 6. Dimensionless lower layer temperatures with if/

144
NRLL

FLOW

RRTEl

KB/S')

o.oo

0.0s

0.10

0.1%

0.20

0

m

o

a

O

a

0

«b

e e

o

8

1

0.0 0.2 -l—

0.4

-«

0.6 P51

-j T—

0.8 1.0 1

Figure 7. Wall boundary layer flow rates with \p

145

DO
Figure 8. Comparison of vent mixing flow rates by two methods

146
Figure 9. Comparison of dimensionless vent flow rate, experiment with theory

147
Figure 10. Comparison of dimensionless layer position, experiment with theory

148
Figure 11. Comparison of dimensionless neutral plane, experiment with theory

149
.
Discussion After J. Quintiere's Report on AN ASSESSMENT OF FIRE INDUCED FLOWS IN

COMPARTMENTS

MITLER: In the last slide you showed, you used the theoretical model and

Jerry Faeth's expression for entrainment.

QUINT IERE: Yes.

MITLER: That could be the reason for the failure of the accuracy.

QUINTIERE: It is possible, as I said, but it is also possible that there are other flows that impact the calculation and will perturb it. In any case, even

if the other flows were contained in the model, the model would still be

approximate. If one can predict the temperatures within the compartment, the

vent flow rate should be able to be done with great accuracy. The entrainment

by the fire plume, then, really bears on the prediction of the height of the

layer within the room.

ZUKOSKI: Are the actual flames above the interface?

QUINTIERE: I think in all cases they were comparable, maybe Dr. Steckler would

care to comment.

STECKLER: In general, yes, flames were above the interface.

ZUKOSKI: I don't believe that Faeth's model is very good for that case and as you get down lower, it may account for some of your problem there.

QUINTIERE: This is the only result we have. We are hopeful that someone else

that has the ability to measure entrainment will measure it for this fire.

ZUKOSKI: In the previous slide, the entrainment by the door jet that was formed, when the interface was below the window sill, did the extra entrainment

by the door jet have an effect?

QUINTIERE: That is not in this calculation. So it may be if we put that into

it.

LEVINE: Dr. Wakamatsu told us of one case where the architects used

mathematical modeling to design the smoke protection in their building. I wonder if there are any other cases like this in Japan. We have been developing

mathematical models and they have not yet been used by the building community.

WAKAMATSU: We are not only using them for small building but also we are using

mathematical models for high rise buildings. We are trying to predict the smoke

movement in high rise buildings, particularly smoke movement in doorways.

LEVINE: What methods do you use to teach the building designers how to use the

models?

WAKAMATSU: The designers depend on professionals who can compute. However,

young building engineers now can compute.

151
,rli ' 0
PRE-FLASHOVER AND FLASHOVER BEHAVIOR

IN COMPARTMENT FIRES

HISAHIRO TAKEDA

University of Tokyo*

*present address : Center for Fire Research, National Bureau of

Standards, U.S. Department of Commerce, Washington, D.C., 2023^*

153
ABSTRACT

New dimensionless variables and parameters which were satisfied with

the scaling effect were introduced into the simple one zone model of

compartment fires. The solutions of the new dimensionless model were

divided into three kinds of types in response to the "F" number, which

was defined as the ratio of the fuel surface area to the floor surface

area. When the F number was more than 0.107, no critical phenomena appeared in the diagram of the burning rate and the ventilation parameter.

While for F < 0.107, the critical phenomena which included the discontinuous jump appeared in this diagram. But the flashover as a transient

phenomenon was not always correspondent to this discontinuous jump. In

this paper the possibility of the occurrence of flashover was discussed

using the the theoretical analysis and some experimental approaches.

From this the flashover was expected to occur in the region of F > 0.107,

and even in the region of 0.0388 < F < 0.107 when A/H/L2 < 0.13.

154
INTRODUCTION

Liquid or thermoplastic pool fires in compartments have been investigated in recent yeards. Quintiere et al.[l] reported the quasisteady state analysis of small scale compartment fires in which they

investigated the energy and mass conservation equations in the two zone

model to obtain the multi-valued results and discussed the problem of

flashover. Also Thomas[2,3] and Thomas et al.[4] presented a qualitative

discussion of the problem of flashover. They thought the discontinuous

jump from one equilibrium state to another was a kind of flashover. The

existance of such discontinuous jump was demonstrated experimentally in

the liquid fuel compartment fires by Takeda et al.[5,6]. They , at the

same time, showed the scale effect of compartment size. Figure 1 displays

their experimental results of the methanol compartment fires in terms of

the mass burning rate of methanol R and the ventilation parameter AjE for

various size compartments with constant fuel surface srea A

v

(=15cm x 15cm)

.

Where L is the compartment size and R^ is the free burning rate (without compartment). The discontinuous jump appeared in the 0.4 and 0.5m compartment

experiments, but did not appear in the other experiments. Clearly this

jump phenomenon depends on the correlation between the compartment size and

the fuel size.

According to Takeda et al._[7], the most important parameter for the prediction of fire behavior may be the ratio of the fuel surface area A to

v the floor surface area L

2

. They called it "F" number, that is F=A

v /L /

In case of PMMA compartment fires the discontinuous jump appeared in the

region of 0.0388 < F < 0.107 from their theoretical predict ion [ 7 ] , which

155
agreed well with the experimental results[7]. In this paper, dimensionless variables and parameters were introduced into the one zone model to

make a more general fire model with some discussions.

156
MODEL OF COMPARTMENT FIRES

[Pre-f lashover fire behavior]

Figure 2 shows the gas temperature- time histories within the compartment for the PMMA wall fire experiments using a small scale enclosure (1 . Om

x 0.9m x 0 . 75mheight) . The number (T) ^ (6) in this figure indicates the

thermocouple position located vertically from ceiling to floor ; (l) was

located 0.045m just under the ceiling, (6) was located 0.045m just above

the floor, and (2) to G) were located between (T) and (5) at regular

intervals. The hot gas layer rapidly came down at about 1400 sec, and (3)

and (b) thermocouples indicated the characteristic temperature jump. The

f lashover may be decided to occur at the time of the jump of (6) thermocouple. In this case the flashover time t^ was 1426sec.

Figure 3 shows the time dependent temperature profiles in the compartment. The boundary between the upper hot gas layer and the lower cold

gas layer could be easily obtained in this figure. If the discontinuous

plane is decided as the inflection point of each curve, we can obtain the

growth behavior of the upper hot gas layer. Figure 4 displays the behavior

of the upper hot gas layer. The flashover occurred at 1426sec and then

the gas temperature within the compartment became almost uniform(see Fig. 3).

So the one zone model may be valid for the post flashover fire mode] .

[Simple one zone model]

As previously reported[7], the simple one zone model including the

mixing controlling step presented the whole aspect of post flashover fire

behavior. The theoretical prediction from this model agreed well with the

157
experimental results[7].

The basic equations of this model are as follows

% %

+ %+ %

+ %

The heat release rate Q is as follows:

for m v < R

a (ventilation control)

for m Y > R

a (fuel control)

Q

c -

r AK m 11 c a

AH Ry/y

c

( 1 )

( 2 )

is the heat loss rate by ventilation and may be written as:

0 =C{m (T-T ) + R( T - T 0 )}

yj p a o %

(3)

is the heat loss rate by wall conduction and may be approximately

written as :

0 = A h( T - T ) W O

(4)

is the feed back energy to the condensed fuel:

QP = AH R

R v

(5)

Q

q

is the radiation heat loss through the ventilation opening:

Q

= Aa{eT4 + (l-e)T 4 - T

4

} o wo ( 5 )

The inflow rate cf air by ventilation may be evaluated by the following:

m = O.SSAv^

a

( 6 )

The burning rate may be described as:

R = R- + AR

t (7)

R^ is the free burning rate and AR is the enhancement of the burning rate

158
by the compartment effect:

AR = A [o{eT 4 + (l-e)T4 - T

4

} + h c (T-T ) ] /AH (8) V WO f O V

And £ is the gas emissivity:

£ = 1 - exp(-kL) (9)

[Dimensionless transformation]

Introducing new dimensionless variables and parameters, we must take

care of the scaling law. Table I expresses the upper and lower limits of

the discontinuous jump appeared in the R-At/H relation, where we can see the

oxygen concentration, the combustion efficiency y, the average gas temperature T and F number are almost constant. So the dimensionless temperature

can be defined as 6 = T/T ( T : ambient temperature) . The normalized burno o ing rate R/L2 and ventilation parameter ArH/L2 are also nearly constant.

As F is nearly constant as shown in Table I,

L

2

'V A (10) v

and if the following relationship is assumed,

R£ ^ A (11)

f v

we can obtain the following:

R

f ^ L

2 (12)

So the dimensionless burning rate can be defined as follows:

X = R/R

f (13)

Similarly the dimensionless mass flow rate of inflow air by ventilation T

can be obtained as follows:

ip = m /R_ (14)

a i

159
Also the following dimensionless parameters are introduced

n - A aT 4 /(AH R_) ( dimensionless radiative heat

R wo c f

transfer coefficient) (15)

n E A hT / (AH R..) ( dimensionless convective heat

c wo c f

transfer coefficient) (16)

a = A/A

o w

a = A /A v v w

V E AH /AH

v c

6 E C T /AH

p o c

Using these variables and parameters, we can obtain the dimensionless

equations of fire model.

6U'(e-i)+x(e-0£.)} + n

c

( 0 -D + vx + u R a

o

{ ee

4 + (i- e )e 4 -i} =

(17)

x

= 1 + (a

v /v) [n R

( e0 4 +(l-e)0 4 -l}+r)

c (0-l )] ( 18 )

160
RESULTS AND DISCUSSION

The calculated results were divided into three kinds of types in

response to F as shown in Fig. 5. The type I has no critical phenomena,

while the types II and III have some characteristic behavior. The type I

corresponds to the experimental results of L=0.15 and 0.25m in Fig.l, the

type II corresponds to 0.4 and 0.5n, and the type III corresponds to 0.7m

except for the isolated island. Figure 6 displays these results in terms

of the dimensional variables R and n . a The jump phenomenon such as type II in Fig. 7 has been already observed

in the work of the liquid fuel compartment fire experiments[5] , but the

isolated island appeared in the type III solution has not yet been observed

experimentally. Probably this isolated island may not be realized under the

ordinary experimental condition. Thomas [2,3] showed the similar predicticin his theoretical prediction, but his approach was not so simple.

The flashover as a transient phenomenon will occur in the regions of

type I and II. It must be noted that the discontinuous jump appeared in the

R-Avir relationship is different from the flashover as a transient phenomenon.

Figure 2 shows the occurrence of flashover in the region of type I

.

We can say the flashover will not occur in the region of type III, that

is to say, F < 0.0388, and even in the region of type II we have no flashover

when Av'lf/L

2 > 0.13 m

a/i

. But in the region of type I (F>0.107) we should th:rabout the possibility of flashover. Figure 8 presents an example to show t:

possibility of flashover for any values of Av^H, where the upper figure for.

the steady state relationship between R and A>TI and the lower figure dor

the R-time histories. From this figure the curves "d", "e" and "f" clear!

161
show the occurrence of flashover, while the others don't so clearly but

we can't eliminate the possibility of flashover. Because the weak flashover

may be expected in the curves "a", "b" and "c". The above discussion was

summarized in Table II.

162
SUMMARY

Some aspects of the pre-flashover and flashover fire behaviors

were investigated using the small scale experiments and the simple

theoretical anlysis. The gas temperature in the compartment has a wide

distribution in the pre-flashover period, but on the contrary it becomes

almost uniform after flashover. So the one zone model is valid to investigate the post-f lashover fire behavior. ‘New dimensionless variables and

parameters were introduced into the simple one zone model to be satisfied

with the scaling effect. The solutions from this model were divided into

three kinds of types in response to F number. And the possibility of flashover was discussed from this theoretical prediction. From this result we

must consider the possibility of flashover in the region of F > 0.107,

and even in the region of 0.0388 < F < 0.107 when Av^H/L 2 < 0.13. On the

contrary, the flashover will not occur in the region of F < 0.0388, and in

the region of 0.0388 < F < 0.107 when A/h/L 2 > 0.13.

163
NOMENCLATURE

A

A

vAw

A/H

c

p

F

H

h

h

f

k

L

m

a

Q

R

T

Tw

AH

c AH

opening area

fuel surface area

wall surface area of compartment

ventilation parameter

specific heat of gas

F number (=A /L 2

) v opening height

wall heat transfer coefficient

fuel heat transfer coefficient

absorption coefficient

compartment size

inflow rate of air by ventilation

rate of heat flow

mass burning rate of fuel

gas temperature

wall temperature

heat of combustion

latent heat of gasficaticn

Greek Symbols

Y fuel to air mass ratio

£ gas emissivity

0 Stef an-Boltzman constant

y combustion efficiency

164
REFERENCES

1 Quintiere ,J .G . , McCaffrey, B.J. and DenBraven,K. , Seventeenth Symposium

(International) on Combustion, pll39, The Combustion Institute, 1979.

2 Thomas, P.H., Eighteenth Symposium (International) on Combustion, p503,

The Combustion Institute.

3 Thomas, P.H., Fire Safety Journal, 3,67,1980/81.

4 Thomas, P.H., Bullen,M.L. , Quintiere ,J .G . and McCaffrey, B. J. , Combust.

Flame, 38, 159, 1980.

5 Takeda,H. and Akita, K. , Eighteenth Symposium (International) on Combustion, p519, The Combustion Institute, 1981.

6 Takeda,H. , Kawaguchi, K. and Akita, K, Bulletin of Japanese Association

of Fire Science and Engineering, 31(2), 19, 1981.

7 Takeda,H. and Akita, K., Nineteenth Symposium (International) on Combustion, p897. The Combustion Institute, 1983.

165
A LIST OF FIGURE CAPTIONS

Fig.l Mass burning rate of methanol R as a function of Aj/h for various

size compartments (L: compartment size) with constant fuel surface area(=0.15m * 0.15m).

Fig. 2 Gas temperature-time histories within the compartment for the

PMMA wall fire experiments using a small scale enclosure (1.0m

x 0.9m x 0.75m height). The number @ 'V' © indicates the

thermocouple position located vertically from ceiling to floor.

Fig. 3 Time dependent temperature profile in the compartment.

Fig. 4 Growth of the upper hot gas layer.

Fig. 5 Solutions of the dimensionless equations of compartment fires.

Fig. 6 Theoretical results of the mass burning rate R as a function of

a/h.

Fig. 7 Behavior of the discontinuous jump in the types II and III.

Fig. 8 Experimental results of PMMA compartment fires in case of 0.4m

enclosure with 0.15m x 0.15m PMMA floor. The upper figure correponds to the steady state mass burning rate as a function of Av^H,

and the lower corresponds to the time dependent burning rate. Where

a: A/H=0.00365m 5/2

, b: Av/H=0.625m5/2

, c: A/H=0.007m 5/2

, d: A./H=

0.0116m 5/2

, e: Ay/H^=0.0157m 5/2, f: A*^0.019m5/2, g: a/h=0.0216

m

5/2

, h: Av/H=0.0242m 5/2

.

166
0

. 5ra

r—

i

m »> i—i O

O

00

>—

'

CM

I

ro

CM

O

167

Fig.
o o o C O

o c c O o

o

r-l 00 MO CM

>—

<

H

O) aamvaadwai

CN

168

Fig.
CEILING

CO

169

Fig.
o

cM3

AlIflNIXNODSIO

170

Fig.
Fig. 5 171
nJ

vo

172

Fig.
[II] 0.0388 < F < 0.107

m

a

I III]

Fig. 7

173
TIME (min)

Fig.

8

174
TABLE

00 O CO 0 rH Tf U5 in 0 [>

04 03 CO CO CO CO CO CO CO CO CO CO CO CO CO

r—

<

f—

'

1—4 r1

r—

l

rH f-H rH rH rH T"H rH T“» r-* H

d o’ o’ 0

’ o’ 0 o’ o' 0

’ o’ o’ 0’ o’ 0

’ o’

a,B

3

•i-) W

o

3

C

U

Co

u M W

•H

'Oo

1j

c*

a;

fe.

a.

O

<N 04 cc 04 O 04 04 04 04 04 04

C- CC *—

>

0 03 04 O'! CO 05 05 05 05 05 05

*“* CO cc 0 O C5 C5 O O 05 O O O O O O

O 0 0 O 0 O O O O O O O O O O

'CL O 0 0 O 0 O O O O O O q q O O —C o’ o’ 0

’ O* o’ o’ o’ o’ o' d o’ o’ 0’ o’ o’

04 0 co 0 t Tf CO TT 04 0 00 CO O 0 0 0 0 0- t"- o* CO X’ 00 00 o- c- O 0 0 0 0 O 0 0 0 co co CO co co co

r-H rH rj H H rH H rH rH q q q q q 0

o’ O* o’ o’ o’ o’ d O o’ o’ 0

* 0

’ o’ 0’ o’

0 O 0 0 O 0 O 0 0 0 0 0 0 0

y—

v

w O 0 0 d w 0 CO 0 in •n m 10 uO lO O O 0 0 0 0 0 0 0 0 0 0 0 O 0

>W' rH rH rH T"< r~l

10 00 CSJ _ 0 05 05 05 05 05

f—

1

f—

«

O 0 O 0 0 0 0 0 05 05 O 0

uO m 'O uO lO 0 X uO q q 05 q 05 05 0

’ o’ o’ 0’ o’ o' o’ o’ o’ 0

’ o’ o’ O* o’

05

10 *H co 04 r-H CO C 3 O: 04 C4 04 0 0 rH 04 rH 04 cs 03 04 0 q q O O q

ci 0 o’ 0 d o’ 0

’ o’ o’ d o’ 0

’ o’ o’ 0

’

»-* rH rH rH rH

14-1 o

w

3

3

3

> C

' n C05 04 O

05 co ,-H 04 T”H O- 0* rcc H r— rr r- T co rH 01 04 CO co co TH CO 0 r—

t

04 co cz co 0 C4 O O 0 r—

<

1-0 04 q O O 0 O rH co iO OI O O q O 0 rH 0

’ o’ o’ d d d d 0

’ rH o’ o’ 0

’ o’ 0 o’

in 92 X lO 04 O uO o- co

04 0m •—1 0 CO

i-O t'* rT Ci 04 X T—

1

00 rH 04 rr 05 co 04 c O rH 03 C5 0 C5 O O 0 O CO CO 0 O 0 O O O ri CO X O O 0 O 0 O

q O 0 G q O 0 O O q q q O q q d O c O d O d O d 0

’ 0’ 0’ d 0

’ 0

’

0 rH H r-H 05 CO 01 CO rco C5 L'- 0 C-* O <0 0 05 co 75 0

0 O r— 01 1.0 0 *7* C4 0 0 O f—

(

CO i-O -7* q O c 0 q rn 04 T q n- °. O 0 q H CO d o’ 0 0 0* O o’ d d 5 o’ o’ 0 o’ o’ 0’

,_H 0 o O 0 000 O

«5> O O 0 0 O O 04 co O r- 0 ..0 0 O O

•rr in i'- 0 O 0

o’ O 3 d d rH r-1 04 CO* O o’ 0 rH C4 CO

175
TABLE

II

176
Discussion After H. Takeda' s Report on PRE-FLASHOVER AND FLASHOVER BEHAVIOR IN

COMPARTMENT FIRES

2 PAGNI: I'm interested in the choice of L in your F number. Does that

constrict you too much to the choice of the shape of the compartment? Why not

use the ratio of the fuel surface area to the entire compartment surface area?

TAKEDA: I don't think your suggestion will change the results greatly; but, if we adopt your suggestion, then compartment shape factor will not come into the

computation. In this case, the shape factor is not incorporated in here. But,

I feel it's better if we incorporate a shape factor into our formula in the

future. In other words, I feel that the introduction of the compartment shape

factor somehow should be incorporated in the future. At this stage, however, a shape factor is not incorporated. As long as the shape of the compartment is

closer or similar to a cubic one, we feel that the floor area can be used

interchangeably here.

177

PRELIMINARY REPORT ON A MODEL TO DESCRIBE THE

FLOW IN THE CEILING LAYER OF A TWO LAYER FIRE MODEL

E. E. ZUKOSKI and T. KUBOTA

CALIFORNIA INSTITUTE OF TECHNOLOGY

OCTOBER, T9 8

3

I. INTRODUCTION

This paper is a preliminary report on a project in which we are

developing the ability to describe the flow field produced within a room by a fire. Our aim is to describe the flow with sufficient

detail that we can make estimates of the heat transfer to the walls

of the room and to objects within the room due to forced convection

and radiation. In this report we will briefly describe some

elements of a model we are developing to predict the flow produced

by a fire plume within the ceiling layer.

To illustrate the problems which concern us consider Figure 1 which

is a schematic of the flow produced by a fire within a room. To

make the flow as simple as possible for this first example, we have

picked a configuration which is axisymmetric and have assumed that

the region of flaming combustion, i.e., the flame, lies below the

interface between the hot and cold layers.

Heat is added to the fire plume in the region of flaming combustion

and above the top of the flame, a purely buoyant plume developes in

which the enthalpy flux related to the ambient fluid is constant.

This plume penetrate the density discontinuity at the interface and

then impinges on the ceiling. The plume flow is turned by the

impingement process and spreads out along the ceiling to form a wall-jet. This jet impinges on the side walls and is turned

downward. As it moves down the vertical side walls, it must be

turned again to satisfy the entrainment needs of the plume and

wall-jet, and the flow through the openings.

Negative buoyancy forces resulting from the development of cool

boundary layers on the side walls will augment the downward

momentum of this flow and the resulting w all-jets may produce

mixing between the ceiling layer gas and the fresh air in the lower

layer. Similar mixing may be produced by the inflowing stream of

cool air induced by the pressure difference across the opening.

A strong return flow is required to feed the flow entrainment into

the plume and wall-jet flows. Some idea of the size of these flows

is given in Figure 1. In this example, we have assumed that the

ceiling layer lies half way between the ceiling and the floor, that

the ceiling layer temperature is relatively cool because of heat

transfer to the walls and that the room has a diameter equal to

tv; ice the ceiling height. If we define m as the flow in the plume

179
Zukoski - 2 -

at the interface, then the flow in the plume at the ceiling level

would be about 3m and the flow in the wall-jet at a radius equal to

the room height would be about 9m. If we consider a steady state

flow and ignore the entrainment in the flow along the side walls,

then the flow out of the opening must be equal to the plume flow m and consequently the total return flow will be about 8m. This large

return flow is responsible for keeping the ceiling layer well mixed

and consequently at a more or less uniform temperature and

composition

.

The wall-jet flow and the return flow for this example are complex

enough but they have been greatly simplified by the assumption that

the flow is axisymmetric . When the room-fire geometry is not

axisymmet ric , the treatment of the wall-jet and the return flow

will be more complex and will require an understanding of the

processes which occur when the wall-jet on the ceiling impinges on

the side walls at the wall-ceiling corner.

A number of physical processes arise here which must be understood

and modeled before a rational description of the whole process can

be developed. Because of space limitations, we will be able to

mention here only a few of the process which we are attempting to

model at present and have restricted ourselves to processes

involved with the plume. We also present a more detailed

description of the plume calculations to give a better picture of

the type of model we are developing.

II. FLAME REGION

At present, the only feature of the flame or the heat addition

region which can be described quantitatively is the height of the

top of the flame. Flame heights can be estimated from correlations

based on extensive set of data and the estimates are probably

reliable to within 15? for flames burning in undisturbed ambient

air. (See the correlation given in Equations 4.) When the flame is

immersed in hot, vitiated air or is blown over by a horizontal

current of air, our knowledge of its height or other

characteristics is less reliable.

A detailed analytic description of the heat addition process for a large diffusion flame is not possible at present. In addition, we

do not have a quantitative measure of the influence on the

characteristics of the plume of the buoyancy jump at the interface

between hot and cold fluid or the effect of the ceiling when the

flame is long enough to impinge on the ceiling.

III. PLUME CALCULATIONS

The flow produced by a turbulent, buoyant plume can be described in

terms of a simple algebraic model with some accuracy for a range of

conditions. Calculations of this type are described here and will

be used to give the initial conditions for the IMPINGEMENT REGION.

1 . POINT-SOURCE PLUME

180
Zukoski -3-

We are interested here in the buoyant plume rising from a point

source of buoyancy into an constant density atmosphere. The recipe

for the Far Field Plume model can be conveniently given in terms of

a dimensionless heat release parameter called Q

fi

:

Q* = Q*(Z) = Q/p* Cp^s/gT Z2

(1)

where, p, Cp, and T are the density, specific heat and temperature

of the ambient gas around the plume, 'g is the gravitational

constant and Z is the elevation above the point source.

When we assume that the profiles for velocity and temperature

difference are Gaussian, then the temperature difference ATm and

velocity Vm on the centerline of the plume, the Gaussian half width

of the velocity profile b, and the ratio of the velocity and

thermal profile half widths s can be expressed as functions of the

Q* parameter, and elevation Z as:

2/3

/\Tm = 9. 12*(Q») 9 b = 0. 13*Z

Vm = 3.87*(Q*)1/<3 1 s = 0.91

(2)

This formulation is in the standard form with the exception that

some of the -constants may differ slightly from those proposed by

Morton(1954) and other authors and the use of the Q* parameter

gives a particularly simple representation.

The plume mass flow rate can also be given in terms of the

parameters used here and is:

m(Z) = 0.21*p/gf Z

2 *(Q«) (3)

2. FREE FIRE-PLUME CALCULATIONS

The buoyant plume which developes above a diffusion flame and rises

through a constant density atmosphere is called a free fire-plume.

Its properties can be calculated with the aid of the point-source

model presented above and the introduction of a number of empirical

factors derived from different experiments. Our approach will be

to replace the fire plume with an equivalent point-source plume for

which we have the simple algebraic representations given above.

This calculation is made more complicated in the room fire context

by the presence of three length scales, the flame height Zf, the

height of the interface between the hot and cold layers Zi, and the

height of the room Zc. In room fires, the flame height Zf can take

on any value and can be larger than the ceiling height.

In this report, we will consider the plume calculations for

conditions in which the flame length is much less than the

interface height; the more complex flows for which Zf > Zi will be

discussed in a later paper. We will also ignore the effect:, of

disturbances arising in the ambient fluid which can have a larg<

effect on the flame and plume. (E.g., Zukoski et al, 1980)

181
Zukosk

i

-4-

We assume that the simple buoyant plume starts at the top of the

visible flame (i.e. f at Zf) where the heat release rate due to

chemical reactions is negligible. Thus, the source of this plume

is characterized by a finite diameter and by finite values of mass

and momentum fluxes. Given these fluxes and the diameter of the

plume at the top of the flame, we can calculate the developement of

the plume at higher elevations by using the same set of

differential equations used by Morton in their original

calculations for the point source problem.

However, given our desire for a simple algebraic representation for

the plume, we have found it more convenient to find an equivalent

point-source plume which has the same heat release rate and the

same far field characteristics as the finite-source plume. Thus by

adjusting the origin for the vertical or Z axis, we can then use

the simple point-source model to estimate the characteristics of

the far field for the fire plume.

Because we do not yet have good measurements for the momentum flux

and diameter of the plume at the top of the flame, we must use

another type of empirical data. These data were obtained by

measuring the mass flow rates in plumes formed above fires and

finding the location of the source for a point source plume which

had the same heat release rate and which gave the best match

between the mass flow rates in the real and theoretical plumes.

Mass flow data presented in a form which makes the location of the

source particularly easy is shown in Figures 2. The data have been

replotted such that a function of the mass flow rate, see Equation

2, is linearly dependent on the elevation Z. Then extrapolation of

this line to the origin of the mass flow parameter will give the

desired location of the origin of the equivalent point-source

plume.

The data suggest that the point-source should be located within a few fire diameters of the base of the flame at a distance close to

Zf below the finite source point. VI e have defined an offset

distance, Zo, such that if Z is measured from the plane of the base

of the flame, the point-source lies at an elevation of (-Zo).

Thus, a positive value for Zo means that the origin of the

equivalent point-source plume lay below the burner.

Values of offset distances are given in Figure 3 as a function of

the ratio of flame height to fire diameter for data obtained at

Caltech by Cetegen et al ( 1 982). We also show our interpretation

of offset data for large fires presented by Heskestad (1981). For

large fires, values of Zf/D are usually small, and consequently the

offset distance will be a small fraction of the diameter of the

f ire . Also note that the correlation given in this Figure depends on the

geometry of the fire-room geometry. When a floor surrounded the

fire and was at the same elevation as the fire, values of Zo were

about 0.3 W D larger than when the fire was supported on a cylindric

burner several burner diameters above the floor.

182
Z u k o s k i -5-

To calculate the properties of the fire plume by the scheme

outlined above, we must first find the flame length Zf and then the

offset for origin of the equivalent point source plume Zo. Flame

length correlations, see for example Cetegen et al (1982), can be

expressed as:

3.3*(Q R cf/3 when Q*D < 1.0

Zf/D = a . (4)

3 . 3* ( Q*D ) /5 when £*D > 1.0

where D is the diameter of the base of the fire and Q*D is the

parameter defined in Equation (1) with the elevation Z replaced

with fire diameter D.

Also, the offset distance correlations are:

0.5 - 0.33*(Zf/D) without floor

Zo/D = 0.8 - 0.33* (Zf/D) with floor

Plume calculations can now be carried out using the equations for

the point-source plume listed above as Equations (2) and (3).

However, we must now replace Z with the distance above the

effective plume source to the point in question, called Ze. Thus,

the vertical dimension is adjusted for the offset Zo, and,

consequently

:

Ze=( Z+Zo)

Note that for large values of Zf/D, Zo has a negative value and

thus the offset origin of the equivalent plume lies below the

source of the fire.

IV. IMPINGEMENT

There is some data available which describes the flow produced by a buoyant plume when it impinges on a horizontal ceiling and

considerably more for isothermal jets. This data allows us to make

reasonable estimates of the velocity and temperature profiles which

result from the turning or impingement processes.

V. WALL-JET

The isothermal wall-jet can be treated with some confidence given

our understanding of boundary layer like flows and a large body of

experimental data. Three problems arise in making a model for the

buoyant wall-jet: First, variations of buoyancy due to the

development of a cold boundary layer next to the ceiling may ef ft .• * the developement of the flow within the wall jet in an unknown

manner. Second, the entrainment rate of the wall-jet depends

strongly on its buoyancy and we are not confident that the mod* ' in use now are satisfactory. Third, if the wall temperature i:

183
Zukoski - 6 -

below that of the ceiling layer, the wall-jet can develope a negative buoyancy which would act to remove the jet from the wall.

At present, we do not know how to treat the flow that will result

when this happens.

Finally, the geometrical complexities described above lead to

problems in treating the development of the wall-jet region.

VI. RETURN FLOW

A strong return flow is required to supply the fluid entrained by

the plume and the wall jet. The calculation of the return flow may

be complicated but the basic processes involved are straight

forward. At present we are developing a simple two-dimensional flow

model.

VII. CONCLUDING COMMENTS

In conclusion, we are developing a model for flow in the ceiling

layer which may be a useful design tool. In addition, in the

process of formulating this model, we are developing a better

understanding of the processes which require further experimental

investigation

.

REFERENCES:

B. CETEGEN, E.E. ZUKOSKI AND T. KUBOTA, Entrainment and Flame

Geometry of Fire Plumes, Report , Daniel and Florence Gug g enheim

J et Propulsion Center f California Institute of Technology

.

Pasadena (1982)

G. HESKESTAD, Personal Communication

B.R. Morton, G.I. Taylor and J.S. Turner, Turbulent

Gravitational Convection from Maintained and Instantaneous

Sources, Pr oc . Ro v . Soc

.

, A 2 3 4 , 1-23,(1956)

E.E. ZUKOSKI, T. KUBOTA and B. CETEGEN, Entrainment In Fire

Plumes, Fire Safety Journal , 3(1980-81)

184
I

185

Figure

1

.

Axisymmetric

Room-Fire
E

M

186

Figure

(2)

Offset

measurement

examples

for

the

0.19

m.

dia.

burner

for

far

field

data

obtained

without

floor.

Lines

have

a

slope

corresponding

toC

m

=

0.21.
- 2

-

Figure 3. Correlation for Offset

187

Discussion After E. Zukoski's Preliminary Report on A MODEL TO DESCRIBE THE FLOW

IN THE CEILING LAYER OF A TWO LAYER FIRE MODEL

QUINTIERE: In the last slide, what does the flame look like as it impinges on your hood?

ZUKOSKI: Up until the time the flame impinges on the hood, it looks like it's a prediffusion flame.

QUINTIERE: Could you give us some idea of the flame volume over the range of

the v value compared to the wood size?

ZUKOSKI: Yes, somewhere in here it's getting up to the top of the hood, but I'd

have to go back and check. I don't believe this is due to the impingement of

the hood because the flame height has been changed by 2/10ths of a meter with

respect to the top of the hood. I think if that were the case, it would show up

in more scatter of the data.

QUINTIERE: In no case does the flame splash over the hood.

ZUKOSKI: No, it may hit the top but it doesn't come all the way down and go

out. The residence times in the hood are thirty to hundred seconds. The

velocities are a few centimeters per second.

EMMONS: As you know, methane in a free burn burns essentially completely

whereas other fuels do not. So, similarly in your apparatus you have complete

combustion when there's enough oxygen; whereas, with some other fuels, this

would not be the case. ZUKOSKI: I have mentioned the formation of soot and so forth.

PAGNI: Two questions, one referring to your last slide and the other to the

previous one. These numbers look similar to those that Professor Sibulkin

presented for boundary layer flames in our meeting in August. Is it possible

that the details of the diffusion flame itself will lead to these values?

ZUKOSKI: I think it is, yes.

PAGNI: What we need is the flame temperature rather than some mean temperature.

ZUKOSKI: We have added excess fuel to this area here and we are just doing

this. As far as we can tell the fuel does not burn. So, you have oxygen in the

ceiling layer, you add methane gas that is mixed up, it goes through the flame

time after time, and there doesn't seem to be much combustion going on. Well,

this is a preliminary feeling. But I think you're right. What's going on in

the flame is where the chemistry is occurring. So that's what we have to

understand, which makes it even more complicated.

PAGNI: You talked about putting a rich oxygen layer in the containers and then

putting a rich fuel jet into that.

ZUKOSKI: Yes.

PAGNI: Why would you be surprised if it burned vigorously?

189
ZUKOSKI: Because we don't see any effect of the inert gas on the combustion

here. Therefore, I don't know that the oxygen that's being entrained would get

aired out to their region where the combustion is going on to have any effect.

If the inert gas has no effect, the oxygen may not have any effect.

ROCKETT: You have added nitrogen to your fuel in some of these experiments.

Does that diluent which presumable would change the flame temperature effect

carbon monoxide curve?

ZUKOSKI : We have not done that here . But to get back to the previous point , if

you take a small fuel jet and put it up into this can and light it, it sits

there and burns. When you get about 50 percent of stoichiometric, the oxygen

mole fraction gets to 12 percent and that little fire goes out. The main fire

continues to run all the way down to the place where the oxygen mole fraction is

2 percent. So it is affected with entraining fresh air, mixing it right and

letting it burn as it goes out.

PAGNI: But if you make the container rich with oxygen, I would expect it to

bum tremendously.

LEVINE: Professor Jerry Faeth at Penn State has looked at this problem and has

been able to reproduce his results based on a Spalding type model and

instantaneous limit mixtures in the plume.

«

19C
THE MODELS TO BE DEVELOPED IN FIRE SAFETY DESIGN PROJECT

Takeyoshi TANAKA

Testing and Evaluation Division

Building Research Institute

Ministry of Construction

191
THE MODELS TO BE DEVELOPED IN FIRE SAFETY DESIGN PROJECT

I. INTRODUCTION

It will take a little more time until "Fire Safety Design Method" is

framed up into the final form. Nevertheless, one of the salient features of

the design method can be already observed in that it attempts to include

fire models as a part of the system. These models are to serve rational

evaluation for fire safety performance of buildings and are supposed to be

included in each of the subsystems of the design method. At present,

discussions are underway in each task group to identify the requirements

for the models, the functions to be implemented in the models etc.

In a few years, which is the period that our project continues, it

is not probable that our understandings on fire reaches the stage where we

can solve, without difficulty, any problems of our concern. But of course,

this does not necessarily mean that using fire models in a problem like

assessment for fire safety is prematured. We must keep it in mind that the

design of the model should be determined in conjunction with the way the

models are used and the feasibility of its development. So far we do not

have fair techniques to predict how a cigarette fire in a waste basket

grows to a fully involved room fire. However, our knowledge on fire is not

considered so insufficient when we study the impact of fire on structural

frame. The functions and the level of accuracy required to fire models are

not independent on the purpose of the model or the way the model is used.

In "Fire Safety Design Method", the fire models are considered more

as a tool for an engineering purpose than as a tool for pure scientific

study of the fire behavior. In this sense, the model does not have to be

totally scientific if it needs to be based on science. In the following, we

will describe how the models are going to be used in the subsystems of

"Fire Safety Design Method" and refer to what kind of features should be

included in the models.

II. EVACUATION/SMOKE CONTROL DESIGN METHOD

The differences in occupancy, configuration etc. of buildings, which

will have significant effects in emergent situation, do not seem to be

sufficiently reflected in the subscribed provisions for evacuation or smoke

control, at least as long as current Japanese Building Standard Law is

192
concerned. This would be all right if there were such a versatile

evacuation/smoke control system that always works effectively for any

conceivable case so we don not have to worry about the difference, but

unfortunately we have found none such by now. Since the effectiveness of an evacuation/smoke control system critically depends on the conditions

associated with occupants, building construction etc., a designer will have

to find out optimum solution for the specific case taking many concerning

factors into consideration. The flowchart shown in Figure 1 illustrates the

design procedure proposed in this design system, in which the models for

evacuees' behavior and smoke control effect play important parts.

II-l. PROCEDURES OF SAFE EVACUATION PLANNING

(0) Premises

This system for safe evacuation planning is based on the following

premi ses

:

(a) : Evacuation must be conducted only through smoke free spaces.

(b) : Evacuation plan must be made for all the occupants.

(c) : Smoke control is a backup system for evacuation, so it must be

designed to conform to the evacuation system.

Premise (a) is introduced since we have no reliable data on people

behavior in the presence of smoke of fire, nor good chances to obtain such

data in near future, and accordingly expect significant difficulty to

reasonably predict the people movement in seriously emergent condition. In this design system, a designer is supposed to implement some measures to

keep the prospected escape routes free from smoke during the time needed so that unpredictable situation can be avoided as best as possible. Some

interpretation will have to be made, however, on the meaning of "smoke

free" since in some cases, for example in case of evacuation in the room of

origin, it is impossible to escape only through literally "smoke free"

spaces. Premise (b) does not imply that all the occupants have to be

evacuated to out of a building but means that all the occupants must be

taken into consideration in the evacuation plan whether they are to escape

to the ground or to stay in some protected refuge.

(1) Selection of Basic Strategy for Safe Evacuation Planning.

The design procedure begin with selecting a basic strategy for

safe evacuation of the specific building in concern.

193
It is considered that Table 1 covers virtually all the practical

basic strategies that can be employed in the event of fire, so a designer

can choose a basic strategy for evacuating the occupants of his building

from Table 1. More than one strategies can be applied to each group of the

occupants of the same building corresponding to their different conditions

in respect of physical or mental ability, location in the building etc.

Once a specific strategy is adopted, every requirement associated

with the strategy, listed in Table 1, must be satisfied.

(2) Elaboration of Concrete Evacuation Planning

According to the basic strategy chosen, more detailed evacuation and

smoke control plans must be worked out. Since smoke control is considered

to be a backup system for safe evacuation, evacuation plan should be

planned prior to smoke control planning. Concrete evacuation planning

consists of an evacuation guiding plan and a design of evacuation support

system.

(3) Evacuation Guiding Plan

This is a plan regarding where and how to evacuate the occupants.

This plan includes determining the type of evacuation e.g. whether it is a total simultaneous one or a selective sequential one. Also special

consideration must be paid for the evacuees who have special problems and

need appropriate assistance in case of evacuation, as in the case of the

evacuation of hospital patients.

Evacuees' population and distributions are given, in principle, as an initial condition for the planning.

(4) Evacuation Support System

This is a system to help materialize the planned evacuation, and

includes: properly designed escape route, fire detection system, emergency

alarming, announcement and communication system, evacuation guiding by the

staffs, emergency lightening system, maintenance of fire equipments etc.

Escape routes must be properly designed so that evacuees can make

their way without difficulty according to the evacuation guiding plan. Fire

detection system includes searching and locating the place of origin by

fire guard, which will affects the initiation time of the evacuation since

usually emergency announcements are delivered after the fire is confirmed.

Emergency announcement must be persuasive enough to alert the occupants

194
well for evacuation but must not cause panic. The contents and the timing

of the announcement must vary depending on the type of evacuation.

In case of hotels, hospitals, schools etc. where evacuation guiding

by the staff is considered to be important, allocation of roles to the

staffs must be well organized.

Some proper inspection system may have to be introduced to check, at

every certain time interval, whether the disaster prevention and evacuation

guiding systems are maintained as is expected by the plan.

(5) Consistency Between Evacuation Guiding Plan and Support System

The design of the evacuation support system must be logically

consistent with the evacuation guiding plan and also adequate with respect

to its reliability, capability etc. to materialize the evacuation guiding

plan.

(6) Prediction of Evacuation Behavior

Based on the evacuation guiding plan, evacuees' movement is predicted

throughout the building. In the prediction, it is assumed that evacuees

behave basically ordinary way as in non-emergent condition since smoke is

not allowed, by the premise, to enter into escape routes. However, some consideration will have to be paid on the possible panic in the event of

evacuation in the room of origin, where the presence of smoke is

inevitable.

Prediction gives the information of the doors that are being opened

due to the evacuation movement as well as the evacuees' distribution in the

building at any given moment.

(7) Elaboration of Concrete Smoke Control Planning

The smoke control planning consists of the designs of smoke control

method and smoke control support system.

Smoke control method must be so designed that, in principle, it never

allows smoke to enter the spaces where and when the evacuees are predicted

to be present.

(8) Planning of Smoke Control Method

This is a plan to deal with when and how to protect the necessary

spaces against smoke infiltration. Smoke control method includes smoke

confinement by the use of physical barriers such as smokeproof door arc

195
danper, natural or mechanical ventilation method and the combination of

both the physical barriers and ventilation.

Of course, smoke control design must not be contradictory to the

evacuation planning. A door cannot be assumed closed in smoke control

planning during the period of evacuation if it is on the escape route.

(9) Smoke Control Support System

In smoke control support system, various systems such as those for

fire detection, fan activation and vent control will be included.

Some checking system may be needed to assure the support system is

maintained at the condition assumed in the design.

(10) Consistency between Smoke Control Method and the Support System

Smoke control support system must be logically consistent with the

smoke control method and also must be adequate in its reliability,

capability etc. to materialize the planned smoke control method.

(11) Prediction of Smoke Control Effect

Prediction of smoke control effect is to check if and how well the

requirements regarding smoke, which are given in Table 1 corresponding to

the selected basic strategy, are satisfied by the planned smoke prevention

system. The doors that are predicted as being left open during certain time

of evacuation, are assumed as open in this smoke control effect prediction

as wel 1

.

(12) Examination of Smoke Control Requirements

Based on the prediction of smoke control effect, whether the smoke

control requi rements ' are satisfied or not is examined.

(13) Fire Spread Prediction

The prediction for fire spread is given using the models that are supposed to be developed in Fire Spread Prevention Design .subsystem. The

input conditions to the prediction will be given from the fire spread

prevention design of the building.

(14) Examination of The Requirement for Fire Spread Prevention

Based on the fire spread prediction, an examination is made on whether or not the requirements for fire spread prevention listed in Table

1 are satisfied. Since what is concerned in evacuation problem is threat to

196
human body, fire spread to a space can be judged by occurrence of the

condition that is untenable for the evacuees in the space.

(15) Prediction of Fire Resistant Behavior of the Structure

Considering the fire spread prevention performance and fire resistant

performance of the structure, the structural response to fire is predicted.

(16) Examination of The Requirements for Structural Integrity

Whether or not the requirements for structural integrity against

fire, which are given in Table 1, is satisfied is examined based on the

prediction.

1 1-2. THE MODELS TO BE DEVELOPED

It will be obvious that the design system described above needs at

least two models, i.e. one for people movement prediction and the other for

smoke control effect. These models need not necessarily be constructed of

brand new theories or techniques etc. Rather, what is more important for

the models is to fit into the design system. Here are some of the basic

concepts of the models to be developed in the project.

1

1 - 2-1 . Evacuation Model

Since smoke free condition is imposed on the evacuation/smoke control

design system, the model will be developed basically based on the findings

and data on people movement obtained in non-emergent condition. In other

words, the prediction given by this model will be valid only when the

circumstance for evacuation is not very hazardous. When the circumstance is

serious, we have no means to quantitatively predict human behavior any way.

The followings ^re what should be addressed more earnestly in developing

the models rather than trying to predict human behavior in genuine

emergency, which is next to impossible.

a) The model shall be able to deal with various types of evacuation

that are possible to be proposed by designers, e.g. concurrent total

evacuation, selective sequential evacuation, assisted evacuation etc.

b) The model shall be able to deal with the evacuation plans for the evacuees of different physical or mental ability.

197
c) The model shall be able to assess the time needed prior to onset of

evacuation due to the different scenarios on fire detection, locating the

place of origin by fire guard, emergency announcement system etc.

d) The model shall be able to give the evacuees distribution throughout

the building at any time during the evacuation.

e) The model shall be able to give the information on whether a specific door is left open or not due to the evacuation.

1 1-2-2 Smoke Control Effect Prediction Model

The basic techniques for predicting smoke control effect have been

developed, based on preceding calculation method for building ventilation,

and well established by now. The next step will be how to incorporate the

technique into the smoke prevention design system. Not only various types

of mechanical ventilation method, but also physical smoke barrier methods

or natural ventilation methods can be proposed by designers, and sometime

the latters may be more reliable if many factors such as maintenance of

equipments, are taken into consideration. In such cases, this model will be

used as a mean to predict buoyancy driven smoke movement in buildings, and

hence need to be able to take care of transient temperature change of the

spaces in buildings. The followings are some of the model needs:

a) The model shall be able to deal with any possible mean for smoke

control, whether it may use physical smoke barriers or ventilation

mechani sm.

b) The model shall be able to predict transient change in temperature

of the spaces that have significant effects on smoke movement in the

building.

c) The model shall be the one that needs only the data that have been

experimentally established or can be obtained without extreme difficulty.

d) The numeric for the model shall be stable, and the computation time

shall be within the reasonable limit.

III. FIRE SPREAD PREVENTION DESIGN.

III-l. THE ROLES AND MEANS OF FIRE SPREAD PREVENTION

Fire spread within buildings can be classified into the following

three for the sake of convenience in discussion.

198
1) Fire spread in the room of origin(A)

2) Fire spread outside the room of origin —- Spread to other rooms(B)

-- Spread to upper floor(C)

Although a fire itself is a continuous phenomenon, this kinds of

classification is often useful because the effective measures to prevent

fire spread differ from one to another among these three. Prevention of

fire spread contributes both to life safety and property protection, but if

aside from the matter of property for simplicity, the role of fire spread

prevention is still significant. The first role is that it partially takes

part in the evacuation/smoke control design system as described above, that

is to remove or mitigate the threat of untenable heat to reach the evacuees. The second role lies in that fire spread prevention is one of the

redundant subsystems for fire protection of buildings. The fire spread

prevention measures helps the other subsystems, such as evacuation, smoke

control , fire extinguishment and structural fire resistance to work more

effectively by reducing heat load or threat.

The role of fire spread prevention is important, however, the

measures that can be practically employed for this purpose are quite

limited as shown in the following:

(A) For prevention of fire spread in the room of origin

It can be said that the almost only practical measures to prevent

fire spread in the room of origin are a) fire retardation of interior

lining, and b) automatic fire extinguisher. The latter is not as promising

as the former, but there are still many buildings that must depend on the

latter because installation of automatic extinguisher is costly and needs

continuous maintenance.

(B) For prevention of fire spread to other room

The measures for this purpose may include fire retardation of

interior finish in the sense that it indirectly contributes the prevention

of fire spread to otner rooms by suppressing fire vigor in the room of

origin, but more straightforward measures are: a) fire proof wall, door,

danper etc., b) fire resistant buffer spaces(fire prevention zone), and c)

fire containment using ventilation method. Of these measures, the most

classical and most popular is a). Measure b) is an idea worth being

considered when the room to be protected is apart from the room of oris in.

Measure c) may have a chance to be used in relation with smoke con*; ] system.

199
(C) For prevention of fire spread to upper floor

This type of fire can also be said as the spread through exterior

openings, and the measures for preventing this are: a) spandrel, canopy

etc., which prevent window flame from touching the windows on the upper

floor, and b) wired window panes, which protects window from being broken

by flame touching.

1 1 1-2. FIRE SPREAD MODEL TO BE DEVELOPED

Although fire is quite a complicated phenomenon that needs a lot of

effort to obtain fair prediction, the practical measures to prevent the

fire spread are disappointingly limited. In order to develop a practical

model, it will be relevant to focus on these measures to prevent fire

spread and address a model that can assess the efficiency of those measures.

The mode of fire spread were classified into the three types as stated above, however, since the actual fire is continuous and hence each

of the classified modes (A)-(C) is just an aspect of the same phenomenon, a comprehensive model would be desirable if such one can be developed. But it

should be kept in mind that our understanding is not ample, in particular,

with respect to the combustion of materials in fire. If we deal with whole

the process of fire with one model, the error due to the deficiency in our knowledge in the material combustion may be enlarged in the prediction of

the later stages of fire. Also, such a comprehensive model may be too broad

in scope of study as well. So, at this moment, we try to develop one model

for each type of fire spread.

(A) Model for Fire Spread in the Room of Origin

(i) The objects of assessment

The important measures to prevent fire spread in the room of origin

are, as mentioned above, fire retardation of interior finish and automatic

extinguisher. Since sprikler has good records on extinguishing performance,

it will probably be reasonable to assume that it never fails to extinguish

fire once it is activated. So the target of our model turns out to be to assess the performance of interior lining. This must be always kept in mind

in working on this model.

(ii) Model Configuration

200
The model considered here is a single room, to which so-called two

layer zone model concept is applied. Each layer is not transparent for

radiative heat transfer, and the temperature of lower layer is not

necessarily the same as ambient temperature. It could be possible to

consider a multiroom model. However, considering current state of our understandings and techniques on fire, it is expected that great deal of our effort must be concentrated on predicting burning behavior of interior

lining in implementing the model, so it will be better to eliminate as many

factors as possible as long as their effects are not significant.

(iii) Fire Source

The fire sources thus referred to here are not ignition sources such

as matches and lighters, but so-called ignited articles such as a waste

basket or a sofa. In building spaces, numerous kinds of things can be fire sources in this sense, but the total heat release or burning rates of those

article must fall in some finite range, and the larger the heat release of

an article, the less the frequency of its emergence as a fire source must

be. A model fire source is specified for each of the rooms of different

occupancy based on fire incident statistic and furniture burning tests.

The fire source location is specified to either of center, wall side

and corner in the room of origin. In prediction of fire spread, source location is set, as a rule, at the corner as long as it is not inadequate.

And only for the cases where setting fire source location at the corner is

irrelevant, the other locations will be specified.

(iv) Heat Transfer to Internal Lining

The heat transfer to ceilings, floors and walls are calculated as the sum of the three kinds of heat transfer, which are fire source radiation,

room layers radiation and room layer convection. Introducing heat transfer

from a fire source unavoidably brings about non-homogeneity to heat

transfer along interior walls in the model, and hence to the temperature of

the internal walls. This must cause radiation exchange between the parts of

the walls, but we neglect this to avoid too much complexity in modeling the

heat transfer.

(v) Thermal Pyrolysis of Materials

Where a material gets heating that exceeds the critical heating of

ignition, it is assumed that the material pyrolyzes at the rate of

201
m" = Q" / L where L : Latent heat of thermal pyrolysis for steady burning(kJ/kg)

Q": Incident heat flux(kw/m ) m": Mass loss rate per unit area(kg/m s)

The pyrolysis of materials below the heating level of ignition criterion is

neglected

.

(vi) Combustion of the gasified fuel

It is assumed that gasified fuel that emerges from pyrolyzed material

burns in room the layers. The combustion of the fuel will be affected by

the condition in the layer. The location of the flame formed due to the

combustion of the interior lining material is not chased. This may make the

heat transfer in the model more homogeneous than the case of real fire, but

it will be too complicated to include the effect of radiation exchange

between the flames on different positions.

(vii) Combustion of combustible furniture

The condition of furniture in a room may vary greatly from one room

to another, however, since the our goal is not to predict fire growth in

general but to assess the performance of the interior lining design, it

will be possible to assume some average condition for furnishing based on some statistical data. The layout should be selected as simple as possible

so that it does not make the heat transfer calculation too difficult.

(B) Model for Fire Spread to Other Rooms

(i) Objects of the assessment

It is required by the evacuation/smoke control design method that

this model must be able to examine whether or not hazardous thermal

condition is expected to the refugees in protected shelters or escape

routes in the event of fire. The room of origin and the spaces in which

evacuees are present may be separated by partitions, fire doors, fire proof

buffer spaces or ventilated spaces, so the model needs to be able to assess

the fire spread prevention performance by these means.

(ii) Model Configuration

Model includes the room of origin, the room to which fire spread is our concern and the spaces between the two rooms. In any of the spaces

involved, two layers are assumed as is the case of a single room.

202
(iii) Fire room condition

To avoid that the errors involved in the prediction of internal

lining combustion is enlarged in the prediction of the later stage of fire,

the fire condition in the room of origin is so specified as is not affected

exceedingly by the difference in internal lining condition. Some fire source that is large enough to cause ordinary combustible in the room of

origin to ignite and bring about a fully-developed fire but still not large

enough to become a controlling factor of fire behavior once the

combustibles in the room starts to burn will be chosen as an initial source. The burning rate of the furnishing materials in the room will be

assumed as proportional to the incident heat flux to the materials.

(iv) Fire spread of lining material in other than the room of origin.

Basically the same method as that in (A) is used for the prediction

of the fire spread on the lining of the rooms. In this case, door jet, in

which combustion may be involved, takes the place of fire plume in case of

the room of origin.

(v) Heat transfer of partition, door etc.

Not only walls but floor, ceiling and door are included in what is

called partition here. Heat transfer to these partition is calculated using

average quantity of fire room gas, in other words, the effect of initial

fire source is neglected.

If the structure of a partition is simple and the thermal properties

of its elements are known, the heat transmission through the wall can be

predicted by carrying out the calculations for thermal conduction within

the walls, and hence the possibility of the occurrence of the thermally

untenable condition to evacuees can be assessed. Unfortunately , the

partitions in real world are not always so simplistic and their thermal

properties have been rarely known. So some test method must be introduced

to produce data on heat transmission properties of various partitions,

together with some relevant correlation theory that enable the test results

to apply to different heating conditions.

(C) Model for Upper Floor Fire Spread Prediction

(i) Object of assessment

This model is to assess the performance of spandrel, canopy and wir- : window pane when seen as means to prevent fire spread to upper floors.

203
(ii) Condition of the room of origin

This is determined in the same way as in (B).

(iii) Fire spread through upper floor window

In implementing a prediction method for fire spread to upper floor

through window, the method presented by Yokoi will be a base to begin with,

although it is probably more desirable to strive some effort for reasonable

prediction on window jet behavior when it contains excess fuel combustion.

CONCLUDING

It is important to use fire models in the fire safety design of

buildings for rationally evaluating various fire protection measures. In the fire safety design method, a couple of fire models are supposed to be

included in each of the design subsystems. Some consideration were made on how the models are going to be used in the "Fire Safety Design Method", and

what kind of features should be implemented in the models in conjunction of

the needs from the design method.

Incidentally, the models to be included in the subsystems for fire

resistant structural design were not discussed because they are beyond the

scope of this paper.

204
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Figure

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YES

F i gure 1 SAFE EVACUATION PLANNING IN FIRE
Table

1

Minimum

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Evacuation

207

NBSIR

A MODEL FOR THE TRANSPORT OF FIRE,

SMOKE AND TOXIC GASES (FAST)

Walter W. Jones

Center for Fire Research

National Engineering Laboratory

National Bureau of Standards

Washington, DC 20234

July 1984

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

209
TABLE OF CONTENTS

Page

LIST OF FIGURES iv

1. INTRODUCTION 1

2 . STRUCTURE OF THE MODEL . 2

3. DERIVATION OF THE CONSERVATION EQUATIONS 8

3.1 Fluid Transport 9

4. SOURCE TERMS 11

4.1 Source Terms: Radiation 12

A. 2 Source Terms: Convective Heating 16

A. 3 Source Terms: Plumes 17

A. A Source Terms: Door Jets 19

A. 5 Source Terms: Fire 21

A. 6 Source Terms: Conduction 22

5. NUMERICAL INTEGRATION 2 5

6 . COMPARISON WITH EXPERIMENTAL DATA 29

7. STABILITY AND COMPLETENESS 31

8. CONCLUSIONS 32

9. ACKNOWLEDGMENTS 33

10 . REFERENCES 33

APPENDIX A: Notation 35

APPENDIX B: Input/Output Format 38

APPENDIX C: BUILD 41

APPENDIX D : FASTPLOT AA

210
LIST OF FIGURES

Page

Figure l. A schema’-- r of one compartment, in the zone model concept.

Two layers u,l) and a single vent are shown 50

Figure 2. Radiation, transport scheme. Shown is the view factor

calculation of surface "i" as seen by surface ” j

" , transmitted through both layers 51

Figure 3. Possible upper/lower mixing mechanisms which occur at

vent jets 52

Figure 4. Comparison of experimental and calculated temperature

profiles for the upper layer in the burn room and

corridor in the "Nike Site" experiments (Table I) 53

Figure 5. Comparison of experimental and calculated interface

height in the corridor of the "Nike Site" experiments

(Table I). See ref. Quintiere et al . (1984) and

Cooper et al . (1981) for an explanation of the

criteria (10%, 20%) used to determine the experimental

interface height 54

Figure 6. Comparison of experimental and calculated upper layer

temperature in the corridor of "B205" experiments

(Table I) 55

Figure 7. Comparison of experimental and calculated interface

height in the "B205" experiment (Table I) 56

Figure 8. An example of the upper layer separation which occurs

in actual flows 57

Figure 9. An example of fire size specification through mass loss

data 58

Figure 10. Sample output from "FASTPLOT”. Shown is one of the

100 kW calculations for the "B205" experiments in the

three compartment configurations 59

211
A. MODEL FOR THE TRANSPORT OF FIRE, SMOKE AND TOXIC GASES (FAST)

1. INTRODUCTION

In recent years there has been considerable research In the area of the

spread of fire and smoke from a room of fire origin to connected compartments. The work is motivated by a need to understand and be able to predict

the environmental conditions which occur as a fire develops and spreads. Much

of the attention has focused on the development of numerical models which are

able to make a reasonably accurate assessment of the environment from ignition. The motivation is two-fold. Being able to correlate laboratory scale

experiments with full-scale tests is desirable from a cost standpoint. More

important, however, from a life-safety and operational standpoint, the ability

to make accurate predictions of the spread of fire, smoke and toxic gases

opens up many possibilities for combating these problems, as well as taking

effective preventive measures. The ability to prevent the hazards from developing becomes especially important as new and exotic materials become available.

This paper describes a model which allows one to predict the evolution of

a fire in a room and the subsequent transport of the smoke and toxic gases

which evolve from this fire. The numerical implementation improves on

previous work, for a review see Jones (1983), in particular by retaining the

conservation laws in their full differential form and solving them as a set of

coupled ordinary differential equations (ODE's). Such a formulation takes

advantage of the effort which has gone into solving such systems of equations.

The result is a numerical scheme which is considerably faster and much more

"rugged" than previous models.

212
The model is assumed to be in a world of uniform temperature T

a and

reference pressure ?

a

, with the outside of a wall at T

g which may not be the

same as the ambient. The discussion is broken down into the basic structure

and fundamental assumptions which go into the model, followed by a derivation

of the predictive equations, a discussion of the source terms, the numerical

implementation and some calculations and comparisons with experimental data.

The notation is given in Appendix A. The numerical implementation of the

model is modular and straightforward. It is designed to be transportable.

2. STRUCTURE OF THE MODEL

The primary element of the model is a compartment. The primary interest

lies in the composition of the gas layers in each of these compartments. As

such, the model is structured around fluid transport phenomena. In this

context, the predictive equations for the gas layers in each compartment

result from conservation of mass, momentum and energy together with an equation-of-state for each compartment. The actual physical phenomena which drive

the transport are then couched as source terms. Such a formulation allows the

greatest flexibility in adding, modifying or deleting terms which are appropriate to the problem being solved.

Each compartment is subdivided into one or more "control volumes." These

control volumes will be of sufficient size that we will require only a few to

describe any system of interest. The choice is based on the premise that the

details which occur within such a volume do not concern us (at present), but

their mutual interaction does. Each of these control volumes is called a

zone. The rationale for such a choice arises from the experimental obsorva213
tion that when a fire spreads, the gas layers in trie compartments actually

stratify into two distinct zones. This is a compromise between a network

model and a finite difference model. The former is computationally fast but

yields no information on the internal structure whereas the latter yields a

great deal of information but requires more computational resources than is

warranted. The two zones are referred to as "upper" and "lower”, respectively. The basic equations describe the mass, momentum and energy transfer from

zone to zone in a fire driven environment. A schematic is shown in figure 1.

In considering dynamic systems, it is necessary to solve a problem selfconsistently . If such is not done, then some of the dynamics may be obscured

or even lost. In particular, discussion of movement of the zone interfaces

must be consistent.

The conservation equations for mass and energy can be written in the form —dm . = I ra, dt . i

1

( 1 )

for mass and from the first law of thermodynamics we have

k (EV) + P f - « + h ( 2 )

together with an equation of state

P = pRT ( 3 )

which closes the set of equations, and with the definitions

214
c V

n

» • • • Q = Q + Q + Q

= net energy input

i R C

i = index of other compartments (i ^ volume of interest).

The term h^ Q (TR

) is relative to the temperature from which this mass parcel,

mdt, came. It includes enthalpy of formation. The equation of state for an

ideal gas is usually used for closure of the system. More correctly it should

be written

especially for applications to fire problems which are not ideal gas problems.

However, for the case of an ideal gas, the derivations and discussion are

simplified, and generalizations can be discussed later. The sign convention

is that positive fluxes on the right hand side of an equation will increase

the quantity being calculated on the left hand side, that is, transfer into a

volume is indicated by a positive flux on the right hand side.

The general form of the model is to divide each compartment into two

zones: an upper zone which contains a hot layer, and a lower layer which is

relatively cool. There may exist one or more fires and plumes in each

compartment and these can usually be considered to be part of the upper zone.

Mass and energy transfer between the zones is provided by the plumes, mixinv'

P = P (p,T,{i)), {i} = set of species (A)

215
at the vents, radiation between layers and flow along the walls. In general a

plume, once created, simply transfers mass and energy from one zone to

another. Another set of equations could be written for the plume, but as long

as it is in quasi-steady equilibrium, considering it to be part of the upper

zone is sufficient. Another way of the looking at the plume is to consider it

so small in mass, energy content and volume that it can be ignored except as a

transfer mechanism. For some problems, however, the plume must be considered

a separate zone along with the concomitant conservation equations. An example

would be when the rise time of the plume is of interest or when the actual

size and composition of the plume is important.

Since the conservation equations are written in terms of the volumes of

these entities, a relationship between the height and the volume is needed,

such as

h

r

V - / ZA (Z) dz (5)

to calculate the layer depths. This removes the usual restriction that the

compartments be rectangular parallelepipeds, and allows calculations for

circular crosssections (aircraft) and trapezoids (atria).

The radiation transport scheme used is fairly simple and derives from the

work of Siegel and Howell [1981]. The view factors which are used in the

calculation of solid angles are concomitant with surfaces which are planes or

discs. The relationship is shown schematically in figure 2. The simplification used here and discussed in more detail by Jones (1983) is retained, but

the actual areas are used, and the exact view factors are used wherever

O 216
possible, Kusada (1976). For example, in calculating the area of the upper

wall, allowance is made for any vents which exist by subtracting their area

from the total wall area. In addition, ceiling and upper wall, lower wall and

floor are treated separately (as pairs). This is necessitated by the possible

use of different materials for the respective surfaces which may have different radiative properties, as well as the different types of convective flow

which occur over each of these surfaces. More correctly, we should consider

three surfaces, ceiling, wall and floor. This is under development. A

problem arises in treating vertical convection as the layer depth tends to

zero.

Actual closure of the model is obtained by assuming that the size of the

compartment is fixed so that

V=Vu+ V

£ (6)

and that there is a single reference pressure

P =

u

at the boundary (interface) of the zones.

(7)

The set of equations which is necessary to describe fully such a physical

system can be reduced by considering the physical impact of some of the terms.

In particular, the pressure should be a general function of position,

P (X,Y,Z), in the compartment, which would require us to include a differential equation for the conservation of momentum explicitly. A general form for

the perturbed pressure might be

217
( 8 )

*TU

P (x,y,t) = P(t) - / p(t)dz + <5P (X ,Y , Z , t

)

o

where P is a reference pressure and is usually the pressure at the base of the

compartment. In the spirit of the "control volume" formulation

<$P * 0.

This implies that acoustic waves are filtered out and that internal

momentum need not be calculated. The hydrostatic term is small in absolute

value in comparison with the reference pressure, so it is not necessary to

carry this calculation through the equation of state. Finally, the time

dependent portion of the hydrostatic term deals with the movement of the

interface, and thus can be ignored if we limit ourselves to problems where the

momentum associated with the discontinuity (alternatively the velocity) is not

significant. Dropping the momentum equation for internal waves increases the

computational time step a great deal since we are not limited by the Courant

time step criterion (time step a grid size/speed of sound). This prohibits us

from considering problems such as deflagration waves and explosions. With

these considerations in mind, we will assume

P = P = P. (9) u l

The pressure in eqn. (9) is the reference pressure at the floor. This

simplification is carried through the conservation equations and greatly

simplifies the resulting predictive equations. However, it is necessary to

retain the hydrostatic term for the flow field calculations at vents. As we

are considering only small changes in the absolute pressure, differences of

these terms will be comparable to the hydrostatic pressure change, eqn. (8).

218
For example, for eqn. (22)

<SP ~ 1 - 1000 pa

whereas

/ (PjTj - p

2 T

2

) dz ~ 100 pa

where the integration is over a vent opening. So the flow can be dominated by

the hydrostatic term whereas the 6P/P < 1%.

3. DERIVATION OF THE CONSERVATION EQUATIONS

A zone model describes a physical situation in terms of integrals of

extensive physical quantities. Thus we deal with total mass rather than mass

density, total energy rather than energy density but temperature is used as

before (an intensive quantity). The integrals are volume integrals whose

boundary surfaces enclose the Euclidean space of interest. The space with

which we are concerned usually is a compartment with zones including a hot

upper gas, a cool (relatively) lower layer, objects, plumes and fires. The

connections occur at the boundary of these zones. Examples of possible

connections are the vents connecting compartments, the radiation from a fire

to the compartment walls, etc. With this basis we can mold the conservation

equations into a form which describes a fire in terms of the quantities which

are appropriate to the control volume approach, intuitively understandable and

lend themselves to measurement.

219
3.1 Fluid Transport

The conservation equations for each compartment of a two layer me del are

dm

u TT

dm „Z dt

= Z m . -*> m

u , 1 u

Z, i z

1

{c m (T - Tj}

dt 1 v u ^ u R

1 1

dP

u - V -T— = Q

+ h

u dt u u — {c m (t - T ) } - V

dt 1 v Z

K Z R;

J

dP

* i dt

+ h

Z

( 10 )

(ID

( 12 )

(13)

In writing these equations, we will make two assumptions. First, that the

fire will not feed mass directly into the lower layer. Second, we will write

the upper layer equation as if there is only one fire. If more than one fire

exists, then a sum over such sources is necessary and if none are present,

then this term vanishes. The source term Q includes all energy transfers due

to radiation and convection and h includes the enthalpy flow. We can rewrite

the energy conservation equations as predictive equations for temperature, in

which case they become

dT dP . dm

U „ U • m V m c -j-— - V -t— = Q + h - c T — u p dL u dt u u p u dt

dm

+ c T

v R dt

E

and

(14)

dT dP „• dm

m „c ~t~~ - V „ -r—- =

Z Q„ + h- cT rt — p dt i dt Z Z p Z dt

dm

,

+ c T

v R dt (15)

220
The right, hand side o: ecn. (14, 15) can be rewritten in a simpler form. The

reference temperature 'T t is chosen arbitrarily. If the only phase change

occurs in pyrolysis o: the fuel, then we can set the reference pressure to

zero and include the pyrolysis energy as a sink, term in the energy release

rate. As T -* 0 we obtain

K.

E u Q

f (u) + Q>) + Q

c

( u ) “ Q

p

®

r

- + c

p ®p

+ c Em. (T. - T ) p . X,U v 1 u

1 1 (16)

and

h * VZ) + Vl) + - c

p

E - T

t

). (17)

i

The equations and assumptions necessary to close this set are

P = pRT (18)

p RT =

u u

p n RT tf l i (19)

with

m = pV ( 20 )

and V = V + V. = constant,

u l

( 21 )

221
The energy source terms {e^, are shown schematically in eqns. (16,

17) but can be much more complex and depend upon the configuration. Combining

eqns. ( 1 0— Li) and (14-17), together with the closure relations, we obtain

dP

=

s dt (S-l)V

dT

u ~dT

t_8

V u (B-l)V

dV

u ~dt" P8

c m T + E

p u u u

where

s c m T +

p u u

c m T + E +

p l l u

and 8 = c /R = y/(Y“0

P

( 22 )

(23)

(24)

(25)

(26)

(27)

It should be pointed out that the equations are written in this form for

the sake of clarity and simplicity. In a numerical implementation there are

better ways to express the source terms which minimize the problem of the

small difference of large numbers.

4. SOURCE TERMS

Equations (22-25) are written so that physical phenomena which affect the

environment are source terms and appear on the right-hand-side. Sources which

appear directly are:

222
1. radiation between the gas layers and walls, fires and other objects,

2. convective heating,

3. flow in plumes,

4. flow in vent jets,

5. nixing at vents.

Phenomena which are included but do not show up explicitly are:

1. radiation between objects,

2. conduction through walls and objects.

4.1 Source Terms: Radiation

In order to calculate the radiation absorbed in a zone, a heat balance

must be done which includes all objects which radiate to the zone. Clearly,

in order for this calculation to be done in a time comensurate with the other

sources, some approximations are necessary.

The terms which contribute heat to an absorbing layer are the same (in

form) for all layers. Essentially we assume that all zones in these models

are similar, so we can discuss them in terms of a general layer contribution.

Radiation can leave a layer by going to another layer, to the walls,

exiting through a vent, heating up an object or changing the pyrolysis rite

the fuel source. Similarly a layer can be heated by absorption of radi jilon

from these surfaces and objects as well as from the fire itself. The

formalism which we will employ for the geometry is that used by Siegel eei

223
Howell (1981) and is shown in figure 2. The radiative transfer can be done

with a great deal of generality; however, as with most models we assume that

zones and surfaces radiate and absorb like a grey-boay with some constant

emissivity ( e <_ 1 )

.

A further assumption consonant with the stratified zone assumption is

that emission and absorption are constant throughout a gas layer. In application to a growing fire, a further assumption is made that the lower layer is

mostly diathermous. Although not a necessary assumption, this reduces the

computation time for this term by 50%. For smoke propagation some distance

from the fire(s) such an assumption will not be valid, but the temperature

will be so low that radiation will not be the dominant mechanism for heat

loss. Flames, plumes, fires, objects and bounding surfaces have some average

shape from which the view factors can be calculated. The walls of compartments are usually flat and rectangular. The gas layers are spheres with an

equivalent radius of

L = 4V/A (28)

and an effective emissivity of

eg

1 - exp(-aL)

.

(29)

224
The terms which contribute to heating of a layer are:

1. fires and plumes,

2. walls,

3. other layers,

4. vents (radiation from other compartments),

5. nonburning objects.

The radiation balance of items 2-5 can be dealt with using the following

notation:

a

a

L

eu, l

eg

- geometrical view factor of surface (j) by surface (k)

=-Q O A - Stephen-Boltzman constant = 5.67x 10 W/m K

- absorption coefficient of the upper gas layer m

^

- mean beam length of the equivalent sphere (m) , defined in eqn. (28)

- emissivity of the upper/lower walls

- emissivity of the upper gas layer

Using the formalism of Siegal and Howell (1981) we have

D = {l - (l-e )(l-e )f } {l - (l-e )f 0

. i } (30a) ^ u'^ g' uu J L ^ ll 1

- {(l-e )(l-e )(l-e ) 2

F .F. 1 ^ } \i J< g ' u£ £u J

nu* [!l - (l- eg Ku

f (1 - (l-^)F ul

- {(l-^)(l-^

g

) 2

< 30b > - (‘- eg

>u ^<w- [i + u-^mi-CgK^ - FMn«grt

*

225
(30c)

Hi - (l- Eu )(l- eg )F uu K l-f u] - (l- EJ(l-Sg ) 2 ^JoT^

- (l-e JF 0 e oT v g X.U u uw

- [jl - (l-e )(l-e )F F. + (l-e )(l-e }f. je oT

4

L v u

v g ' uu £u v u

; ^ g ' Zu J g g

Finally

,

Q(upper) = A £ n /D

u u u

Q( lower) = A^IT^/D.

To this must be added the energy radiated by the fire. A heat transfer

balance with the fire is not necessary simply because the amount of heat

radiated by the fire is usually much greater than that absorbed by the fire.

In order to investigate flashover, however, this calculation must be generalized to include the fire and lower layer absorption in the radiative heat

balance equation rather than relying on the postulate that superposition of

the terms is sufficient.

A simple example of the results can be given for the case

for which we have

Q

= -o[e T

4 A + (l-e )t

4

(a +A J - T

4

A

-

g

L g u ^ g

; uw v u uv J uw u

Gg

T

*w

A

d

T

4

A ] + Fp Qp (31)

a uv J f f

226
where Aj = area of the upper/lower layer discontinuity

A uv/ = area of vents which the gas layer "sees”

A^ = area of the upper wall (including ceiling)

= fraction of the fire which radiates times its view factor for

the gas layer.

A = A

u + A

d

4.2 Source Terms: Convective Heating

Convection is the mechanism by which the gas layers lose (or gain) energy

to walls or other objects. Conduction is a process which is intimately

associated with convection but as it does not show up directly as a term for

heat gain or loss, it will be discussed here.

Convective heat flow is energy transfer across a thin boundary layer.

The thickness of this layer is determined by the relative temperature between

the gas zone and the wall or object surface, Schlichting (1955) and Turner

(1973). We can write the heat flux term as

where the transfer coefficient can be written as

\ \

C

y

(Gr • Pr) 1/3.

(32)

227
The terras are:

Aw

Gr

Pr

k

l

C„

= area of wall(s) in contact with the zone

= Grashoff number = g£,J *T - T I /

5 r W I g

= Prandtl number = 0.7

= thermal conductivity of the gas = 2.7 x 10

= length scale - /h~

7 / T + T \ 4 / 5 -7 ( Sm w

N

u

v

= coefficient which depends on orientation, Turner (1973)

= Nusselt number

-10

/

T

, + W7M

- 7.18 x 10 \~2—~)

For the cases of interest

Orientation Coefficient Condition

Vertical 0.130 Gr x Pr > 10 8

Horizontal 0.210 T > T

g w

Horizontal 0.012 T_ < T

g w

The coefficients for horizontal surfaces apply to a slab over the zone. For

the inverse of this situation the coefficients should be reversed.

4.3 Source Terms: Plumes

A fire generates a plume which transports mass and energy from the fire

into the upper layer. In addition, the plume entrains mass from the lower

layer and transports it into the upper layer. The former generally increases

the upper zone internal energy whereas the latter will have a cooling effect.

For a fire which is consuming mass at a rate m^ , heat addition will be

228
Some fraction, xD » will exit the fire as radiation and the remainder will be

left to drive the plume. We can emperically devide the heat transfer i to

relative fraction of pvrolysate which participates in the combustion. Also,

once combustion occurs, a fraction of the energy leaves the fire as radiation

external effects as radiation, e.g., other fires, and vitiation. The latter

efficiencies relate to sootiness and Froude number. The mass flow in a plume

comes from a correlation of experimental data given by McCaffrey (1983). This

correlation divides the flame/plume into three regions:

Entrainment in the intermittent region agrees with the work, of Cetegen et

al . (1982) but yields greater entrainment in the other two regimes. This

difference is particularly important for the initial fire as the upper layer

is far removed from the fire. In this formulation, the total mass flow in the

plume is given by the above correlation and the fuel pyrolysis is related to

it by

actual combustion and simple gasification. The former, denoted by X

c

> is the

and convective energy ({1 -xd }Q)* The former is a function of such

K

flaming

:

m

p = 0.011 Q (Z/Q 2/5)0. 5 66 z/q 2/5

< 0-0g

intermittent

:

m - 0.026 Q (Z/Q

P

2/5^0.909 0.08 < Z/Q

2/5

< 0.20 (33)

plume

:

m = 0.124 Q (Z/Q 2/5)1.895 0.20 < Z/Q

2/j

P

m + m = f (mz, Q)

p v

5 x ( 34 )

given above.

229
4.4 Source Terms: Door Jets

Flow at vents is governed by the pressure difference across a vent. In

the control volume approximation the general momentum equacioc for the zones

is not solved. Instead, the momentum transfer at the zone boundaries is

included by using Bernoulli's solution for forced flow. This solution is

augmented for restricted openings by using "flow coefficients.” The modification deals with the problem of constriction of velocity streamlines at an

orifice.

There, are two cases which apply to these models. The first, and most

usually thought of in fire problems, is for air or smoke which is driven from

a compartment by buoyancy. The second type of flow is due to a piston effect

which is particularly important in the early stages of a fire. Rather than

depending on density difference between two gases, the flow is forced, for

example, by volumetric expansion when combustion occurs.

The results used for this model are those of Bodart and Jones (1984) and

will not be duplicated here. The notation used is:

S = smoke

A = air

ij = flow from compartment (i) to (j)

P = floor pressure (reference)

230
The order of the letters indicate the type of atmosphere from which the fluid

is coming and to which it is going. As many as three neutral planes can exist

for such flows. Two mixing phenomena which occur at vents are similar to

entrainment by plumes. For the case when hot gas leaves a compartment and is

driven by buoyancy into the upper layer of a second compartment, a door jet

exists which is analogous to a normal plume. Mixing of this type occurs for

flow

and is discussed in detail by Zukoski (1982) and Tanaka (1980). The other is

much like an inverse plume and causes contamination of the lower layer as cold

gas from a compartment flows through a hot layer in a second compartment and

is driven by buoyancy (negative) into the lower layer. Quintiere et al.

(1981) discuss this phenomena for the case of crib fires in a single room and

deduce the relation

This term is predicated on the Kelvin-Helmholz shear flow instability and

requires shear flow between two separate fluids. The instability is enhanced

if the fluids are of different density since the equilibration distance is

proportional to Vp. A schematic of this type of flow is shown in figure 3.

As can be seen, mixing into the lower layer of a room occurs under the same

conditions for which the "door-jet" mixing to the upper layer occurs.

SA > 0

(36)

231
4.5 Source Terms: Fixt

Currently we can deal with two types of first. The first is a specified

fire. Then the mass pyrolysis rate is specified and the heat release rate

becomes

0fcfp^uf'fpf = h i - c (T - Tj m - Q m (37)

whereas the mass loss rate, m^ , is related to the pyrolysis rate by

h - xf)

As the burning efficiency becomes 100%, all of the volatiles are burned, and

nothing remains for sooting. The heat release goes into radiation and

enthalpy flux

Vflre) =

Q

c (fire) » (l - XR

) Q

f

.

The term Q (fire) then becomes the driving term

c (see eqns. (33, 34)).

in the plume flow equation

This approach is extended for a pool fire. A pool fire is basically the

same except that it is driven self-consistently by reradiation from the

compartment and the flame itself. From Rockett (1983) we have

232
Q = Q (ext) + Q_, - Q__ + Q - Q ,. *f R Aflame RR tonv cond

( 38 )

where X R

I

^f lam

^RR

»^conv

»^cond

= external radiation to the fuel source

= radiation from the flame back to the fuel

= fuel surface reradiation

= enthalpy flux away from the fire

= conductive heat loss from the fuel to the surroundings

4.6 Source Terms: Conduction

Conduction of heat through solids is not a source term in the sense

mentioned earlier. That is, loss or gain of energy from solids occurs by

convective heating, which in turn is influenced by subsequent gain or loss

through the solids. However, as much of the net heat loss from a compartment

occurs through loss to the walls, as well as heating of interior objects, the

form of heat propagation in solids will be discussed here.

The equation which governs the heat transfer in solids is

V

2

! (39)

dt PC

and is a linear parabolic equation. As such, it must be solved by a different

technique than is used for the ordinary differential equations which describe

mass and enthalpy flux. In order to couple these systems in a reasonable way,

we appeal to the principle of time splitting. Simply stated, we have two

systems of equations which are decoupled as long as the time step used is

short compared to the characteristic time scale for either set of equations.

233
Wall temperatures change and the characteristic time for energy flux through a

solid is characteristically on the order of minutes. By using a time step of

no more than one second the applicability of time splitting is assured.

Currently the model assumes two walls, the upper wall (and ceiling) which

is in contact with the upper layer, and the lower wall (and floor) which is in

contact with the lower layer. A refinement will be to separate the ceiling

and upper wall, and the lower wall and floor. This will be useful since walls

are generally constructed of materials whose thermal properties are different

than the ceiling and floor. A further assumption is that conduction is one

dimensional only. That is, the heat equation is

8T _ k_ _3j[

3t " PC

9x

2 (40)

and the solid behaves as an infinite slab in the other two space dimensions.

A corollary to this is that the wall in contact with the gas layer changes

temperature instantaneously as the layer interface moves up and down. Such a

formulation is not entirely satisfactory as there is a finite equilibriation

time for the solid. An additional refinement will be to extend this equation

to two dimensions to track the layer as it moves up and down. So far, the

only zone model to attempt to include this effect is discussed by Jones (1983)

and Mitler and Emmons (1981). Even in this case the attempt was made only to

include heat loss from the upper layer as it moves down and comes in contact

with cool lower walls. However, the phenomenon is important, as is discussed

by Quintiere et al (1983), especially as the thermocline in the wall will

influence the direction in which the wall boundary flow propagates.

234
Conduction through solids occurs in two places: the compartment walls

and interior objects. The technique used is the same in both cases, although

the boundary conditions on the equation may be different. Generally a slab is

cut into N intermediate slices (N+l nodes). Then eqn. (40) is solved for each

slice. The actual finite difference used is a time centered, implicit scheme

which is symmetric about the nodes. For the interior nodes we have

qU+ll - j

[T’ +1 + q_j] + {'q + |[T 1+ . - 2T. + T._,]} (41a)

where

At k_

Ax pc

and for the edge nodes

± + (T

i

+

2

[' i+1 (41b)

The temperature at the starting time at node ”i” is T^ and at time t+5t it

is T! . The number of nodes is chosen to reduce the residual error to some

l

reasonable value, say less than 1%. Use of N > 20 will improve precision with

no concomitant increase in accuracy. This technique would allow one to use

different constituents for each slab, although such is not done in the current

implementation. Each time step requires both an initial condition and one

boundary condition. We start with the internal temperatures in each case, and

the flux on the "hot” side. The usual scheme is to set the far side boundary

condition to zero heat flux (which allows heat build up in the interior) or to

approximate the far side exterior as a constant temperature bath. Either

235
technique is satisfactory unless this far side happens to be the interior

boundary for another compartment.

5. NUMERICAL INTEGRATION

The problem of the spread of fire, smoke, etc. has been formulated as a

set of differential equations. These equations are derived from the conservation of mass and energy. As a result, most of the equations are non-linear

and first order ordinary differential equations (ODE). The exception to this

rule is the heat conduction equation which is a linear parabolic equation, in

one or two dimensions. The former can be solved using implicit predictorcorrector methods, Conte (1965), and the latter successive over-relaxation

(SOR), Mitchell and Griffiths (1980).

In the numerical implementation, we have relied on the validity of a

technique called time splitting. Simply stated, we have decoupled equations

which have greatly differing relaxation times, that is

- — = L

n dt n

where varies by more than an order of magnitude for each process. Except

for the driving program which invokes the hydrodynamics, species transport and

thermal conductivity, the various modules which incorporate the physical

processes are exercised separately and interact as source terms. This

splitting technique is standard but the inherent assumptions should be checked

when implementing a new numerical model. In addition, a check should be made

at each time step to insure that the relevant stability criterion (similar to

a Courant condition for fluid flow) is not violated.

236
For both types of equations the solution at each time step is found by an

implicit scheme. The implicit method allows us to implement the numerical

solution as a time centered algorithm. This insures reversibility in the

physical phenomenon, at least for non-dif fusive systems. A test of this

assertion is to exclude thermal conduction, integrate from an initial condition to some final time, and subsequently, by changing the sign of the time

step, we should be able to return to the starting position. A time reversal

calculation is an important step in assuring ourselves that the integration

scheme itself is not dissipative and thus will not relax to an incorrect final

state. This is a real property in non-dissipative physical systems and should

be mirrored as closely as possible in a numerical model. When conductivity is

included, such reversibility ceases to be strictly valid, of course.

An additional virtue of the time centered scheme is avoiding the

bifurcation which can occur in pure leapfrog schemes. The disadvantage is the

one additional source calculation required at each time step. This time

appears to be short, however, in comparison with the "corrector” phase of the

implicit scheme.

The order of the integrations is as follows:

(1) Estimate the values for pressure, etc. at tQ

+ 6t.

(2) Find the source terms for eqns. (22-25) based on the time centered

values (t Q + 1/2 6t)

.

237
(3)

Integrate eqns . (22-25) using the source terms defined at the time

centered positions.

(4)

Repeat steps (2) and (3) until convergence is reached.

(5)

Integrate the conduction equation using the SOR technique.

The following illustration shows where each of these time-step points is,

in relation to steps (1-5):

(1) tQ

> tQ + 6t

(2) tg >X< > tg + 6t

(3) tg >tg + <5t/2 > tg + St

(4) tg > tg + St

(5) tg > tg + St

estimate values at (tg + St)

find sources at (tg + St)

integrate from (tg) to (tg + 5t/2)

repeat steps (2) and (3)

integrate conduction equation

Since each step is of at least second order accuracy, the overall scheme

3 will also be second order accurate (0(5t )). The relative error allowed at

-3

each time step is ~ 10 . Thus the precision is greater than the precision of

the computer being used (at least as long as these calculations are being done

in single precision).

As for the integration scheme itself, it is derived from an Adam-Bashford

backwards difference scheme, Conte (1965), of order k=l. This yields a single

3

step predictor and second order corrector, 0(6t ). These equations become

"stiff" if the individual source terras are large, which leads to a short time

step, yet the total source function may be tightly coupled if the solution is

238
being approached asymptotically. Another possibility is that the source terms

for the various equations differ by more than an order of magnitude. In

either case, the usual time step criterion would require a time step which is

prohibitively short. It is possible to modify the Taylor expansion used in

obtaining the predictor-corrector scheme to use the asymptotic nature of the

equations to enhance the speed of the solver, Young and Boris (1977).

The general form of an equation is

Using the notation n(0), q(0), £( 0) , f ( 0 ) are the initial values at time (tQ),

and n( 1 ) , q(l), £(1), and f ( 1 ) are the values at the new time (tQ + 6t) , we

obtain first for the normal equations

dn

dt q - in = f

predictor n(l) = n(0) H j

f(0) (42a)

corrector n(l) = n(0) + (f(0) + f(l)) (42b)

and for the stiff equations

predictor n(l) = n(0) + (43a)

corrector n(l) = n(0) +

2 <5t {f(0)+q(l)-£(l)n(0)|. (43b) l+6tU(0)+£(l) }

239
The corrector must be iterated until some specified error criterion is

reached. If the specified error can not be reached in a small number of

iterations, say two or three, then the time step must be reduced. It turns

out to be advantageous to half the time step for each instance that a reduction is required , and increase it by only 10% for each subinterval that the

error criterion is satisfied.

6. COMPARISON WITH EXPERIMENTAL DATA

The series of tests which serve as a data-base for this analysis are

based on a two-room fire scenario by Cooper et al. (1981) and an ongoing

series of full scale validation tests at the National Bureau of Standards.

The former was a two-room configuration, consisting of a burn (or fire) room

and a corridor. It is referred to as the "Nike Site” in later discussions.

The latter is a three room configuration with the additional room being a

target room for testing high density occupancy, referred to as "Building

205.” The geometry of each of these configurations is shown in Table I.

Comparisons between the model and experimental data are for fires of

100 kW. Figures 4 and 5 show the comparison for the Nike Site tests for the

upper layer temperatures in the burn room and corridor, and the interface

height in the corridor. Figures 6 and 7 show a similar comparison to the

current experiments in B205, a full scale facility at NBS. It is apparent

from a comparison of Fig. 4-7 that plume entrainment is estimated very well

but that the door jet entrainment is underestimated. We can see this from the

good agreement between experiment and theory in any compartment which contains

a primary plume whereas in other compartments the predicted temperature is too

240
high and the layer depth too small in comparison with experimental values.

This underestimation occurs in the regions which McCaffrey (1983) calls the

flaming and far field regions. In the intermittent region, where the results

of McCaffrey (1983) and Cetegen et al. (1982) agree, the entrainment rate

appears to be correct.

Another factor which gives rise to disparity between theory and

experiment is the assumption, in the model, of known and uniform wall

materials. In the experiments, walls consist of several materials in a

composite such as calcium-silicate board over gypsum. Allowing for these

factors, the agreement seems quite good. As research continues, these

discrepancies will be resolved.

Table I.

Burn Vent Corridor Vent

Nike

Site

Depth^

Width

Height

Area

Volume

4.3

3.3

2.3

14.2

32.2

1.07

2.00

2.14

11.1-20.2

2.4

2.3

26.6-48.4

61.2-112.3

0.95

0.15

0.14

Burn Vent Corridor Vent 1 Target

Depth 2.3 12.2 _

1 2.3

Bldg. Width 2.3 1.0 2.4 1. 0/1.0 2.3

205 Height 2.2 1.9 2.4 1. 9/2.0 2.2

Area 5.5 1.9 29.7 1. 9/2.0 5.5

Volume 11.8 • 72.6 11.8

Note 1: V1/V2: VI is from corridor to target room and V2 is from corridor to

the ambient.

Note 2: Lengths are in meters, areas in square meters and volumes in cubic

meters

.

241
7. STABILITY AND COMPLETENESS

There are a number of phenomena which are either not included or need

additional work. They are:

1. Wall effect - two dimensional, unsteady heat flow

2. Separation of flow - vents

3. Ceiling jet - transit time

The first refers to the finite thermal inertia of the wall as the hot

layer moves down (or possibly up). There will be a two dimensional thermocline in the wall which differs from that in the compartment. Although this

has only a small direct effect, it can lead to flow along the walls which can

subsequently contribute to contamination of the lower layer. Such effects

become particularly important as the smoke travels further from the fire

source and temperature differentials become small.

The second problem is quite important for asymptotic predictions,

especially near the room of fire origin. Currently we assume that hot gas

mixes with hot gas or cold with cold gas as it traverses a vent. This was a

reasonable approximation while the lower layer was assumed to be ambient. Now

that we calculate the lower layer temperature, we find that the recirculating

gas may have a temperature on the order of the lower layer of the room into

which it enters. A particular example will demonstrate the effect. In a two

compartment calculation, Jones and Quintiere (1933) found that the layer

outside of the burn room is lower than that in the compartment of fire origin.

As there is no source of heat in this second compartment and cooling occurs

242
due to mixing, the upper layer in this adjacent space is cool relative tc the

upper layer in the fire room, and even comparable in temperature with the

lower layer. Currently we assume all of the hot gas in the adjacent roost.,

which flows into the fire room, will be deposited in the fire room upper

layer. As can be seen in figure 8, Evans (1983) this assumption leads to

discrepancies in prediction versus experiment. A better approach is to divide

the incoming flow into two components: for flow into compartment (i) from

with the remainder going into the lower layer. This occurs only after an

interface discontinuity has been established.

The third problem will only be important for very long corridors (20 m)

or very tall compartments or shafts. Also, it is only a transient phenomenon.

For purposes of siting smoke detectors, for example, this transient may be

important

.

The fire and smoke transport model, as described in this paper, is quite

detailed and complete as far as our current understanding of fire phenomenology is concerned. It draws on a great deal of the research into fires which

have occurred over the past ten years, pulling together much of the best work

which has been done in the field. The numerical implementation is of particular interest because it is extremely durable. The problems discussed in the

section "Stability and Completeness" need to be addressed if we are to carry

this work further, such as to fires in high rise hotels or on aircraft

compartment (j), we have a component into the upper

8. CONCLUSIONS

carriers.

243
9. ACKNOWLEDGMENTS

Two NBS cooperative students, Alicia Fadell and Charles DeWitt have

contributed to this effort. Ms. Fadell was instrumental in implementating the

"BUILD'' program which generates the configuration and description files for

the "FAST” model. Mr. DeWitt is responsible for "FASTPLOT" , a routine which

enables one to analyze rather easily the extensive output available from

"FAST.”

10. REFERENCES

Carslaw, H.S. and Jaeger, J.C., Conduction of Heat in Solids, Oxford

University Press, London (1959).

Cooper, L.Y., Harkleroad, M. , Quintiere, J. and Rinkinen, W. (1981), An

Experimental Study of Hot Layer Stratification in Full Scale Multiroom Fire

Scenarios, ASME 81-HT-9, Milwaukee.

Cetegen, B.M. , Zukoski, E.E. and Kubota, T. , Entrainment and Flame Geometry of

Fire Plumes, Ph.D. Thesis of Cetegen, Cal. Tech. (1982).

Conte, S.D. , Elementary Numerical Analysis, McGraw-Hill, New York (1965).

Evans, D. , private communication (1983).

Jones, W.W., A Review of Compartment Fire Models, National Bureau of Standards

(USA) IR 83-2684 (1983).

Jones, W.W. and Fadell, A., A Device Independent Graphics Kernal , to be

published as an NBSIR.

Jones, W.W. and Quintiere, J.G. , Prediction of Corridor Smoke Filling by Zone

Models, Comb. Sci and Tech 1

1

, 111 (1983).

Kusada, T. , NBSLD, The Computer Program for Heating and Cooling Loads in

Buildings, National Bureau of Standards (USA) BSS 69 (1976).

McCaffrey, B.J., Momentum Implications for Buoyant Diffusion Flames, Comb, and

Flame _52_, 149 (1983).

Mitchell, A.R. and Griffiths, P.F., The Finite Difference Method in Partial

Differential Equations, J. Wiley & Sons, New York (1980).

244
Mitler, H.E. and Emmons, H.W. , Documentation for CFC V, The Fifth Harvard

Computer Fire Code, Home Fire Project Tech. Rep. #45, Harvard University

(1981).

Quintiere, J.G., Steckler, K. and Corley, D. , An Assessment of Fire Induced

Flows in a Compartment, submitted for publication in Fire Science and

Technology (1984).

Quintiere, J.G., Steckler, K. and McCaffrey, B. J. , A Model to Predict the

Conditions in a Room Subject to Crib Fires, First Specialists Meeting

(International) of the Combustion Institute, Talence, France (1981).

Rockett, J.A., Experimental Determination of the Heat Flux to a Burning

Surface, to be published in Fire Science and Technology.

Schlichting, H., Boundary Layer Theory, Pergammon Press, New York (1955),

translated by Kestin, J.

Siegal, R. and Howell, J.R., Thermal Radiation Heat Transfer, McGraw Hill Book

Co., New York (1981).

Steckler, K.D. , Quintiere, J.G. and Rinkinen, W.J. , Flow Induced by Fire in a Compartment, Nineteenth Symposium (International) on Combustion (1982).

Tanaka, T. , A Model of Multiroom Fire Spread, National Bureau of Standards

(USA) IR 83-2718 (1983).

Tanaka, T. , A Model of Fire Spread in Small Scale Buildings, Building Research

Institute (Japan) RP #84 (1980).

Turner, J.S., Buoyancy Effects in Fluids, Cambridge University Press (1973).

Yokoi, S., Study on the Prevention of Fire Spread Caused by Hot Upward

Currents, Kenchiku Hokoku No. 34 (1960).

Young, T.R. and Boris, J.P., A Numerical Technique for Solving Stiff Ordinary

Differential Equations Associated with the Chemical Kinetics of Reactive

Flow Problems, J. Phys. Chem. 81, 2424 (1977).

245
Appendix A - Notation

A

B

C, C'

c

•E

E

F

ij

g

H

h

h

c

i >j

k

L

m

m

N

P

O area (m^); A^, A^, Aj are the upper and lower compartment surface areas

in contact with the upper and lower gas layer, fig. ( l ) , respectively.

A^ is the interface area between the upper and lower layers. In

section 4.4, "A" is used as a variable in the flow equations to

indicate air.

width of a vent (m)

flow coefficient = 0.6-0. 7 for both smoke and air

specific heat - Cp, cv (J/kg/K)

energy release rate (J/s)

internal energy of the gases - see eqn. (2)

view factor - relative area of "i" as seen by " j

” (dimensionless)

acceleration of gravity (9.8 m/ s )

height (m), H

u

, H^, are the upper and lower limits of a vent - fig. (1)

enthalpy (J/kg/K)

heat of combustion - theoretical (J/kg)

compartment indices

thermal conductivity (J/s/K)

mean beam length (m) equivalent opaque sphere

mass (kg)

mass flow (kg/s): m^ - rate of release of volatiles

m - entrained into a plume

e m. - fuel burning rate = v m

f e v m - mass entering room "i" from room "j"

m - flow rate in plume (m = m + m J p

r v p v height of the neutral plane (m)

pressure (pa): P P - floor reference pressure

P^ - outside ambient pressure

O 246
Q

R

S

t

T

V

Z

a

y

rale heat added or lost (J/s):

\

upper, lower zones, respectively

fire (h m ) c v objects

radiation

convection by walls

radiation added to upper gas laver

radiation from surface ”k"

combustion energy lost by

formation of volatiles

gas constant for specific mixture

smoke - section 4.4

time (s)

temperture (k) T - ambient

a

T„ - external wall

c

T

u

- upper wall

T „ - lower wall

i

Tr

- reference temperature for enthalphy flow

T - upper zone temperature

T

v

“ pyrolysis temperature

volume (m )

layer thickness (m) - ZL = interface height in compartment (i)

absorption coefficient of upper gas laver (m

-

^), thermal diffusivitv

(m2 /s)

ratio of specific heat ( c p/c v

)

247
£ emissiviLy (dimensionless): surface "i

P

K

6 . . J3

At

Ax

mass density (kg/m )

thermal conductivity

Kronecker delta = 0

= l

(j/msK)

i * j

= J

e.i - upper gas layer

£ - upper comparuaenl surface

£

^ - lower compartment surface

p . - density of the lower layer in

U1

compartment (i)

time step (s)

spatial discretization

Subscripts - In general "u" and "l" indicate upper and lower gas layer,

respectively. For area and emissiviLy variables, reference is to

the compartment itself.

248
Appendix B

Shown in Table II is a sample input for FAST. The organization is that

control is at the beginning, followed by component information, connections,

wall properties, a description of the fire, species generation information and

finally file descriptors for graphics and the dump file.

In general, the first word in each line is a key word and must be

included. The explanation of this file will be by example:

Line

12

3

4

56

7-10

11-16

17

18-27

28

29

30

31

32

Meaning

version and title

time step information

600 number of seconds for the calculation

120 + print interval

120 + dump interval (requires files)

1 + graphics interval (requires files)

0 -* hard copy counter

Number of floors - not used with this version,

but retained for compatibility

Total number of compartments

Maximum number of openings between compartments (<4)

ambient temperature,

compartment geometry, W x L x H x Floor

(1 NROOM)

connection configuration (outside is compartment

NROOM + 1)

1 number of walls used in the calculation

thermophysical properties of the upper and lower

walls respectively (units are SI except

energy (kj) and power (kW)).

which compartment the fire is in

type of fire (currently only a gas burner is

allowed)

number of intervals for production rate“

interior position of the fire to establish

entrainment rate (1 - center)

fuel properties necessary for partial combustion

1.0 > fraction of pyrolysis which burns

0.0 + fraction of water in the fuel

0.750 + fraction of carbon in fuel by weight

0.25 -* fraction of hydrogen in fuel by weight

0.00 + fraction of oxygen in fuel by weight

49758 heat release rate (kJ/kg)

300. fuel inlet temperature

0.0 fraction of heat which exits the fire plume

in the lower layer as radiation

^Currently an upper and lower wall are used. This will change shortly to four

walls to reflect the physical difference among the ceiling, walls and floor.

2 Figure 9 shows a sample fire production curve.

249
33 mass loss rate at each end point (kg/s),

LFMAX + 1 e 2 34 area of the fire at each end point (m ) 35 height of the base of the flame (m)

36 duration of each Lime interval (LFMAX)

37-40 fractional production rate of species 3, 7, 9 & 10^

first number is species (l -* 12)

second number is a conversion factor

third through LFMAX + 3 are fractional production

rates 4

41 termination label (required)

42-44 file descriptors

DISFG = plan view"*

CONFG = layer information^

DUMPR = dump file for FASTPLOT

There are two primary output files for the model. The first is binary

(UNIT = 9) and is used by the routine "FASTPLOT" described in appendix D. The

other is an ASCII file (UNIT = 6) and usually is displayed on the printer.

Units are SI (MKS) except for energy which is in kj. The meanings of the

symbols, in the order which they appear, are:

Initial

Timestep Output

TIME

U. TEMP

L. TEMP

U. VOLUM

U. DEPTH

C. TEMP

F. TEMP

EMS

EMP

ADS

QF

QR

QC

Pres mass

reiterate the input parameter, generally in the order

of input

simulated time (s)

upper layer temperature (K)

lower layer temperature (K)

upper layer volume (m^)

vertical thickness of the upper layer (m)

ceiling temperature at the surface (K)

floor temperature (K)

flow into the upper layer from the plume (kg/s)

pyrolysis rate (kg/s) area of the fire (m^)

enthalpy release rate of the fire (kW) to the upper

and lower layer

total radiant energy to the upper and lower

layers (kW)

total convective heating of the upper and lower

layers (kW)

floor reference pressure (pa)

vent flow from 1 + j (kg/s) - sec (section 4.4)

•^Species 1-12 are N

2

, C^, CO

2

, CO, HCN , HCL, ThHC , H

2 O, smoke density, total %

LC^q, smoke number density and HCL number density.

^Fraction of the mass burning rate at the corresponding endpoint (see line 33

and figure 9).

^Format for the graphics files is given in the NBSIR by Jones and Fadell.

250
Species concentrations listed by species

mass

M/V

PPM

PPM-M

total mass of that species in the layer (kg) mass per unit volume multiplied by the conversio

factor shown in line 37-40 of the input fuel.

Unity leaves this value in (kg/m^).^

parts per million of the total molecules presen

dosage which is an integral of (PPM) over time

(PPM - minutes)

Table II

1 - VERSION 15 Toxic hazard evaluation

2 — Timesceps 600 L20 120 1 0

3 - NFLOR 1 NUMBER OF FLOORS IN THE CALCULATON

4 - NROOH 5 TOTAL NUMBER OF ROOMS

5 - NMXOP 1 6 TAMS 300.

7 - HI - F 0.0 0.0 0.0 0.0 0.0

a - WIDTH 3.3 2.4 2.9 2.4 3.3

9 - DEPTH 4.3 1La .a 9.9 9.9 4.3

10 - HEIGH 2.3 2.3 2.3 2.3 2.3

11 - HVENT l 2 1.07 2.0 0.0

12 - HVENT 2 3 1.07 2.0 0.0

13 - HVENT 3 6 0.95 .15 0.0

14 - HVENT 2 4 1.07 2.0 0.0

15 - HVENT 4 6 .95 .10 0.0

16 - HVENT 2 5 1.07 2.0 0.0

7 - WALLS 2 3 - COND .0012 .0012 .0012 .0012 .0012

19 - SPHT .840 .840 .840 .840 .840

20 - DNSTY 2000 . 2000

.

2000 . 2000 . 2000.

l - THICK 0.50 0.50 0.50 0.50 0.50

- EMIS3 0.8 0.8 0.8 0.8 0.8

- CCND .0012 .0012 .0012 .0012 .0012

24 - SPKT .840 .840 .840 .840 .840

25 - DNSTY 2000. 2000. 2000. 2000. 2000.

26 - THICK 0.50 0.50 0.30 0.50 0.50

27 - EMISS 0.8 0.8 0.8 0.8 0.8

23 - LFBO l ROOM OF FIRE ORIGIN

'.9 - LFBT l TYPE OF FIRE (GAS BURNER)

30 - LFMAX 6 NUMBER OF INTERVALS FO FIRE GROWTH

31 - LFPOS l POSITION OF THE FIRE (CENTER)

32 1.0 0.0 .750 .250 .00 49758

33 - FMASS .002 .002 .002 .002 .002 .002

34 - FAREA .5 .5 .5 .5 .5 .5

35 - FHIGH .0 .0 .0 .0 .0 .0 36 - rTIKE 60. 60. 60. 60. 60. 60.

37 - SPECI 3 1.0 1.0 1.0 t.o 1.0 1.0

38 - SPECI 7 1.0 .025 .025 .025 .025 .025

39 - SPECI 9 3500. .02 .02 .02 .02 .02

40 - SPECI 10 31.2 1.0 1.0 1.0 1.0 1.0

41 - ENDSP

42 - DISFG NIKE 13 A. DAT

43 - CONFG SIKE13B.DAT

44 - DUMPR TOXIC. DMP

300. .002

.5.0

1.0

.025

.02 1.0

.0

1.0

.025

.02

1.0

^This conversion factor allows

density, LC^q or whatever.

the user to convert this output to an optic
Appendix C

Tne program BUILD is used to construct data files for configuration

display. These files can then be used by FAST to display a decision tree

either interactively or as a graphics streaming file. Both the configuration

file for display as well as information on position and type of display for

the decision tree are built by this program. The commands are:

ADD [VERTEX, EDGE, POLYGON] (default = VERTEX)

add vertex - create vertices by specifying three (x, y, z) coordinates;

add vertices to the work file

add edge - create edges by specifying two vertices; add edges to work

file

add polygon - create polygons by correcting vertices. A minimum of three

vertices are required to define a polygon, and there is an internal maximum specified by NPVERT.

DELETE [VERTEX, EDGE, POLYGON] (default = VERTEX)

delete vertex - delete vertices and any edges or polygons which are connected to the deleted vertices

delete edge - delete edges

delete polygon - delete polygons

DISPLAY [ALL, VERTEX, EDGE, POLYGON] (default = ALL)

display all - display all edges and polygons in graphics mode

display vertex - display all vertices and their line numbers in graphics

mode .

display edge - display all edges in graphics mode

display polygon - display all polygons in graphics mode

DUPLICATE

Duplicate a polygon at another location - askes for a displacement vector.

END

End the program.

ERASE

Erase the display screen.

252
GET [filename] (default = INFILE)

Open an existing file and assign the filename to INFILE; the elements of

this file make up the new work file.

KELP

List all the BUILD commands, their corresponding options, and the default

values

.

LIST [VERTEX, EDGE, POLYGON] (default = VERTEX)

list vertex - list the world coordinates, window coordinates, and the

vertices of the work file on the display screen

list edge - list the edges of the work file on the display

list polygon - screen list work file's polygons on the display screen

MOVE [VERTEX, POLYGON] (default = VERTEX)

move vertex - move a vertex from its present location to a new location - asks for a displacement vector

move polygon - move a polygon from its present location to a new location - asks for a displacement vector

PRINT [ALL, VERTEX, EDGE, POLYGON] (default = ALL)

print all - list the work file's world and window coordinates,

vertices, edges, and polygons on the printer

print vertex - list the world coordinates, window coordinates, and

vertices of the work file on the printer

print edge - list the work file's edges on the printer

print polygon - list the polygons of the work file on the printer

SAVE [filename] (default = OUTFILE)

Save the current file under the specified filename; assign the filename to

OUTFILE.

STATUS

List the filenames stored in INFILE and OUTFILE; indicate the current

number of vertices, edges, and polygons and the maximum number of each

element allowed.

WINDOW

Create the work file's window space by specifying minimum and maximum x and y coordinates for display. Defaults to WORLD.

A

53
WORLD

Create the work, file's three-dimensional world space by specifying x, y, and z coordinates. All structures must be contained in this cartesian

coordinate system.

254
Appendix D

FASTPLOT is a data analysis program which runs in conjunction with

"FAST." The results for ’TAET” are dumped to a data file after each

prescribed desired time step. FASTPLOT has the capability to form a list of

variables, read in their values at each time interval, list out the values in

tabular form, graph the values (hard copy or screen), and save the variables

in a file for future reference.

The FAST model models a fire in one of several compartments, or rooms,

and follows smoke and toxic gases from one compartment to another. We are concerned with variables in both the upper and lower layers.

The list of variables presently available through FASTPLOT are:

2 AREA burning area of the fire (m )

CONCENTRATION species density in parts per million

CONVECTIVE heat loss from layer to solid surface due to

convection (kw/m“)

DOORJET bouyant mass flow through a vent (kg/sec)

DOSE species concentration integrated over time

( ppm-min)

ENTRAINED mass entrained by a plume (from lower layer to

the upper layer)

INTERFACE height of the two-zone discontinuity (m)

MASS mass density in a layer (kg/m )

MDOTFIRE mass loss rate of the fire source (kg/sec)

NEUTRAL

NEUTRAL 2> neutral planes (maximum of three) for each vent

NEUTRAL 3)

PLUME total mass flow into the plume (kg/sec)

PRESSURE reference pressure at the floor of the

compartment (pa)

QC total convective heat gain by a layer

QF total enthalpy increase from the fire source

QR total radiative heat gain by a layer

RADIATION heat loss from layer due to radiation (kw/m")

TEMPERATURE temperature of the layer (C)

255
VENTFLOW mass flow through a vent (kg/sec) - bidirectional

VOLUME volume of the upper zone (m )

WALLTEMP temperature of the wall (C)

The CONCENTRATION, DOSE, and MASS also have associated with them a species number.

The main control of the program is carried out in the subroutine

WHICHONE. It does the actual building of a list and the processing of the

options. The possible options available to the user are:

ADD

C RANGE

CLEAR

DEFAULT

DELETE

END

HELP

LIST

PLOT

REVIEW

SAVE

Upon running the program, the first input encountered will be that of the

dump file generated by FAST. Most of them will be of the form:

f ilename.DMP

Next, the user will be asked to input the option which he wishes to have

performed. The following is a description of each of the options available.

They are in the order that they usually will be encountered. However, some may be executed before the others without any problems. The minimum number of^

characters required to recognize an option is enclosed in the parenthesis at

the beginning of each word.

1. (DE) FAULT

This enables the user to set his own default parameters for the

following

:

COMPARTMENT #

VENTFLOW DESTINATION

LAYER

SPECIES // CHARACTER SET FOR PLOTTING

This option may be done at any time and if it is not done the defaults

are set to "l, 2, upper, 9, and 4”, respectively. Hie purpose of this option

is to change the defaults available for other commands and data input.

256
2. ( VA) RIABLES

The purpose of this option is to allow the user to recall the possible

variables that are available for use. They will be listed on the screen.

3.

(AD)D

This command is used to build a list of variables. When an option is

requested ADD may be entered by itself or together with a list of variables

that are to be added. If it is entered alone a message will be printed asking

for the variables that are to be added to the list. For example:

> ADD

- INPUT VARIABLES TO BE ADDED > or

> ADD TEMP, PRES,

For each variable selected there is a series of questions that will be

asked as to the type of that variable wanted. Questions asked about all

variables are:

WHICH COMPARTMENT? -> WHICH LAYER? ->

If VENTFLOW is chosen the compartment origin and destination will be

requested; if CONCENTRATION, MASS, or DOSE are selected the species number of

each will be requested.

The maximum number of variables allowed on the list at any one time is

25. If the list is full or the variable is presently on the list the addition

will be disallowed and another option requested.

4.

(DEL)ETE

When this option is entered the present list of variables will be printed

out to the screen and the user will be asked to input the variables to delete

by the number associated with them on the list. They must be entered on a single line separated by commas or blanks.

If the variable number that is input does not correspond to one that is

currently on the list it will be skipped. After the deletions have been

processed a new list is presented and another option requested. If the list

is presently empty then that fact will be stated in an error message.

5.

(HE)LP

This command may be input at any time that the user is asked for an option. It's purpose is to simply list out to the console a list of the

available commands and a brief explanation after which another option will be

asked for.

257
6. ( RE ) VIEW

At times the user may wish to see what is presently on his list before

entering a command. This may be done with the REVIEW command. It will print

out the current list along with the compartment number, soecies, and layer of

each of the variables. After the printing of the entire list the option

request is again displayed.

7.

(LI)ST

After variables have been added to the list and their data values read

in, the user may list out the values of any of the variables on the list to

either the printer or the console. The user will input the device number

(5 = CONSOLE, 6 = PRINTER), and the list of variables presently on the list

will be displayed. He will then be asked to input the corresponding number(s)

of the variable(s) to be listed out. They must be entered on a single line

separated by commas or blanks. The maximum number of variables able to be

listed at one time is 8 for the printer and 5 for the console.

8.

(PL)OT

This option is central to the data analysis. After entering this command

the current list of variables will be displayed along with their numbers. The user will be asked to input the number of the variable(s) to be plotted from

the list. They should be entered in a string separated by a comma or a blank

space. For example:

ENTER VARIABLES TO BE PLOTTED -> l, 2, 3,

4

or ENTER VARIABLES TO BE PLOTTED ->1234

After entering the variable numbers, the number of the device which the

graph is to be plotted on will be asked for.

The possible devices are:

1 . CALCOMP

2. PRINTER

3. LEXIDATA

4. SCREEN

The maximum number of plots per call to PLOT is limited to 4. They will

be printed in the following order on the device depending on the number of

graphs per page:

l 2 1 2

3 4 3

FOUR THREE

258
l 1 2

TWO ONE

If more than 4 variables are input only the first four will be accepted

and the remaining ones disregarded. If a variable number not on the list is

entered, an error message will appear, the list will be reprinted and the

input will be asked for again. This will continue until all variables entered

are currently on the list.

Before the graphing is done the user is given the opportunity to change

the range of the X and Y axes. The maximum and minimum values of the X and Y axes will be displayed, followed by a request for a change in each, which will

be of the form:

CHANGE (X or Y) AXIS TO? ->

If no change is desired simply enter a <RETURN> and the next axis change

will be displayed. If a change is made the value will be entered and the same change request will be made again. This will be repeated until a <RETURN> is

entered

.

When all the changes have been made, if any, the graph of that particular

variable will be plotted. After it has been completed the next variable’s

maximum and minimum will appear and their changes input as before.

After the final graph has been completed the option request will be

displayed and a new option may be entered.

9. (SA)VE

This option allows the user to save the values of the variables on the

list in a file. The format used will make the data compatible with an experimental data processing program designed for handling of data in the Center for

Fire Research.

The user will be asked for the name to be used for the file. A check

will be made to see whether that file presently exists or not. If it does the

user will be asked if he wants to write over the old file with this new data.

If his answer is NO, nothing will be placed in the file and another option

requested. If, however, he does want the file rewritten, or the file does not

already exist, the new file will be created and the data stored in it.

Each variable on the list will be dumped with the following format at the

beginning of each block of data:

16 , 16 , A6 , * COMMENT

The first 16 will be for the number of data points for that variable, the

next 16 is for the number given to that variable on the list, and the A6 is

for the actual variable name. Everything after the * is a comment block and

will be filled with information relevant to that particular variable, such

259
things as species number, compartment number, layer, etc. The actual

numerical data will be dumped using the format 7E11.5.

10. (CL)EAR

The input of this command empties the variable list.

11. (CH)ANGE

This option restarts the program by asking for a new file and resettin

all variable lists.

12.

(EN)D

This function terminates the execution of the FASTPLOT program.
Surface

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Discussion After W. Jones’ Report on A MODEL FOR THE TRANSPORT OF FIRE, SMOKE,

AND TOXIC GASES (FAST)

ZUKOSKI: I'd like to comment on that last slide that you have. It seems to me

that in a real case if you have a recurrent flow going from the second room into

the back of the fire room that, in reality, is going to form a third layer. You

have to make your mind up which is the worst alternative. If you’re worried

about toxic materials flowing into the lower layer of the fire room then I would

put it all in the ceiling layer. It forms a third layer, an intermediate

layer. At least in the experiments we've done, it tends to form an intermediate

layer and you have to make your mind up whether you want to treat that as a part

of the ceiling or as part of the floor layer.

JONES: You're correct.

ZUKOSKI: If you treat it as part of the ceiling layer you underestimate the

ceiling temperature.

EMMONS: It is correct that the third layer would be formed. However, the

compensational time required to solve problems with additional layers is quite

large. I suspect the best kind of a compromise might be to divide the inflow

between the upper and lower layers dependent upon the temperature of the inflow

gas, the temperature of the upper layer and the temperature of the lower layer

in proportion. This same idea may be important in other respects. With a simple two layer model one can present flashover by igniting another small

fire. The model does this because a small heat source carries a considerable

volume of lower layer air up into the upper layer and decreases it's temperature

and hence it's radiation. Thus, again we either need a third layer, or more, or

we divide the material between the upper and lower layer in some reasonable way.

JONES: Your proposed solution to partitioning is what I favor, otherwise we tend to defeat the whole point of going to the simplified single zone models.

QUINTIERE: I think on these so-called partitioned flows for fire growth, they

may not be very important, but for hazard to humans, particularly in terras of

multi-room models, it could be very important in deciding the hazard

condition. So, for human hazard evaluation, one may want to look more seriously

at these flows.

PAGNI : With regard to the high temperatures far from the source in your ship

calculations, three possible causes suggest themselves. I would like you to

comment on whether all three are important, or if you think one dominates. Our

intuition can be fooled by a vertical stacking and that may be an important

effect. Also, the ship construction is not what we're familiar with, the

material properties of the steel are different from most walls. Lastly, the

fire strength is rather large, and I assume that it was turned on as a step

function at one megawatt.

JONES: To answer the last statement, that's the way the fire started in this

particular scenario, experimentally as well as in the model. I point out thut

vertical passages in ships are a very small cross section and, in general, the

walls are actually quite well insulated and seldom uncovered. Finally, the

temperature in an absolute sense is not high.

271
MORITA: When you mentioned the instability of computation, are you talking

about the technical mathematical sense of instability or are you talking about

the phenomenal sense? Are you using the word "instantaneous" in a sense of

phenomena, and when you think about flashover, I'm sure that there is both

instability in both senses.

JONES: Yes, that is correct. I was referring in particular to the numerical

instability which has plagued many of the zones models to date. There exists

also the actual phenomenological instability associated with fractional

differentiation. One has to be very careful including a self-consistent fire

model in order to make correct predictions in that regime. However, we will

have to do more experimental work to uncover the kinetic effects which become

very important in that regime.

MITLER: Did you confirm experimentally, at the Nike site, the results that you

show the calculations for?

JONES: Not in that last calculation, no. There are two projects under way, one here to hopefully confirm that as part of the validation study which Sandy Davis

is undertaking, and the Coast Guard is performing ship fire tests against which

we hope can validate this model for shipboard fire validations.

272
SMOKE MOVEMENT AS A DENSITY CURRENT

Makoto Tsujimoto

Fucalty of Engineering

Nagoya University

Furo-cho, Chikbsa-ku

NAGOYA 464

273
SMOKE MOVEMENT AS A DENSITY CURRENT

Makoto Tsujimoto

1. INTRODUCTION

It is evident that the driving force of smoke movement is the heat

generated by conbustion in the fire room. But it is not clear what kind of

flow the heat makes after blowing out from the fire room. Considering corridors and staircases as a sort of stream tubes, the

smoke movement in the buildings must be classified into two large groups,

a pipe flow and an open channel flow. It is considered that the expansion

as a result of excess heating in a fire room produces the pressure gradient

and forms the pipe flow like Fig 1-a, while the bouyancy of smoke itself

forms an open channel flow below the ceiling like Fig 1-b.

In the real scale fire experiment^ , it is observed as follows.

" In a corridor facing to a fire room, smoke moved almost horizontally

in a clearly stratified layer along the total length of corridor. And

after flash over, the thickness of the smoke layer increased quickly

and the smoke came down near to the floor. After the moment,

the thickness of the smoke layer decreased and the counter flow of fresh

air appeared. " In view of this, it is not so long that the smoke behaves like a pipe flow, so it is significant to investigate the property of smoke

movement as an open channel flow. In case of an open channel flow, the

bouyancy of the smoke itself, which is (thickness of smoke ) x ( diference

of density), is the driving force of the smoke. Such a flow like this

is also called " density current ". At present, many models for the analysis of smoke movement in the

building, for example Wakamatsu '

s

2)

, adopt the equation of air movement

through the opening between two rooms with different temperatures. This

method is not proper to explain the smoke movement along the long corridor

without partitions.

In case behaviour of smoke movement as a density current is revealed, it

will be able to solve the smoke movement as an unsteady density current in

horizontal and inclined direction.

According to the studies concerned to the head movement of density

Q\ current , it is only obtained the relation between velocity, thickness and

density difference of the head by the experimental data. So it is

impossible to calculate the head velocity in unsteady state provided that

the smoke flow rate and the temperature from the fire room are given as a boundary condition.

This report is concerned only with the smoke movement in steady state as

a density current, and compares the calculated values used the equations

introduced by Ellison & Turner ^ with the experimental data about the smoke

movement below the horizontal and inclined ceiling.

274
2 . THEORY

2.1 Governing Equations

Ellison & Turner4) considered the steady state of a layer moving up a ceiling over a stationary ambient fluid like Fig.l. They showed the

momentum equation as follows, which represents the momentum balance of the

fluid contained in the elementary volume of unit width by x, x+dx, y=0, y=oo,

2

d(V " } = -CdV

2-~(S £H2

cosa) + S^gllsind ( 1 ) dx

where VH

„ 2.

= [lv dy

> f® 2

V~H = J

( v dy

VHg = T(P -P/Pjgv dy

S H^g = L(P o -p/p Q )gy dy

1 B cl

s

2

h£ = J; (p -p/p )g dy

v:flow velocity along a ceiling

p: density of flow

P a

: density of ambient fluid

arslope angle of a ceiling

C(j:drag coefficient

S lt S 2

: dimensionless coefficients depend on profiles

of velocity and density difference

And they considered that heat loss to the ambient is neglisible , and

showed the equations for continuity of mass deficiency and for entrainment

as follows.

I'

(P -p/p )gv dy =VIIg = const (2)

B B d(VH)/dx = VE (3)

E : entrainment factor, a function of Ri

From the examination of the experimental data in Section 3 for the flow

below the inclined ceiling, heat loss is neglisible because of the

shortness of stream. So Eqs. (1),(2),(3) can be used.

While for the horizontal flow the heat loss can't be neglected , and within

the extent of the experiments in 3.1, it is confirmed from the measured

values that there is no increase of flow rate by entrainment. So the

following equations, which represent the over all heat loss and the

conservation of mass, may be used instead of Eqs. (2), (3).

275
-~<VHg)/Vg (4) = -K

-^-flvpg dy = 0 > “^{Vll(g-g)} =0 (5)

where K : coefficient equivalent to heat transfer coefficient

2.2 Boundary Condition

In treating the open channel flow, it is necessary to examine whether

the flow is tranquil ( subcritical ) flow or shooting(supercritical ) flow.

According to Ri numbers, which wehe determined by measured values of the

experiments in Section 3, it is confirmed that the flow below the

horizontal ceiling is tranquil flow and the flow below the inclined ceiling

shooting flow. In the case of tranquil flow, the condition of the end of

corridor is important because the disturbance of downstream propagates

upstream.

In the case of 3.1.2, the flow is opened to the atmosphere at the

end of corridor. So it is considered that the flow turns from tranquil

to shooting there. And this is used as the boundary condtion. The detailed

discussion is found later.

3. EXPERIMENT

3.1 Smoke Movement below the Horizontal Ceiling

3.1.1 Measurement

The corridor in which the experiments were made is shown schematically

in Fig 3. The experimental conditions were provided by varying the area of

alcohol pool in the fire room and the length of corridor. Each temperature

in the corridor was measured by C-A thermo-couple. The profile of velocity

was measured by smoke wire and the absoulte value of one typical point of

this was obtained by measuring the dynamic pressure of flow.

The examples of measured temperature and velocity are shown in Fig. 4.

The temperature and velocity profiles made into dimensionless form by the

each maximum value and the thickness of smoke layer (distance from ceiling

face to the point v=0) are shown in Fig 5. According to these results, it

is considered that profiles are conserved throughout the flow. The value of

Sl=0.58 is obtained by these profiles using the transform equations in

Eq. (1).

276
3.1.2 Comparison with Theory

Introducing the equation Ri=HgcosOt/V 2 (5-2)

and arranging Eqs. (1) , (4) , (5) under the condi t ionCK. =0

.

— = {Cd+(1+S Ri )

( -K — ^- ) } 3Ri/ ( 1-2S Ri ) H (G)

dx 1 g 3 1 — = { Cd+ ( 2-S Ri )

( -K — )-S KRi } / ( 1-2S Ri ) (7)

dx 1 g 1 1

By the Eqs. (6), (7), it is considered that Ri=l/2S1 is the turning point

of flow, and the flow is tranquil flow on Ri>l/2S1 and shooting flow on RK1/2S1 . This is identical with the flow below the inclined ceiling in

paragraph 3.2.2.

By the observational result that the smoke rises at the end of corridor

like a water fall upside down, it can be made a decision that the flow

turns from tranquil flow to shooting flow at this posotion.

Therefore as the condition of the end

Ri e = l/2Si 4 =Hege/Ve2 (8)

from equation (5)

VeHe(g-ge) = M (9)

where M:mass flow rate across the section,

obtained by measured values

Subscript e means the end of corridor

If it is given one of three values (ge,He,Ve) in an arbitrary manner,

the others are determined by Eqs. (8), (9). And substituting these values

into Eqs. (6), (7) as the boundary condition at the end of corridor, the

values in upstream (g,H,V) can be calculated. Then, in order to determine

three values at all points, He is varied so that the calculated value (for

example g) in the most upstream point may be approached to the measured

value (g) in the same point by repeating approximation.

Then in Eqs. (6) and (7), Cd and K are not determined and remained as an experimental constant. These can be obtained by temperature and velocity

profiles at the face of walls if they are measured exactly. But the

measurement is not so accurate that the values of Cd,K are determined in

the way that the calculated values reconcile to the measured value within

the extent that can be estimated by the profiles. Providing Cd=0.017,

K=0.9, the calculated values correspond to the measured values are shown in

Fig 6. The difference of calculated values by varying the value of Cd is

shown in Fig 6-a. As a result of this, in the case that the flow of smoke

is steady tranquil flow, it is appeared that the values of V,H,g can be

calculated numerically from the turning point of downstream , if mass flow

rate and temperature of smoke at the most upstream point of corridor are provided

.

277
3.2 Smoke Movement below the Inclined Ceiling

3.2.1 Mesurement

The slope for the experiments is shown schematically in Fig. 7. Because

of the scale limit of the room for experiments , the length of the slope is

not enough. The experimental conditions were provided by varying the

inclination angle, power of the heater , and r.p.m. of fan. The conditions

for the experiments are showed in the table 1.

•The method to measure temperature and velocity are same as 3.1.1,

except the absolute value of velocity. The anemometer with temperature

correction was used for it. The example of measured temperature and

velocity is shown in Fig. 8. It is evident that the velocity is accelerated

by the bouyancy of the flow even in a short distance.

The temperature and velocity profiles in dimensionless form is shown

in Fig. 9 like Fig. 5. Though the variation of dimensionless profiles is more considerable than that of the horizontal flows, it is ignored in this paper.

The values of Sl=0.36 and S2=1.09 are obtained by profile.

3.3.2 Comparison with Theory

Arranging the equations (1) , (2), (3) using (5),

dRi _ 3Ri ( 2-S , Ri ) E-S 2 Ri tana + Cd

(1Q)

dx

dH

dx

H l-2S,Ri

( 1+S , Ri ) E-S 2 Ri tana+Cd

1-2S ! Ri

( 11 )

In calculation of (10), (11), Cd=0.017 obtained in 3.1.1 is used.

For E, Alpert deduced Eq. E=0 . 075exp ( -3 . 9Ri ) from the experimental

data by Ellison and Turner

In this paper, E in each experiment is obtained by Eq.(12) from the

experimental values.

< VH

>x- ... - (VH) x= ... /v. ( 12 ) x= is 3. 0-1. 5

' x= »- 5

Results are shown in Fig. 10 and Eq.(13) is derived from it,

E=0 . 29exp (-3 . 6Ri ) (13)

The result of calculation using Eqs . ( 10 ) , ( 11 ) , ( 13

)

are shown in Fig. 11.

The boundary condition of calculation is the measured values in X=1.5m.

And according to Fig. 11 it is clear that calculated values agree with the

observed values on the tendency which H and V increase along the flow.

278
4 CONCLUSION

1) The method to express the smoke movement as a density current in term

of the equations by Ellison and Turner is shown.

2) In the case that the flow of smoke is tranquil flow in steady state,

and that the flow turns from tranquil to shooting at the end, the

properties of flow (V,H,'g) can be calculated numerically if mass flow

rate and temperature of smoke at the most upstream point are provided.

3) In case of smoke movement along the inclined ceiling, it is observed

that the flow is shooting under the condition that the inclination

angle is more than 5°.

ACKNOWLEDGMENTS

The author is indebted to Dr.Tokiyoshi Yamada, Mr . Shigeaki Matsumoto , and

Mr.Ikuo Watanabe who assisted in data collection and analysis. Also, the

encouragement and suggestions of Dr.Heizo Saito and Dr.Osami Sugawa were greatly appreciated.

REFERENCES

1 ) Tetsudo-Kenchiku-Kyokai , Chuotetsudobyoin-Kasai-J ikken-Hokokusho , ( Jul

.

1968) (in Japanese)

2) Wakamatsu , T . , Calculation Methods for Predicting Smoke Movement in

Building Fires and Designing Smoke Control System, ASTM-NBS Symposium

, .Washington, D.C. (Mar . 1976)

3)

for example:

Keulegan, G. H. ,The motion of saline fronts in still water, 12th progress

report on model laws for density current, U.S. Nat . Bur . Standards , No . 5831

,

(1958)

Simpson , J . E ., A comparison between laboratory and atmospheric density

currents , Quart . J.R. Met . Soc . 95 , pp 758-765 , ( 1969

)

4) Ellison, T.H. .Turner J . S ., Turbulent entrainment in stratified flows,

J. Fluid Mech . 6 , pp 423-448,(1959)

5) Alpert , R . L ., Turbulent ceiling—jet induced by large-scale fires , Techn i cal

Report No . 22357-2 , Factory Mutual Research ( Sep . 1974

)

279
Disxance

from

ceiling

(cm)

~y? ~J7 "77 77"

a) Pipe flow

l-'lg 1 Two typeu of

77 77 77? 77 b) Open channel flow

amok o movement Mg 2 Mag (am of flow below

the Inol Jned cel 1 lug

Tempera lure Vel oci ty

nr. | ( )("i/sec)

I absolute value

. by dynamic pretiaure

o X = 1

0

1 n

«> X = 30m

° X -05 m

Fly 4 Typical profiled of (a ) tempera lure , and

(1.) velocity In horizontal ceiling

Fig 5 I’roflleo of velocity mid dentil ly difference In normalized form

280
0

0 2

0 4

0 6

ni 0

1.0

2.0

3 0

0 5

10 30 50 A 70m

a) Experiment 1-1, K=0.9

OAX meuaured value m/sec

"* calculated value

b) Experiment 1 - 2 , K=0 . 9 , Cd= 0. 017

10 20 3 (Ini X

0.5

1 0 m/sec

Od x measured value

calculated value

c) Experiment 1-3, K=0 . 9 , Cd=0 . 01

7

0 5

^ ^ OAX BietiHin ed value m/sec

calculated vii 1

1

d) Experiment ]-4, K-^0 . 9 , Cd 0. 01

7

iig 6 Measured values of experiments and calculated values by E()S . ( 1 0 ) , ( 1 ] )

281
Distance

from

ceiling

Distance

from

ceiling

The flow rate is regulated by varying

the r.p.m. of fan '*%ss£

The temperature difference

of outlet is regulated

by heater

W 5 Wo

©

Temperature profile

by thermo-couple

Velocity profile

by smoke wire

©!©

|« 9o° ^

FJg7 Diagram of Inclined celling

Temperature Velocity

b) Experiment 2-5, dl = ]0.0<’

8 Typical profiles of temperature

e and velocity in Inclined celling

Fig 9 Profiles of velocity and density difference

In norma I I zed form

282
E

O.l-i Table 1 Condition of menuuremen

t

0.05

0

fie io

E=0.29BXP(-3.6lU )

EXP 2-2 /EXR2-S yP\ A /EXP2-3

\ 10 0. los'c. \

\ /*

z

3

' / ^

QR2-4

b'=0. 075 EX P ( -3 . 9H1 r—

by R.I.. Xlpert ^ ==\ Ri 0.5 1.0

The values of E measured In experiments

EXP-110. tenne "

1 ncl 1 na 1 1 on

angl^e ~f empera ture

d 1 f f e rence _Qf_0Ullet

flow rate’

2-1 2-2 2-3 2-3 2-5

5.0° 7.5° 7.5° 7.5° 10.0°

75° C 75° C 35°C 35°C 75°C

1 t 1 2 1

Mow role 2 in alrnoul a hull of flow rule 1

2.0 X(h, 25

1.6

0. U . 0.1 I

EXP. l-\

ni! 2-3

0 . 2

0.4

2.0 XlM ) 2.6

oVJI^2 5 — jjj

•

t‘1'2 I ur-i» 2

Menu. .red vuluee CJ^XP.-2-l +:KXH.-2-2 ^:EXl>.-2-3 0 : EXP . -2-4 X 1 EXP. -2-5

Culc.lluled value

Fig 11 Measured values of experiments and calculated values l.y lJ<|s . ( 10 ) , ( 1 1 )

283

Discussion After M. Tsujimoto's Report on SMOKE MOVEMENT AS A DENSITY CURRENT

EMMONS: You have added some interesting and useful data on the steady ceiling

jet. Are you also going to study the non-steady ceiling jet? The non-steady

ceiling jet is very important in fire development as the fire comes out of one room and travels at some speed down a corridor.

TSUJIMOTO: On page 1, about 10 lines from the bottom of my report, I discuss

this. The velocity of smoke is the same, for example, as the velocity of water

flow. I have not yet completed my studies.

ZUKOSKI: In Figure 10, there's a discrepancy between what you used for the

entrainment and the products of Ellison and Turner as determined by Ellison. We

agreed that the experiments of Ellison and Turner, although they're the only

experiments in the field, have to be looked at very hard.

TSUJIMOTO: On entrainment, we have performed some studies, but we agreed that

we have to do more precise measurements.

PAGNI : What is the smoke layer?

TSUJIMOTO: We use ni chrome wire coated with paraffin heated electrically.

QUINTIERE: Do you plan to study the effect of a partition at the end of a corridor on the smoke layer predictions?

TSUJIMOTO: We are not planning to do it.

285

GENERAL DISCUSSION

PAGNI: I think the Japanese work presented earlier by Tanaka is very important

in that it couples the physics of the smoke movement well with the human

behavior part of the escape and evacuation procedure. We need more of that kind

of coupling.

HIRANO: Since it seems there are no other comments, we would like to show two

video tapes as I promised earlier. Dr. Quintiere will comment on the first tape

and Dr. Takeda will comment on the second video tape.

QUINTIERE: This tape was shown to me by Dr. Saito. So, someone from the

Japanese delegation more familiar with material being burned may wish to comment

on this material. I will only say that this is a small-scale experiment with

steel foil over plywood, I believe. You will observe a peculiar fire phenomena,

the walls and ceiling. The ignition source is a crib fire. I believe it will

occur again.

EMMONS: How large is the test chamber?

TANAKA: Approximately one meter by one meter by two meters.

QUINTIERE: This kind of a fire experiment with wall and ceiling lining has gone

on in many countries for many years. New materials create serious problems

because test methods do not predict this fire phenomena. Now Dr. Takeda will

show you another fire phenomena that is unusual.

NELSON: Anybody have any phenomenological explanation or hypothesis?

QUINTIERE: This is a steel foil, not aluminum foil, so perhaps you do not burn

through the foil, you simply cook the pyrolysis products through steam and then

you reach a flammable mixture.

NELSON: In the days of the steel-clad wood core fire door, we had to vent the

fire doors by cutting a hole in the steel to prevent destruction of the door

from the distillate. Maybe if it were vented, the problem would disappear.

QUINTIERE: It's vented into the room.

NELSON: No, we cut a hole to vent directly into the wood.

EMMONS: Experiments performed by Alex Robertson at NBS about twenty years ago

in a one path meter non-flammable chamber with a small crib showed oscillatory

smoke ejection. It did not go poof.

QUINTIERE: Would you like to see it one more time.

HIRANO: Yes.

MITLER: Did I understand correctly that this is a vertical panel of plywood

covered by a vertical foil of steel?

QUINTIERE: Dr. Tanaka, would you describe the material.

287
TANAKA: I am not quite sure, but I understand that the surface is covered with

thin laminated iron plates with the exception of a seam in the front plane, a small lining was used.

GANN: This is the same building with the same material?

QUINTIERE: This is different material. Just fire wood, I think.

ZUKOSKI: It also shows how big the room is there.

TAKEDA: This is not a unique phenomena, but under ordinary circumstances this

type of experiment extinguished itself.

ROCKETT

:

Did you weigh the PMMA while it was burning?

TAKEDA: We did not weigh it.

EMMONS

:

How much was left?

TAKEDA: Eighty percent of the original PMMA was left. The mechanism of

extinction is that because of a too high concentration of gas or there was another reason. It isn't clear that extinction was probably due to the too

highly concentrated gas, but as for the effect of fluid dynamics, we have to

conduct further experiments to find the answer.

EMMONS:

door?

Was the vent 16 centimeters high in the middle of the wall or was it a

TAKEDA: Center.

QUINTIERE: Sixteen by what?

TAKEDA: Sixteen by 11.

ROCKETT: Do I gather from what you said that you measured the oxygen

concentration in the room?

TAKEDA: No, we didn't, but we would like to.

MITLER: Was the fire ventilation limited, as far as you can tell?

TAKEDA: I believe so.

KAWAGOE

:

: Did you measure the temperature inside?

TAKEDA: Yes, we did. We did not observe an unordinary temperature increase.

The temperature went up drawing the ordinary curve, perhaps it was higher than

the usual, but the temperature dropped abruptly.

WAKAMATSU : Do you feel that you can reproduce the same test?

288
TAKEDA: Even though we conducted this particular test once, several years ago

we conducted a great number of similar tests using alcohol. At that time we repeatedly observed the oscillatory phenomena and also we observed phenomena of

abrupt extinction. So, I feel that there is a high degree of reproducibility of

this particular test.

ZUKOSKI: It would be interesting to find out the behavior with a pilot flame in

the box. We've done similar experiments which were ventilation limited at the

bottom of a large cylinder with a flame in the bottom of a large cylinder. The

fire goes out but we had an ignition source that would reignite.

EMMONS: In fact, if you had a charring fuel, I believe it would not have gone

out because the char would have reignited it. PMMA has only a gas flame. If

you go poof, it goes out.

ROCKETT: Several years ago Stanley conducted experiments in a room approximately the same size, with a door and a simulated sprinkler mounted

directly outside the door. The spray produced quite fine droplets. Both gas

flames and PMMA fires on the floor were extinguished by application of the water

outside the door. Extinguishment occurs when the measured oxygen concentration

in the room had been lowered by steam generated from the sprinkler to

approximately 14 to 15 percent oxygen. Relative to Prof. Emmons' comment, when

the PMMA was surrounded with aluminum foil on the side and bottom,

extinguishment did not always occur because a small flame remained between the

aluminum foil and the side of the PMMA. In this case, as the temperature of the room dropped and the efficiency of conversion of water into steam decreased, the

fire would reestablish at a reduced size.

COOPER: You have assembled a lot of data on quasi-steady conditions that

ultimately lead to flashover or oscillations or extinguishment. The dimensions

of your apparatus are fairly small but it seems that it may be useful to try to

model these, to use the existing models, and to compare them with your data.

Since you have so many different sets of conditions, it is reasonable to model

them. Have you thought of doing this?

TAKEDA: As for the comparison of the model and the result of the experiments, I presented a talk on that subject in the International Combustion Symposium last

year in Haifa, Israel.

COOPER: Does this include modeling of the early times of fire?

TAKEDA: That particular comparison did not include early time.

COOPER: This is the calculation that I'm wondering about... an early time

comparison, the quasi-steady early time.

TAKEDA: You are asking about early time, when oscillation or flashover will

take place, is that correct?

COOPER: I'm talking about times before flashover, prior to times when

temperatures exceed, let's say, 300 or 400°C.

TAKEDA: At the current time, I do not have models which will include those

early times.

289

MATERIALS FIRE PROPERTIES AND TEST METHODS

Takashi Handa and Harold Nelson

Session Chairmen

Materials Fire Properties and Test Methods

by

Patrick J. Pagni

Mechanical Engineering Department

University of California

Berkeley, CA. 94720

I ntroduction

Per the resolutions of the Sixth Meeting of the UJNR Panel on Fire Safety

and Research, this introductory progress report will address identification of

material fire-related properties necessary to serve as inputs to a performance

fire code. The concern here is with definition. The question of the

appropriateness of existing fire test methods, which have been reviewed in the

literature [1-5], will not be considered. Recent developments in test methods

and suggestions for new test methods [6-8] will also be delayed until a concensus has been reached on which properties must be quantified. With this

goal in mind the material properties required by current compartment fire computer codes are examined. The amount and geometry of each material present,

the compartment geometry and acceptable protocols for determining convective

and radiative transfer coefficients are assumed to be known.

Properties

Consider a division of these properties into three phenomenological categories: 1) heat transfer, 2) steady combustion, and 3) fire spread.

The first category is dominated, as noted by Rockett at the recent Emmons

Conference [9], by the properties: k, the thermal conductivity, defined as

293
2

the ratio of that portion of the local heat flux due to molecular motion to

the negative of the local temperature gradient; p, the density, defined as the

mass per unit volume and c, the specific heat capacity, defined as the specific enthalpy increase required to raise the local temperature one degree. I

concur that these three properties must be known for all materials in every

habitable structure. In the walls, both bearing and non-bearing, and in the

interior and exterior surface finishings these properties dictate the heat

loss from the compartment at early times and can have a critical influence on

the probability of flashover as discussed by Thomas et al . in the analogy between flashover and thermal ignition [10-12]. In the contents of the room,

these properties also play an important role as the thermal inertia, kpc,

which strongly influences characteristic temperatures and as the thermal diffusivity, k/pc, which determines the characteristic times for unsteady behavior.

The properties which dominate steady combustion are those [13,14]

included in the definitions of the mass transfer number, B = (QpY^ - h

$

) /L

and the mass consumption number, r = M

f /Y fs v Q

M

Q

. These are: L, the

effective latent heat of pyrolysis; Q

p

, the enthalpy (heat) release per mass

of oxygen consumed; h

$

, the surface enthalpy (temperature) in the gas phase;

Vf Mf/v Q

M

q

, the stoichiometric fuel to oxygen mass ratio, assuming complete

combustion to CO2 and 1^0, and Yfs the surface fuel mass fraction which is

known from Y^

s = (BY^

t

- Yq^ M^/v

q

M

q

) / ( 1 + B) if Y^. the fuel mass fraction in the pyrolysing material, is known. The quasi-steady, local, compartment oxygen mass fraction, Y , will be known from computer calculation. The

effective latent heat of pyrolysis consists of the pyrolysis enthalpy plus the

specific enthalpy required to bring a unit mass of fuel from ambient tern294
3

perature to the surface temperature plus the radiative emission on an unusual

per mass basis minus the radiative influx on that same basis, i.e.,

= Ah

p +

< T

s- TJ + (q"

c - q

H

1 n )/AH

. ( 1 )

where Ah

p

, c, T

$

and q"

s = es

arT s 4 are material properties, but q"

in

and thus

m" depend on the environment and therefore must be separately specified [15].

The heat release, when expressed per mass of oxygen consumed, is practically

an universal constant, 13 ±1 kJ/gm 0^. The activation energies for surface

pyrolysis are sufficiently high that surface temperatures do not change significantly over a wide range of pyrolysis rates. The chemical composition of

the pyrolyzed material determines the stoichiometry, i.e.,

C

x Hy

0

Z + (x + y/4 - z/2) 02 > xC0

2 + y/2 H2

0 (2)

and therefore,

v f

M

f = 12x + y

+ 16 z v

"oMo 32x + 8y - 16z

is known, assuming the pyrolyzate's net chemistry is the same as the chemical composition of the original material. Refinements necessary to include

time varying properties as might be found in material with significant char

can be discussed in the next meeting's material fire properties progress

report. For now a start can be made here.

The final problem is to determine material properties required to predict

unsteady fire growth. The correlations in Figs. 10-13 of Ref. 16 suggest two

essential non-dimensional groups: a Peclet No.,

295
and a Damk'bhler No.,

exp <-E

g /RT

ft ) (5)

Three new material properties are introduced: T^, the flame temperature; Ag,

a global gas phase reaction rate pre-exponential; and Eg, a global gas phase

reaction rate activation energy. P, the pressure, and U^, the gas velocity,

are compartment parameters. In addition for most fire growth problems, flame

radiation plays a crucial role. The radiant heat flux from a flame depends on T^, on the flame geometry specified by a flame height, x^

£

, and shape or, at

the least, by a quasi-steady mean beam length, » 4lfya where j* is the flame

volume and a. is the total flame surface area and on the average soot volume

fraction in the flame, f , [18,19].

Cone! usions

Improvements will be required [20] since this property list is based on

many assumptions of limited validity which cannot be discussed in detail in

the space permitted here. In summary, the following are the fire-related

material properties to be determined for all contents and components of

habited structures (with units indicated in parenthesis):

k thermal conductivity (E/LTt)

p

c

density (M/L^)

specific heat capacity ( E/MT

)
5

E

A

L

9

g

effective latent heat of pyrolysis (E/M)

heat release/mass of oxygen consumed (E/M)

pyrolyzate net chemical composition

pyrolyzate fuel mass fraction

fuel surface temperature (T)

flame temperature (T)

flame average soot volume fraction

flame mean beam length (L)

flame height (L)

global reaction rate pre-exponential (M/L^t P )

global reaction rate activation energy (E/mole)

It might be concluded that these fire-related material properties are simply

engineering material properties and that, while there may be unique firerelated needs, there may not need to be unique fire- related test methods.

References

1. American Society for Testing and Materials, "Symposium on Fire Test

Methods," A.S.T.M. Special Technical Publication, Philadelphia, PA.,

1962

.

2. National Fire Protection Association, "Fire Protection Handbook," 15th

Edition, N.F.P.A., Boston, MA., 1981.

3. American Society for Testing and Materials, "Annual Book of ASTM

Standards; Part 18: Thermal Insulation; Building Seals and Sealants;

Fire Standards; Building Construction; Environmental Accoustics," 1694

p., Philadephia, 1982.

4. International Conference of Building Officials, "Uniform Building Code,"

1982 ed; Whittier, CA., 1982.

5. National Research Council of Canada, Associate Committee on the National

Building Code, "National Fire Code of Canada," 180 p., Ottawa, 1980.

6. J. de Ris, "Flammability Testing State-of-the-Art," Technical Report

J .1 .0H0J2.BU , Factory Mutual Research Corporation, Norwood, MA., June

1983.

297
7.

6

Tewarson, A. and Pion, R.F., "A Laboratory-Scale Test Method for the

Measurement of Flammability Parameters," Technical Report No. 22524,

F.M.R.C., Norwood, MA., October 1977.

8. V. Babrauskas, "Heat Release Rate Measurements with the Cone

Calorimeter," Emmons Conference on Fire Research, August 23-25, 1983,

N.B.S., Gaithersburg, MD.

9. J. Rockett, "Data for Room Fire Models," Emmons Conference on Fire

Research, August 23-25, 1983, N.B.S., Gaithersburg, MD.

10. P.H. Thomas, "Fires and Flashover in Rooms - A Simplified Theory," Fire

Safety Journal , 3_, 67-76, 1983.

11. P.H. Thomas, M.L. Bullen, J.G. Quintiere and B.J. McCaffrey, "Flashover

and Instabilities in Fire Behavior," Combustion and Flame, 38, 159-171,

1980. — —

12. Y. Hasemi , "Thermal Instability in Transient Compartment Fire,"

Proceedings of the Sixth Meeting of the UJNR Panel on Fire Safety and

Researach, pp. 452-461, Tsukuba, Japan, 1982.

13. P.J. Pagni , "Diffusion Flame Analyses," Fire Safety Journal, 3, 273-285,

1980.

14. L. Orloff and J. de Ris, "Froude Modeling of Pool Fires," Nineteenth

Symposium (International) on Combustion, pp. 885-895, The Combustion

Institute, 1982.

15. A. Tewarson, "Heat Release Rate in Fires," Fire and Materials , £,

185-191, 1980.

16. A.C . Fernandez-Pello and T. Hirano, "Controlling Mechanisms of Flame

Spread," Combustion Science and Technology , 32 , 1-32, 1983.

17. J. Quintiere, M. Harkleroad and D. Walton, "Measurement of Material Flame

Spread Properties," Combustion Science and Technology , 32 , 67-90, 1983.

18. S. Bard and P.J. Pagni, "Carbon Particulate in Small Pool Fire Flames,"

ASME Journal of Heat Transfer , 1Q3 , 357-362, 1981.

19. R.A. Beier and P.J. Pagni, "Soot Volume Fraction Profiles in

Forced-Combusting Boundary Layers," ASME Journal of Heat Transfer, 105,

159-165, 1983.

20 . H.W. Emmons, "A View of Fire Safety from the Twenty-Third Century,"

Emmons Conference on Fire Research, August 23-25, 1983, N.B.S.

Gaithersburg, MD.

298
Discussion After P. Pagni's Report on MATERIALS FIRE PROPERTIES AND TEST METHODS

ZUKOSKI: Do you have any comments concerning the treatment of composite

materials, such as the foams you talked about which have gas pockets?

PAGNI: I think for that kind of foam we could treat the composite with an

average property for that material. But for other kinds of composites where

they are non-honogeneous and there are layers and threads connecting different

fabric, we would need the properties of each part.

EMMONS: It seems to be that we also need, in addition to the suggestion which

you have for individual materials, the corresponding "cost" of the corresponding

list for furniture items and other built items. The difficulty of having a fundamental treatment of a manner of fire spread on a large chair, given the

information on the individual material, will probably be so complex as not to be

a reliable method.

PAGNI: Based on past experience, you are probably correct.

QUINTIERE: Do you see the place for phenomenological type parameters, other

than just material properties, such as heat transfer type coefficient

parameters? We have had some success with this in dealing with flame spread.

PAGNI: Yes, I think that's a very useful contribution to be determined in this

analysis, if the radiative and convective transfer coefficients, as well as the

geometry, are known.

QUINTIERE: I do not mean that we should define the heat transfer coefficient.

I mean we should define parameters like heat transfer coefficients.

PAGNI: There are many phenomena which are so imprecisely known that such

coefficients are not only a good idea, they are also necessary. But, I think it

might be a mistake to use those when we have the more fundamental alternatives.

299

RECENT ADVANCES IN MATERIALS FIRE PROPETIES

AND TEST METHODS

Hiroaki SUZUKI

Building Research Institute

Ministry of Construction

Seventh Joint Meeting

UJNR Panel on Fire Research and Safety

Washington, U.S.A. , Octoher 2i+-28, 1983

301
Recent Advances in Materials Fire

Properties and Test Methods

H. Suzuki

This report deal with studies on fire properties of materials and some

test methods which have been developed in these years in order to grasp the

fire behavior of materials and/or to classify materials by their fire

performance.

1. Fire Properties of Materials

Flame spread over materials is one of factors for prediction of fire

growth in a room. Inducement of a proper formula which will be commonly

applied to more materials is an important theme. Many scientific studies for

flame spread and their application to practical use have been pursued. No

common fomulae , however, have been introduced to be applied to many

materials with different properties.

The formula " which wasintroduced by the researchers^ of

f P

Factory Mutual at the 15th Combustion Symposium in Tokyo in 197^-, has still

been used as a typical equasion. Efforts for improvement of this equasion

changing flow rate of atmosphere, inclination angles, materials etc. have

been made in order to apply practical use.

302
The other method for study of mechanism of flame propagation has been

persued with changing dynamic environmental conditions. Hirano et

2 ) 3 ) al, for example, have studied the difference of flame propagation by

changes of flow rate of environment. This may become an effective method to

predict the spread of fire in a dinamic atmosphere in a room, in the future.

in

K. Kishitani et al. have measured flame spread of PMMA at the

vertical position and get a relationship between the height of flame (Xf)

and the position of the melting front (Xp). That is Xf=CNXpn

, where c\=U.68

and n=0.7 for PMMA of 0.5cm in the thickners.

K. Akita et al . ^ have pursued a theoretical study of combustion of

PMMA under the natual convection. They deal with effects of different Shumit

number and heat loss from the surface of the materials which due to

diffusion coefficients of the pyrolysis products and oxygen.

The theoretical result meet the experimental one in the reagion of

0.75-2.5 of Schmidt number when a bigger number than that of oxygen for the

pyrolysis products is taken.

^

\ r-7 \ T. Mikado et al. and K. Uchida et al have studied on electric wire

coated with polyvinyl chloride K. Uchida et al. have conducted a

relationship between the damaged. Length of electric wire coated with

polyvinyl chloride using a vertical test method. The relationship is written

as follows

Le=-lo ln(x-Xm)+l_^

where 10,1^ and Xm are constant, Le is the damaged length, x oxygen index of

atmosphere

.

303
On the other hand, weight loss, heat release and smoke production from

8 ) "building materials and furniture have "been continued "by F. Saito et al.,

S. Fujikawa^ and K. Kawagoe et al.~^^

2

K. Kawagoe et al. have obtained 35,000 Kcal/m h of irradiation heat

release flux from flame which was calculated from the data at the distance

of 1.5m, 2.0, 2.5, 3.0m from the center of burning cribs. A camera with a

fish eye lens was used for the measurement of the shape effect of the flame.

2. Fire Test Methods and Classification of Materials

A box model test method is going to be applied as a new test method

for evaluation of fire resisting composite materials of foamed plastics

covered with thin inorganic materials, in addition to the current fire tests

executed by the ordinance of Ministry of Construction, Japan.

A box shaped specimen of 0.8U x 0.8U x 1.68 (W x H x D in meters,

without the floor and a wall for opening) is to be located in a bigger box

made of asbestos-cement-parlite board (0.3 x 0.67 in meters for openings on

one of two smaller walls). About 2 Kgs of cribs are to be used for the fire

source in addition to the specimen. Combustion products are collected into a

hood with a duct where temperatures, velocity of the flow, and combustion

gases (CO, CO^, 0^ ) are measured. Heat released rate is calculated by the

12 ) method which has been developed by W.G. Parker, et al.

A test method for ignitability has been developed at the committee

13

)

ISO/TC 92/SC 1 for these years and round robin tests have been carried

304
out among some laboratories in some countries.

An ad hoc committee for the ignitability was organized in the

lh)

Architectural Institute of Japan and has followed the ISO test method.

The purpose of the ad hoc committee is to do testing of ignitability of

materials, and to do comparison of six different types of radiometers, used

in some countries.

Some plastics burn to blow off flames from openings of buildings whose

interior materials of foamed plastics catch fire. Some fire retarded foam

plastics show a peculiar phenomenon which is based on the balance between

heat release rate and cooling effect by draft when burn. This phenomenon

occurred in foamed plastics with stable tissue without being melt when

heated.

For an evaluation of fire retarded foamrd plastics, especially

polyisocyanulate which has self-extinguishing property, in order to classify

these foamed plastics which used in warehouses, a fire test method has been

developed with 0.5ml of ethy alcohol in a small cup for the the heat

15) source.

The classification is made by the area calculated from temperaturetime curve which measured in the vent. This test method is only valid for

constract among industries.

H. Suzuki^ ^ and H. Miyazawa^^ have tested the flame spread of

building materials by 25 feet tunnel test method and ISO fire spread of

flame test method, respectively.

305
References

1) L. Orloff et al. Fifteenth Symposium (international) on Combustion, P37,

Aug (197*0.

2) Hirano, T. , Sato, K. , and Minami , H.

, "Response of Flame Spread Phenomena

to Ambient Air Stream Velocity Changes," Proceedings of the 6th Joint

Panel Meeting UJNR Panel on Fire Research & Safety, 597-615 ( 1982 )

.

3) Sato, K. , Miki , K. , and Hirano, T. , "Flame Spread over Paper in an Air

Stream with a Velocity Change," in Fire Dynamics and Heat Transfer, ASME

HTD-Vol . 25, 9-15(1983).

h) K. Kishitani, S. Sugawara and E. Hamada : Annual Conference of

Architecture, Field of Fire, P.2809, Sep. 1983.

5) K. Akita, T. Hirano and H. Ohtani : Annual Conference on Fire Research,

Japanese Association of Fire Science and Engineering, P.73 May 1983.

6) Mikado, T. and Akita, K. /'Burning Characteristics of Grouped PVC

Cables," J. Fire & Flammability, 13 , 2U-32 ( 1982 )

.

7) K. Uchida and T. Hayashi ; Annual Conference on Fire Research, Japanese

Association of Fire Science and Engineering, P.31, May 1982.

8) F. Saito and M. Yoshida ; ibid, P.2805, Sep. 1983.

9) S. Fujikawa ; ibid, P.2803, Sep. 1983.

10) K. Kawagoe , T. Mizuno and K. Shinoda : ibid, P.2803, Sep. 1983.

11) F. Saito ; Umpublished.

12) W.G. Parker : NBSIR 81-2U27-1, March, 1982.

13) ISO/TC 92/SC 1 : Technical Report TR 5657-Fire Tests-Reaction to

Fire-Ignitability of Building Products, N36, June, 1981.

306
lU) Report of the Ignitability Test Method ; Technical Repot of Ad Hoc

Committee of Ignitability Test, Architectual Institute of Japan, 1982.

15) Nihon Kagaku Bohka Kyokai ; Technical Report of Ad Hoc Committee for

Insulation Materials for Warehouses, March, 1979*

16) H. Suzuki ; Annual Conference of Architecture, Field of Fire, P.2813,

Sep. 1983.

17) H. Miyazava ; ibid, P.2815, 1983.

307

Discussion After H. Suzuki' s Report on RECENT ADVANCES IN MATERIALS FIRE

PROPERTIES AND TEST METHODS

GANN: This test method that is to be proposed, do you have some idea of the

physical form? What will the test method be like?

SUZUKI: We showed a videotape yesterday. We used a box approximately one meter

by one meter by two meters. This is a box model test method.

309
'
IDENTIFICATION OF FIRE PROPERTIES RELEVANT

TO THE PREDICTION OF FIRE GROWTH

Archibald Tewarson

Factory Mutual Research Corporation

Norwood, Massachusetts 02062 U.S.A.

(For Seventh U.S.-Japan Natural Resources Panel Meeting

On Fire Research And Safety, National Bureau of Standards,

Washington, D.C.)

September 1983
SCOPE

In this paper, fire properties of materials relevant to the prediction of

fire growth are identified and techniques and apparatus for quantification are described.

1. IDENTIFICATION OF FIRE PROPERTIES OF MATERIALS

The fire properties of materials relevant to the prediction of fire growth

are:

1 . 1 Properties Associated With Fire Initiation And Spread

1) Critical heat flux (q" ) below which fire cannot be initiated. Fire

Cl initiation can be defined as the onset of fuel vapor generation, piloted ignition or autoignition.

2) Energy (E) required to reach the critical heat flux. Energy is . . related to the thermophysical properties of the materials and configuration^

(

'S 2

r q'o' 1 pa

kAT.

1

q"M e = constant; a = t

1 =

E

where, p

AT^= temperature required for fire initiation above ambient temperature;

q” = heat losses; and q" = heat flux applied to the material.

3)

Flame spread rate coefficient (C) , expressed as

v

,

( 1 )

lermal diffusivity; k = thermal conductivity;

C = (u/a6

f q^)

1/2

( 2 )

where, a = a(h/k)' ’ ~f and h = heat transfer coefficient.

= flame heat transfer distance; q" = flame heat flux;

C is related to the thermophysical properties and configuration of the materials.

The flame spread rate coefficient, the critical heat flux and the associated model developed by Quintiere ^

or other models can be used to predict

the generation rate of fuel vapors in growing fires.

1.2 Properties Associated With Fire Hazard

The hazard contributed by a fire is expressed in terms of generation of

heat and various compounds ("smoke," toxic and corrosive products), all of

which depend on the generation rate of fuel vapors and availability of oxygen.

The fire properties relevant to the prediction of growth rates of heat and

various compounds, ("smoke," toxic and corrosive products) are:

1) Heat of combustion (H^) which is defined as the ratio of heat release

rate (Q^) to the generation rate of fuel vapors (G^)

H

± = Q

i

/G

f (3)

Heat release rate in fires is defined as the actual heat release rate (6 ) and has a convective and a radiative component, respectively, defined as con- vective heat release rate (Q ) and radiative heat release rate (Q^) . In a similar fashion, actual, convective and radiative heat of combustion, H^, H^ and

H respectively, can be defined. The ratio of actual heat of combustion to the

R

312
heat of complete combustion of the material is defined as combustion efficiency

(x ), and its convective and radiative components, x

c and respectively.

The product of heat of combustion and predicted generation rate of fuel vapors

is equal to the predicted heat release rate in a growing fire.

2) Yields of various compounds ("smoke," toxic and corrosive products)

(Y.) which is defined as the ratio of the mass generation rate of a compound j

(G^) to the generation rate of fuel vapors (6^)

,

Y = G /G

f

. (4)

The products of the yield of the compounds and predicted generation rate of

fuel vapors are equal to the predicted generation rates of the compounds in

growing fires.

3) Mass attenuation coefficient of "smoke" (a) which is defined as the

ratio of the optical density of "smoke" per unit path length (D) to the generation rate of fuel vapors (G^) per unit volumetric flow rate of the mixture of

air and fire products (V^)

,

o = D/(G

f

/V

T

) . (5)

The product of mass attenuation coefficient and the predicted generation rate

of fuel vapors and volumetric flow rate is equal to the optical density in

growing fires.

4) Suggested corrosivity parameter (C ) , which may be defined as the

ratio of rate of corrosion of a metal (m) to the generation rate of fuel vapors

(G^) , where vapors are bubbled through a fixed volume of water,

C

r = m/G

f

. (6)

(3) This parameter has been developed recently , and needs to be examined

further so that it may become useful for the prediction of corrosivity of the

compounds generated in growing fires.

5) Toxicity parameter (T ) , which may be defined (by modifying the con- ventional definition used in the fire field) as the ratio of the generation rate

of fuel vapors (6 ) to the total volumetric flow rate of well mixed air and

fire products (V ; , required to achieve a toxicological end point (incapacitation,

death, etc.):

T,- eA • (7)

Tx may be modified further, as follows:

Tx

= (1 - x) G

f

/V

T

, (8)

where x is the mass fraction of fuel vapors converted to nontoxic compounds

such as CO and H^O.

6)

Ventilation parameter ($)

,

which is defined as the ratio of mass flow

When <f> >1, fire is defined as overventilated and when <f> <1, fire is defined as underventilated.

313
1.3 Properties Associated With Fire Detection And Extinguishment

Fires can be detected through heat or compounds generated in fires; thus,

the fire properties identified as relevant in Section 1.2 would also be relevant

for fire detection.

Fires can be extinguished through interference in the combustion chemistry

by 1) reducing oxygen concentration by agents such as N2 , CO2 , foams, etc., and

2) interacting with flame chemistry by agents such as Halons, dry powders, etc.

Fires can also be extinguished by cooling the flame and the burning materials.

In either case the heat release rate, flame heat flux, generation of various

compounds, and the generation of fuel vapors must be reduced below some critical

values for the extinguishment of the fire. Since extinguishment is the reverse

process of ignition, the critical values for various fire properties associated

with extinguishment by N2

, CC> 2

, foams, Halons, dry powders, water, etc. may be

very similar to the fire properties associated with ignition. For example, the

generation rate of fuel vapors for polymethylmethacrylate at or below which

piloted ignition cannot be achieved is very similar to the value of the generation rate of fuel vapors where flame is extinguished by water spray and by re- ducing the oxygen concentration. Thus, the extinguishment parameter (Ex) relevant to the prediction of growing fires may be suggested as^''

Ex = AP/P , (10)

where AP is the change in a fire property as a result of application of a known

amount of the extinguishment agent, and P is the property in the absence of

the extinguishment agent. P can be any one of the fire properties associated

with heat release rate, generation rate of an individual compound, or generation

rate of fuel vapors.

2. QUANTIFICATION OF FIRE PROPERTIES RELEVANT TO THE PREDICTION OF FIRE GROWTH

2 . 1 Apparatus

For the quantification of fire properties, the most suitable apparatus that

have recently been developed are: 1) the National Bureau of Standards Cone

. (5) Calorimeter developed by Babrauskas

^ ; 2) the Ohio State University Heat

Release Rate Apparatus'®'; and 3) the Factory Mutual Combustibility Apparatus ^ ' At Factory Mutual, three combustibility apparatus are used''

7 ': 1) Small-scale apparatus for samples -.10 cm x 10 cm x 10 cm high;

2) Intermediate- scale apparatus for samples -.30 cm x 30 cm x 30 cm high;

3) Large-scale apparatus for samples _300 cm x 300 cm x 300 cm high.

All apparatus operate under very similar principles. In the small-scale and

intermediate-scale apparatus radiant heaters are used as external heat sources.

In the small-scale apparatus both forced and natural air flow are used where

air can be heated and contaminated by various compounds. In the intermediateand large-scale apparatus, only natural air flow is used.

In all three apparatus, all the products generated in the fire are captured

along with ambient air in long sampling ducts where measurements are made for

total flow rate of the mixture of air and fire products, gas temperature, con- centration of various compounds, and optical transmission. In addition, measurements are made for piloted and autoignition, and generation rate of fuel vapors.

The mass flow rate and oxygen concentration in the inlet air in the small-scale

apparatus are also measured.

and

314
2 .

2

Measurements

2.2.1 Fire Initiation

The critical heat flux (q" ) and energy (E) are quantified by measuring

time to ignition as a function of external heat flux. E is then equal to time

to ignition x external heat flux. Figure 1 is a plot of 1 /E as a function

of external heat flux (q") for the piloted ignition of varioul polyolefin cables.

The intercept on the q"-lxis is defined as the critical heat flux (q^r

) • From

eq (1) and the slopes in Figure 1, pa/kAT can be calculated for conditions

where

q J

« q”.

Quintiere'' ' has developed a model and has described the technique for the

quantification of flame spread rate coefficient, (C) , in eq (2). Currently we

are using Quintiere’s model for flame spread rate for vertical cables about

60 cm in length, exposed to external heat flux at the lower end.

2.2.2 Heat Of Combustion

For the quantification of heat of combustion (H ) using eq (3)

,

the ratio

of heat release rate and generation rate of fuel vapors is determined as a function of time under various experimental conditions. The actual heat re- lease rate is calculated from the generation rates of CO and CC^ and occasionally

verified by using the oxygen depletion technique of Huggett' 0 ^. The convective

heat release rate is calculated from gas temperature, total mass flow rate of

the mixture and the specific heat of air at the gas temperature. The radiative

heat release rate is calculated from the difference between actual and convective

heat release rate, because losses are negligibly small in our apparatus.

Table 1 lists data for some selected materials for overventilated fire

conditions. For simple materials for overventilated fires, the heat of combustion is found to be independent of the fire size and shape of the materials

and fire stages (growth and steady state).

2.2.3 Yields Of Various Compounds

For the quantification of the yields of various compounds (Y ) , using

eq (4)

,

the ratio of the generation rate of compounds and fuel vapors are determined as functions of time under various experimental conditions. The

generation rates of the compounds are calculated from the concentrations of

the compounds and total volumetric flow rate of the mixture of air and fire

products

.

Table 2 lists data for some selected materials for overventilated fire

conditions. For simple materials for overventilated conditions, the yields of

major compounds are found to be independent of the fire size and shape of the

material and fire stages (growth and fully developed)

.

2.2.4 Mass Attenuation Coefficient Of "Smoke"

For the quantification of the mass attenuation coefficient of "smoke" (o)

using eq (5)

,

the ratio of optical density per unit path length at three wavelengths of light to the generation rate of fuel vapors per unit volumetric flow

rate of the mixture of air and fire products is determined as a function of

time under various experimental conditions. Table 3 lists data for some selected

materials for overventilated fires. For simple materials for overventilated

conditions, a is found to be independent of fire size and shape of the material

and fire stages (growth and fully developed)

.

315
2.2.5 Suggested Corrosivity Parameter

(3 ) For the quantification of the suggested corrosivity parameter , fuel

vapors are bubbled through a fixed volume of distilled water (100 m£) . A mild

steel probe is immersed in the solution and its resistance is measured as a function of time. The resistance changes because of loss of metal due to corrosion. From the measurements, the rate of corrosion of the metal is determined

and is divided by the generation rate of fuel vapors. Data for some selected

materials are listed in Table 4.

The suggested corrosivity parameter needs further refinement so that it

may become useful for the prediction of corrosion potential of compounds generated in a growing fire.

2.2.6 Ventilation Parameter ((ft)

The ventilation parameter, 4> , is calculated using eq (9) from the ratio of

total mass flow rate of inlet oxygen to the generation rate of fuel vapors per

unit stoichiometric oxygen to fuel ratio.

The ventilation parameter, d), is found to be a function of Pagni’s

normalized flame height, For polymethylmethacrylate (PMMA) , cellulose and polyvinyl chloride (PVC) in our apparatus' ,

a 34 / <f) 1.5 (ID

As <f> decreases, increases, i.e., increase in "excess pyrolyzate" i.e., fuel

vapors which are not consumed in the flame which produced them'^*"^'. The

combustion efficiency and generation efficiencies of products of complete com- bustion decrease and the generation efficiencies of products of incomplete com- bustion increase with increase in the "excess pyrolyzate" for PMMA, cellulose

and PVC in our experiments using the small-scale combustibility apparatus '**'

.

The "excess pyrolyzate" concept is applicable to the prediction of fire

growth (see Reference 10 and comments on the paper) . We have been examining

this concept for enclosure fires of PMMA reported by Quintiere efc al^ 1 ^' In

conjunction with PMMA data obtained in our small-scale apparatus^).

Quintiere et al '~^) have reported the values of induced air flow rate,

generation rate of fuel vapors, and gas temperature for steady-state enclosure

fires of PMMA pools for several ventilation openings and pool areas. If we

assume that the oxygen concentration in air entering the fire is either normal

or close to the normal value, then the value of <p can be calculated from eq (9)

for enclosure fires of PMMA pools. Since the sum of the induced air flow rate

plus the generation rate of fuel vapors is equal to the total mass flow rate

of the mixture of air and fire products, m , leaving the enclosure, the con- vective fraction of the combustion efficiency (x£

) can be calculated as follows,

xc = m, c p

AT/G

f

H

t

, (12)

where c is assumed to be the specific heat of air at the gas temperature;

AT = gal temperature above ambient in the enclosure; and <= net heat of com- plete combustion of PMMA (25 kJ/g). The calculated data on the basis of the

above mentioned assumptions are shown in Figure 2 by open circles. The data

from the FM small-scale apparatus taken from Reference 4 are also included in

the figure by dark circles. A reasonable agreement between the two sets of

data can be noted, considering that: 1) heat losses in enclosure fires, even

at the steady state, are expected to be higher than in the FM small-scale

316
apparatus; and 2) mixing and entrainment processes are expected to be somewhat

different in the enclosure and in the small-scale apparatus.

The relationship between Pagni's normalized flame height (X_^) and ventilation parameter (4>) is shown in Figure 3, taken from Reference 5 . As cf> decreases Xf£ increases and thus "excess pyrolyzate" is expected to burn outside

the compartment and contribute to fire growth.

2.2.7 Suggested Extinguishment Parameter

The extinguishment parameter (Ex) is quantified by applying known amounts

of water from a nozzle, by reducing the total air flow entering the apparatus or by adding N£ or CO

2 into the inlet air. The generation rates of fuel vapors, heat

and various chemical compounds are determined in the presence and absence of the

extinguishment agents and Ex calculated from eq (10)

.

Table 5 lists some selected values of Ex determined experimentally for PMMA

fires with various water application rates at different external heat flux values

in our small-scale apparatus ' '

.

3. SUMMARY

Pertinent fire properties of materials for the prediction of fire growth

have been identified and techniques and apparatus for their quantification are described. The most suitable apparatus are the NBS Cone Calorimeter, the Ohio

State Heat Release Rate Apparatus and the FM Combustibility Apparatus. It is

suggested that for the quantification of fire properties in these apparatus ^hg

2) flame spread developed by Quintiere'^ ; 3). Induced air flow rate for corn- following concepts be considered: 1) "excess pyrolyzate" developed by Pagni

t , \ 3) induced air flow rate for

partment fires developed by Quintiere et al

' 1 ^ and examined further by

Stickler et al ^ 1 ^; and 4) ignition, combustion and product generation efficencies developed by Tewarson^ . It is also suggested that these apparatus

be considered for the quantification of corrosivity, toxicity and fire extinguishment parameters in a fashion which is useful for the prediction of hazard and

fire extinguishment for growing fires.

Acknowledgement

This work is supported by a grant No. NB83NADA4021 from the U.S. National

Bureau of Standards, Center for Fire Research, which is deeply appreciated.

317
REFERENCES

1. Tewarson, A, Ignition of Electric Wires And Cables (under preparation).

2. Quintiere, J., Fire And Materials 5, 52, 1981.

3. Tewarson, A., Khan, M.M. , and Steciak, J., "Combustibility of Electrical

Wire and Cable for Rail Rapid Transit Systems, Volume I. Flammability,"

Technical Report July 1982, Contract DTRS-57-80-C-00073 , Agency Code

DTS-852, Transportation Systems Center, Cambridge, MA.

4. Tewarson, A., and Steciak, J., Combustion And Flame (in press).

5. Babrauskas, V., "Development of the Cone Calorimeter - A Bench-Scale

Heat Release Rate Apparatus Based on Oxygen Consumption,"

National Bureau of Standards, Washington, D.C., Technical Report

NBS1R82-2611 , November 1982.

6. Smith, E.E., "Heat Release Rate of Building Materials" Ignition, Heat

Release and Noncombustibility of Materials, ASTM STP 502, American Society

for Testing and Materials, Philadelphia, PA, 1972, p. 119.

7. Tewarson, A., "Quantification of Fire Properties of Fuels and Interaction

With Fire Environment," U.S. National Bureau of Standards,

Washington, D.C., Technical Report FMRC J.I. 0E0N6.RC, April 1982.

8. Huggett, C., Fire And Materials , 4_, 61, 1980.

9. Tewarson, A., "Physico-Chemical And Combustion/Pyrolysis Properties of

Polymeric Materials," (paper in preparation).

10. Pagni, P.J. and Shih, T.M., 16th Symposium (International) On Combustion , The Combustion Institute, Pittsburgh, PA, 1976, p. 1329.

11. Pagni, P.J., Fire Safety Journal 3, 273, (1980/81).

12. Quintiere, J.G., McCaffrey, B.J., and Den Braven, K.,

17th Symposium (International) On Combustion , The Combustion Institute,

Pittsburgh, PA, 1978, p. 1125.

13. Stickler, K.S., Quintiere, J.G. and Rinkinen, W.J., 19th Symposium

(International) On Combustion , The Combustion Insitute,

Pittsburgh, PA, 1982, p. 913.

318
TABLE 1

HEAT OF COMBUSTION OF SOME SELECTED MATERIALS FOR VARIOUS

POOL SIZES FOR OVERVENTILATED CONDITIONS3

Pool Heat of Combustion

Material Apparatus

Area

(m2

) Actual

(kJ/g)

Convective Radiative

Rigid Poly- Large .7 16.4 10.8 5.6

urethane Small 0.008 15.8 6.5 9.3 Foam

Methanol Large 4.68 18.7 15.6 3.1

2.32 18.8 15.7 3.1

Small 0.008 19.4 17.1 2.3

PMMA Large 2.37 24.2 15.8 8.4

Intermediate 0.073 23.8 14.9 8.9

Small 0.008 24.4 17.9 6.5

Hydrocarbon Large 2.37 35.6 23.8 11.8

Transformer Small 0.008 38.2 25.1 13.1

Fluid

Heptane Large 0.93 41.2 26.8 14.4

Small 0.008 37.7 19.9 17.8

aTaken from Reference 7

TABLE 2

YIELDS OF MAJOR COMPOUNDS FOR SOME SELECTED

MATERIALS FOR OVERVENTILATED POOL FIRES 3

Pool

Material

Area

(m 2

) co

2 CO HCN "Smoke 1

Methanol 4.68? 1.29 <0.001 - - 2.32

b 1.30 <0.001 - -

0. 008

a 1.32 <0.001 - -

PMMA 2. 37 b 2.11 0.008 - - 0.073

d 2.10 0.010 - - 0.008d 2.15 0.011 - 0.022

Heptane 0. 93

b 3:83 8:8tf

- 0.008“

Rigid Polyurethane ' ?b

d 1.50 0.027 0.010 - Foam 0.008a 1.51 0.036 0.012

Polyvinylchloride 0.008d 0.40 0.057 - -

Polystyrene 0. 008d 2.2 0.071 — 1 0.15

Polypropylene 0. 008d 2.9 0.025 - 0.077

“Taken from References 7 and 9 “From large-scale combustibility apparatus

c From intermediate-scale combustibility apparatus

^From small-scale combustibility apparatus

319
Figure 1 Inverse of piloted ignition energy as a function

of external heat flux (taken from ref. 1)

x

• o'H

<0Q- O

O' •E

PMMA POOL FIRES

o 0 05Tr» 5 Endoture

Ref. (12 ) • FM Small-Scale Apparaiut Ref (4) o

° °o o °

o

o

o

o 10

ooi J I l Uni.

001 010 J I I 1 I I 1 J- J I I I 1

1

II

^H02^f ko2

10 100

Figure 2 Convective fraction of the combustion efficiency as a function of the ventilation parameter

320
TABLE 3

MASS ATTENUATION COEFFICIENT OF "SMOKE"

FOR OVERVENTILATED FIRESa

Material Mass Attenuation Coefficient

of "Smoke" (m2 /g)

Red Oak 0.113

Polymethylmethacrylate 0.161

Polypropylene 0.224

Polystyrene 0.730

aTaken from Reference 9

TABLE 4

CORROSIVITY PARAMETER FOR OVERVENTILATED FIRES

a

Micrometer of Corrosion

Material of Steel/g of Fuel Vapors

Polyvinylchloride polymer 3.0

Polyolefin cable 3.8

Ethylene propylene/polyolefin cable 1 .

6

Silicone/polyolefin cable 1.7.

Teflon cable 8.0

aUsing 100 m2, of distilled water; data taken from Reference 3

^Under nonflaming conditions

TABLE 5

EXTINGUISHMENT PARAMETER (Ex) FOR PMMA FIRES USING WATER SPRAYS

3

Extinguishment Parameter Calculated From

External Heat Water Application Fuel Actual Heat Generation

Flux (kW/nr) Rate (g/m2 s) Generation Release Rate Rate of CO

0 1 0.17^ 0.14

b 0.06

10 1 0.07 0.09 -

15 1 0.02 0.08 —

15

aData taken

2

from Reference 7

0.13

b

0.16

b

0.13

^Close to flame extinguishment

321
0.10 L0*

10.0

Figure 3 Pagni's normalized flame height as a function

ventilation parameter (taken from ref. 4)

322
Discussion After A. Tewarson's Report on IDENTIFICATION OF FIRE PROPERTIES

RELEVANT TO THE PREDICTION OF FIRE GROWTH

SAITO: You stated that the generation of smoke and gas depends on the

ventilation and infrastructure of materials, but I thinks that the heat flux also

will work as a factor. I may have missed that when you mentioned the heat flux,

but don't you think that will have something to do with it?

TEWARSON: In my presentation, in the first few slides I concentrated on generation of fuel vapors where I mentioned what parameters were important, and

flame heat flux was one of those.

SAITO: The generation rates of smoke and fuel vapors, of course, are related to

the ventilation for combustion rates. When we think about wooden material being

burned, and the fuel vapor and the gas being ventilated, the properties of gas

and fuel vapor will change in accordance with the pyrolysis and the charring of

the material, in this case, wood.

TEWARSON: Yes. It is also a function of time. For example, in enclosure

fires, if it is a hot layer which sits there for some time, depending on the

temperature of the hot layer, there may be an additional pyrolysis going on as a result of which, for example, the alcohol, the aldehydes that come out from wood

will go into carbon monoxide and one would see very high ratios of CO over

CO

2

. For example, in the enclosure fires which were done at NBS by Gross and

Robertson, they reached almost a veritable limit of .56.

MITLER: As Prof. Emmons has pointed out a number of times, the equations of

nature are independent of time. Therefore, you cannot have these properties as

a function of time directly; I'm sure you must mean indirectly as integrals of

certain properties.

TEWARSON: Yes, of course.

SAITO: My question is whether or not that property of a fuel gas and the smoke

will change in accordance with heat flux levels? I don't think that this

property can be expressed simply or directly with equations such as heat flux

times time.

TEWARSON: There are two things we have to keep in mind and, of course, there

will be complications. However, at least for simple fuels, we find that for

overventilated conditions for these properties are constant. But for

underventilated sets, they may change so one may have to do some kind of

approximations

.

GANN: It has been our experience that both the quantity or rate of product

generation and the nature of those products is extremely dependent on the rate

of energy input to the sample.

323

CONCEPTS ON FLAME SPREAD TESTING

Tos'nisuke Hirano

Engineering Research Institute

Faculty of Engineering

University of Tokyo

Bunkyo-ku, Tokyo 113

325
CONCEPTS ON FLAME SPREAD TESTING

Toshisuke Hirano

1. INTRODUCTION

The fire growing process depends on the flame spread over comhustible

material surfaces of floors, walls, ceilings, equipments, pieces of

furniture, etc., so that the limit or rate of flame spread over a certain

material is considered as a measure of hazard of that material at accidental fires. So far, several types of flame spread testing have been

proposed for the performance assessments of various materials under fire

conditions. All of these tests jre based on experimental evidences

and/or theoretical concepts [ 1-6] .

Recently, extensive studies on flame spread over solid combustibles

have been performed, and the controlling mechanisms of flame spread have

been made clear to a further extent [ T ]- At this time, it seems worthwhile

to reconsider flame spread testing on the basis of the present understanding of the controlling mechanisms of flame spread.

2. CONTROLLABLE FACTORS

2.1 Factors Affecting Flame Spread Phenomena

Since the purpose of a certain flame spread test is to evaluate

the performance of each material under fire conditions, the performance

of the material under various conditions, which are supposed to be

similar to those at real fires, should be inferred by using the results

of the flame spread test.

Obviously, the flame spread phenomena depend on the gasification, mass

diffusion, combustion reaction, heat transfer, and solid temperature rising

processes near the pyrolysis ( or evaporation) front and leading flame edge

(Fig. l). In some cases, the melting or charring process should be added

to these processes. Every factor that is related to the above processes

must affect the flame apread phenomena. Effects of such a factor on the

flame spread phenomena have been examined in many previous studies [7]*

Based on those studies, a set of the conditionds, under which a flame

spread test is to be performed, should be determined. A brief description

on the effects of each factor on the flame spread phenomena seems helpful

_

to consider flame spread testing.

^Numbers in brackets refer to the literature references listed at the end

of this paper.

2

For flame spread in gas flows opposing the direction of propagation, the

pyrolysis front is very close to the leading flame edge, while for flame

spread in gas flows in the same direction as that of propagation, the flame

leading edge preced-es the pyrolysis front. In the latter case, the spread

rate of the pyrolysis front is often adopted for discussion on the flame

spread mechanisms.

326
2.2 Effects of Each Controllable Factors

Flame Spread Direction

One of the most familiar factors which affect the flame spread

phenomena is the direction of flame spread. It is well known that the

flame spread phenomena depend strongly on the inclined angle of the

test piece and the direction of flame spread[ 8—lU ] . The upward flame

spread rate is usually of a few orders in magnitude larger than the

downward one. Also, in general, upward spread is accelerative, while

downward one is steaay[7]* Further, under real fire conditions, a flame spreads not only in the direction opposed to or concurrent with

that of the gas flow induced by the buoyancy, but also in the lateral

direction[6,15]

•

When a material is burning, a gas flow is induced due to the

buoyancy effect of the hot combustion products. The mass transfer

process obviously depends on this gas flow, and its change causes the

changes of other processes. The effects of the flame spread direction

on the flame spread phenomena are attributable to the fact that the

variation of the flame spread direction affects the gas flow near the

pyrolysis front, where main processes of flame Spread occur.

Test Piece Dimension and Configuration

The downward flame spread rate for thermally thin sheets of a solid combustible is known to be inversely proportional to the thickness,

while that for thermally thick sheets is independent of the thickness

[13,16]. A similar relation is valid for the flame spread along rods of

a solid combustible [ 10]

.

As mentioned previously the flame spread phenomena depend on the

temperature rising process of the unburned material ahead of the pyrolysis front to its gasification temperature. This process is closely

related to the heat transfer process to the unburned material. A part of

the heat to the unburned material is transferred through the solid phase.

The ratio of this part of the heat to the total heat to the unburned

material is negligible for the thermally thin sheets and increases with

the test piece thickness to a constant[7 ,l6] . Based on this discussion,

the dependence of the flame spread phenomena on the test piece dimension

can be interpreted [ 7]

•

The effect of the test piece width or configuration of the flame

spread phenomena is also expected to be significant in some cases [ 13,17 , because the heat transfer process can be easily supposed to depend or. these factors.

327
External Radiation and Test Piece Temperature

Under real fire conditions, a certain part of the solid combustible

in a room is generally exposed to the radiation from other burning parts

before the leading flame edge reaches there. Thus, many studies of the

external radiation effect on the flame spread phenomena have been

performed[ 10 ,lU ,17-22]

.

At an initial stage of a fire, the external radiation intensity is

low, and a quasi-steady assumption of the surface temperature may be

valid. Under such a condition, the flame spread rate increases with the

external radiation intensity. At a developed stage of a fire, on the

other hand, the external radiation intensity is usually so large that the

temperature of the exposed surface continues to increase until the leading

flame edge reaches there or it ignites [6]. In this case, therefore, no test

can be performed at a steady state.

The external radiation affects largely the heat transfer process.

The temperature of the material surface increases with the external

radiation intensity. This temperature rise reduces the difference of

the temperature far from the leading flame edge and that for the pyrolysis

reaction. Consequently, the flame spread rate increases [ 7 ] . This effect

of the temperature rising of the unburned soild surface is usually more

significant than that of the radiative heat flux to the surface in the

preheat zone just ahead of the pyrolysis front during flame spread.

Heat Sink

If there is a certain heat sink such as a backing or frame of

larger conductivity for a thin sheet of a solid combustible, the flame

spread rate over it is lower than that without such a heat sink[l3,23].

This effect is obviously due to the reduction of heat transferred to

the unburned material. At the same time, it has to be noted that if the

backing material enhances the heat transfer to the unburned material

ahead of the pyrolysis front, the flame spread rate becomes larger [13].

Ambient Gas Flow

A gas flow inside a chamber is easily induced by burning only a small

amount of combustible material. To simulate real fire conditions, therefore, an ambient gas flow of a finite velocity should be considered.

The effects of an ambient gas flow on flame spread phenomena have

been examined in previous studies in detail[7]. When the ambient gas

flow is opposed to the flame spread direction, its increasing reduces

the spread rate to extinction[ 18 ,22 ,2U-27 ] . On the other hand, when

it concurs with the flame spread direction, its increasing enlarges the

spread rate[l8,28].

328
Under real fire conditions, an ambient gas flow is likely to

fluctuate. The results of recent studies on the flame spread over a paper sheet in an air stream with a velocity change indicate that the

fluctuation of the ambient air flow affects significantly the flame

spread phenomena[ 29 ,30 ]

.

Obviously, the mass transfer process and other processes relating to

it near the pyrolysis front must vary with the ambient gas flow, and

its effects on the flame spread phenomena are attributable to the variation of these processes with the ambient gas flow[7].

Ambient Oxygen Concentration

In order to reveal the chemical kinetics of flame spread processes,

the informations of flame spread phenomena in the atmospheres of various

oxygen concentrations are very important. Also, fires in artificial airs

should be considered in particular cases. Thus, flame spread experiments

nave been performed by varying ambient oxygen concentration.

In general, the flame spread rate increases with oxygen concentration

[23,26,31]. The increase of the flame spread rate is mainly attributable

to the increase of the chemical reaction rate.

Ambient Pressure

In particular circumstances where there is a possibility of fire

occurrence, the ambient pressure is not always atmospheric pressure.

Also, on the pressure model experiments for simulating fires, the pressure is above atmospheric pressure. Furthermore, the flame spread

experiments under a reduced pressure give us important informations of

the flame spread mechanisms. Thus, many studies have been conducted of

the ambient pressure effects on flame spread phenomena[ 23 , 31-33].

As the oxygen pressure is increased, the flame spread rate increases and

its limits for other factors expand.

The thermal and mass diffusivities , pyrolysis and chemical reactions,

induced buoyant force, etc. depend on the pressure. The variation of the

flame spread phenomena with the ambient pressure is attributable to the

variations of these quantities with the ambient pressure.

Gravity furml

For a particular purpose, the flame spread experiments have been

conducted by varying the gravity f o»gc [ 31 ] Since the buoyancy

depends on the gravity fe^gc. , the flame spread phenomena, closely related

to the buoyancy , must be emphasized with the increase of the gravity

£-t^e-p

.

329
Test Facility and Procedure

If the size of a test chamber is sufficiently large, its effect may

be neglected. However, if it is small, the flow induced at the burning part

of a test piece in it may affect the flow field near the pyrolysis front

and the gas composition in it. Consequently, its size usually affects

the spread test results.

In some cases, the procedure of testing also affects significantly

the spread test results. For a material which is likely moisturized, the

period from the instant of picking the test piece up from a drying

chamber to that of igniting affects the results. Also, for flame spread

tests under external radiation, the initial stage of the pyrolysis reaction

starts at the exposed surface before the front of the main pyrolysis zone reaches there. This means that the surface characteristics changes with

time, sc that the period from the Instant of setting a test piece to that

of igniting affects the results. Other effects of the characteristics of

the Ignition system or ignition procedure on the flame spread phenomena

are likely to be significant in some particular cases.

2.3 Secondary Effects Caused by Changing Controllable Factors

When a controllable factor is changed, some other factors changes

consequently. Such changes of other factors are sometimes unexpected

and often neglected in the interpretation of the effect of the controllable factor on the flame spread.

The most significantly affected factor when almost every controllable

factor except for itself changes is the gas flow near the pyrolysis front.

A typical example of such a case is shown in Fig. 2. When the intensity

of external radiation to a thin sheet of paper is changed, the gas velocity

profile ahead of the leading edge of the flame spreading over it changes

consequently [ 22] . This change in the gas velocity profile causes the

heat flux profile in the preheat zone as shown in Fig. 3. Similar effects

of the gas flew change caused by changing other controllable factors

are expected.

The radiation from a spreading flame also changes when every

controllable factor is changed. If the flame size or flame temperature

increases by changing a controllable factor, the radiation from the flame

must increase. Since the flame size increases with the test piece

dimension, the intensity of flame radiation increases and the increase

of the flame spread rate with the test piece dimension is expected.

In particular cases, especially in the case under near-extinction

conditions, the flame spread phenomena depend strongly on the area of the

pyrolysis zone. A typical example of this effect is shown in Fig. U[30].

When the ambient air flow velocity u is instantaneously increased

330
from that u for stable flame spread to that u^ just above the stable

flame spread limit, delayed extinction is observed[29,30] . In Fig. U, the

dependence of the time T from the velocity change to extinction on u

is presented. It can be found that T depends not only on u^, but also

or; u^, i.e., the dependence of on u

qo1 cannot be neglected in this case.

It is usual that in the discussion on the flame spread limit, the

balance between the residence time and the chemical reaction time at the

leading flame edge is considered. This balance depends on the gas velocity, temperature, and species distributions near the leading flame edge,

which are supposed to be affected by the pyrolysis zone length.

There must be many unknown secondary effects caused by changing

controllable factors. To reveal those secondary effects, detailed

studies are needed.

3. A DESIRABLE FLAME SPREAD TEST

3.1 Characteristics to be Evaluated

Of the characteristics representing the performance of a certain

material under fire conditions, the limiting conditions of flame spread

and/or the flame spread rate under particular conditions are estimated

in the previously established flame spread tests [1-6].

In order to estimate the limiting value of a factor for flame

spread, only the factor concerned has to be changed by keeping other

controllable factors constant. If only the oxygen concentration is

changed, the limiting oxygen index can be obtained[l]. The limiting

radiation intensity for flame spread can be evaluated by changing the

radiation intensity [3, ^,6]

.

For estimating the flame spread rate under a certain set of

conditions, all controllable factors should be kept constant. It is

obvious that a large number of test runs are needed to reveal the dependence of the flame spread rate on only one factor. Thus, it is practically

impossible to examine the flame spread rate under every imaginable set of

conditions by means of only a certain flame spread test.

3.2 Requirements for a Flame Spread Test

Once a test method of flame spread is established, many data for

various materials have to be obtained by using it. Therefore, the most

important reqirement for a test method of flame spread is the feasibility

to repeat tests.

Based on the test results, the performance of a material should be

331
distinguished from that of any one of other materials. Thus, the

reproducibility of the test results is required.

Furthermore, by using the test results obtained under a certain

conditions, the behavior of the tested material under another set of

conditions is desired to be predicted. This means that the test results

must be of generality.

A flame spread test should be at least of these three characteristics,

i.e., feasibility, reproducibility, and generality.

3.3 Possibility to Satisfy the Requirements

By p^ovidi^g an appropriate test facility and test conditions,

desirable "^ac‘ili^y and reproducibility can be satisfied. However,

it is not so easy to realize the generality of test results. Upward

flame spread phenomena seem difficult to be predicted by using only the

results of downward flame spread tests. Flame spread phenomena in an oxygen enriched atmosphere cannot be predicted by using only the results

of flame spread tests.

In order to predict the performance of a material under conditions

different from those at the tests, the characteristics of the material

such as its thermal and chemical properties and the knowledge mentioned

in the section 2 are needed in addition to the test results. In such a case, the purpose of the flame spread test seems to be only to provide

a reference for the prediction.

In some cases for evaluating the performance of a material under

fire conditions, its thermal and chemical properties or the flame spread

mechanisms might be more important than the results of the flame spread

tests

.

However, the above discussion has not been presented to deny the necessity of flame spread testing. At present, flame spread testing is the

most convenient means to evaluate the performance of a material under

fire conditions. Furthermore, even if a reliable prediction method

would be established, a certain flame spread test should be done for the

confirmation of the predicted results.

A flame spread test of a feasible procedure to obtain reproducible

and general results is desirable. Such a flame spread test will be

established on the basis of better understanding of the controlling

mechanisms of flame spread. Once a complete spread test is established,

flame spread over a material under every imaginable set of conditions

will be predicuable by using its results and the thermal and chemical

properties of the material.

332
k . CONCLUDING REMARKS

Flame spread testing for evaluating the performance of a material

under fire conditions is reconsidered on the basis of the present

understanding of the controlling mechanisms of flame spread.

Brief description on the effects of controllable factors on the

flame spread phenomena is presented. The effects of even the test

facility and procedure cannot be neglected in some cases. The discussion

on secondary effects caused by changing controllable factors are also

performed. The secondary effects are sometimes unexpected and often

neglected in the interpretation of the effects of the controllable

factor concerned on the flame spread phenomena.

A desirable flame spread test should be at least of a feasible procedure to obtain reproducible and general results. By providing an appropriate

test facility and test conditions, desirable feasibility and reproducibility

can be satisfied, while it is not so easy to realize the generality

of the test results. In particular cases, for evaluating the performance of a material under fire conditions, the thermal and chemical

properties of the material or the flame spread mechanisms might be

more important than the results of the flame spread tests . What

the flame spread test can provide in such cases is a reference for the

prediction of flame spread phenomena.

At present, however, flame spread testing is the most convenient

means to evaluate the performance of a material under fire conditions.

It is desirable that flame spread over a material under every imaginable

set of conditions is predictable by using the results of a flame spread

test and the material properties. Such a flame spread test will be

established on the basis of better understanding of the controlling

mechanisms of flame spread.

333
REFERENCES

1. Fenimore , C. P. and Martin, F. J .

, "Flammability of Polymers,"

Combustion and Flame, 10_, 135-139(1966).

2. Fristrom, R. M. , Grunfelaer, C., and Hunter. L. W. ."Exploratory

Studies in Polymer Ablation, Ignition and Extinction by the Moving

Wire Technique," Combustion and Flame, 27_, 33-*+9(l976)

.

3. Rockett, J. A. /'Mathematical Modeling of Radiant Panel Test Methods,"

in Fire Safety Research, National Bureau of Standards, NBS SP *+11,

Nov. (197*0 .

Quintiere, J. G. ,"The Application and Interpretation of a Test Method

to Determine the Hazard of Floor Covering Fire Spread in Building

Corridors," in Fire Safety of Combustible Materials, University of

Edinburgh , Edinburgh (1975).

5. Mikado, T. and Akita, K. ," Evaluation of Flammability of Polymers for

Electric Cable," J. Fire & Flammability, 12, 1*43-156(1981).

6. Quintiere, J. G. ,"A Simplified Theory for Generalizing Results from

a Radiant Panel Rate of Flame Spread Appratus," Fire and Materials,

5. } 52-60 ( 1981 ).

7- Fernandez-Pello , A. C. and Hirano, T. /'Controlling Mechanisms of

Fire Spread," Fire Science and Technology, 2_, 17-5*+ ( 1982 ): Combustion

Science and Technology, 32, (in press )( 1983)

•

8. Markstein, G. H. and de Ris, J. N. /'Upward Fire Spread over Textiles,"

l*+th Symposium(lnt . ) on Combustion, The Combustion Institute,

Pittsburgh, Pa., 1085-1097(1973).

9. Sibulkin, M. , Hetelhut , W. , and Feldman, S. /'Effect of Orientation

end External Flow Velocity on Flame Spreading over Thermally Thin

Paper Strips," Combustion Science and Technology, £, 75-77(197*+).

20. Sibulkin, M. , Lee, C. K. /'Flame Propagation Measurements and Energy

Feedback Analysis for Burning Cylinders," Combustion Science and

Technology, £, 137-l*+7(l97*+)

.

21. Hirano, T. , Noreikis, S. E. , and Waterman, T. E . /'Postulations of

Flame Spread Mechanisms," Combustion and Flame 2£, 353-363(197*+).

12. Hirano, T., Noreikis, S. E. , and Waterman, T. E. /'Measured Velocity

and Temperature Profiles of Flames Spreading over a Thin Combustible

Solid," Combustion and Flame, 03, 83-96(197*+).

13. Fernandez-Pello, A. C. and Williams, F. A.

, "Laminar Flame Spread over PMMA Surfaces," 15th Symposium( Int . ) on Combustion, The Combustion

Institute, Pittsburgh, Pa., 217-231(1975).

334
14. Kashiwagi , T. and Newman, D. L. , "Flame Spread over an Inclined Thin

Fuel Surface," Combustion and Flame, 2 6_, 163-177 ( 1976 )

.

15. Quint iere, J. G. , Harkleroad, M. , and Walter, W. /’Measurement of

Material Flame Spread Properties," National Bureau of Standards,

NBS IR 82-2557, August ( 1982 )

.

16. Hirano, T. , Koshida, T. , and Akita, K.

, "Flame Spread Mechanisms over PMMA Surfaces, Bull. Japanese Association of Fire Science and

Engineering, 2£, 33-39(1977)-

17- Mikado, T. and Akita, K. /’Burning Characteristics of Grouped PVC

Cables," J. Fire & Flammability, 13, 24-32(1982).

18. Hirano, T. and Sato, K. /’Effects of Radiation and Convection on Gas Velocity and Temperature Profiles of Flames Spreading over Paper," 15th Symposium( Int . ) on Combustion, The Combustion Institute,

Pittsburgh, Pa., 233-2^1(1975 )

•

19 Kashiwagi, T./’A Study of Flame Spread over Porous Material under

External Radiation Fluxes," 15th- Symposium/ Int . ) on Combustion, The

Combustion Institute, Pittsburgh, Pa., 255-265(1975).

20. Fernandez-Pello, A. C. /’Downward Flame Spread under the Influence of

Externally Applied Thermal Radiation," Combustion Science and

Technology, 17, 1-9(1977).

21. Fernandez-Pello, A. C. /’Upward Laminar Flame Spread under the

Influence of Externally Applied Thermal Radiation," Combustion

Science and Technology, 17_, 87-98(1977).

22. Hirano, T. , and Tazawa, K.,"A Further Study on Effects of External

Radiation on Flame Spread over Paper/’ Combustion and Flame, 32_, 95-

105(1978).

23. Frey, A. E. and T’ien, J. S .

, "Near-Limit Flame Spread over Paper

Samples, Combustion and Flame, 26_, 257-267(1976).

24. Hirano, T., Sato, K. , and Tazawa, K. /’Instability of Downward Flame

Spread over Paper in an Air Stream," Combustion and Flame, 26, 191-

220 ( 1976 ).

25. Tazawa, K. and Hirano, T.

, "Upward Flame Spread over Paper in an Air

Stream," Bull. Japanese Association of Fire Science and Engineering,

27, 9-16(1977).

26. Fernandez-Pello, A. C., Ray, S. R. , and Glassman, I . /’Downward Flame

Spread in an Opposed Forced Flow," Combustion Science and Technology,

19, 19-30(1978).

335
27- Fernandez-Pello , A. C. , Ray, S. R. , and Glassman, I., "Flame Spread

in an Opposed Flow: The Effect of Ambient Oxygen Concentration,"

l8th Symposium (int . ) on Combustion, The Combution Institute,

Pittsburgh, Pa., 579-589(1981).

28. Fernandez-Pello, A. C., "Flame Spread in an Forward Forced Flow,"

Combustion and Flame, 36, 63-78(1979).

29. Hirano, T. , Sato, K. , and Minami , H. , "Response of Flame Spread Phenomena

to Ambient Air Stream Velocity Changes," Proceedings of the 6th Joint

Panel Meeting UJNR Panel on Fire Research & Safety, 597-615(1982).

30. Sato, K. , Miki, K. , and Hirano, T. ," Flame Spread over Paper in an Air Stream with a Velocity Change," in Fire Dynamics and Heat Transfer,

ASME HTD-Vol. 25, 9-15(1983).

31. Altenkirch, R. A., Eichorn, R., and Shang, P. C., "Buoyancy Effects

on Flames Spreading Down Thermally Thin Fuels," Combustion and Flame,

37, 71-83(1980).

32. Alpert, R. L. /'Pressure Modeling of Upward Fire Spread," Factory Mutual

Research Corporation Report No. OAOR8.BU(l979)

.

33. Alpert, R. L. ,"The Role of Radiation in Pressure Modeling of Upward

Fire Spread," ASME-AIChE National Heat Transfer Conference, San Diego,

CA., ASME publication No. 79-MT-28(l979)

.

336
CombllSti On rpart i nnl ft

Figure 1. Schematic representation of the processes of flame spread over the surface of a solid combustible, a: opposed gas flow;

b: concurrent gas flow.

337
‘z/g-*

( 3dvms y^dvd wodd honvisiq

:

distance

from

s

=

0.026

cm;

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V t ft1

338
339

Figure

3*

Net

heat

flux

profiles

to

the

unhurried

solid

in

the

prehea.t

zone.
340

Figure

b.

Dependence

of

the

time

T

from

the

ambient

air

velocity

change

to

extinction

on

the

ambient

air

velocity

before

its

change,

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:

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:

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6

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cm).
A METHODOLOGY OF THE SENSITIVITY ANALYSIS OF

BUILDING PROPERTIES ON THE OCCURRENCE OF FLASHOVER

Yuji Hasemi

Research Member,

Guest Worker,

National

Building Research Institute

Center for Fire Research

Bureau of Standards

341
1 INTRODUCTION

Elucidation of the correlation between physical properties of buildings,

furniture, etc. , and fire hazard is obviously counted among the most important

objectives of the research of "fire properties". A sensitivity analysis of

the properties on the occurrence of so-called flashover should be one of its

central problems, since flashover is generally regarded as the transient

process which has the most significance on fire safety in buildings.

As the prediction of fire phenomena is essential for a quantitative

evaluation of fire safety, mathematical models of building fires are thought

to be useful tools for the research of fire properties; however, it seems that

methodologies of the practical application of the mathematical fire models to

fire safety evaluation have not been discussed sufficiently in spite of the

considerable improvement of the physics and convenience of the models. Some

concepts representing fire hazards or characteristic fire phenomena including

flashover are still very "descriptive" or ambiguous, and it seems that they

are not useful as measures for engineering fire safety design; one important

thing in developing methodologies of quantitative evaluation of fire safety

using mathematical fire models is a mathematical characterization of these

concepts.

Recent studies on the global behavior of enclosure fires have correlated

one of the mechanisms of flashover with the instability of the solution of a

mathematical model of fire [1,2]. Characterizing flashover as the thermally

unstable realm in a fire, concepts representing the fire safety of flashover

will be formulated by using the stability of the basic equations describing

342
the fire growth. The stability of a system of ordinary differential equations

can be investigated according to the sign of each eigenvalue of its functional

matrix; however, it may not be easy to investigate the nature of the functional matrix of the functions forming a zone model because the structure of zone

models is becoming complicated more and more through the improvement of their

physics. While the Ljapunov function has been conventionally applied to

evaluate the stability of a system of ordinary differential equations whose

analytical treatments such as the calculation of derivatives are difficult, it

seems to be still difficult to find a Ljapunov function generally applicable

to zone models of fire.

The critical condition for flashover to appear is represented in the

stability theories by the singularity of the Jacobian of the basic equations

of a zone model; the condition should be equivalent with the extremum of the

curvature representing the equilibrium state of a zone model [2]. The

extremum of the equilibrium curvature of a model described as

V. • dT./dt = H.Oj, T

2

, ..., T

n

), i = 1, 2, n (1)

can be obtained by calculating the maximum or the minimum of one parameter

under H^(T^, T

2

, •••, T

R

) = 0 as the constraint condition. Since a lot of

practical techniques including numerical methods which work without calculation of derivatives of the objective function have been developed to solve

such optimization problems, the extremum is thought to be a more practical

idea than the singularity as the description of the critical condition.

343
The analysis of the author's previous report [2] has also shown that the

temperature of each zone at the extremum of the equilibrium curvature can be a

measure of the thermal state at the onset of flashover. Consequently, optimization techniques will be useful tools for quantitative fire safety design if

we only discuss the critical conditions on the occurrence of flashover and its

onset.

A procedure to solve an optimization problem with constraint conditions

is generally divided into two stages, the transform of the problem to an

optimization problem without constraint conditions and its solution; the

important thing in applying optimization techniques to the evaluation of

flashover using zone models is to adopt a way which does not need a calculation of differentials at each stage. In this paper, we will discuss the

problems arising from the application of optimization techniques to the

present problem and show a few examples of sensitivity analysis of the

building properties on the appearance of flashover. As the mathematical fire

modeling is still being developed, the focus of the paper is not to show a

practical list of fire properties, but to derive a methodology to get it using

zone models.

2. NONLINEAR CHARACTERISTICS OF ENCLOSURE FIRES

The methodology described in the introduction assumes the existence of an

extremum in the equilibrium solution of a zone model; recent theoretical and

experimental works on enclosure fires have shown some nonlinear characteristics of enclosure fires which suggest the existence of multiple equilibria of

burning behavior, namely the existence of the extremum (Figure 1) [1-5]. The

344
existence of multiple equilibria was first predicted theoretically by Thomas

who analyzed fire growth using the Arrhenius law of reaction rate [3].

Quintiere et al have shown the existence of multiple equilibria on a quasisteady zone model which assumes the proportionality of fuel volatilization

rate to the heat flux applied to the fuel surface [4]

.

On the basis of this

Thomas et al have shown how the radiation feedback would lead to the appearance of thermal instability and correlated this mechanism with flashover

[1]. Takeda et al [5] have shown experimentally a discontinuity in the rela

tionship between the fuel volatilization rate and opening factor, which was

expected from the stability theory of flashover [1,2]. This chapter will

describe some nonlinear characteristics of the experimental enclosure fires

which are related to the basic assumptions of the present study .

2.1 Description of Experiments

Experiments were conducted using a 0.40 m cubic enclosure of calcium

silicate with methanol in square trays (0.10, 0.15 and 0.20 m) as the fuel

(Figure 2). The fuel was supplied to the tray so that the height of fuel

surface could be maintained. The set-up is almost similar with Takeda et al

[5], except for the opening which was designed such that its width could be

easily changed during an experiment. Measurements were made on temperature,

velocity at the opening and fuel consumption rate. Total heat flux to the

fuel surface was measured on 0.15 m tray.

See reference [6] for more detail.

345
2.2 Experimental Results

Figure 3 shows the relationship between opening factor and fuel

consumption rate at the steady state. The fuel consumption rate of each tray

appears to change dramatically at one value of opening factor. The flame

behavior is also quite different across the discontinuity; for opening factors

less than the criticality, the flame formed above the tray has reached the

ceiling and flowed out of the opening, whereas it has remained just above the

tray for the opening factors greater than the criticality. The discontinuity

in the fuel consumption rate is, thus, thought to correspond with the boundary

between the ventilation-controlled and fuel-controlled regimes.

Figure 4 through Figure 6 show the time histories of ceiling temperature

measured at 0.10 m apart from the center of the trays, and it is clearly seen

in Figure 4 and Figure 6 that a rapid temperature rise which is attributed to

so-called flashover is particularly seen for such opening conditions as

leading to a ventilation-controlled fire. Although the difference among the

time-temperature curves is not so significant for 0.15 m tray, it is quite

obvious in the time history of the total heat flux to the fuel surface

(Figure 7). The above results demonstrate that the discontinuity seen in

Figure 3 should correspond with the critical condition for flashover to

appear. Figure 8 shows examples of hysteresis in the relationship between

fuel consumption rate and opening factor, which were obtained by changing the

opening width slowly in the direction shown with arrows. Although Figure 8

does not appear to reproduce the curves in Figure 3 partly due to the enforcement of the enclosure for significantly longer experiments, the existence of

hysteresis implies the existence of two extremum conditions in the equilibrium

346
state, one of which should correspond with the critical condition for flashover to appear.

3. NUMERICAL CALCULATION METHOD OF THE STABILITY LIMIT

OF THE EQUILIBRIUM SOLUTION OF ZONE MODELS

The extremum of a function, f(x) , under the constraint conditions

g^(x) = 0, i = 1, 2, ...,n can be obtained without calculating its partial

derivatives by a successive search of the optimum of the augmented Lagrange

* function of f(x). The augmented Lagrange function of f(x), L(x)

,

is defined

as

* m m o L(x) = f ( x) - l p.g.(x) + k l g . ( x)

,

k > 0 (2)

i=l i=l

where p.^ is the Lagrange multiplier of x

i and the third term of the RHS is the

* penalty for the break of the constraint conditions. The optimum of L(x) can

* be obtained by iterating temporary optimization of L(x) under assumed value of

*

p i (i = 1, 2, n) until L(x) becomes considerably stable. The advantages

of the augmented Lagrange function method are the fast convergence due to the

existence of penalty and that the sensitivity of a break of each constraint

condition on calculation results can be evaluated by the value of the responsible Lagrange multiplier.

The purpose of this chapter is to discuss practical problems in applying

the above method to the estimation of flashover criteria from a zone model ot

fires. The discussions will be made by comparing the extremum of the equilibrium curve of a simple zone model calculated by the above method and its

analytical stability limit. The model used for the analysis is described .c.

[ 2 ]

347
( 3 )

Vj • -jj

1 - HjfTj, T

2

) = (1-e) o(t

2 - Tj) + eo(l\ - T*)

+ an^T

£ “ T J

+ exp ( a “ E/RT

i) + Q

0 i + Q

x

( 4 )

The heat transfer between each zone and the ambience, Qqj or Qq 2> is

described as Q . = a (t - T.), i = 1 , 2 at the steady state. Assuming

The combination of Q| and Q2 at the criticality can be obtained

analytically by substituting the combination of T^ and T£ which satisfies

equation ( 5 ) into H^(Tp T^ ) = H^(t^, T2) = 0 [ 2 ]. The criticality in terms

of Q| and Q2 can also be calculated by an optimization to search the maximum

of either of Q| and Q2 under a given value of the other of Qj and Q2 and

Hj(t^, T2) = t^T^, T2) = 0 as a constraint condition. Applying the augmented

Lagrange function method to calculate the critical condition in terms of Qj

,

the augmented Lagrange function will be

T. = T , the stability limit of the equilibrium of the model is described as

X I

L*(T rT

2

) = -Q

1 " (p

1 H1 + p

2 H2

) + k(H^ + H^) ( 6 )

348
3.1 Critical Conditions on the Occurrence of Flashover

While it is generally believed that the precision of an optimization

using penalty terms would be improved by increasing the value of penalty

coefficient, k, it is also anticipated that, if k is considerably large, the

direction of the search might be strongly governed by a penalty term of the

augmented Lagrange function so that the "real" optimum might never be

approached. Here, we will discuss the determination of k by applying the

augmented Lagrange function method to the model described by (3) and (4) under

the parameter conditions shown in Table 1.

Figure 9 shows the critical condition of the heat flux to the zone 1

,

calculated for various values of Q2 and k = 100. Some numerical results are

considerably far from the analytical stability limit, and Figure 9(b)

obviously demonstrates that a numerical criticality is significantly influenced by the initial setting of temperatures. Most of the numerical results

concentrate on the curve ^(t^, T

2

) = 0, and this implies that the augmented

Lagrange function would be strongly governed by the constraint condition

^(Tj, T

2

) = 0. Distribution of the augmented Lagrange function with the

resulting values of the Lagrange multipliers shown in Figure 10 demonstrates

that the curve representing ^(t^, ) = 0 forms a significant "watershed" on

the distribution of the objective functions. In such a case, a search in an

axial direction from the apparent optimum, A, will give a larger value of L*

than that at the point A; the point A would be taken for the "real" optimum.

349
Figure 11 shows the criticalities calculated for k = 0.01 in terms of

heat flux, , Q2 and temperature, respectively. The numerical results seem

to be in good agreement with the analytical stability limit; however for a

still smaller value of the penalty coefficient, i.e. , k = 0.0001, L* appears

to be governed almost only by during the first iteration cycle, and this

has resulted in a slower convergence of the objective function.

While the precision of a numerical calculation on such simple models as

the above example can be checked by comparing its results with those obtained

analytically, this way of investigation is not applicable to complicated

models. Considering that the error in the above example is attributed to the

sensitivity of a constraint condition on the value of the augmented Lagrange

function, we can assume that the value of each Lagrange multiplier could be a

measure to evaluate the precision. The value of each Lagrange multiplier is

obtained as a by-product of the iterative calculation of the optimum of L*.

Table 2 summarizes the resultant Lagrange multipliers, X^ and X^, of the above

study for k = 100, 0.01 and 0.0001. The absolute value of X^ is far superior

to Xj for k = 100, whereas X^ and X^ are comparable for small values of k.

This implies that the value of L* would be strongly governed by ^(t^, T

2

) if

k is considerably large because the order of the possible values of

Hj(t^, T

2

), ^(Tj, T

2

), Qj and Q 2 should be comparable in the early stages of

a compartment fire. The above calculation also suggests that the value of the

penalty coefficient should be chosen such that the constraint conditions would

not govern L* strongly after a hyperplane practically satisfying one

constraint condition has been approached. In other words, if 0(f) > o(p^g^)

is satisfied for the resultant value of p^, the calculated optimum of L* is

thought not to be far from its real optimum; this seems to offer a useful

350
guide to check the precision of the numerical results. As the order

of |Q | should be comparable with ) | , the condition for a

calculation result to be adequate is that jp^| is not far from 1.

3.2 Estimation of the Thermal State at the Transition of Fire to Flashover

Characterizing the so-called flashover by the instability of the energy

conservation equations describing fire growth, the onset of flashover can be

formulated as the singularity of the Jacobian of the functions forming the

energy conservation equations; we will refer to the temperature of each zone

at the singularity as the "critical temperature" [2]. The critical temperature of combustible zone, T

c

, is supposed to have its upper and lower bounds;

the upper bound corresponds to the asymptote of T

c to T. + T

q or T. •> 0,

T^ 4 T

c

. The lower bound, on the other hand, should be the asymptote to

T^ + 00

, T^ ^ T . Practically, the upper bound of T

c can be obtained from the

equilibrium solution of a zone model by substituting T- = T

Q or T. = 0,

T^ ^ T

c into the model and optimizing a parameter appearing as a constant term

in the basic equations. The lower bound can be estimated by the similar

optimization assuming a considerably large constant heat supply to each zone

except for the combustible zone. Figure 12 shows that the critical temperature of the zone 1 of the model described by (3) and (4) approaches to its

analytical lower bound by the increase of the heat supply to the zone 2.

As the temperature of any zone in the fire room will never be lower than

ambient temperature, the asymptote of T

c to T^ -> TQ is thought to give the

actual upper bound of the critical temperature. The asymptote of T

c to

T^ -> 0, a more strict condition, may offer an easier calculation.

351
4. APPLICATION TO A QUASI-STEADY MODEL

In order to demonstrate that some evaluations concerning flashover can be

made practically using a zone model, we will apply the methodology described

in the former chapter to the quasi-steady model of Quintiere et al [4]

.

Although Takeda et al [5] have pointed out some problems to be refined in the

model, we will use it for convenience because the detailed description of its

program has been published. It should be noted in advance that the methodology described in the former chapter is basically applicable to any zone

model described in a system of ordinary differential equations.

The enclosure for the study is a 40 cm cubic room with pool fire as the

fire source. Model formulation and the data of the standard condition of the

enclosure are described in Table 3 and in Table 4, respectively. Assuming the

proportionality of fuel volatilization rate to the heat flux to the fuel

surface as well as the dependence of reaction rate on the oxygen supply condition of the enclosure, it is possible that the model has an instability due to

the radiation feedback from smoke layer, ceiling, etc. to the fuel surface.

This implies that multiple equilibria may appear for some parametric conditions.

4.1 Estimation of the Flashover Criteria

While the critical condition for the occurrence of flashover can be

obtained in terms of every parameter appearing in a model, practical measures

for fire safety design should be the critical conditions in terms of such

specifications as size or combustibility of furniture or building components.

352
Let the conditions in Table 4 be the standard conditions, we will investigate

the influences of combustion heat of combustible objects and heat transfer

coefficient of walls on the relationship between the volatilizing area and

opening width at the criticality. The augmented Lagrange function for this

problem is

n n

L* = f " l P, * g, + k I g, (7)

i=l i=l

where f is the parameter to be optimized, g^ is the LHS of the i-th constraint

condition, namely one of the energy balance equations and the mass balance

equations in Table 3. k = 0.01 has resulted in A, » 0(10 *) ~ 0(10°) in all

cases studied here.

Figure 13 depicts the and W

Q relationship for three conditions of

combustion heat, one of which was chosen to represent methanol; the result

obviously shows that the sensitivity of combustion heat on the stability limit

is significant and that combustion can be an index to evaluate fire safety

concerning flashover. The results of similar calculations on different values

of heat transfer coefficients of the surrounding walls (Figure 14) show that

the sensitivity of the heat transfer coefficient on the criticalilty is

considerably less significant. Considering that it should be difficult to

control the heat transfer coefficient of walls without influencing the daily

conditions of room environment, a control of fire growth through thermal

properties of wall should not be productive.

353
4.2 The Upper Bound of the Critical Temperature of Smoke Layer

Radiation feedback from the ceiling, smoke layer, etc., to fuel surface

is one of the most important mechanisms leading to the appearance of thermal

instability in the present model. Temperature of the ceiling or smoke layer

seems to represent an onset of the occurrence of flashover. Figure 15 shows

the upper bound of the critical temperature of the smoke layer which was

calculated by substituting the ambient temperature into the ceiling temperature appearing in the quasi-steady model. The steady-state smoke layer

temperature is higher than the upper bound of the critical temperature for

every opening condition; this implies that a rapid temperature rise of smoke

layer which should be attributed to flashover would appear before a steadystate fire is approached.

5. CONCLUSIONS

Correlation between the nonlinear characteristics of enclosure fires and

the critical condition of the appearance of one mechanism of flashover was

clarified experimentally. It was also shown that the criteria can be calculated directly from an equilibrium state zone model of enclosure fire by using

the augmented Lagrange function method. CPU time to obtain one critical

condition was approximately twice the time to calculate one steady state

solution.

354
6 . ACKNOWLEDGMENTS

The author is grateful to the contribution of Mr. T. Tokunaga, formerly

of the Science University of Tokyo, who collaborated on the experiments

described in chapter 2.

355
References

[1] Thomas, P.H., Bullen,M.L., Quintiere,J .G. and McCaffrey, B. J. ,"Flashover and

Instabilities in Fire Behavior", Combustion and Flame, 38, p. 159(1980).

[2] Hasemi ,Y. /'Mathematical Basis for Physical Evaluation on Flashover", BRI

Research Paper, No. 88(1981).

[3] Thomas, P.H. /'Some Problem Aspects of Fully Developed Room Fires", ASTM-NBS

Symposium on Fire Standards and Safety, NBS, Washington, D.C. (1976)

.

[4] Quintiere,J.G. , McCaffrey, B. J . and DenBraven,K. /'Experimental and Theoretical

Analysis of Quasi-steady Small Scale Enclosure Fires", NBSIR 78-1511(1978).

[5] Takeda,H. and Akita ,K.

, "Critical Phenomenon in Compartment Fires with Liquid

Fuels", 18th Symposium(International ) on Combustion, University of Waterloo

(1980).

[6] Hasemi ,Y. /'Theoretical and Experimental Study of Flashover", CSNI Specialist

Meeting on Interaction of Fire and Explosion with Ventilation Systems in

Nuclear Facilities, Los Alamos(l 983)

.

For numerical optimization methods, see

[7] Jacoby, S.L.S. et al /'Iterative Methods for Nonlinear Optimization Problems",

Prentice-Hal 1 (1972)

.

[8] Powell, M.J.D. ed. ,"Nonl inear Optimization 1981", Academic Press(1982).

356
Terminology! Except for those defined in Table 3 and Table 4)

A/H : Opening Factor(E(Opening Factor )X/Height of Opening)

Cp : Specific Heat of the Mixture of Combustion Products and Air

E : Activation Energy

Q.j

: Heat Generation or Heat Application to the Zone "i"

R : Gas Constant

T : Absolute Temperature

V

i

: Heat Capacity of the Zone "i"

X

d

: Height of Smoke Layer

t : Time

c : Absorption Coefficient

a : Stefan-Bol tzman Constant

A : Augmented Lagrange Function

\p. . : Shape Factor to see "j" from "i"

1 J

357
table 1 Input of the Parameters for the Case Study

E/R 10 4 K 20 kcal/m2 hK

e 0 Q-ia 20 kcal/m 2 hK

a 4 . 88xl0 8 kcal/m2 hK 01 0 1 2 kcal/m 2 hK

To j Ta

300 K a 0 2 2 kcal/m 2 hK

Table 2 Relationship between the Penalty Coefficient and the Resultant

Values of Lagrange Multipliers

"k" Lagrange Multiplier for

Hi(T 1} T 2 )=0

Lagrange Multiplier for

H 2 (Ti,T 2 )=0

100 -0.781 62.5

0.01 -0.991 0.744

0.0001 -0.999 0.758

358
Table 3 Outline of the Quasi -steady zone model (Based on [4])

(a) Volatilization Rate of Fuel Gas, m^

ih = q A /{C« 7 (T -T ) +AH } v s v fuel K s a

J v

(b) Burning Rate,

m, = m , m /m > r* b v a v m /r*, m /m < r*

a a v

(c) Energy Balance of Each Zone

7 K. .A. .(T.-T.)+ l e.e .(1-e. 0^ • -A. .(T

1t-Tll)+ V m..C (T . T'J 13 3 I ud ud d u ajj; ^U 3^ ^3 'f'S 13 3 ^ aua ^3 P 3

^ ^ ^«7 ^

3

= 0 , i=l J 2J .. J n

(d) Flame Height, HL

tij, = 16.5

S /(r

* + Pa/P

y)^

—5— - r nu, co = l+AH/r*C T

p^g(l-co) b a g a

(e) Air Flow Rate through Opening, m (inflow), m (outflow)

2 a

xd

K

= 3“Wop/2gCl-VT?

) (Vxdi- (Vj£)

= (^)un {(6Xd+U^-l}, gs|{l-u)/5ir2 gp

2kyi2ih ua

\ = |aW0P

a/2gCTa

/T

?

) Cl-Ta

/T

?

) CHe

-X„)

3

(f) Height of Neutral Zone, X

H AP n

Y = 2. n p (1-T /T )g a a g

b

(g) Mass Balance of the Enclosure

m +m -m =0 a v g

-T.)+Q

l' A

359
Table 4 Input of Parameters for the Case Study

Theoretical air to fuel mass rate, r* 6.45

Combustion heat, AH 2.23xl0

7 J/kg

Heat of Volatilization, AHy l.lxlO6 J/kg

Temperature of fuel volatilization, T

o 340 K

Density of fuel gas, Py

1.9 kg/m3

Specific heat of fuel, Cj?ue i

2.52 J/kgK

Temperature of diffusion flame. 1400 K

Absorption coefficient of flame. 1 7 -1 1.3m

Heat transfer coefficient at fuel surface. 2.5 W/m2 K

Absorption coefficient of smoke layer, 1 . 9 m

1

Thermal conductivity of wall. 0.14 W/mK

Heat transfer coefficient at floor, 10 W/m2 K

Heat transfer coefficient through ceiling. 5 W/m2 K

Orifice coefficient of opening, a 0.7

Specific heat of air, 1046 J/kgK

Temperature of ambient air. 300 K

Density of ambient air, Pa

1.18 kg/m

3

360
Figure 1 Nonlinear Characteristics

of Enclosure Fire

o

+-> Q_

•r-S_0

co

<D Q

01

Arbitorary Building Property

Stable Equil ibrium

(Ventilation C.ontroled)

.^-Unstable Equi1 ibrium( Fuel

Controled)

Stable

Equi 1 i brium( Fuel ControTe?

Figure 3 Relationship between

Opening Factor and Fuel Consumption

Rate( 0.4m cubic enclosure)

(Sol idrventilation controled,

0pen:fuel controled)

361
Figure 4 Time History of

Ceiling Temperature

(0.10x0. 10m Tray)

Figure 5 Time History of

Ceiling Temperature

(0.15x0. 15m Tray)

Figure 6 Time History of

1000

Ceiling Temperature o'

(0.20x0. 20m Tray)

Temperaturei

cn oo

0

0 30 40

362

10 20

Time (min)
Figure 7 Time History of Total

Heat Flux to Fuel Surface

(0.15x0. 15m Tray)

£ 0 — 1 — 0 15 30

Time (min)

Figure 8 Hysteresis of Fuel Consumption Rate to Opening Factor(0.20m Tray)

363
Figure 9(a) Comparison of Analytical

and Numerical Criteria on the Occurrence

of Flashover(Numerical Calculation by

Augmented Lagrange Function Method with

k=l 00)

Figure 9(b) Comparison of Analytical

and Numerical Stability Limit of Equi1 ibria(Numerical Calculation by Augmented Lagrange Function Method with

k=l 00)

Figure 10 An Example of the Distribution of Augmented Lagrange Function

in the Near Field of one Equilibrium

Curve on

364
Figure 11(a) Comparison of Analytical

and Numerical Criteria on the Occurrence

of FI ashover(Numerical Calculation by

Augmented Lagrange Function Method with

k=0 . 01

)

Figure 11(b) Comparison of Analytical

and Numerical Stability Limit of Equi1 ibria(Numerical Calculation by Augmented Lagrange Function Method with

k=0. 01

)

Figure 12 Comparison of Analytical

and Numerical Lower Bounds of the

Critical Temperature of Zone 1

365
Figure 13 Influence of Combustion Heat

of Material on the Criteria of the Occu- rrence of Flashover

Figure 14 Influence of Wall Heat

Transfer Coefficient on the Criteria

of the Occurrence of Flashover

Figure 15 Upper Bounds of the Critical

Temperature and Steady-state Temperature

of Smoke Layer(The bounds were estimated

by Augmented Lagrange Function Method)

Wo (in)

366
Discussion After Y. Hasemi's Report on A METHODOLOGY OF THE SENSITIVITY ANALYSIS

OF BUILDING PROPERTIES ON THE OCCURRENCE OF FLASHOVER

EMMONS: Flashover is identified in this analysis as a point of instability. In

the literature, experimentally flashover has been identified as various

things. The movement of flame from initial objects to many others, the burning

of the hot layer, the flames come out of the door, ventilation limited. Has

there been any validation of the new definition on the basis of instability?

Which of these phenomena are being described, if any?

HASEMI: First, we have to assume that flashover itself is a very sense oriented

concept. Therefore, there are various definitions of flashover but one thing

which is consistent in all of the definitions of flashover is that there is a sudden change in temperature. In an experiment where liquid fuel, such as alcohol, is used, the burning area of the combustion peak will not change.

Therefore, flashover, being a sudden change in temperature, is difficult to take

place. In this experiment, the changes in temperature are rather mild. The

temperature change such as this, can be considered the one which corresponds to

flashover in cases of fire. The previous diagram corresponds to the particles

of 10 centimeters. A sudden change in temperature you saw in a previous slide

corresponding to here; these boxes show the area where the temperatures did not

change much. The same phenomena is happening even though the sizes of fire sources have changed. I think one may assume that this continuity is the limit

of where flashover takes place. For the materials we used in this experiment,

as I said, the combustion area will not change. We may need a different

definition of fluctual graph when the combustion area changes as well as the

temperature. But I feel that this way of thinking can be applied when, for

instance, a bed is burning, in which there is also a fire, the fire source is

fixed.

EMMONS: When one optimizes a function with a LaGrange multiplier, the LaGrange

multiplier generally has an important, sometimes very important, physical

meaning. Have you identified any physical meaning with respect to your LaGrange

multiplier. For example, in statistical mechanics, the LaGrange multiplier is

the temperature. Do the physical quantities you have used correspond to any

important physical phenomena?

HASEMI: We adjusted very simply by optimizing it, so I don't think in this case there was any physical meaning.

EMMONS: Yesterday Dr. Takeda introduced a factor f. Have you calculated the f factors for your critical conditons to see whether or not they agree or disagree?

HASEMI: I did not calculate the f factor. As I said yeserday during the

discussion time, even though I do not understand the physical meaning of our f parameter, when we use methanol, even if f is large, this continuity will tak>>

place.

ZUKOSKI: In the experimental apparatus, was the height of the ceiling, the

interface between the hot layer and the cold layer, measured? Did it change

dramatically when you went across the instability?

HASEMI: We measured the hot layer and it changed drastically when finer u u

! took place.

367
QUINTIERE: In conjunction with Prof. Emmon's first question, isn't it possible

for us to distinguish between a definition of flashover based on our senses and

observations and causes of flashover, which are mechanisms for what we then

perceive to be flashover. I think if we can agree on such definitions, then

perhaps we would clear up some facets of discussion.

HASEMI: Flashover is defined in a very sense oriented way. But at least when

we compare the flashover, in fire or in simulation, I think we need a definition

of flashover in accordance with the mechanism and also we need a mathematical

definition.

368
FIRE ENGINEERING TEST DEVELOPMENT: BENCH-SCALE

TESTS TO PREDICT FULL-SCALE BEHAVIOR

Vytenis Babrauskas

Center for Fire Research

National Bureau of Standards

Washington, D. C.

Paper for presentation at

7th UJNR Panel on Fire Research and Safety

October 24-28, 1983

369
FIRE ENGINEERING TEST DEVELOPMENT: BENCH-SCALE

TESTS TO PREDICT FULL-SCALE BEHAVIOR

Vytenis Babrauskas

Center for Fire Research

National Bureau of Standards

Washington, D. C.

Abstract

The work done at the National Bureau of Standards (NBS) over the last ten

years in predicting full-scale fire behavior from bench-scale tests is

summarized. Test methods for flooring materials, mattresses, and

upholstered furniture are discussed. An emphasis is placed on the newer methods of measuring rate of heat release, in both full and bench scale,

which use oxygen consumption as the measurement principle. Even though

current predictions are based on data correlations rather than a complete

analytical model, it is seen that good agreement is obtained.

Key words: Fire tests: flame spread; mattresses; rate of heat release;

upholstered furniture; wall linings

370
Introduction

In earlier times bench-scale flammability tests were used merely to rank

products or materials according to some intuitive sense of performance.

In the United States credibility of this approach was challenged by the

actions of the Federal Trade Commission (FTC) around 1974 against several

plastic foam manufacturers. The FTC reasoned that the results from a number of standardized tests, approved by the American Society for

Testing and Materials, a consensus standards group, were misleading

because their ratings, as used, did not correspond to actual full-scale

fire experiences with the same products.

The typical response to the FTC action was to consider most bench-scale

testing dubious and to go to full-scale testing in many cases. Over

the intervening years a substantial amount of expertise in full-scale

testing has now been gained and significant data bases built up in

several product areas. With that experience came the realization that

full-scale testing has its own drawbacks. Cost is an obvious limitation. More troublesome is the question of inter-laboratory comparability. So far there has not been a single round-robin series demonstrating

that one laboratory could replicate another’s findings. Informal observations have shown, instead, that minor factors in setup, specimen preparation, or test operation can significantly influence the results.

Bench-scale tests are generally at least an order of magnitude less expensive than full-scale fires. Also, inter laboratory agreement is usually

much easier to reach. Thus, significant benefits can be seen to benchscale testing _if adequate validity in predicting full scale performance

can be achieved. The approach that is needed is to establish a firm

relationship between the full-scale hazard that is to be quantified and

the bench-scale measures of the appropriate variables. This relationship has to be established for both very high hazard and very low hazard

materials, with a suitable number of intermediate points. Further

testing can then be done only in the bench-scale. Because of the practical complexities of real combustibles, a separate relationship has to

be determined and proved out for each different class of products, e.g.,

371
a test procedure developed for beds is. of little use for measuring

ceiling panels. Note that this does not imply that standardized benchscale tests cannot be developed, but rather that test conditions and data

analysis procedures need to be validated for each separate product class.

Variables of Interest

In the course of the last decade the realization has come that the single

most important variable in describing a fire is the rate of heat release.

This is, in fact, what we mean when we ask "how big is the fire?" While

this may seem obvious now, it is important to realize that until the late

1970 ’s there were essentially no fire studies done where rate of heat

release was presented, as a function of time, for a fire of interest.

Thermal effects of fire are not the only ones of concern. Toxicity and

smoke obscuration can also constitute limits to escape or survivability.

We realize now that these may be expressed not as independent variables

but as multipliers to the basic burning rate. The present state of

understanding of toxicity and of soot production is rather crude.

Although there is hardly such a thing as a strictly material fire property, independent of boundary conditions, such an engineering assumption

is often operationally useful. For engineering calculations at the

present time, toxicity and smoke production are considered as constants,

per gram of material. The toxicity or smoke problem then becomes separable into a burning rate (kW or, better, kg/s) multiplied by a toxic

species or soot generation constant in units per-kg-pyrolysate. These

properties are taken as constants only to the first approximation

further studies will presumably lead to more detailed characterizations.

Describing the rate of release of heat and toxic species and smoke production is generally sufficient to characterize the full-scale source

fire (we will not consider here the distribution of the fire products

throughout a building or its effects on the structure). Other questions

of practical importance can be seen to be intimately connected to rate

of heat release. For instance, time to initial item ignition or second

item ignition, flame spread rates, and time to flashover are all factors

in determining the complete rate of heat release history.

372
Bench-scale testing is occasionally, but rarely, simply testing of reduced

scale models. More commonly, in order to determine the complete full-scale

performance, physically separate processes must be separated in bench-scale

testing. To make this clear, the full-scale heat release rate can be

expressed as

ifs (t) = z 4 f S ,i (t) A

fs,i (t>

where q r (t), the full-scale heat release rate, as a function of time, is is

to be viewed as a summation over i objects or areas, . . With each

I S, 1 area is associated an incremental heat release rate, q. .. Objects fs,i

enter the summation only after their ignition. The areas involved,

A,. ., are functions of time, as indicated, since a flame spread process

1 S , 1 may well be an important part of the fire development.

How should the (t) terms be evaluated? In the very simplest case,

the combustible may be thick, homogeneous and heated by a uniform heating

flux. In that case, a Ax by Ay small specimen tested in bench-scale can directly give the required full-scale q”

g (t) value.

Such a simple case rarely occurs in practice. More commonly

the incident fluxes may be non-uniform and difficult to determine; — the material may be thin and subject to burnout;

the material may be layered, rather than homogeneous;

the actual thickness may be much greater than testable in benchscale, thus not permitting a similar burning time;

the full-scale object(s) may be highly irregular and not feasible

to approximate by plane surfaces; or

the full-scale fire may involve melting, collapse, or other largogeometry changes.

373
Each such practical limitation will effectively prevent the specimen's

behavior from being successfully analyzed by the simple model above.

In that case a more empirical approach, based on appropriate correlations, is required. The results cannot then be expected to predict

fine details of the burning process, but should at least predict important features, such as peak heat release rate.

In addition to bench-scale tests for heat release rate and for smoke and

toxic species production, two other variables emerge as important:

ignitability and flame spread. Bench-scale procedures are needed to

determine these, for use in prediction relationships.

Examples of Quantitative Methods

The first example of a "modern" fire engineering test method — one with a rigorous connection between full and bench-scale — was the flooring

radiant panel test, developed in 1975 [1]. The variable to be predicted was the flame spread along corridor carpeting, as a function of radiant

fluxes from the ceiling layer. A full-scale data base was established

for floor irradiances. Based on this, a flame spread test was developed

which allowed the minimum external flux required for flame propagation

to be determined. This test method was later adapted to also serve for

the testing of attic floor insulation.

The next example is the burning of institutional mattressas. In this

program [2,3] a series of full-scale tests on simulated beds was conducted

in a realistic manner — a full set of bed linens was used and ignition

was with a trash-filled plastic wastebasket. An examination of the

results showed that flame spread and ignitability played no role, since

these were controlled solely by the (standard) bed linens and not by the

mattresses. The rate of heat release was clearly the most important

quantity to determine. Optical obscuration properties were also

measured in full-scale and could be determined in bench-scale.

In bench-scale, a research quality heat release rate calorimeter had

just been developed by Tordella in 1978 for making such measurements

[4]. Since irradiance values and burning areas were not known in the

374
full-scale, the proper bench-scale conditions — the heating flux and the

averaging period — had to be determined by best-fit techniques. Details

2 have been given in [3], where it was shown that a 25 kW/m irradiance

and a 180 s averaging period gave the best results. Figure 1 shows the

correlation obtained. Smoke measurements were made in the NBS smoke

chamber according to a technique developed by Breden and Meisters [5]

and analyzed as described in [6]. The results are shown in Figure 2.

Test specimen details are listed in Table 1. It can be seen that total

heat content would not be a sufficient measure of the fire performance,

and that there is some correlation between generic material classes and

actual heat release rate, but that correlation is not strong enough to

obviate the need for bench-scale testing.

The technique adopted for making bench-scale heat release measurements

for mattresses was the NBS-II calorimeter [4]. This instrument, while

having numerous attractive features for research use, is costly and

complex and could not be expected to be used for regular testing purposes.

At about the same time the principle of oxygen consumption was being

actively explored for use in fire testing applications. The principle

of oxygen consumption measurements is based on the observation that the

rate of heat released per gram of oxygen used is nearly constant for all

hydrocarbon fuels. Correct heat release rate measurements by normal

means had been extremely difficult to do in bench-scale and essentially

unfeasible in full-scale. Fortunately, oxygen concentration measurements are relatively easy to make to a suitable precision in both

full and bench scale. This was initially studied at NBS in 1974 by

Parker [7], later by Sensenig [8] and others, and systematized by

Huggett [9] and Parker [10]. It has also been applied to make, for the

first time, accurate heat release measurements in full-scale room

fires [ 11]

.

The application of the oxygen consumption principle to bench-scale tests

was first done as a modification to a widely available commercial test

apparatus [12]. This showed that significant improvements in accuracy

were thus made possible but that to fully utilize the principle would

require an apparatus designed from the start for this type of operation.

This work was started in 1980, the apparatus was completed in 1982 [13]

375
and has been termed the "cone calorimeter" because of the truncated cone

shape of the heater (figure 3). The apparatus, which is relatively

simple to construct and operate, can be used to heat uniformly up to 100

2 kW/m specimens in either a horizontal or vertical orientation, and to

measure up to 12 kW heat release rates. In addition to determining mass

loss rates and heats of combustion, analyzers for CO, CC^, H^O, and

total hydrocarbons are used to aid in combustion characterization.

About five years ago also we started realizing that conducting room fire

tests may not be the best way of characterizing the full-scale burning

behavior of discrete, floor-standing combustibles, especially furniture.

The reasoning was followed that the important variable to determine was

the free-burn rate of heat release. This value would then be applicable

as input data to predicting room fires in rooms of any description,

during pre-f lashover burning. Conversely, if measurements were made in room fires where f lashover was reached early in the test, subsequent

data would not be applicable to any other fire scenario. The free-burn

rate of heat release could not have been readily determined without the use of the oxygen consumption principle. With its use, however, it

became straightforward to design a "furniture calorimeter" [14]. A view

of the furniture calorimeter is shown in figure 4.

One major test series has been conducted so far where both these two

newest measuring instruments were employed, the furniture calorimeter

for full-scale data and the cone calorimeter for bench-scale data. A

series of upholstered chairs and sofas, constructed with various frame,

filling, and fabric materials, were tested in full-scale [14]. Specimens

consisting of filling/fabric composites were then prepared and tested in

the bench-scale cone calorimeter. For predicting the peak rate of heat

release, the following model was adopted

q fs

= b • q[ s

* [Ml * [FF] • [SF]

where q is the full-scale peak heat release rate (kW) ; <j is the IS bs

heat release rate per unit area determined in the cone calorimeter

2 (kW/m ); M is the mass of the full-scale specimen, excluding non-combustible

376
parts, if any (kg) ; FF is a frame factor; and SF is a style factor derived

from the full-scale tests. The frame factor was found to be

1.66 for non-combustible frames

0.58 for melting plastic frames

0.30 for wood frames

0.18 for charring plastic frames.

The style factor is needed to account for enhanced fire involvement of

curvy surfaces and is set between 1.0 for rectilinear items and 1.5 for

highly curvy ones. The factor b is a scaling factor and has to be determined from a data correlation; the best fit was obtained for b = 0.63

2 m /kg. The test specimens are described in Table 2. Figure 5 shows the

results — good agreement is achieved.

Flame spread tests have been available in the United States for more

than 40 years. Traditional ones, however, are very limited — the

heating fields are poorly defined; melting, composite, or fabric materials usually cannot be accommodated; and a theoretical analysis is not

available. Recent NBS interest started with the formulation of a theory

by Rockett [15] for radiatively dominated flame spread. Several apparatuses have been constructed in recent years for measuring flame spread

in a way as to give theoretically analyzable results. The latest (shown

in figure 6) was designed especially for fabric/filling composites. It

subjects horizontal specimens to a uniform irradiance and shows fabric

tension to be maintained during the course of burning. Work is in

progress on this apparatus. Data analysis will use validation by com- parison to full-scale tests on identical materials.

Ignitability does not play as strong a role in determining fire hazard

as do the rate of heat release and flame spread properties. This aspect

is illustrated in figure 7, where systems ranging from a highly fireresistive wool/neoprene combination to a well flammable polyolefin/

unretarded polyurethane foam are shown. The tests were conducted usin,-

the cone calorimeter, as a separate ignitability apparatus is net needed.

The differences are real but are not very large. The area where it iy

377
perhaps most important to quantify ignition behavior is for computing

the ignition of the second-to-ignite object in a room fire. This problem is amenable if a separation of variables is made: the radiant heat

fluxes of the assumed f irst-to-ignite item can be measured and combined

with the ignitability curve generated for the second-to-ignite item.

Irradiances as a function of height and radial distance have been

measured and catalogued for a number of furniture items [16]. There is some suggestion that these irradiances could be predicted from mass loss

rate or rate of heat release data, but a firm connection has not yet

been established [14,16].

Conclusions and Future Directions

This brief review has shown how full-scale/bench-scale test correlations

have been pursued at NBS and illustrated some successes of the last ten

years. It is evident that for the product classes where in-depth studies

were undertaken good predictiveness was obtained. For numerous other

product categories, however, studies still remain to be done. Areas

where additional efforts will be placed in the future include the treatment of combustible room wall linings, and the prediction of burning

rates in post-f lashover room fires.

Bench-scale measurement techniques will also continue to be upgraded.

The existing standard technique for smoke production measurement [17] is

a static one and has, therefore, some distinct limitations. The development of the cone calorimeter has provided a good dynamic combustion products generation environment. Work is now being started to develop two

methods of smoke measurement with the cone calorimeter. The first is a filter mass sampling technique, using a gas stream probe with a con- trolled flow rate. The second is an optical technique (figure 8) using

a He-Ne laser light beam.

378
References

1. Benjamin, I. A., and Adams, C. U., Proposed Criteria for Use of the

Critical Radiant Flux Test Method, (NBSIR 75-950). [U.S.] Nat. Bur.

of Stand. (1975).

2. Babrauskas, V., Combustion of Mattresses Exposed to Flaming Ignition

Sources, Part I. Full-Scale Tests and Hazard Analysis, (NBSIR 77-1290)

[U.S.] Nat. Bur. Stand. (1977).

3. Babrauskas, V., Combustion of Mattresses Exposed to Flaming Ignition

Sources, Part II. Bench-Scale Tests and Recommended Standard Test,

(NBSIR 80-2186) [.U.S.] Nat. Bur. Stand. (1981).

4. Tordella, J., and Twilley, W. H., Development of a Calorimeter for

Simultaneously Measuring Heat Release and Mass Loss Rates (NBSIR

83-2708). [U.S.] Nat. Bur. Stand. (1983).

5. Breden, L. H., Meisters, M., The Effect of Sample Orientation in the

Smoke Density Chamber, J. Fire and Flammability , 234-247 (April 1976).

6. Babrauskas, V., Applications of Predictive Smoke Measurements, J^_

of Fire and Flammability . 12 , 51-64 (January 1981)

.

7. Parker, W. J., An Investigation of the Fire Environment in the ASTM

E84 Tunnel Test (Tech, note 945). [U.S.] Nat. Bur. Stand. (1977).

8. Sensenig, D. L., An Oxygen Consumption Technique for Determining the

Contribution of Interior Wall Finishes to Room Fires (Tech. Note 1128).

[U.S.] Nat. Bur. Stand. (1980).

9. Huggett, C., Estimation of Rate of Heat Release by Means of Oxygen

Consumption Measurements. Fire and Materials . 4_ 61-65 (1980).

10. Parker, W. J., Calculations of the Heat Release Rate by Oxygen

Consumption for Various Applications, (NBSIR 81-2427) [U.S.] Nat. Bur.

Stand. (1982).

11. Proposed Method for Room Fire Test of Wall and Ceiling Materials and

Assemblies. American Society for Testing and Materials (Nov. 1982).

12. Krause, R. F., Jr. and Gann, R. G., Rate of Heat Release Measurements Using Oxygen Consumption. J^ Fire Flammability , 1

1

, 117-130

(April 1980).

13. Babrauskas, V., Development of the Cone Calorimeter — A BenchScale Heat Release Rate Apparatus Based on Oxygen Consumption

(NBSIR 82-2611). [U.S.] Nat. Bur. Stand. (1982).

14. Babrauskas, V., Lawson, J. R., Walton, W. D., and Twilley, W. H.,

Upholstered Furniture Heat Release Rates Measured with a Furniture

Calorimeter (NBSIR 82-2604). [U.S.] Nat. Bur. Stand. (1982).

379
15. Rockett, J. A., Mathematical Modeling of Radiant Panel Test

Methods, pp. 90-96 in Fire Safety Research (SP-411). [U.S.] Nat.

Bur. Stand. (1974).

16. Babrauskas, V. , Will the Second Item Ignite? Fire Safety J

.

, 4^

281-292 (1981/82).

17. Standard Test Method for Specific Optical Density of Smoke

Generated by Solid Materials (E 662) . American Society for

Testing and Materials, Philadelphia (1979).

380
TABLE 1

Mattress specimens tested in Full and in Bench-scale

Specimen

Combustible

Mass

(kg)

Total

Fuel

(MJ)

Filling

Material

Ticking

Material

Bench-Scale

Heat Release ! (kW/ni )

M01 14 415 polyurethane polyvinylchloride 399

M02 6 184 polyurethane polypropylene 138

M03 11 225 cotton felt polyvinylchloride 60

M04 19 742 latex polyvinylchloride 479

M05 6 175 polyurethane rayon 179

MO6 12 268 cotton/nylon/

polyester

batting

polyester 127

MO 7 13 287 cotton, jute cotton 43

M08 18 474 neoprene cotton 89

MO9 3.2 95 polyurethane polyvinylchloride 152

M10 6 149 neoprene polyvinylchloride 83

(a)

(a) Measured in OSU apparatus; all other measurements in NBS-II apparatus.

381
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Tested

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of mattresses in room fires

383
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384
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386
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values for upholstered furniture measured in the

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387
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389
390

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Discussion After V. Babrauskas' Report on FIRE ENGINEERING TEST DEVELOPMENT:

BENCH-SCALE TESTS TO PREDICT FULL-SCALE BEHAVIOR

JIN: On the bench model, are the tests run as ambient oxygen concentation?

BABRAUSKAS: In the bench scale test, we have run all the tests just as ambient

oxygen concentration » In the case of comparing the furniture calorimeter to the room fire, I think there was agreement before the start of testing that we would

expect this to agree well up to the point of flashover. The interesting

question was: What happens after flashover? We knew that if we went into

ventilation limit then, of course, there is no comparison with free burning

rate. So we designed a series of experiments to reach flashover, to go past

flashover, but not to go into ventilation limiting. The variations that we got

in the tests were about a random variation. This was only tested for the

upholstered chair, and upholstered chairs, when they burn, have a pretty big

fire. If, for instance, we would have a room with very many, very small

packages, then that may not be true because each of these fires will be small

and will not be optically thick. So this would be very interesting to study but

we have not had a chance to study that yet.

PAGNI: When we used oxygen depletion, we have some difficulty getting accurate

results and I think perhaps Dan Gross or someone else at the Bureau, along with

Archie Tewarson, has instead developed a method using CO and CO

2

, which we found

to be more accurate. Would you consider that as useful in your efforts?

BABRAUSKAS: No, and for a very good but maybe not an obvious reason. First of

all, I would say that it is possible to get good, low noise in oxygen

readings. We can put a stripchart recorder on the output of an oxygen meter

running nitrogen and get +_ 50 ppm as the RMS noise, and that is possible to

achieve with well set up commercial equipment. Now that is not quite the answer

to your question. The real answer is the difference between what Archie studies

and what I study. Dr. Tewarson usually likes to study simple materials where he

has had an ultimate analysis. I feel it's my obligation to be able to test non- homogeneous composites and, of course, the CO

2 valence would not be so useful.

HIRANO: When you conducted the ignition test, how did you place test p,

horizontal or vertical?

BABRAUSKAS: We did both; in the case of the data that I showed, they were horizontal.

HIRANO: Did you find any difference between horizontal and vertical?

BABRAUSKAS: Usually about 15 percent.

391

MATERIALS FIRE PROPERTIES AND

TEST METHODS TO BE DEVELOPED

Hiroaki SUZUKI

Smoke Control Division

Environment, Design and Fire Department

Building Research Institute

Ministry of Construction

Seventh Joint Meeting

UJNR Panel on Fire Research and Safety

Washington, U. S. A. , October 2U-28, 1983

393
MATERIALS FIRE PROPERTIES MD

TEST METHODS TO BE DEVELOPED

H. Suzuki

1. Introduction

Many test methods have been developed in countries for evaluation

of building materials against fire. Each test method, however, only

watches a certain phase of a fire. The data from these test methods

actually give information about partial fires, but most of them seem to

show an apparent fire properties. They are not essential to evaluate

actual fire properties of materials in a building fire. Recently,

therefore, a new test method has been required to develop measurement of

real properties of materials in fire.

This paper deal with a direction of getting materials fire

properties which are needed for prediction of fire growth in a building.

2. Items Required for Input Data in Modeling

In order to predict a spread of fire in a room/building, materials

fire properties are essential to be known. Materials fire properties

can’t be taken as physical values like specific heat, latent heat etc.,

but also taken as evaluation standard for fire hazard.

394
Then the concept of "easiness of spreading of a fire" or "easiness

of occurrence of flashover in a room" must he established.

Oxygen consumption indexes and B number introduced by Spalding1 ^

may be example for indexes of "easiness of spreading of a fire."

Inducement of evaluation indexes will be required for fire properties.

For the application of the fire growth model in a room/building,

the new proper fire test method which will supply the following items

will be required.

A. Ignitability of materials

B. Latent heat of materials

C. Chemical composition of thermal decomposition products

D. Released heat accompanyed by thermal decomposition of materials

E. Heat transfer in complex elements

F. Thermal property of simple compartment made of non-combustible

materials

A. Ignitability of Materials

When we predict the growth of a fire in the coarse model which was

presented in "The Models to be Developed in Fire Safety Design Project"

by Tanaka in the theme 2 "Fire Growth Prediction", pyrolysis of

materials may be considered to occur in proportion to the received heat

flux of the materials. Then, any ignitability test can be negligible.

However, many materials are treated by fire retardant agents, or

covered with non-combustible materials, so we can take as thermal

395
decomposition occurs after ignition of materials.

If we consider the ignition of materials, it occurs under the

circumstance of existence of radiation and pilot flames. As ignitability

depends upon the intensity of radiation as well as heated time,

ignitability should be written as a function of intensity of radiation

and time. This means that the time until sufficient amount of combustion

products is released to ignite. Therefore, there is no need to consider

the effect of concentration of oxygen in the environment.

B. Latent heat of materials

The mass loss rate of materials can be calculated as follows

M"=Q"/L

where L : latent heat of thermal pyrolsis for steady burning, Q"

:

incident heat flux (Kw/m ), M": mass loss rate per unit area (Kg/m S).

Heat transfer can be calculated. Latent heat of materials is needed

as properties of materials.

C. Chemical composition of thermal decomposition products

As the thermally decomposed products of materials are assumed to

burn in the room, the composition of the decomposed products is required

to be known in order to get the composition of gases in the room when

the materials burn steadily. If it is difficult to know the chemical

composition of the decomposed products, then the original composition of

396
materials will be substituted for this purpose. In this case, there may

occur the difference between the composition of original materials and

the decomposed if the original become char.

D. Released heat accompanied by thermal decomposition of materials

The bomb calory metry is one of methods for getting released heat

from combustible materials. In many cases, however, materials remain

charred residue at actual fires. But there may occur the difference

between the values from the calorimetry and from an actual fire. The

value at the steady burning of materials will be required for modeling.

E. Heat transfer in Complex elements

Building elements are abundant in variety of their composites which

involve hollows, insulation materials, etc. Moreover it is difficult to

know the thermal properties of the most composite materials at elevated

temperatures. Therefore an appropriate test method for getting the

thermal property of these materials will be most practically reliable.

In this case, various data will be obtained according to the heating

conditions

.

As it is difficult to carry out nemerous number of tests using

actual sizes of building elements, another research for the criteria o!

heat transfer from the exposed surface to the other side will be

397
required to get a fanction as follows

f(li, t)

where Ii : Intensity of incident heat flux

t : time

The surface temperatures of the exposed materials relate to the

heat transfer between the materials and combustion products in the fire

room. The temperatures should be determined as the same way.

F. Thermal property of a simple compartment made of non-combustible

materials

In a complex compartment, the thermal properties through the

partitionings should be pursued by both of experimental tests and

theoretical heat transfer. In this case, the accuracy, however, cannot

be satisfactory. And moreover it will cost to carry the experiments.

In a simple compartment made of non-combustible materials, it may

be easy to evaluate the heat transfer through the partitionings by

resolving thermal equation. This may be applicable to the different

thermal conditions the elements.

As this method may be only applicable to non-combustible materials,

the thermal properties of many materials at elevated temperatures will

be desired to be measured.

398
Discussion After H. Suzuki' s Report on MATERIALS FIRE PROPERTIES AND TEST

METHODS TO BE DEVELOPED

GANN: You've laid out a very ambitious list of needed tests. Do your plans or BRI plans include developing any of those in particular?

SUZUKI: Are you asking about a test method in order to obtain fire properties

or are you talking about the modeling which is necessary prior to the

development of test methods?

GANN: Specifically, the fire property measurement methods.

SUZUKI: As I said before, we do not have any ideas concerning the test

method. Are you asking whether or not we are in the process of developing these

test methods?

GANN: Either in the process of developing or have you any specific ideas for

what you would do first?

SUZUKI: Even though I do not have any concrete ideas at this time, I am sure

that some of the ideas proposed in my presentation can be investigated.

399

GENERAL DISCUSSION

SAITO: What we are looking for, Dr. Babrauskas, is how we can get properties of

full-scale tests from the result of bench-scale tests. When we conduct those

tests we have to know many combustion parameters of the materials; there are several parameters we can consider, including the combustion rate or heat

release rate. But I have a very optimistic thought, that as long as we can get

accurate heat release value in terms of time history, this parameter can be

successfully applied from bench-scale tests to full-scale tests as far as prediction of properties are concerned.

BABRAUSKAS: We have tried both per unit area and per unit gram in analysis of

the data. What I think is best to do is to normalize per unit of surface

area. There is a problem in doing that with furniture, however. With furniture

in the full-scale we don’t have a way of easily measuring the area. But, it's

much easier to measure the weight of the full-scale specimen. We measure in the

bench-scale per unit 100 mm x 100 mm area and then multiply, not by the area in

the full-scale item, but by the weight. I know that is an empiricism, but it

works better than nothing; measuring of areas, I think, is too arbitrary with

full-size irregular objects.

NELSON: Dr. Suzuki, does your concept of modeling the room of origin include

modeling a combustible lining?

SUZUKI: It is included in our thinking as part of the materials, but it is not

included as part of the gradual burning state.

NELSON: Gradual .. .meaning before flashover?

SUZUKI: Propagation.

NELSON: If so, I believe you also said that you assumed that all of the

material burned in the room of origin.

SUZUKI: When the temperature rose to a certain degree within a certain time, we consider that material will be burned in a formal manner.

NELSON: You are assuming that no pyrolysis products will be discharged unburned

through the vent in the room. Is that correct?

SUZUKI: I think that is possible, some of the pyrolysis products will escape

through the vent unburned. But in our experiment we are trying to keep the

lining as simple as possible and, as the temperature increases, pyrolysis gases

will be generated and these will burn in layers. If the oxygen is not

sufficient in these layers, then those pyrolysis products will escape through

the vents.

NELSON: Our test experience with rooms lined with plywood indicate a large

portion of the pyrolysis products escaped the room and burned outside.

TANAKA: In my models, fuel inputs are specified. So, in order to accommodate

just what you said, we have to have some data concerning the fuel rates for

materials, for example, some kind of test or experiment in order to accommodate

that.

401
NELSON: That's the same with the model that Jones showed you and the model that

Cooper is using and several other models.

PAGNI: Dr. Hasemi, in your paper, are the titles of Tables 1 and 2 switched?

HASEMI: Yes, that is correct.

PAGNI: I want to know when I can get away with the smallest possible penalty

coefficient? When can I use your model with 10 ?

HASEMI: One thing which is necessary is that the penalty coefficient can be

prefixed and the LaGrange multiplier cannot be prefixed. However, the

evaluation of results can be done only by applying the LaGrange multiplier. In

order to get the accurate result of the calculation, two LaGrange multipliers

should be approximately the same. In this case, the penalty coefficient is

illustrated as k is about .01 and it varies quite close. One is .01, the other

is .001 but these are quite similar as the result of the calculation. But,

empirically I can tell you when the penalty coefficient is very small, I take

too much time to calculate it. So, in reality, what is desireable is that the

LaGrange multiplier should be in the same range and at the same time k values

should be quite large. So, in this case, when k is .01 computation is much

faster than when the k is .001; not only is the computation faster, but the

accuracy is about the same.

PAGNI: When you say the LaGrangian multiplier should be the same, do you mean

that the two LaGrange multipliers for 1 k are the same? Or, do you mean that

for two different k, when I do the computation, I get LaGrange multipliers which

are similar for the two k?

HASEMI: LaGrange multiplier will be dominated by these constrained

conditions. Therefore, you will get as many LaGrange multipliers as constrained

conditions, and these LaGrange multipliers desirably should be the same. So

that is what is desirable and in actuality, that is what is desirable ideally,

and they do not have any relationship to penalty coefficients.

HANDA: During today's presentations, I felt that each one by the Americans was closely related to the subject of the session. I'm sure that they all are utilized in the Harvard computer code. I would like to know. Dr. Babrauskas

,

are you going to make your paper available to the Harvard Code? That is, as you

have obtained the value of bench-scale tests, are you planning to use these

values as parameters?

BABRAUSKAS: Well, I think we can use them in a computer code as soon as there

is a proper place in the computer code to accept that kind of data. At the

moment, we're waiting for that, but the moment is not yet here. We can gather

the data and we can hold onto it, and we can wait for those computer subroutines

to become available. When they are available, then this will be an opportunity

to put the data in there and hopefully to get a good prediction.

402
COMBUSTION TOXICITY AND 2ND EXPERT MEETING OF THE COOPERATIVE

RESEARCH GROUP OF COMBUSTION PRODUCTS

Richard Gann, Koichi Kishitani , and Fumiharu Saito

Session Chairmen

403

PROGRESS REPORT

on COMBUSTION TOXICITY RESEARCH IN THE U.S.

by

Dr. Richard G. Gann

Chief, Fire Measurement and Research Division

Center for Fire Research

National Bureau of Standards

In the last few years, smoke toxicity has progressed from being only a

suggested factor in fire hazard to a measurable parameter of considerable

dispute. Much of this has been realized since the Sixth UJNR Panel Meeting.

At present, despite the controversial status of the field, many manufacturers

of both materials and finished products are considering or performing

(confidential) toxicity testing, and consideration of several methods for

standard testing or regulatory use is underway.

A variety of approaches to measuring combustion product toxicity has

appeared. These are presented in detail in recent reviews of current

measurement capability. The report by Be nj amin/ Clarke Associates (1) was

commissioned by the National Fire Protection Association. The Southwest

Research Institute document (2) reflects the interest of the plastics

industry. The Arthur D. Little study (3) responds to the commercial and

political pressures for product control. Each of these reviews discusses the

strengths and weaknesses of the available approaches, devices, and measuremen

philosophies. Each review presents significant reservations regarding each

apparatus and/or procedure, leading to the general conclusion that more work

is necessary before current capability becomes encoded.

405
Nevertheless, there are three methods under consideration in committee E-5

(Fire Tests) of the American Society for Testing and Materials (ASTM). These

were developed by Hilado at the University of San Francisco (A), by Birky,

Levin, and coworkers at the National Bureau of Standards (5,6) and by Packham

and Stacy at the Weyerhaeuser Co. (7). All are in the early stages of subcommittee discussion and are progressing at a slow pace. Only the NBS method

has been subjected to an interlaboratory evaluation (8). Limited discussions

on toxicity testing have also occurred at meetings of the National Fire

Protection Association (NFPA).

In addition, the State of New York has funded a study to determine whether

regulation of commercial products by their smoke toxicity is practical (3).

Using an extensive list of operational criteria, the contractors identified

two test methods, those of NBS (6) and the University of Pittsburgh (10),

which were then submitted to extensive test. i. They concluded that, while it

was at present inappropriate to pass or fail products based on smoke toxicity,

the performance (under the Pittsburgh test) of products to be sold in New York

State should be published. The State has solicited the reaction of the technical peer community to these recommendations; it has not yet acted on the

input

.

Relatively few materials have been "tested” to date. (The exception is

Hilado* s work. However, serious questions have been raised as to what that

method actually measures.) Of those few, virtually all produce smokes that

are roughly comparable to each other in their acute inhalation toxicity.

Otherwise stated, the LC^q values for a wide range of materials lie within a

factor of ten. The one substance found to date that lies outside this range

406
i 3 polytetraf luoroethylene (PTFE), whose smoke toxicity appears to be one

hundred to one thousand times that of other smokes. Recent studies have

confirmed hypotheses that this high toxicity depends strongly on the combustion conditions (9). However, the specific toxicant in the smoke and its

generation mechanism are still unknown.

The principal result of all of these exploratory studies is that there is now

a small but experienced community that is prepared to investigate both the

measurement and physiological issues in a scientific manner. Indeed, our

thinking in this field has evolved from the early concept of searching for a

"super toxicant , " to recognizing that the measurement of the acute inhalation

toxicity of fire smoke is but one component needed to evaluate the total fire

hazard of a situation. This component has to be combined with such other

factors as ease of ignition, rate of heat release, quantity of material

present, its orientation, proximity to other combustibles, ventilation conditions, the presence of fire protection systems, and the building occupancy to

assess the total hazard. Mathematical models of fire growth are beginning to

be modified to include a capability for toxic hazard analysis.

In this context, it becomes even more important to know the "why" of a

material's toxicity. If the LC^g can be explained on the basis of the known,

"prime" toxicants, such as CO, HCN, HC1 , etc., then we can consider the

material as "normal" and use the gas generation data as input into the hazard

model. If, on the other hand, an unexpectedly high toxicity (not explained by

the prime toxicants) is observed for the smoke, then clearly further examination of that material and its combustion behavior is warranted.

407
What, then, are the pressing toxicity measurement issues to which research

efforts must be directed to enable a confident assessment of toxic hazard?

We need:

1. A rationale and design for an appropriate small-scale combustor for

generating smokes that can replicate those produced in the wide range

of real fires.

2. Criteria for quantitative transport of these combustion products from

the combustion chamber to the test animals and/or analytical instrumentation.

3. Appropriate animal models to examine diverse toxicants and various

sublethal effects: incapacitation, non-fatal physiological damage,

disorientation.

4. Experimental studies to explain the effects of the interaction of

combinations of harmful smoke components.

The likely timeframe for success in these directions is uncertain. While much

effort is being expended in debating the propriety of testing and in

performing such tests, there are few active laboratories and scientists in the

U.S. performing research. At present, NBS, Southwest Research Institute, and

the University of Pittsburgh are the principal Institutions involved, although

American industry is conducting some highly important experiments related to

specific products. All of these studies will serve to advance our knowledge

of fire toxicology, but at a slow rate.

In view of this situation, it is all the more important that we build on

related studies in other countries. In that way, by the Eighth Panel Meeting

we hope to have advanced to the point where we can discuss the merits of a

specific toxic hazard analysis methodology.

408
REFERENCES

1. Clarke III, F. B., "Toxicity of Combustion Products: Current Knowledge,"

Fire Journal, p. 84, September 1983.

2. Kaplan, H. L., Grand, A. F., and Hartzell, G. E., "A Critical Review of

the State-of-the-Art of Combustion Toxicology," Southwest Research

Institute Report No. 01-6862, June 1982.

3. Anderson, R. C. , Croce, P. A., and Sakura, J. D. , "Study to Assess the

Feasibility of Incorporating Toxicity Requirements Into Building Materials

and Furnishing Codes of New York State," Arthur D. Little, Inc., Report

88712, 1983.

4. Hilado, C. , Journal of Fire and Flammability, _2_, 298, 1975.

5. Birky, M. M., Paabo, M., Levin, B. C., Womble, S. E., and Malek, D.

,

"Development of Recommended Test Method for Toxicological Assessment of

Inhaled Combustion Products," National Bureau of Standards Report NBSIR

80-2077, 1980.

6. Levin, B. C. , Fowell, A. J., Birky, M. M. , Paabo, M. , Stolte , A., and

Malek, D., "Further Development of a Test Method of the Acute Inhalation

Toxicity of Combustion Products," National Bureau of Standards Report

NBSIR 82-2532, 1982.

409
7. Packham, S., "Proposed Method of Test for Toxic Combustion Products,"

submitted to ASTM Committee E-5, 1981.

8. Levin, B. C. , Paabo, M. , and Birky, M. M. , "An Interlaboratory Evaluation

of the 1980 Version of the NBS Test Method for Assessing the Acute

Inhalation Toxicity of Combustion Products," National Bureau of Standards

Report NBSIR 83-2678, 1983.

9. Williams, S. and Clarke III, F. B. , Fire and Materials, _6, 161, 1982.

10. Alarie, Y. C. and Anderson, R. C., Toxicology and Applied Pharmacology,

31 , 34 1 , 1979.

410
Discussion After R. Gann's Progress Report on COMBUSTION TOXICITY RESEARCH IN

THE U.S.

ROBERTSON: I'm involved in TC92 , the subcommittee on toxic hazards and fire,

and my own feeling is that we have been missing one of the important and, I think, perhaps one of the crucial problems in toxic fatalities and that is the

irritancy of fire gases on the victims. I have a feeling that many of the

fatalities are probably caused by the loss of vision due to the extreme

irritancy of many decomposition products. The victims are forced to become

disoriented; they are forced to exist until they're dead in a toxic atmosphere.

YUSA: You mentioned that we need data which can be used as input to the

mathematical models which, as you mentioned, is one of the most important

projected needs we face at this time. I'm sure that you do not have a complete

idea what kind of input data we vrould be needing, but do you have any feeling

what sort of data for inputting?

GANN: If the toxicity of the combustion products can be represented by a small

number of single gases and we know how to combine the toxic effects of those

gases, then the gas data itself goes into the model. The math models right now

can handle gas transport and gas solution. If the toxicity of the combustion

products is more complicated, and if the combustion products are non- condensible, then we can use a diluted LC^q perhaps in the model. If it is not

a simple material and if some of the products are condensible, we don't know

what to do.

411
ff

.
U.S.A. - CANADA - JAPAN

COOPERATIVE RESEARCH ON EVALUATION

OF

COMBUSTION GAS TOXICITY

(OVER VIEW)

October 1983

Fumiharu SAITO, Dr. Eng.,

Testing LaboratoryCenter for Better Living

413
Introduction

The development of toxic evaluation method for combustion

products from materials upon building -fire is an important problem

to the estimation of toxic potential on actual fire and to the development

of a new material. Toxic evaluation method for combustion gas includes

testing procedure with testing apparatus and heating means, and physiological evaluation method for products released during combustion.

Sorts and quantities of combustion products from materials depend on

the burning condition, i.e. the aspect of fire. Therefore, in order to

develop more reasonable testing method, it is necessary to clarify

combustion behavior of materials in a full scale compartment as well as

the component and quantities of combustion products, and to reproduce

them by a laboratory scale experiment. The toxicity of combustion

products should depend on a physiologically reasonable evaluation method.

As the development of toxic evaluation method of combustion gas

from materials needs many research works, the joint research has been

proceeded in cooperation among USA, Canada and Japan. About the

assignment scope of each research on these studies for three countries,

the basic agreement was adopted in Ottawa in June, 1982, followed by

opening the specialists -meeting of three countries in Japan in November

1982. For these studies, research expenses from the special funds of

the Science and Technology Agency in Japan has been provided to the

related research organizations. As the research work in Japan was

actually started in begining of this year, the scheduled research plan

is regretablly obliged to be delayed.

1. Research System

For the proceeding of this research work. Research Promotion

414
Committe (Chairman: Prof. K. Kawagoe) were established in Science

and Technology Agency. Three working Groups were also established

as sub -organization in the Committee as follows:

WG 1 : Setting up of burning conditions and analysis of

combustion process (Dr. F. Saito)

Elucidation of heat -load onto materials and burning

behavior, using a full scale compartment

WG 2 : Development of testing apparatuses (Mr. M. Furuya)

Development of testing apparatuses which can be

adapted for thermoplastic and non -thermoplastic

materials, and also can reproduce burning conditions

obtained from the results of research works of WG 1.

WG 3 : Toxic evaluation of combustion gas (Prof. Y. Nishimaru)

Toxic evaluation by animal test using pure gas, physiological analysis, and studies on toxic evaluation

method by chemical analysis.

Although each WG sometimes has a meeting individually, basically they have joint-WG meetings in which they have been proceeding

their studies obtaining mutual understandings, because the WGs have

close relations each other. The mutual relations of each WG are shown

in Fig. 1.

2. 1983 Research Budget

According to the basic principle of Science and Technology

Agency, research works have been divided into Phase I and 11. On

415
Phase I, it has been required to design burning test apparatuses and

to make a draft of toxic evaluation and method, which can be proposed

to ISO. From the results of Phase I, it will be decided whether

research plan of Phase II can be approved or not.

In 1982 fiscal year, 530,000 Dollars in total of research expenses were distributed to 5 national research institutions, 2 universities and 1 organization.

In 1983 fiscal year, however, the situation is that budget may

be decreased to about 280,000 Dollars and the research plans shall

be changed.

3 . Future Works

On the last stage of Phase I, the execution of a round robin

test in Japan using developed testing apparatuses and the design of

basic plan for full scale fire experime nts have been scheduled.

As the scope of these studies cover many fields, it is necessary

to have full understanding for each research work and to clarify mutual

research assignments in order to proceed the research works more

efficiently with cooperation of three countries. Therefore, it is very

important to have close exchange -informations with each other.

416
WG-2

f

IT.

2

i—

i

Z

*v

2

417

G

)

YOKOHAMA

CJTY

UN.IVEHCITY

STUDIES ON DETERMINATION OF BURNING CONDITION FOR THE TOXICITY TEST

by

Takeyoshi Tanaka

Building Research Institute

Ministry of Construction

Japan

419
STUDIES ON DETERMINATION OF BURNING CONDITION FOR THE TOXICITY TEST

INTRODUCTION

In an attempt to contribute the relevant experimental data on the

burning condition of products and materials in fire to the rational

designing of the laboratory scale test apparatus to be developed in the

U.S. - Canada - Japan trilateral project for toxicity assessment, it was decided that, in charge of the respective institute, Japan conducts the

researches on the following subjects:

(A) Analysis of Burning Condition in Fire:

(al) Burning Condition in Early Stage of Fire (by SUT),

(a2) Burning Condition in Developing through Developed Stage of

Fire (by BRI).

(B) Investigation into Burning Behavior of Materials in Fire:

(bl) Burning Behavior of Building Materials (by BRI)

,

(b2) Burning Behavior of Plywoods (by FFPRI)

,

(b3) Burning Behavior of Textile Products (by RIPT)

,

(b4) Burning Behavior of Daily Goods (by FRI)

.

The subjects classified into (A) aim at analyzing the thermal and

atmospheric condition to which materials are exposed in fire, and those

classified into (B) intend to produce the data pertaining to the

combustion of materials in realistic fire situation with which the data

from the laboratory scale tests can be compared to examine whether the

test apparatus is designed properly in any respect.

Of these subjects, some are supposed to start from the second fiscal

year according to the research plan, and some are somewhat behind the

schedule because of budgetary reason etc. So, only three of these, which,

at the moment this paper is written, have not advanced either as was scheduled, are described here.

(Note) SUT

BRI FFPRI

RIPT

FRI

Science University of Tokyo

Building Research Institute, Ministry of Construction

Forestry and Forest Products Research Institute,

Ministry of Agriculture and Fishery

Research Institute of Polymer and Textile,

Ministry of International Trade and Industry

Fire Research Institute, Ministry of Home Affair

420
BURNING CONDITION IN EARLY STAGE OF FIRE

Various types of furniture are considered to be the major media to

develop a small fire e.g. a lighted cigarette or a candle fire to a hazardous one. The increasing use of plastic materials to furniture may

bring more rapid fire spread than ever, so there is growing importance in

studying the burning behavior of furniture to better understand the nature

of fire in early stage. The bum tests were run in the test room of Center

for Fire Science and Technology, Science University of Tokyo for various

kinds of chairs as a representative furniture to investigate into the

intrinsic burning properties and the potential hazard of the chairs.

The bum room and the positions of measurement probes are shown in

Figure 1. The measurements were made of the temperature profile of the

fire plume, weight loss of the chairs, optical smoke density in the room,

flame height, smoke layer height in the room, radiation from the flame,

doorway flow velocity, 0^, C0? , and CO concentration in the room. Here are some of the primary findings of the experiments:

(a) Burning Rate

The ratio RW*, which is given as

w - wTmax

RW* = (1.1) w - w

o Tmax

where w : residual weight of the chair

w

q

: original weight of the chair

w^ : final residual weight of the chair

Tmax

is plotted with time for each chair. The burning rate of a chair just

after the ignition may vary one after another depending on the way it is

ignited, but if we focus our attention on the primary period of the

burning, almost every chair looks to exhibit similar tendency. The test

data on weight loss were analyzed assuming that the burning rate of a chair at any given time within primary period of burning is proportional

to the residual weight, hence the burning rate of each chair was reduced

to the following expressions:

-At

R = A w e i . o

421
where R : burning rate

t : time

A : constant that is specific to the material

Table 1 shows the value of constant A experimentally obtained for each

chair.

(b) Flame Radiation

As is shown in Figure 3 for example, the changes of burning rate and

radiation flux look very alike, and a close relationship can be perceived

between the two. In fact, by looking into the burning rate and radiation

flux at at the most vigorous period of burning, it can be found that the

measured flame radiation flux is proportional to the burning rate.

Also, the relationship described as follows:

Qr ^ X'

1 - 80

[1.3)

can be observed between the experimentally measured radiation flux(Q

R

) and

the distance of the radiometer from the fire source center (X)

.

These findings and the data regression as shown in Figure 4 yield

the final result as follows:

Qr

= 274 R X

-1 * 8

(1.4)

where R : burning rate(g/s)

X : distance from the center of fire(m)

2 Qr

: radiation heat flux(kcal/m h)

BURNING CONDITION OF DEVELOPING THROUGH DEVELOPED STAGE OF FIRE

This study is to analyze the thermal and atmospheric condition to

which products or materials are exposed in fire by means of full scale

experiments. The experiments are supposed to be run using full scale fire

test facility of BRI, which is shown in Figure 5. However, with the

limitation in the expense and work force, it is difficult to run a large

number of experiments until we get fair results. It is felt that to

conduct the experiments and to analyze the results effectively, we have

to, first of all, get some means to reasonably estimate the rate of flow

422
Through the doorway of our test facility. The flow rate must be given from

some easily and quickly measurable quantities because otherwise we will

have to conduct very long experiments even for studying the phenomena at

steady state condition, and furthermore we will have a lot of trouble when

we attempt to investigate transient fire.

Although it was encouraging that Steckler(l) has successfully

correlated the opening flow rate with the temperatures in the fire room

and at the opening, we had not been sure that the same kind of correlation

holds for our case where test facility consists of two rooms, and fire was expected to be more intense than the Steckler's case. Consequently, the

preliminary tests for doorway flow rate were conducted with the

consultation of Steckler of NBS, who were invited to Japan during the

experiments. The test data were reduced in basically the same way as Steckler's. The results of out- and inflow rate, which are respectively

shown in Figures 6 and 7, suggest that the doorway flow can be reasonably

estimated by the room temperatures and a simple hydrauric model with 0.68

for flow coefficient.

Once we have the inflow rate of air through the opening at our

disposal, we can proceed to estimate the mole outflow rate of species.

Assuming that the compositions of the fuel are known, the mole outflow

rates of species are given as follows:

. s .o

n^. — n, ^

i

w.

X

A

CO,

+ X

A

CO

( 2 . 1 )

. o

= ru

A A

alX

co9 + " xco'

1

; *4 " : ;(x

co9 xco^ . o ru ( 2 . 2 )

a X

. s n

A

C09

CO,

. on

o. (2.3)

a X

CO

CO (2.4:

423
X°

. o

D

A

X C0)

. o (2.5)

d A

- (X

. o V

CCh

+ XCO^ . o

( 2 . 6 )

and also heat release rate in the bum room can be given as follows: By

applying the oxygen consumption method to the room,

1 A

E

1

* a ^ XC0

Q

=

2 XC0^

+

2

^ ^CO? + XC0^ ' X

“ E

2') XA

CO

\\

(2.7)

and these equations are related with mass inflow rate of air as given by

the following equations:

.o \

(1 n ‘V °

2

= V' ( 2 . 8 )

A

0

(1 - Xn0

) (1 - X°

h J

2 o^ (2.9)

„ Ho 0

.o 2

n.. n — in H 2° D- 3 (2.10)

where D’= W (1 - X ) (1 - X ) + W X (1 - ^ ) + W X (2.11)

2 2 2 2

424
It can be said that the above equations for the mole outflow rates

of species through the opening of the fire compartment provide a basic

tool to analyze the phenomena that are going on in the fire room. The

symbols in the equations are given in Appendix.

BURNING BEHAVIOR OF DAILY GOODS

This study, conducted by Fire Research Institute, aims at

contributing basic data on toxicity hazards, in particular to the

determination of burning condition for toxicity test apparatus as well as

to evacuation, rescue and fire fighting activity etc. Various kinds of

combustibles are burned in the semi-full scale model compartment under

forced ventilation condition, and the generation characteristic of species

from the combustible are investigated.

A small scale combustion chamber has a disadvantage in that it

cannot produce a realistic fire condition. By a tube furnace, on the other

hand, one may run tests under the conditions that is nothing to do with

real fire, since it can attain any condition. Contrarily, full-scale tests

are too costly to run, although most desirable in the other respect. This

study using semi-full scale compartment will play a part to bridge the

small scale to large scale fire tests.

(1) Experimental Setup

The apparatus used for this experiment is a cubic steel chamber

lined with insulation material as shown in Figure 8, and is equipped with

a mechanical air supply system, a vent and a weight loss measurement

system.

Various liquid fuels, and element materials of products i.e.

n-hexane, wood, cotton, methacrylate, polyetyrene, polystyrene etc. are to be burned as the fuel, and analysis is to be made of the gas sampled at

the vent together with air supply rate, mass burning rate, smoke density,

and the room temperature profile.

(2) Test Results

The experiments and the analysis of this study are still under way,

so the followings are the outline of the intermediate findings.

CO, Acrolein and NO^ are mentioned as the primary toxic combustion

products of n-hexane and wood. The maximum generation of CO was 0.3 g per

425
1.0 g fuel for wood and that of n-hexane was less than half of that value

for wood. The maximum generation of acrolein was about 3 mg both for wood

and n-hexane.

The generation of acrolein, CO and C0 9 for the wood combustion are plotted versus "air supply rate/buming rate" (relative burning rate) as shown in Figure 9-(l), (2), and (3). The generation rate of C0 o per unit

weight loss tends to be small at initial period when water vaporization is

included in the weight loss. The generation of acrolein is largely

affected by temperature, in other words by whether or not flame is formed,

in which a secondary decomposition occurs. A significant fluctuation was observed in the generation of CO probably because of the difference of

temperature in local position in the chamber. The generation rates both of

CO and acrolein due to the burning of PMMA and PE were smaller than the case of n-hexane. It is suspected that the flame formed in case of the

burning of these material facilitate the transition of CO to C0

?

. When the air supply rate was large, flame was observed above the

vent (or chimney), which means the combustion was not completed, in a strict sense, at the bottom of the vent, where the gas was sampled for the

analysis. But in case that flames are observed, the gas analysis shows

that the concentrations of CO and organic species are rather low while C0

? concentration was high, so the sampling point would not have made much

difference if it were positioned above the flame.

The concentration of NO^ higher than 100 ppm were not observed.

The data of the various gas components in the combustion product gas

other than acrolein are now being analyzed.

REFERENCES

(1) Steckler , K.D. : Flow Induced by Fire in A Compartment, NBSIR 82-2520,

1982.

(2) Mizuno,T. and Kawagoe,K.: Burning Behavior of Upholstered Chairs, to

be presented to the 7th UJNR meeting as a support paper, 1983.

(3) Nakaya,I., Tanaka, T. and Yoshida,M. : A Measurement of Doorway Flow

Induced by Propane Fire, to be presented to the 7th UJNR meeting,

1983.

(4) Parker, W. J. : Calculation of The Heat Release Rate by Oxygen

Consumption for Various Application, NBSIR 81-2427-1, 1982.

426
Figure 1. Experimental Setup of Burning Tests of Chairs

• Temperature

O Smoke density

© Radiation

a Flow velocity

Gas concentration

427
incn

428

Figure

2.

Reduced

Residual

Weight

RW
c

•HE

m

2: 1—

1

H

09 09 0V 0£ 01 0L

(oss/2) .iraqo v 9° SuxiLzng

429

Figure

3.

Burning

Rate

and

Radiation

Intensity
<

<4-1 O

0

S3 <

oo

'cr o

o

CM "Sf oi *3- to to to

M- W TO VD Cl VD o o •—< o o o o

o o o o o o o

as >

oooooooo

O CM O \D vD CM

I LO tO LO MD CTl LO

I O O CD O O O

I O O O O CD O I o o o o o o

O H

c- lo o o

o o

c o

0

0 HrMO'jLnoNcoCiO (M TO T in vD n

(u -.m/TEOsO xnijj ibsh uoiiEip-efc'

430

ri

pure

'l

.

Radiation

Heat

Flux

as A

Function

of

R/X
kTDo

Cl3O

c_> O

lZ

CD

c£CQ

M-iOPo

aj UL

+->

(/) <D H

<u •H

u.

rtv

oo

d 3 O ~

LO CD

0>

S-i 3

DO •H

431
432

Figure

6.

Correlation

of

Opening

Mass

Flow

Rate

with

Idealized

Flow

Model

(Outflow)
(S/6>()3iVy MOld SSVW 9NIN3dO

433

Figure

7.

Correlation

of

Opening

Mass

Flow

Rate

with

Idealized

Flow

Model

(Inflow)
Smoke

meter

434

Figure

8.

Experimental

Arrangement

of

FRI
Ex

ha

O _o

Csl

. O

o oo

° OCDO

CD o

po rsi

(S| dines 6/6) 20D

S-CJ T3O

O

CDc

c

s-3

CD

4-> 03

Scr> c

s- -Q

C\J \ O CD

<_> -<-> “Ocoo

c

CDo

u

03

<D

tC3C

S->>

Q.O-3

CO

S03

( a| diups 6/6w) luajo-oy

435
Appendix: A METHOD TO ANALYZE THE BURNING BEHAVIOR GASEOUS FUEL

IN COMPARTMENT FIRE EXPERIMENTS

Combustion in fire usually consists of the thermal decomposition

of solid combustible and the gas phase combustion of the gasified fuel.

Since it is quite difficult to deal with such coupling phenomena, it

will be more prudent to approach the gas phase combustion only first of

all separately from the solid decomposition.

The experimental facility shown in Figure A-l can be used to investigate the phenomena that take place in the gas phase combustion in

fire by burning gaseous fuel in the bum room. The primary targets of

this experiment are, for the first step:

(1) To obtain empirical relationships between the indexes that

describe the fire phenomena, e.g. the consumption rates of fuel

and oxygen, the generation rates of carbon dioxide and carbon

monoxide and etc., and the factors that affect the burning

behavior, e.g. fuel input rate, air inflow rate, room fire

temperature, species concentrations, etc.

(2) To investigate into how the species in the effluent gas from the room of origin undergo change in the adjacent room. and for the next step:

(3) To elucidate the mechanism of gas phase combustion in fire and to develop a model to predict the combustion, in particular the

formation of the species in fire room.

To address these goals, it is obvious that not only the species

concentration but also the consumption or generation rates of the

species are needed. For this purpose, of course, if the more gas

analyzers are available, it will be the more advantageous, however, they

are often practically limited to those for oxygen, carbon dioxide and

carbon monoxide in point of view of reliability and ease of handling.

So, it will be indispensable to implement the way to obtain the above

mentioned rates making best use of the gas analyzers available. The

method described by Parker(l) regarding the application of oxygen

consumption method will be most suggestive.

It is assumed here that the following chemical formula holds for

the combustion of the fuel used in the experiments:

436
CaVcN

d

* (a

g b c b d

- - + )0 — (a -g) C0

? + - H 0 + g CO + - N 242 2 2"

which seems to be a reasonable assumption for engineering objectives.

Among the species that appear in the formula, the generation rate of

carbon monoxide will strongly depend on the fire conditions, and also

there is a chance that a part of the input fuel flow out of the room

when the input rate largely exceeds the air supply through the opening.

.S.S .5 .S .S .S Let n,. n~ n„n , h rn , nu _ and n,T be the mole outflow rate of

i, U9 , LU9 Lu ^2^

fuel, 0 7

, CO,,, CO, H^O and , respectively. We only deal with a quasisteady condition, then the conservation equations for each species turns

out to be as follows:

. s .0 . * n^ — n^ - n^.

. s n

0

2 n* W_p (a

g b c

- + ) 2 4 2 nL = n* W

f

(a - g) CO,

nco

n

f w

f

s

nH

2 0 nH

? 0

+ n

f

W

f

"

. s .0 . * „

n

N

= n

N

+ n

f

W

f

' 2 2 2

CD

(2)

C3)

(4)

(5)

(6)

. * .0

where n^, W^ and n^ are respectively the mole burning rate, mole weight

and mole input rate of the fuel, and ri° , n° and ri° stand for the

O2 h 2 u n 2 mole inflow rate of 0^ , f^O and N

2 from exterior space, which is assumed

to be at ambient condition in any aspect.

We assume that the gas analyzers are available only for 0„, C0 o and CO, and water is filtered out in the sampling line before the

analyzers. Assuming in addition that the fraction of each species in the

sampling line is the same as that in the sampled gas, we have the

following relationships between the mole flow rate of each species and

its measured value:

437
A "0,

*o

- t7)

- "f

* A o,+ Aco,* A co+ an

2

. s A

n C0,

xco

= : C8)

-S . S . S . S .S n

f

+ n 0 o + nC0o + nC0

+ n

N

2

. s A

nC0

X = (9)

.5 . S .5 . S . S ru + nn + nro + n + n f 0

2 C09 CO

From Eqs.(3), (4), (8) and (9), we get

A

XC0

g

= a (10) xA

+ xA

C0

2 CO

Also from Eqs.(2), (7), (3)+(4) and (8)+(9)

s g b c A

n

n

- n- W (a - - + - - - Off ) X

2 4 2 °2

= (11) n

f w

f {(a - g) + g } xco?

+ x co

• Noting these relations, the mass burning rate of fuel, n^ can

be given as:

A A

XC0?

+ xco

n

f W = n° (12)

A A 1 A b c A A

u

2 a(X

0 9 + XC0

2

+

2

XC0^

+ ' “ )(XC0

2

+ ^O-1

Substituting Eq. (12) into Eqs.(l)-(6) yields the equation for each

species in the effluent gas from the room of origin as follows:

438
A A

1 XC0 9 + x co Af = n°

f

' n° (13)

r r W

£

D 2

A 1 A b c A A

a(X

C0 9 +

9 XC0} + ( 4

" 2 )(XC09 + XC0 } 0

" 02

• "°

2

- ^ “

T

"°

2

C 14 )

A

a Xfn

• s 2 -° nco

= n

o

(15:) 2 - D 2

A

a xco \o = n

o

C16) tu

D 2

b A A

- (XC0

+ xco

}

• s .o 2 C0 2 C0.o V

= V

+ I'"- \ W

d A A

- (x + X ) .s .o 2 co 2 LU .o nN

= nN

+ n

0

(18)

n

2 2 D 2

A A 1A bcA A

where D = a(X

Q ^ + X^ + - X^) + (---) (X^ + xco) (19)

Since n

0.

. o

n.

. o H

2 0

and nN

2 in the Eqs . (12) - (19) are mole flow? rates

of oxygen, water vapor and nitrogen that flow into the burn room, they

can be easily estimated provided that the air inflow rate is given. The

other quantities are either known or measurable. So, it follows that the

consumption rate of fuel and oxygen, and the generation rates of carbon

monoxide can be obtained.

439
In addition, if the oxygen consumption method is employed, the

heat release rate in the burn room can also be obtained as follows:

According to the oxygen consumption method,

Q

= W

Q ^

{ E

1 (n

Q ^

- n

0 ^)

" CEj - E

2

)

- nCQ } (20)

where E^ : Heat release per unit mass of oxygen consumed due to

complete combustion (MJ/kg 0 9 )

E

9

: Heat release per unit mass of oxygen consumed due to burning

of CO to C0

2 (MJ/kg 0 9 )

Substituting Eqs. (14) and (16) into Eq. (20) and eliminating n^ and n^

yield:

Q

=

A 1 A b c A A

E l< a <XC0,

* - xco>

* t-

- -)( xco

2

+ W } -

D

1 A

E

2'1 2

XC0 o

( 21 )

Mole flow rate of 0 ?

, H

2 0 and N,, that flow into the bum room can

be obtained also based on the method given by Parker(l). Assuming that

inflow air is not polluted with CO

?

, we get

o

o

.0 .o .o nN

2

+ "0

2

+ nH

2 0

. o

. o V . O .0 . o "N

2

+ n

°2

+ nH

2 0

( 22 )

(23)

(24)

When the gases are analyzed by filtering out water in sampling line, the

relationships between mole flow rates and measured concentration will be

440
(25)

. o n„

.o .o n

N

2

+ n

0

2 S

’

. o

n,.

.o .0 nN

+ n

0

2 2

Then, from Eq. (21) / (Eq. (21) +Eq. (22) ) and Eq. (24) we obtain

or

. o

n o

= X,

. o .o *0 + *N

n0

+ n

u N

2 2 2 2

<S. - xo

2

' XS

2

'2 “2 ~2

* "2

- V2

c 1 - W2 A

0 A0

We cannot measure , however, since we have XQ

+ X^ = 1. 2 2 2 A° A

0

^2

= ^2 ^

" Xh2°”

) = ^ " X°

2

^ ^

(26)

(27)

A H

? 0 analyzer may not be available, but the way the concentration

of Hn 0 can be estimated is also given in Ref. (1)

.

To obtain the mole outflow rate of each species, we further need

to have fairly accurate inflow rate of air through room opening, m . If

3. we can have accurate enough air inflow rate, we can use the following

relation:

W

N

2 n

N

2

+ W

0

2 n

0

2

+ W

H

2 0

nH

2 0 m

a (28)

.0 .0 .0 Dividing Eq. (28) by + n

Q

+ nR Q

, we get

.0 .0 .0 CL nN

+ n

0

+ nH 0

= o o“

W

N

2 Xn2

+ W

0

2

X0

2

+ W

H

2 0

XH

2 0

(29)

Substituting this into Eqs . (22) - (24) , and using Eq.(25) and (26) yield:

. o

X°2

(1 ' S0

’ n = m (30)

441
. o m

a (31)

7

. 0 n„ m (32)

D' a

A

0

where D' = W (1 - Xn ) (1 - X N„ 0_ I

o

(33)

Equations (12) -(19) and (30) -(33) provide a way to obtain the mole

outflow rates of species and thus present a basic method to analyze what

is going on in the room of origin. Probably the same discussion as the

above can be applied to the doorway opening between the adjacent room

and the exterior space to analyze the phenomena that take place in the

two room structure. This is important, in particular when one attempts

to clarify how the excess fuel behaves outside the room of origin.

REFERENCES

(1) Parker, W.J. : Calculation of the Heat Release Rate by Oxygen

Consumption for Various Applications, NBSIR 81-2427-1,1982.

442
•H•H

CJrt u-

+-> c

<DE

•Hu

<DPiXw

<D XH

4-1Oo

•r-T +J

rtE0) Xa

coi <

CD4a0£

a.

443

Discussion After T. Tanaka's Report on STUDIES ON DETERMINATION OF BURNING

CONDITION FOR THE TOXICITY TEST

TSUCHIYA: Dr. Tanaka performed experiments in which CO and CO2 occurred from

burning wood. We have done similar experiments but on a smaller scale. Is it

possible to combust the data into our methods of expression so that we can compare our results?

TANAKA: First of all, this study was conducted not by me but by Mr. Morikawa of

the Fire Research Institute. I am not sure whether or not this kind of

combustion will be possible or not but I'm sure Dr. Saito may be able to help.

He has more knowledge about this matter.

GANN: Dr. Tanaka, in your two room burn experiments, do you think that the

outer room affected the flow through the doorway between the rooms? Or, worded

differently, would you expect the same results if the outer room were not

threatened?

TANAKA: I think it's possible that the next compartment has a certain effect on

the floor. When conducting this test between the second compartment and the

outer space, there was a very large opening. So at the current stage because of

this opening, I don't think there was a substantial effect of outflow from the

doorway. I think it will be wise to study, when we conduct the next experiment,

more openings between the second compartment and outside, so we can check what

kind of effect it has.

STECKLER: Certainly if a hot layer forms in the second room, it will affect

flow through the doorway. In these experiments a hot layer certainly did

form. The flow is driven through the doorway as a result of the differences

between the static pressure profiles. The temperature profiles in the room, in

turn, establish the pressure profiles. The second room certainly does have an effect on the flow through the door. These experiments confirm that this

relationship with this model works when you are working between two rooms, both

with hot layers.

GANN: We have an informal report from Southwest Research that they burned a large room, with a large fuel load and it flashed over. They then repeated the

experiment with a corridor connected outside of the room and the same fuel in

the room and no flashover. I have not seen the data upon the gases coming out

the door of the room, but I suspect that they are two very different cases.

ALARIE: In the chair burn experiments, how were the chairs ignited?

MIZUNO: We used about 150 of methanol and we used Softex, that is a kind of

illustration board, and we soaked the illustration board with methanol and put

it on the chair and ignited it.

ALARIE: Please show us again the residual way versus the time way? The best

chairs are chairs #6 and #9. What are they made of?

MIZUNO: Chair #9 is kind of traditional type of chair and in a similar

material. Chair #6 is polyurethane foam. I think that either way the

upholstery is treated with a retardant. The furniture we used to burn are u^>*d ones so we do not have much information about the treatment.

445
ALARIE: What are the worst chairs, chairs #5 and #13, made of?

MIZUNO: I think the filling is the same as in #6 and #9. However, the

upholstery cover was easier to ignite, easier to burn and also #6 was much

easier to burn and it burned quickly.

446
CONDITIONS CONDUCIVE TO THE GENERATION OF HYDROGEN

CYANIDE FROM FLEXIBLE POLYURETHANE FOAM

by

Barbara C. Levin, Maya Paabo,

Mary Lou Fultz and Cheryl Bailey

Fire Toxicology Research

Center for Fire Research

National Bureau of Standards

Washington, D.C. 20234

7th Joint Meeting

U.S. - Japan Panel on Fire Research and Safety

UJNR, Washington, October 1983

447
Conditions Conducive to the Generation of Hydrogen

Cyanide from Flexible Polyurethane Foam

Introduction

The greatest number of fire deaths in the United States results from

fires which occur in one and two family residences [1]^. While the initiation

of most U.S. fires are attributed to heating and cooking accidents, those

fires responsible for the largest percentage of fire deaths are initiated by

cigarettes inadvertently discarded on soft furnishings, such as upholstered

furniture and bedding materials [1,2]. Similar results have been found in

Canada and the U.K. [3]. One of the scenarios leading to these fire deaths is

envisioned as follows: the occupant falls asleep with a lit cigarette which

drops into the crevice of a chair where it smolders for an undetermined length

of time. The person may wake during this time and go to bed not realizing the

cigarette is still smoldering in the chair crevice. The unsuspecting family

may be asleep when the chair finally ignites causing a fire which can now

spread and produce flashover conditions in the room. In many of these cases,

the family members die from smoke inhalation (not burns) either in their beds

or close to their beds, an indication of little or no effort to escape.

Whether the occupants are incapacitated or killed by the toxic combustion

products which are generated by the early smoldering conditions or those

generated when the chair bursts into flames is unknown.

More than 90% of the upholstered furniture manufactured today contains

some formulation of flexible polyurethane foam [4]. In 1980, over three

million tons of flexible polyurethane were produced for use in the furniture,

transportation, building, leisure, and shoe industries [5]. Flexible poly-

^Numbers in brackets refer to the literature references listed at the end of

this paper.

448
urethane foams, therefore, are important materials to evaluate for fire

safety. Most of the tests that have been proposed for upholstered furniture

assess ignitability characteristics, burning rates, and smoke

production [3]. In addition, the toxicity of the total gaseous atmosphere

produced by the thermal decomposition of flexible polyurethane foams under

different conditions has been examined [6,7,8] and extensive chemical analyses

of the combustion products have been performed [9].

All nitrogen-containing polymers, including flexible polyurethane foam,

are potentially capable of producing the highly toxic combustion product -

hydrogen cyanide (HCN) . This work describes a two-phase thermal decomposition

process which simulates a realistic fire scenario. These circumstances

produce higher concentrations of HCN from flexible polyurethane foam than if

the same material is thermally decomposed under strictly smoldering,

pyrolytic, or flaming conditions.

Materials and Methods

The flexible polyurethane foams, GM-21 and GM-24, that were used in this

study were obtained from the Products Research Committee (PRC) on the Fire

Safety Aspects of Cellular Plastic Products, Office of Standard Reference

Materials, National Bureau of Standards [10]. The formulation of GM-1 consisted of 68% polyol (glycerine-based polyoxypropylene and ethylene glycol)

and 24% isocyanate (toluene diisocyanate 2,4 isomer - 80%; 2,6 isomer -

20%). The formulation of GM-24 is the same as GM-21 except for an added

chlorinated phosphonate ester fire retardant (4.7% by weight).

449
GM-21 was tested under small-scale laboratory conditions according to the

NBS toxicity test method [7] under flaming (25°C above its autoignition temperature) and non-flaming (25°C below its autoignition temperature)

conditions. The material samples in these experiments were decomposed in a

preheated cup furnace (Fig. 1) located below the 200 liter animal exposure

chamber (Fig. 2). The system is static, i .e . , all combustion products generated in the cup furnace go directly into the exposure chamber and remain

there. Syringe samples of the gaseous atmosphere were analyzed for HCN with a

gas chromatograph equipped with a thermionic detector [11]. In most

experiments, natural convection was the only means of mixing the gases in the

chamber. However, in some experiments, the addition of a stirrer to the

exposure chamber made no difference in the measured gas concentrations when

compared to the experiments without the stirrer. This indicated that satisfactory mixing occurred even without the stirrer.

Large-scale room burns of GM-21 were performed as follows: slabs of

polyurethane foam (approximately 41 x 64 x 15 cm) were placed on a load cell

in a room (2.4 x 3.0 x 3.0 meters) (Fig. 3). Smoldering of the foam was

initiated by a heated wire. In other experiments, polyurethane chairs were

burned in the same room. In these experiments, the smoldering was initiated

by a lighted cigarette placed into the crevice formed by the seat cushion and

right side arm. Smoldering proceeded for approximately one hour before the

chairs burst into flames. In both the large-scale room burns of slabs and

chairs, the HCN sampling point was from the 1.7 meter probe (Fig. 3). The

gases in the room were not homogeneous, but layered due to the hot buoyant

plume

.

450
Experimental Results

When GM-21 was tested according to the NBS toxicity test method, toxicologically insignificant concentrations of HCN were generated (Fig. 4).

Thirty mg /i and 20 mg/£ of GM-21 produced 15-20 ppm and 5-10 ppm of HCN in the

flaming mode and non-flaming mode, respectively. Burning the polyurethane

foam under flaming conditions from the start did not produce the increased

amounts of HCN regardless of the temperature at which the cup furnace was

set. Figure 5 shows two flaming experiments, one where the cup furnace was

set at 420°C and the other where the furnace was 800°C. In both cases, no

more than 20 ppm of HCN was generated throughout the experiments, which, in

these cases, lasted 60 minutes.

In the large-scale room burns of slabs of GM-21, little HCN was

generated (approximately 10-20 ppm) as long as the material continued to

smolder. However, if after an initial smoldering process, the material burst

into flames (a phenomenon, which often occurred), the levels of HCN rapidly

increased (Fig. 6). This increase in HCN immediately following the point of

flaming was also seen in experiments in which the polyurethane foam chairs

were burned (Fig. 7).

Dr. Alarie , using the University of Pittsburgh toxicity test method, has

also observed an increase in HCN generation when GM-21 bursts into

flame [6]. In the University of Pittsburgh method, the material is thermally

decomposed at temperatures which increase 20 °C per minute and will flame when

it reaches its autoignition temperature.

451
In order to understand this HCN production, we attempted to reproduce the

large scale conditions in a small scale laboratory test. First, we heated

GM-21 at 375°C (non-flaming conditions) in the cup furnace for different time

periods and then raised the temperature of the furnace in an attempt to ignite

the remaining sample. Ignition was not achieved, but heating the residue

caused a large increase in HCN. Figure 8 shows the HCN production after

heating the samples (20 mg/£) at 375°C for various times from 15 minutes to

60 minutes. As long as the temperature of the cup furnace remained constant

at 375°C, less than 20 ppm of HCN was generated. At the arrows, the temperature of the furnace was raised such that the temperature increased at a rate

of approximately 13 °C per minute until it reached 800 °C when the experiments

were terminated. The large increase in HCN follows the rise in temperature in

each case. Figure 8 also shows a pronounced dip in the HCN concentrations

about 20 minutes after the start of the temperature ramping. The reason for

this reduction in HCN at this point is not known.

Examination of the residue at the end of the 375° temperature exposure

showed both a black char and a yellow oil. The black char was removed and

placed into a clean cup furnace which was preheated to 600 °C. Figure 9 shows

that most of the HCN is generated by heating the black char, although small

amounts were produced when the yellow oil was heated. These results differ

from those of Woolley [9] who heated flexible polyurethane foam at a low

temperature (200-300 °C) and then collected and condensed the yellow smoke that

was emitted. When the condensed yellow smoke was heated to 800-1000 °C, HCN

was generated. In the NBS experiments, the residue remaining after the

initial low temperature exposure was heated, not the smoke condensate.

452
As we now knew that the HCN was being produced from the char that was

formed during the initial low temperature exposure, we hypothesized that

increasing the char yield might increase the HCN production. Since many

phosphorus-containing fire retardants in polyurethane foams act by increasing

the char yield, we tested GM-24, a fire retarded PRC material. Figure 10

shows that the fire retarded foam produced twice as much HCN as the corresponding non-fire retarded foam when exposed to this two phase decomposition

procedure. Residues from both GM-21 and GM-24 were generated from 30 minute

low temperature exposures (375°C). These residues, when removed, cooled,

weighed and reheated to 800°C, produced approximately the same amount of HCN

as their respective virgin foams exposed to the two phase decomposition procedure without interruption (Fig. 10).

The possibility that the HCN was adsorbed on the char and released by

heating was examined by both alkaline and acid extractions of the chars. No

HCN was produced indicating that the HCN is not adsorbed but more likely is

being generated from the breakdown of a nitrogen-containing compound peculiar

to the char. Elemental analyses of the foams and the chars showed that the

percent nitrogen (% N) relative to the starting material is increased in the

char (Table 1). The fraction of nitrogen in the fire retarded char (GM-24) is

equivalent to that found in the non- retarded char. Table 2 shows that

0.3 grams of char were formed from heating 3.88 grams of GM-21, whereas

0.7 grams of char were formed from 3.88 grams of GM-24. It is thus likely

that the fire retarded char produces twice as much HCN upon heating because

GM-24 produces twice as much char as GM-21.

453
If all of the nitrogen in the foam formed HCN, the theoretical yield of

HCN from the total foam (3.88 grams or 20 mg/H) would be 1450 ppm. In experiments at 375°C, an average concentration of 10 ppm or 0.7% of the total theoretical yield is observed. At 800 °C, 8% of the total nitrogen appeared as

gaseous HCN. Analysis of the chars in the same way showed that 40% of their

total nitrogen was recovered as HCN. These results suggest that the nitrogencontaining compound found in the chars is more likely to generate HCN when

heated than the nitrogen-containing molecules in the original foams. More

work is in process to determine the chemical and physical mechanisms of HCN

production from the chars.

Conclusion

This study has shown that simple, single-mode thermal exposures (flaming

or non-flaming) of flexible polyurethane foam do not generate the HCN found in

the dominant real fire situation. A two-stage chemical process in which first

a char is formed during the smoldering of the polyurethane and then HCN is

produced when that char is heated is the more likely and potentially more

dangerous scenario. The chemistry of the process remains to be elucidated.

References

1. Fire in the United States, 2nd Edition. Federal Emergency Management

Agency, U.S. Fire Administration; July 1982, 181 p.

2. Clarke, F.B. and Ottoson, J., Fire death scenarios and fire safety planning. Fire J. 70_:20-22, 117-118 (1976).

3. Sumi, K., and D* Souza, M.V., Fire safety of soft furnishings - an

overview. Fire and Materials Jk16-22 (1982).

4. Krasny, J., National Bureau of Standards, personal communication 1983.

5. Woods, G. , in Flexible Polyurethane Foams. Chemistry and Technology.

Applied Science Publishers, London and New Jersey (1982).

454
6 . Alarie, Y.C. and Anderson, R.C., Toxicological and acute lethal hazard

evaluation of thermal decomposition products of synthetic and natural

polymers. Tox. Appl . Pharm. 51 :34 1-362 (1979).

7. Levin, B.C., Fowell, A.J., Birky, M.M., Paabo, M., Stolte, A., and

Malek, D. , Further development of a test method for the assessment of the

acute inhalation toxicity of combustion products. Nat. Bur. Stand.

(U.S.) NBSIR 82-2532, June 1982, 143 p.

8. Hilado, C.J., Relative toxicity of pyrolysis products of some foams and

fabrics. J. Comb. Tox. _3_: 32—60 (1976).

9. Woolley, W.D. and Fardell, P.J., The prediction of combustion products.

Fire Research _1_: 11-21 (1977).

10. Products Research Committee. Materials bank compendium of fire property

data. Nat. Bur. Stand. (U.S.), [Washington, DC] February 1980.

11. Paabo, M. , Birky, M.M., and Womble , S.E., Analysis of hydrogen cyanide in

fire environments. J. Comb. Tox. 6:99-108 (1979).

455
1000

ml

QUARTZ

BEAKER

92

mm

O.D.

15

cm

high

456

HEATING

ELEMENT

IN

BOTTOM
Ui5 c/> o- &

is °

UI <

457 • auw

<u •u

<u rH

83oaI r-l iH

COno

u-tuVXe

83 XO0) u3

COo

a.xw• CM0) V-3

<50 •H
3.0m

458

Figure

3

.

Configuration

of

large-scale

test

room.
(ujdd) NOH

c

E

UJ

5

h459

Figure

.

HCN

generation

from

small-scale

laboratory

tests

on

flexible

polyurethane

foam,

GM-21.
CM CM t-

(uJdd) NOH

o

oo

o

N.

o

<0

o

in

o

o

CO

o

CM

o

o

c

E

Hi

460

Figure

5.

HCN

generation

from

flexible

polyurethane

foam

(GM-21)

decomposed

in

the

flaming
(ludd) NOH

o o o o o

T- CO CO cv O

1HDI3M 31dWVS %

461

Figure

6.

HCN

generation

and

weight

loss

during

large-scale

room

burn

of

flexible

polyurethane

foam,

GM-21.
LU

s

p

(uidd) NOH

462

Figure

7.

HCN

generation

from

the

thermal

decomposition

of

flexible

polyurethane

foam

chairs.
(uidd) NOH

463

Figure

8.

HCN

generation

from

flexible

polyurethane

foam

(GM-21)

exposed

to

a

two-phase

decomposition

process.
(uida) NOH

464

Figure

9.

HCN

generation

from

flexible

polyurethane

foam

(GM-21)

and

the

black

char

and

yellow

oil

residues.
(uidd) NOH

O

LU

oc<

oc

LU

CL5

LU

hCLo v

£>

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03

CMI X

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01c

01oo 2uX

01

>-• D

00

>H

U-.

465

polyurethane

foam

and

their

residues.
Table o O

Q 0> <0

N- 10

CM CM O O • • o o

0) CM •cT

m CL

Q

Q

Q CO «5t <*

msm z o% 2 Z Z IB o oi CM < w X

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_l

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CD (0 CD 10 CD 10

yj

a

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CM 2 < GO 2 < m o O &» k> &Z3 cu <C 3 cu a js; JS a £ £

LL

O o llO o

466
GENERATION

OF

HCN

FLEXIBLE

POLYURETHANE

FOAM

TJ0

w.) 0 O 00 CO 0 <0 >OO 0

CO

O

cc

O z 0

LO • 1 CO• 0 0 0 XA

CO

CO

CO o

2oc O O CO Ea aam O O

q. ° E x u>

Q.

m ^ d CO o

CM

O

CM

O

CO

CM

lO o

DC

Li.

OX CDo

+-I o

k.oo

SZ

I- o

IT)

CMT

® 3 CO

£2

O

CO

CM

U)

CD « 5 s o

UD

CMS -5 01 CO

=> CO

£2

467

Char

610 -

200

(0.7

g)

Discussion After B. Levin : s Report on CONDITIONS CONDUCIVE TO THE GENERATION OF

HYDROGEN CYANIDE FROM FLEXIBLE POLYURETHANE FOAM

TSUCHIYA: I remember there was an instance in Japan, about 10 years ago, in

which two elderly people were killed in a small fire involving a polyurethane

mattress. As a result of this incident, there were serious discussions between

a person representing the polyurethane industry and two toxicologists who

analyzed hydrogen cyanide level in blood. The study on the evolution of

hydrogen cyanide from various nitrogen-containing materials involving

polyurethane was advanced very much, five to ten years ago in Japan. I'd like

to comment on Mr. Morita's work on the generation of hydrogen cyanide. I hope

you are aware of that paper in the Journal of Combustion Toxicology. Also we performed our own study on the subject and included these results. I'd like to

mention the formation of hydrogen cyanide in fire. Hydrogen cyanide formation

is almost proportional to the nitrogen content of materials, except in some materials like polyethylnitrate , which produces hydrogen cyanide much easier

than others. The second point, in pyrolysis conditions hydrogen cyanide

formation depends on temperature, the higher the temperature, the easier the

formation of hydrogen cyanide. In flaming, the temperature after pyrolysis of

the sample increases. From smoldering to flaming the temperature increases,

that's why hydrogen cyanide formation is viscous. For a rather brisk flame,

hydrogen cyanide was formed and consumed in the flame. Once hydrogen cyanide

formed but by the flame, hydrogen cyanide is consumed and it is converted to

nitrogen oxide. So, probably what you are finding in your experiment can be

explained this way. Another point, in flame retardant polyurethane, you found

more than non-treated polyurethane. So I suspect in non-treated polyurethane,

flaming is easier. In flaming, the temperature is higher than treated

polyurethane

.

LEVIN: In the experiments that we did in the hot furnace, there was no flame.

We just heated the chars. When we tried to heat the material immediately, it

would flame and we did not see the cyanide. But in the experiments where we smolder for 15 or 30 minutes and then raise the temperature, we did not see any

flaming. . .just heating the chars.

ALARIE: You said that when the sample is heated prior to ignition, there is a better way to represent real-life situations in terms of HCN production for

smoldering polyurethane. Is that what you said?

LEVIN: I said that it simulates the more realistic situation.

ALARIE: So, if this is correct, I will put a statement to you. Since the small

scale combustion system of the University of Pittsburg simulates exactly the HCN

release of the real-life situation of smoldering polyurethane, would you agree

that the University of Pittsburgh method is a much better method than the NBS

method?

LEVIN: I do not think that any one method at this time is going to tell us all

that there is to know about how materials react in fire.

ALARIE: That was not my question. I asked a very specific question for a very

specific material under a very specific condition. It is clear to me that the

NBS way of decomposing polyue thane in no way comes even close to Simula tiny

smoldering polyurethane.

469
LEVIN: I think it does show us how smoldering polyurethane reacts. What it

doesn't do is show us this transition from the smoldering to the flaming. I think it was through our efforts now that we have found out about the char

formation.

ALARIE: But I think this is irrelevant. What is relevant is this: If, when

you bum polyurethane in the NBS combustion system and you get no hydrogen

cyanide whatsoever, while in the real-life condition you generate a tremendous

amount of hydrogen cyanide, then it's obvious to me that the NBS method does not

simulate the real-life condition. To me that's the important aspect of it.

LEVIN: Well, I have to agree that we do realize there are some limitations to

the combustion system that we now have. It is for this reason that we are now

designing a new combustion system.

ALARIE: Thank you, that's what I wanted to hear. To me there is no sense doing

toxicity with systems that are nowhere close to producing the gases that we see

in real life situations. Now I would say that when you start working with a combustion system, it's difficult to predict if it will match, let's say, a medium scale situation. We don't do real large scale, more medium scale. But,

I think when you find afterwards that the method is not good, you should stop

using it.

470
DEVELOPMENT OF LABORATORY TEST APPARATUS FOR

EVALUATION OF TOXICITY OF COMBUSTION

PRODUCTS OF MATERIALS IN FIRE

Shyuitsu Yusa

Organic Materials Division

Building Research Institute

Ministry of Construction

Seventh Joint Meeting

U.S. -Japan Panel on Fire Research and Safety

UJNR, Washington, DC, October, 24-28, 1983

471
DEVELOPMENT OF LABORATORY TEST APPARATUS FOR

EVALUATION OF TOXICITY OF COMBUSTION

PRODUCTS OF MATERIALS IN FIRE

Shyuitsu Yusa

1 . INTRODUCTION

To develop a laboratory scale burning test apparatus is one of

the main goal of the United States-Canada-Japan Trilateral Research

Group on Toxicity of Combustion Products from Building Materials and

Interior Goods.

In Japan, according to the planed activity. Building Research

Institute, Ministry of Construction, and Research Institute of Polymer

and Textile, Ministry of International Trade and Industry are conducting research programs on developing the laboratry scale burning test

apparatus for the evaluation of the toxicity. The main research program

is shown in Figure 1, and both BRI and RIPT are in the step of the

examination of characteristics of the apparatuses. The apparatus

developed at BRI is designed to suplly air in furnace and the one

developed at RIPT is closed type.

The BRI has proceeded the study using a testing apparatus for

evaluation of toxicity with thermal radiation and forced ventilation.

The goal of this study is to develop laboratory test apparatus that is

able to evaluate the toxicity of combustion products of materials in

fire both by biological method (namely animal exposure method) and by

chemical analysis method. In this test apparatus, the burning condition is to simulate the condition to which the materials are exposed

in real fire. It is desirable that the test apparatus be made capable

of producing useful data for the assesment of toxic hazards as well as

being used for the purpose of screening the extremely toxic materials.

In case of evaluating the toxicity of combustion products of

materials by the procedure which makes the test animals inhale the

products until some kinds of symptom appear, there will be various

factors for variation such as scatter in the animals themselves.

472
Furthermore, the condition of generation of toxic products will vary

due to variation in combustion condition, e.g., furnace geometry,

air aupply rate, material size, combustion mode, etc.

Both BRI method 1 ) and NBS method 2 ) have, limited suitability for

low density materials, laminates, coated specimens, and many other

commercial products because of using the crucible type combustion

furnace. Therefore, in the first step, the test apparatus is designed to use a thermal radiation device. An advantage of this test

method is that it permits the evaluation of many end use materials.

The surface of materials are exposed to heat, which is the way materials are likely to be exposed in certain stages of a real fire.

Additionally, the atmospheric oxygen concentration which may affect

the gas phase combustion can be controlled.

The laboratory toxicity test apparatus that we are seeking to

develop in this project is supposed to be given the burning condition determined based on the analysis of the full scale fire experiments. However, there are still many other flexibilities in designing the test apparatus which may affect the test results, e.g.,

geometry and dimensions of the furnace, dimension and orientation

of test samples, heating method and flow system. Accordingly, we

will take an approach to these items in the second step.

2. BASIC DESIGN OF THE APPARATUS

Taking into account the goal of this project, and assesing the

advantage and disadvantage of various kinds of toxicity test methods

and flammability test methods in Japan, United States, Canada and

some other countries, we started the development of the apparatus

with a trial development of the apparatus whose specifications are

described in the following, and set up the apparatus as shown in

figure 2.

473
(1) The combustion system

cheating system

: furnace

:air supply system

:test sample

(2) The exposure system

: exposure method

canimal

( 3) Measurements

:mass loss

: chamber atmosphere —

reffect to animals

electric radiation heater (cone furnace of ISO type)

cone shaped quartz tube (40 mm in

inner diameter at the upper part, 164

mm in inner diameter at the lower part,

3 mm thick)

mechanical supply (air, air +N 2 mixture) , air temperature control system

commercial products,

horizontal orientation and vertical

orientation*

static, whole body exposure,

15-30 minutes of exposure,

more than 16% of O 2 chamber concentration, less than 35°C of chamber temperature

species: mouse

continuous measurement during the test

continuous measurement of the concentrations of C> 2 , CC>2' CO, and temperature: concentrations of HCN and HC1

at a fixed time interval

time to incapacitation, time to death,

LC^g , etc

.

Note: * In the second step

3. METHOD OF TESTING

(1) Examination of Characteristics of the Test Apparatus

The characteristics of the quartz tube furnace are examined by

burning the several representative materials i.e. insulation board,

lauan, polymethylmethacrylate ( PMMA) , etc. under several sets of

474
conditions of radiative flux, O 2 concentration, air supply rate,

supplied air temperature, and analysing the concentrations of O 2 /

CC> 2 / and CO at the top of the quarts tube. In the tests of quartz

tube furnace, test samples are burned also in vertical orientation

to explore the feasibility of testing thermoplastics and thermosetting materials with the same furnace.

Experiments of this series, however, have not carried out wholly, and, therefore, partial data have been released in this report.

(2) Animal Exposure Tests

As stated earlier, static exposure is the basic method to expose

animals to combustion products. Since air is aupplied mechanically

and may cause unsuitably high pressure in the exposure chamber, some

device such as an air bag is introduced to prevent the high pressure

and still to retain the advantage of static exposure method. Furthermore, this system could have a constant volume in which the combustion

products diffuse by emptying the air bag inside the exposure chamber.

The exposure chamber is designed to make flexible the time to

introduce the combustion products to the chamber so that only the

combustion products from steadily durning materials could be introduced. Additionally, it is also designed to produce a square wave

exposure condition to the animals. The nominal volume of the chamber

is 125 liters, and the volume of the air bag is about 60 liters at

maximum.

However, no data have as yet been released showing test results

obtained from the animal exposure test. Therefore, findings of this

test method concerning biological assay cannot be drawn at this time.

(3) Method of Conducted Tests

The object of these tests is, first, to obtain the information

for discussing whether the apparatus is to represent burning condition and burning behavior of materials in fire, and secondly, to collect the data for conducting animal exposure tests appropriately.

475
The materials used for testing are indicated in Table 1. The

materials were made into specimens 10 cm in diameter and 10 mm in

thickness, and conditioned in a constant humidity chamber maintained

at 50 to 60% relative humidity at a temperature of 21-25°C for a period of more than 72 hours prior to testing.

The testing apparatus is as indicated in Figure 2 and comprises

combustion device and an exposure chamber of 125 liter capacity made

of polymethylmethacrylate. The cone quartz combustion tube is held

inside a cone radiative electric furnace, called ISO cone heater.

The cone quartz tube is 40 mm, and 164 mm in diameter at the upper

and lower parts, and 3 mm in thickness. The mass loss of the samples during the tests is measured continuously by the load cell.

From the bottom of the quartz tube and around the sample, air or

air, N 2 mixture (this time air only) is supplied to continue the

combustion. At the top of the cone quartz tube, the gasket is set

up to make the time to introduce the products arbitrary so that a selected part of combustion could be introduced.

The gas concentration in the exhaust path is measured by a magnetic type analyzer for O 2 , and by an infrared ray analyzer for CO 2

and CO.

Radiative flux level is fixed to 2.5 w/cm , and samples are

under flaming conditions as earlier as possible by using electric

spark ignitor. The supplied air rate is varied for each material

from about 3.8 to 15.3 liter per second per unit surface area of sample (%/sec/cm 2

) . Those figures correspond to 5 to 20 %/min in the

tests

.

4. RESULTS AND CONSIDERATIONS

Since all experiments have not yet conducted, general conclusion on animal exposure method must await further research for development. However, following results have been drawn on the characteristics of combustion for char forming materials.

476
The mass loss rate of insulation board is nearly divided in

two phases, i.e., flaming and embers states as shown in Figure 3*

In the flaming state, the mass loss rate is affected by air supplying rate and shows about two weak peaks. However, by visual observation, the flame was got out of shape under shorter air supply than

5.0 Jl/sec/cm^.

The evolution of CO from insulation board differs due to the

air supply rate as can be seen from the CO concentration in Figure

4, and the extent of variation is greater than that of mass loss

rate even if considering the dilution effect of the air supply.

The CO evolution under the embers situation is relatively high,

and this can be seen more clearly from CO/CO2 ratio which is

indicated in Figure -5, and from the relationship between CO yield

and air supply rate shown in Figure 9. This property will come

into question in developing appropriate strategy for dealing with

combustion toxicity by using animal exposure method.

Above characteristics may apply to the results of lauans as

shown in Figures .'6 to 9 , and it is concievable that wooden materials may have similar characteristics. So problem will be encountered with corresponding the combustion toxicity of embers situation to

real fire scenarios when these materials are burned away.

Therefore, for the evaluation of combustion toxicity by the

animal exposure method, it will be one of the useful method to

expose animals to the specific burning conditions such as flaming

and/or embers.

5 . REFERENCES

[1] Yusa, S., Saito, F. and Yoshida, M. , US-Japan cooperative

research on evaluation of toxicity, paper presented at the

6th Joint Meeting, U.S. -Japan Panel on Fire Research and

Safety, UJNR, Tokyo, May 10-14, 1982.

477
[ 2 ] Levin, B. C. , Fowell, A. J., Birky, M. M. , Paabo, M. , Stolte,

A. and Malek, D., Further development of a test method for the

assassment of the acute inhalation toxicity of combustion

products, Nat. Bur. Stand. (U.S.), NBSIR 82-2532 (1982).

[3] Furuya, M. , Closed-type Burning Testing Apparatus for Plastic

Materials, to be presented at the 7th UJNR Joint Meeting as a support paper, Washington D.C., Oct. 24-28, 1983.

478
Table

1.

Materials

tested

fjD >1— in

-M-O LO • •H g CN o

CO 0 • ! c \ o X)

<D tj> Q • O

cnW

<Dc —

^ g o o

o g 1—1

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x:

EH

g T3 TS p P p

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CQ CQ

t

P

td0

1—1 X!

fd •H G

P 0

cu •H

-p -P

fd fd G

S r—

1

G

G fd w G

G fd H

1

479
Consideration

of

design

factor

of

apparatus

J

H ^—.

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H

CQ Pi '

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CL 0 a •H p X

COdp

p

X

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rd

p CD

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O - Eh H d C

—

0) a, Pi

p 0 Eh

X

H CQ

dO CL,

p Pi >Cl

H

co -p

— cl CM Pi

CD

d o —

x

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d -p

a

d Eh 4-1 - c P p >i O Cl, 0 CD 0

rd rd -P

M

X

X

a P >i Pi CO

d

x

a P — o p

d

rd 0 -P •H

p 0 to d a) -p >iX

4-4 c 0 0 cn CO

X

C 0 0 rH p d *H a a) o 0 o p cl o

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•H 0 0 o dd

p

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O CD CD £ a)

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x

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p

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cl <D -p -P - X c cn -P rd d a) o 0 0 (D

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X CM S <—i <—i

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p E a •H TO 0 c p p < d

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&L

480
Exposure

Chamber

Made

of

5-1 CD

4-> c >4 0 54 •H fd

4-1 54

<d 4-> 54 *H 54

4-1 XI CO CU C 54 C C

<u < •H c o O •H c CO P 0 4-1 XJ c o — o 0 •H

4-1

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cu <d 0 c E

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X >4 o -h 0 rH *H td 0 < < O o W CL, U T3 u H < 03 XI

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481

Figure

2.

Test

apparatus
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in

in

co

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(%) 03 MOIiVSiNaONOO

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482

Figure

3.

Mass

loss

rates

of

insulation
483

insulation

boards
oCN

IT)

LD

O

(%) 03 N0J,VHJjN30N03

4-> CO2

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484
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485

Figure

8.

C0/C0

0

ratios

at

the

combustion
CO

YIELD

(g/g

of

sample)

486
Discussion After S. Yusa’s Report on DEVELOPMENT OF LABORATORY TEST APPARATUS

FOR EVALUATION OF TOXICITY OF COMBUSTION PRODUCTS OF MATERIALS IN FIRE

ALARIE: I would think that the apparatus that you have been building and have

shown us is the best that will be available for toxicity and I think it went a little bit this way. Dr. Yusa mentioned that the modelers will ask the mass

loss rate and the radiative blocks. If we look at the methods that are available today, we have the National Bureau of Standards method, it does not measure the mass loss rate, it does not measure radiated flux. We have the

University of Pittsburgh method, it measures the mass loss rate but it does not measure radiated flux. The method that you are proposing will measure both,

both will be available. I think your method also will have one big advantage

over everybody else and that is you can do a square wave exposure at any time

during your burning, and nobody can do that. I have one question: How do you measure hydrogen cyanide in combustion gases today?

YUSA: As for the analysis of hydrogen cyanide, at a certain time the Japanese

JIS method specified the calorific method, but we are just about to start the

construction of an apparatus to use ion chromatography. This also will be able

to measure HC1.

ALARIE: The reason I ask that question is that a lot of HCN data in the

literature, I think, is suspect because in the older methods there was too much

interference. I think it’s very important to have a very, very good method for

HCN when we do toxicity experiments.

487

Evaluation of a method for acute toxicity

of smoke from polymeric materials

Yves Alarie, Ph.D.

Professor of Respiratory Physiology and Toxicology

The Toxicology Laboratory

Department of Industrial Environmental Health Sciences

Graduate School of Public Health

University of Pittsburgh

Presented at the 7th United States-Japan Panel on Fire Research

and Safety, October 24-28, 1983 at the National Bureau of Standards

489
Introduction

There is a need to develop methods to evaluate the acute toxicity of smoke

from synthetic and natural materials. This need arises from the fact that

synthetic polymers, because of their chemical composition, will release smoke

qualitatively different from smoke obtained from commonly used natural polymers such as cotton and wood. Also the rate of release of smoke from synthetic polymers can be much higher than for wood and finally the yield of

principal toxicant(s) may be higher. An ideal solution would be to have a complete qualitative and quantitative chemical analysis of the smoke but this

cannot be obtained easily. Therefore, we rely on animal models to rapidly

evaluate possible differences in potency of smoke from various materials.

There are two basic problems with this approach. The first one is that a fire

model must be used to decompose the samples. The second one is extrapolation

to humans of the results obtained in animals. This report presents the approach we have taken (1,2) the basis for ranking materials for their acute

toxicity, the reasons why in general smoke from synthetic materials is more toxic than smoke from wood and the corrections to be made in extrapolating the

results to humans.

Fire Model

There is no perfect small scale method to simulate large or medium scale

fires. Also there is no single small scale method capable of supplying energy

in the same manner to all possible samples in need of investigation. A large

enough muffle furnace where any sample can be heated by radiation and con- vection seems to be the only solution available but several other methods have

been used (3). Thus, using such a furnace with a linear heating rate of

2Q

u C/mir#ute an attempt was made to simulate a developing fire, leaving the

material being investigated to react to the energy being supplied.

The general criteria followed in this approach, with a diagram of the apparatus used presented in Figure 1, were as follows:

1. The final temperature reached should be high enough to decompose all

the samples.

2. There should be sufficient air (oxygen) available surrounding the

sample at all times during decomposition.

3. Temperature (or energy) should not be above what is normally found in

average fires.

4. Residence time of decomposition products at elevated temperature is

important. If the residence time is very long decomposition products

will be further degraded to gases such as CO, C02* H

2

O, HCN, NO?, HC1,

HBr and HF with proportional decrease in the larger molecular “weight

constituents. This is to be avoided since it simulates incineration

rather than a fire condition.

5. The method should permit investigation of non-flaming or flaming

conditions or the first one followed by the second one if autoignition

occurs as energy is being supplied.

490
6. The rate at which the samples are decomposing (mass loss rate) must

be monitored.

7. The furnace (or system) must be large enough to accomodate low density materials, layered materials, composite materials, etc. in a configuration appropriate for their intended use.

8. Monitoring of gases such as CC^, O

2 and CO is required as a minimum. For nitrogen or halogens containing polymers measurements of HCN,

HC1 , HBr, HF are required. Such measurements are required to explain the

toxic effects and to extrapolate the results obtained in animals to

humans.

9. The combustion system must allow for concentration-response relationships for acute toxicity to be obtained. This can be accomplished in two

ways, a) the size of the sample can be changed while keeping the dilution

air constant or b) the size of the sample can be kept constant while

changing the dilution air. In the approach presented here we have used

the first way but both are equally valid.

Acute Lethality

By definition toxicity is based on the amount of chemical or physical agents

necessary to produce a given level of effect and classifications for potency

are made by comparing the dose, on a mg/kg basis, to kill 50% of the animals

(4,5). For inhalation toxicology classes of toxicity are based on a fixed

period of exposure and determination of the concentration to kill 50% of the

animals following the exposure (5). This is referred to asgthe LC50 and since

it is an exposure concentration given in ppm or in mg/nr it is not an ex- pression of toxicity as with an oral LD50 given in mg/kg but rather an ex- pression of exposure intensity necessary to produce a given effect. Nevertheless, the dose received by the animal will in proportion to the exposure

concentration, albeit this quantity is seldom known or measured, and the LC50

is taken as an expression of toxicity and used to compare the potency of

various chemicals. Since the objective in toxicological studies of smoke from

polymeric materials is to compare the potency of various materials it follows

that the LC50 must be determined. This must be determined for a fixed period

of exposure and in this field 30 minutes has been arbitrarily selected as "appropriate" for fire situations. The second interesting aspect about toxicity is rapidity of action since time to escape from a fire is a critical

element. Thus two gases having the same potency or toxicity, i.e. similar

LC50, may have different rapidity of action which is important to know.

Unfortunately, since determination of the LC50 requires that all animals be

exposed for the same period of time and deaths be observed following exposure

little can be obtained to determine the rapidity of action and this approach

is not as useful in combustion toxicology as it is for general inhalation

toxicology. The approach can be modified so that both toxicity or potency as well as rapidity of action can be measured simultaneously. This can be done

as follows recognizing that biostatisticians will raise minor objections

because not all animals will be exposed for the same period of time:

1. A reference material is selected against which all other materials

will be compared.

491
2. Exposures to various concentrations of smoke from the standard material are conducted so that 50% of the animals will die at the end of the

time period selected (i.e. 30 minutes). Thus the LC50 (amount of material loaded in the furnace necessary to produce sufficient smoke to kill

50% of the animals) and the LT50 (time of exposure at the LC50 required

to kill 50% of the animals) are obtained. Thus both potency and rapidity

of action are measured. Obviously this will necessitate a series of

experiments with proper statistical analysis of the LC50 value. There is no statistical evaluation of the LT50 in this protocol. This value is

obtained by reviewing the data from the series of experiments conducted

and finding the time at which 50% of the animals were dead at the calculated LC50 value or the experiment closest above this value.

In practice it is impossible (unless one is incredibly lucky) to kill 50% of

the animals at exactly the end of the time period selected and one must accept

the LT50 to be close to the exposure time selected. In the example given

below when wood (Douglas fir) was selected as the reference material the LT50

obtained was 22 minutes instead of being at 30 minutes which was the desired

time. The important points to consider with this approach are as follows:

1. All materials to be tested will be compared to the standard on the

basis of a fixed biological effect, i.e. 50% mortality (LC50) but the

time to produce this effect (LT50) at this exposure concentration will

vary. It is important to remember that comparison of rapidity of ac- tion(LT50) can be made only when the level of effect for all materials is

the same, i.e. at the LC50, or in practice as close as possible to it.

2. The LT50 is not a measure of toxicity since it reflects absorption

and distribution of the inhaled materials as well as their intrinsic

rapidity of action. In combustion toxicology it also depends on the rate

at which the toxicants are produced in the apparatus used to decompose

the materials. In the examples given below the beginning of the planned

30-minute exposure period was initiated with the start of decomposition

of each material. This varied considerably among materials and also as given below the rate of decomposition of materials varied widely.

Materials and Methods

a) Thermal decomposition and animal exposures.

The system for thermal decomposition and animal exposure has been given in

details previously (1) and schematically presented in Figure 1. Briefly,

samples were decomposed by heating them at 20

uC/minute, starting from room temperature, in the furnace with the airflow through it maintained at 11

liters/min. The smoke from the furnace was then diluted with 9 1 iters/mi n of

air and entered the 2.3 liter glass exposure chamber. For each experiment

four male Swiss-Webster mice were used. The exposure started when 0.2% weight

loss occured for each sample (corrected in the cases of halocarbons blown

foam) and continued for a period of 30 minutes or until all animals died.

Animals which died during the 30 min. of exposure and 10 min. recovery period

Were counted in the LC50 statistical evaluation. The time at which 50% of the

animals died was recorded at the sample weight killing 50% of the animals or the sample weight nearest above it. The description of one series of samples

tested with this method is given in Table 1 with the LC50 and LT50 values

obtained.

492
Results and Classifications

Table 1 presents the LC50 and LT50 values of materials tested and Figure 1 also presents these results as well as a suggested way to combine both the

LC50 and LT50 results to arrive at classifications A, B, C or D. In Figure 2

the classification for concentration-response relationship (toxicity or potency) was arrived at by placing the LC50 value of Douglas fir (taken as a reference material) at the middle of an order of magnitude on a logarithmic

scale. All materials with an LC50 within this order of magnitude are then

classified "as toxic as wood." Then classifications of more toxic and much

more toxic than wood follow, each spanning an order of magnitude.

The classification for time-response relationship (i.e. rapidity of action)

was also arrived at by using Douglas Fir as the reference material. The LT50

was placed at the middle of one-half an order of magnitude on a logarithmic

scale. However, it should be noted that the time scale was arranged so that

one order of magnitude on the time scale of this graph is equivalent to two

orders of magnitude on the concentration-response scale. This is arbitrary

but helps in separating materials for their rapidity of action. Again, classifications of faster and much faster acting than wood follow. To combine both

potency and rapidity of action quadrants were included in Figure 2. The

quadrants are parallel, all starting from the potency scale and ending on the

time scale to encompass areas defining four classes of materials. Thus, a summary of potency and rapidity of action can be easily presented for materials in comparison to wood or any other material used as a standard.

Reasons for differences in toxicity between synthetic polymers and wood.

The results in Table 1 and Figure 2 show that there are differences between

synthetic polymers and wood and between wood and cellulose fiber insulation.

Of the materials reparted in Table 1 and Figure 2 the following examples were

selected to explain how such difference occured.

Wood vs. cellulose fiber insulation

As shown in Figure 3 CO increased just before and with flaming ignition con- tinued to increase and was the main toxicant responsible for the death of the

animals. Cellulose fiber (a heavily flame retarded sample) did not ignite and

decomposed very differently than wood and with a much higher yield of CO.

Thus, this sample was found to be approximately 6 times more toxic than wood

and the reason is the much higher yield of CO.

Phenol formaldehyde foam and urea formaldehyde foam

Figure 4 illustrates some interesting characteristics of these two materials. Both are known to be highly resistant to flaming and did not ignite

during the test. The weight loss was only 50% for phenol formaldehyde but the

yield of CO was very high and, therefore, this sample was found to be 10 times

more toxic than wood because of this high yield. On the other hand urea formaldehyde released less than 100 ppm of CO but yielded a high amount of

hydrogen cyanide and since this gas is more toxic than CO the reason for this

sample being 25 times more toxic than wood is obvious. What is interesting to

note is that most of the cyanide was produced above 450°C and from a very

493
small quantity of sample remaining above this temperature. Both phenol formaldehyde and urea formaldehyde released formaldehyde at low temperatures.

Polytetraf luoroethylene

Decomposition of this sample started at high temperature as shown in Figure

5. There was negligible amount of CO released but the toxicity was found to

be extremely high. In fact this sample was found to be 150 times more toxic

than wood. The reason for this finding is that polytetraf luoroethylene yields

octof luoroisobutylene (6) which is extremely toxic (7). The LC50 for a 10-

minute exposure in rats for this gas was found to be 17 ppm (7). This is at

least 10 to 20 times more toxic than hydrogen cyanide. Therefore, it is not

surprising to find such a high toxicity for this polymer. Similar results

were found for polyf luoroethylenepropylene (8) which also releases the same extremely toxic gas (6).

Polystyrene foam

The results are shown in Figure 6. Here the generation of toxicants is ex- tremely rapid and because there is less air volume available for dilution very

high concentration of CO as well as other toxicants are reached rapidly.

If we take the average of the LC50 and LT50 values for series of synthetic polymers we have tested we find them to be 5 to 6 times more potent and

to kill animals almost twice as fast as with wood. From the examples given

above and published data (1,2) the reasons for these findings can be summa- rized as follows:

i) some polymeric materials release a much higher yield of CO

than wood

ii) some polymeric materials release HCN which is more potent and

faster acting than CO, the principal toxicant obtained from

wood

iii) some polymeric materials release perf luoroisobutylene which

is extremely toxic and obviously more potent than CO, the

principal toxicant obtained from wood

iv) some polymeric materials release toxicants which may be the same as wood but because the mass loss rate is so much faster

than wood there is less dilution air available to reduce

their toxicity.

Extrapolation of the results for humans

If the principal toxicants are CO or HCN extrapolation of the results obtained

in mice can be made for humans since their mechanism of action is the same in

both species although their action is more rapid in mice than in man due to

their difference in minute ventilation/body weight ratios (10,11). The lethal

levels in humans for these gases (10) is also close to the potency ratio found

in mice since the LC50 was 166 ppm for HCN and 3,500 ppm for CO for a planned

30-minute exposure (9).

494
Difficulties arise in the case of polymers releasing large quantities of HC1,

HBr and HF. These gases are highly water soluble and reactive and are very

effectively scrubbed by the nose of small rodents thus greatly lowering their

toxicity in comparison to what would happen in humans (12, 13,14). This is

illustrated by the fact that 1,000 ppm of HC1 is considered dangerous for

humans for a short period (11) while the LC50 for 30 minute exposure in mice

was found to be 10,157 ppm (12). However, if a tracheal cannula is fitted in

mice to by-pass the nose the LC50 in cannulated mice is only 1,095 ppm, in

agreement with the predicted dangerous level in humans. Similarly the LC50

for thermal decomposition products from polyvinylchloride was found to be 15.2

grams in normal mice but only 2.2 grams in cannulated mice (12). No difference was found for the LC50 of CO or HCN between normal and cannulated mice

(9). Therefore, when HC1 is the major toxicant the LC50 found in normal mice

must be divided by 7 to 10 in order to extrapolate to humans and this must be

done with polyvinylchloride. There may be other instances when such correction factors will be needed depending upon the nature of the principal toxicants) involved.

Reproducibility of the results

For any test method it is important to have some estimate of the reproducibility of the results. This can be obtained from the data presented in Table

2. The reproducibility is quite good considering that there are two sources

of variability, i.e. decomposition of the samples and biological variation.

In fact the results obtained here are well within the variation obtained with

oral LD50 tests (15)

.

Extrapolation to medium scale fire

The number of experiments performed with medium scale fires are too few to

permit firm conclusions to be reached. However, in both instances (16, 17)

materials tested in the small scale test described above were ranked in the same order of toxicity in medium scale fire tests.

Conclusions

A test method has been developed to evaluate the acute toxicity of smoke from

natural and synthetic polymers. It is useful to rapidly determine if smoke

from various materials is more potent and faster acting than smoke from

wood. With appropriate chemical analysis of the smoke and knowing the mass

loss rate the differences in toxicity can be explained.

495
References

1. Alarie, Y. and Anderson, R.C. Toxicologic and acute lethality hazard

evaluation of thermal decomposition products of synthetic and natural

polymers. Toxicol. Appl. Pharmacol. 51^ 341-362, 1979.

2. Alarie, Y. and Anderson, R.C. Toxicological classification of thermal

decomposition products of synthetic and natural polymers. Toxicol.

Appl. Pharmacol. JT7, 181-188, 1981.

3. Kaplan, H.L., Grand, A.F. and Hartzell, G.E. Combustion Toxicology,

Principles and test methods. Technomic Publishing Co., Lancaster, Pa.,

1983.

4. Klaassen, C.D. and Doull, J. Evaluation of Safety: toxicologic evaluation. Chapter 2. In: Casarett and Doull 's. Toxicology the Basic

Science of Poisons, Second Edition. Doull, J., Klaassen, C.D. and

Amdur, M.O. Eds. MacMillan Publishing Co., N.Y., 1980.

5. Hodge, H.C. and Sterner, J.H. Tabulation of Toxicity Classes. Am.

Indus. Hyg. Assoc. Quart. 93-96, 1949.

6. Arito, H. and Soda, R. Pyrolysis products of polytetraf luoroethylene

and polyf luoroethylenepropylene with reference to inhalation

toxicity. Ann. Occup. Hyg. 20^, 247-255, 1977.

7. Smith, L.W., Gardner, R.J., and Kennedy, G.L. Short-term inhalation

toxicity of perf luoroisobutylene. Drug and Chem. Toxicol. 5_, 295-303,

1982.

8. Y. Alarie and Stock, M.F. Toxicity of Teflon^, similar results

obtained with radiant-convective heat sources or in hot fire gases.

Fire and Materials, in press.

9. Mati jak-Schaper, M. and Alarie, Y. Toxicity of carbon monoxide, hydrogen cyanide and low oxygen. J. Combust. Toxicol. 9_, 21-61, 1982.

10. Haldane, J, The action of carbonic oxide on man. J. Physiol. 18^, 430-

462, 1895.

11. Henderson, Y. and Haggard, H.W. Noxious gases and the principles of

respiration influencing their action. Second and Revised Edition,

Reinhold Publishing Corp. N.Y., 1943.

12. Anderson, R.C. and Alarie, Y. Acute lethal effects of polyvinylchloride thermal decomposition products in normal and cannulated

mice. Society of Toxicology Meeting, Abstract of papers, page A-3,

1980.

13. Morris, J.B. and Smith, F.A. Regional deposition and absorption of

inhaled hydrogen fluoride. Society of Toxicology Meeting, Abstract of

papers, page A-4, 1980.

496
14 .

15.

16.

17.

18.

Morris, J.B. and Smith, F.A. Regional deposition and absorption of

inhaled hydrogen fluoride in the rat. Toxicol. Appl. Pharmacol. b£,

81-89, 1982.

Weil, C.S., Carpenter, C.P., Est, J.S. and Smyth, H.F., Jr.

bility of single oral dose toxicity testing. Amer,. Ind.

J. 27_, 483-487, 1966.

Reproducing. Assoc.

Alarie, Y., Anderson, R.C., Stock, M.F., Dombroske, R.L., Keller, L.W.,

Havduck, L.W. and Park, R.E. Toxicity of thermal decomposition

products; an attempt to correlate results obtained in small scale and

large scale tests. J. Combust. Toxicol. 58-68, 1981.

Alarie, Y., Stock, M.F., Matijak-Schaper, M. and Birky, M.M.

of smoke during chair smoldering tests and small scale tests

same materials. Fundam. Appl. Toxicol., in press.

Toxicity

using the

Anderson, R.C., Croce, P.A., Feeley, F.G., III and Sakura, J.D. Study

to assess the feasibility of incorporating combustion toxicity requirements into building material and furnishings codes of New York State.

Final Report to Department of State, Office of Fire Prevention and

Control, Albany, N.Y. May 1983.

TABLE 1 Samples Tested and Summary of the Results

Abbreviation Sample name—description LC30

(g) LT50

(min) Class*

PRC materials* GM 21 Flexible polyurethane foam 12.9 13 B GM 23 Same as GM 21, with fire retardant 10.4 18 B GM 23 High resilience, flexible polyurethane foam 8.3 19 B GM 27 Same as GM 25. with fire retardant 14.4 15 B GM 29 Rigid polyurethane foam 10.4 28 B GM 31 Same as GM 29, with fire retardant 8.2 23 B GM 35 Rigid polyurethane foam, fluorocarbon blown 7.5 17 B GM 37 Same as GM 35. COt blown 8.0 15 B GM 41 Rigid isocyanurate foam 6.4 18 B GM 43 Same as GM 41, contains some polyurethane 6.1 16 B GM 47 Polystyrene expanded 5.8 11 B GM 49 Same as GM 47. with fire retardant 10.0 9 B GM 57 Phenol formaldehyde —phenol resin, expanded with blowing agent

6.3 20 B

Non-PRC materials PTFE Polytetrafluoroethylene resin 0.64 8 C PVC Polyvinylchloride (92% homopolymer) 7.0 10 B PVC-A* Polyvinylchloride (46% homopolymer) 15.2 15 B PVC-CN Polyvinylchloride (92% homopolymer

-i- 5% zinc ferrocyamde)

2.3 7 C

PCP-CN Polychloroprene (92% homopolymer

+ 5% zinc ferTocyanide)

2.5 6 C

ABS-3 Standard acrylonitrile/butadiene/styrene 6.3 9 B Mod. Modacryiic 4.9 18 B Wool Wool fibers —undyed 3.0 27 B UF Urea formaldehyde foam 2.5 22 B

Cellulose Blowing type cellulose fiber insulation 11.9 21 B

D. Fir Douglas Fir 63.8 22 A

Fiberglas Fiberglas building insulation, 3.5 in. thick with paper and vapor barrier35.7 25 A

P.E. I Polyester resin—commercial acrylic modified unsaturated34.8 14 B

P.E. II Polyester resin —experimental acrylic modified unsaturated

57.4 18 A

H.P.E. Polyester resin —Styrenated halogen modified 14.4 16 B SPF Wood Compressed spruce, pine, fir slab 1

48.7 19 A

“ From Fig. 2

‘ Obtained from the Product Research Committee (PRC) sample bank at the National Bureau of Standards

* In the previous article (Alane and Anderson. 1979) this sample was erroneously identified as being 92*7 homopolymer

497
TABLE 2

Reproducibility of LCgg values

LC50 in grams loaded in the furnace

Material

University of

Pittsburgh

Biotecs**

Laboratory Arthur D. Little***

Douglas fir* 64

78

56

57

61

64

59

50

Average for Douglas fir + (S.D. ) = 61.1 (8.2)

Phenol Formaldehyde

Foam (GM 57)* 6.3 7.4 4.8

Polyester-Fi berg lass

PEI* 35 36

Polyester ^Fiberglass

PE II* 57 58

Vinyl coated wire* 15 15

Polyurethane foam

flexible 13 9

Polyester-Fiberglass

Halogen retardant

HPE* 14 15

* Samples used by all laboratories was furnished by the University of Pittsburgh.

** Data supplied by Dr. C.P. Carpenter.

***From reference 18.

498
Figure 1. Experimental arrangement to study toxicity of smoke from thermal

decomposition of synthetic or natural polymers. From Alarie and

Anderson, 1979.

In this system the sample is placed on a platform connected to a weight

sensor so that weight loss can be recorded during thermal decomposition. The

temperature of the furnace increases from room temperature at 20°C/minute up

to 900°C or until the material is entirely decomposed. The animals, 4 mice,

are placed in restraining tubes (animal plethysmograph) with only the head of

the animals protruding into the exposure chamber. Air flows through the chambe

continuously and is regulated at 20 liters/minute. The air drawn into the

chamber comes from the furnace (11 liters/minute) and 9 liters/minute of diluting air supplied at 15-16°C. Exposure of the animals to the smoke produced is

initiated when the material begins to decompose and continues for 30 minutes

unless all the animals die. A recovery period of 10 minutes is observed

following exposure. In these experiments respiratory rates of the animals are obtained by attaching a pressure transducer to a port on each animal plethysmograph. This also permits recognition of sensory irritation and asphyxiation

during exposure to the smoke. Death is determined to have occurred if no respiratory effort is made by the animal ‘for a period of 17 seconds.
CONCENTRATION - RESPONSE

MUCH MORE MORE TOXIC AS TOXIC

TOXIC WOOD

THAN THAN WOOD AS WOOD

Fig. 2 Each point represents the amount of material (gram on the X axis) which produced

sufficient smoke to kill 30% of the animals (LC50) and the time (minutes on the Y axis) required to

kill 50% of the animals (LT50) using that amount of material. Reading the graph vertically each material is classified in terms of potency while each material is classified in terms of onset of action by

reading horizontally. To combine both, parallel quadrants separate class A. B, C. and D. For clarity some materials listed in Table 1 have been omitted. However. Table 2 contains the results for

all materials.

Figure 3. Decomposition pattern of Douglas fir and cellulose fiber (with flame

retardant) and carbon monoxide evolution. Arrow at second death

indicates the temperature at which the second of four exposed

animals died (50% lethality).

500
Figure 4. Decomposition pattern of phenol formaldehyde foam and urea formaldehyde

foam with evolution of formaldehyde, carbon monoxide and hydrogen

cyanide. Arrow at second death indicates the temperature at which

the second of four exposed animals died (50% lethality).

FURNACE TEMPERATURE °C FURNACE TEMPERATURE *C

Figures 5 and 6: Decomposition pattern of polytetrafl uoroethyl ene (PTFE) and

polystyrene foam with evolution of carbon monoxide. Arrow at

second death indicates the temperature at which the second

of four exposed animals died (50% lethality).

501

Discussion After Y. Alarie's Report on EVALUATION OF A METHOD FOR ACUTE TOXICITY

OF SMOKE FROM POLYMERIC MATERIALS

PAGNI: If the HC1 is more toxic in the mice than in the humans, don’t you have

to multiply by that factor instead of divide.

ALARIE: No. The HC1 is less toxic for mice than it is for humans. The reason

for this is that in mice it is absorbed in their nose and it is prevented from

reaching the lungs and the systemic circulation. To simulate a human with a mouse, we can bypass their nose by putting a tracheal cambia; when we do that,

the order in mice is the same as in men,

PAGNI: Does the protocol by which you change the temperature in the furnace

change your class results?

ALARIE: If we change the heating rate, it will change the mass loss rate. By

changing the mass/loss rate, we can change the toxicity.

TSUCHIYA: You said that perfuroisobutylene is 30 times more toxic than HCN.

How do you get this number?

ALARIE: Because we do an LC^q on perfuroisobutylene. We do an LC^q on HCN and

then we do an LC 5q on CO. So we have the ratio perfuroisobutylene, HCN, and CO.

TSUCHIYA: When you show the relation between time and concentration of carbon,

you classified plastic in three categories. You showed the carbon lines of your

unit in log scale.

ALARIE: That's correct.

TSUCHIYA: Isn't it better to use a straight line?

ALARIE: No, biological systems move in a progressive manner. We humans are not

differentiators; we are integrators. If you want to change our reaction by a lot, you have to change the dose by a lot. So, if you double the dose, you

usually don't do very much. You have to go three times, ten times, 30 times,

100 times. So all biological responses are plotted on a logarithmic scale, not on an arithmetic scale.

TSUCHIYA: No. It's all right on a logarithmic scale but that boundary isn't

shown as linear.

ALARIE: No, it shouldn't be there and you put that back in. You want the

quadrant to be curved and not straight lined, because you want to punish the

materials that are fast acting. If we would need to do this, I think we would

accomplish it just as well as when you do this. But, it would give us more categories and I don't want to make too many categories at this time. This is

also why I made this range fairly large ... that ' s one order of magnitude. I think if we made a smaller range it would be very difficult to depend on.

TSUCHIYA: Are you taking arbitrary decisions and drawing lines?

ALARIE: No, I don't think it's an arbitrary decision to give negative poi.it s r very fast acting materials. That is not arbitrary at all.

503
TSUCHIYA: How about data obtained by Southwest Research Institute?

ALARIE: There is no data presented by Southwest Research Institute that

confirms Haber's Law. Haber was a very brilliant German toxicologist. He used

Haber's Law for a very specific purpose. It is for cumulative toxic effect with

time. The two principle killers we have in the smoke are CO and HCN. Neither

one of them is a cumulative poison, and neither one of them will every fit

Haber's Law by any test.

TSUCHIYA: But do you know the data... I don't know Haber but the data presented

by Packham, Patel.

ALARIE: The data is worthless! The best data on CO and HCN was presented by

the Japanese. That's the best data and the data from the Japanese will deny any

Haber's Law. The data from the Japanese is in the previous conference. They

have these curves for HCN and for CO with the time in the concentration. This

is the best data and one of my students reproduced the data of the Japanese. It

is always log scale. There is no such thing as plotting these curves on arithmetic scales. The Japanese plotted them on the log scales. We plot them

on the log scales.

NISHIMARU: Using mice I think one has shown the ratio was 7 to 10 for the level

to human being and what was the basis for that ratio?

ALARIE: We see in humans that about 1000 parts per million of HC1 would kill a human being in a short time. We did the experiment with noble mice and we found, I think, 10,000 parts per million would kill those noble mice, which is

10 times higher than this. Then we took mice with trachael cannulae and we found that about 1000 parts per million would kill them. When we did the same experiment with polyvinyl chloride and noble mice, the LC^q was 50.2 grams.

When we used a tracheal cannula, the LC^q was 2.1 grams... so this is about 7 times. That's why we picked 7 to 10. We also did the same experiment with

noble mice and tracheal cannulated mice with CO and with HCN and with a synthetic polymer that releases CO. There is no difference in the LC^q. It's

only when HC1 is the primary toxicant that we have to apply this factor.

NISHIMARU: The tracheal cannula you used in testing for toxicity results in a very unique experiment. We would like to know if you found any discrepancy

between the results obtained from mice and the results obtained from rats?

ALARIE: The results we obtained for HCN and CO in mice are the same as the

Japanese results for those two gases in rats. However, for the irritant gases,

mice are much more sensitive than rats.

NISHIMARU: We obtained the same results, but why did you pick the difference

between rats and mouse irritants?

ALARIE: We know they are more sensitive than rats but I don't know why.

504
SUPPORT PAPER

Theme

Toxicity

Closed-type Burning Testing Apparatus

for Plastic Materials

by

Masazo Furuya

Research Institute for Polymer and Textile.

Agency of Industrial Science and Technology

Ministry of International Trade and Industry

7th Joint Meeting

U.S. -Japan Panel on Fire Research and Safety

UJNR, Washington. DC. Oct 24-29, 1983

505
Closed- type Burning Apparatus

For Plastic Materials

By

Masazo FURUYA

The aim this study is to develop a laboratory testing appratus

which can evaluate the toxicity of combustion products of plastic

materials. This appartus has a ciosod-type chamber. Both gas component

and smoke density, resuling from combustion of plastic materials,

can be determined correctly. By equipping a mause monitor with the

exposure chamber, tht animal toxicity due to the gas is also eva- luated conveiently.

Test Method

1. Apparatus

As shown in Fig. 1-1. the chamber (0.5 n? ) is consisted of combustion section, smoke-density measuring section and gas analysis, Volume of the animal exposure chamber is 0.125 m^

.

The combustion section has heating furhace, sample pan and sample

weighting device, the heating furnace is heated electrically, and

provides a constant voltage control device.

2. Smoke-density measuring device

The device consists of a light source and a receptor, and provides

a smoke deposit preventing means, a means of maintaining a constant

voltage and an indicator.

3. Gas analysis

A non-diffusion type infrared spectro-photometer shall be used for

analysis of CO and CO-j gases. The analysis shall be carried out

continuously by suctioning gas from the combustion chamber at the

rate of 3 - 5 1/min.

HCI and HCN gases are taken from the chamber by suction at the rate

of 5 1/min into each appropriate absorbent solution, and are analysed

506
quantitatively by thiocyan mercuric acid method and pyridine-pyrezolone method respectively.

Results and Considerations

1. Effect of the mass of test portion on the test result

Preliminary tests were carried out with various mass of test portions

of PC, PS (cellular) and PA, their behaviours in burning and thermal

flow vary depending on their chemical structures and forms. The test

results are shown in table 1.

The values: of burned mass calculated from the burned residues and the

mass of test portions used are plotted as shown in Fig.l. From Fig. 1

it can be seen that the linear relation exists between the mass of

test portion and the burned mass for each polymer, and its burning

rate is nearly constant.

2. Relation between the burned mass and the smoke density

The relation between the burned .mass and the smoke density of three

polymers under the same burning conditions is shown in Fig. 2.

For PS and PC, a line nearly passing through the original point of a graph is obtained, while for PA bending in a line is seen at around

4 to 5 grams of the burned mass and indicating its pecuriality.

Fig. 3 shows the relationship between the burning rate and the amount

of generated smoke per 1 g of the test portion. In case of PC, a tendency of saturation in the amount of evolved smoke can be seen

with increase in the mass of test portion, while in case of PA, an amount of smoke tends to increase with increase in the mass of test

portion.

Thus, such distinction appeared in the behaviour of smoke evolution

among- them makes it possible to characterize the polymers.

3 . Relation between the burned mass and the formation of CO and CO

2

507
Fig. 4 shows the relationship between the burned, mass of each of three

polymers and its evolved amount of CO under the same burning conditions.

From this graph it can be seen that there exists a linear relationship

between them, though an amount of CO varies with the type of polymer.

Fig. 5 is the converted graph of Fig. 4 into that of an amount of evolved CO per 1 g of sample. The amount of CO per 1 g of sample for PS

increases with greater mass of sample, and for PC and PA decreases with

increase in the mass of sample. As to C02 the similar mode can be seen

in Fig. 6.

When plotted these values correlating CO with C02, Fig. 7 is obtained.

Fig-. 7 shows apparently that the value of ratio C0/C02, that is a tendency to incomplete burning, becomes to be greater with increse in

burned mass of sample.

4. Burned mass and consumed oxygen concentration

Oxygen consumed by burning is expressed as

Consumed oxygen concentration (fo) = (Oxygen concentration in

the chamber at test starting) (fo) — (Oxygen concentration in

the chamber after burning) ($)

.

Fig. 8 shows the consumed oxygen concentration in relation with the

burned mass of PS, PC and PA, respectively.

Ignition time and burning time with various mass of samples are shown

in Fig. 9.

Since amounts of smoke, CO and C02 generated by combustion of polymers

vary with their burned mass as seen in figures above mentioned, in the

comparison of the burnning behaviours of the various polymers, it is

convenient to use the values expressed in per nit mass of each.

It may be considered in most cases that the relation between the burned mass and the amount of evolved smoke or gas is of linear, although

it can not expected its line drawn would always pass through 0 point

on the graph.

508
Nevertheless, in rating of the burning behaviours of polymers, no confusion would, take place when making comparison with the values per

unit mass. Furthermore, with such comparison it is possible to characterize the mode of formation of smoke or gas among polymers.

In this method values of evolved smoke, CO and C02 calculated per unit

mass of burned sample are designated as an index of evolved smoke

( Ics ), an index of evolved CO (ico ) and an index of evolved C02

(lco2 ), respectively.

5 • Experimental test results

Experimental test were carried out on various commercially available

plastics by means of the proposed method at the three levels of test

temperatures of 350 +_ 10°C, 550 _+ 10°C and 850 _+ 10°C. For the purpose

of comparison a wood sample was also tested.

Materials tested are shown in table 2.

5.1. Burning behaviour

Formation of smoke and gases by burning of plastics are closely related to their burning behaviours and depend on the circumstance condi- o — tions of burning.

Ignition time, burning time, burning rate and the percentage of burned

mass of each test sample at 550 °C and 850°C are shown in tables 3 and

4- In table 3j distinction of burning behaviour among plastics can be

seen, with indicating characteristic values by type of plastic.

At 850°C these difference in burning characteristics among them become

lesser substantially as the case of the percentage of burned mass which shows 100^ or near to 100^.

Table 4 shows the burning behaviour such as ignition time and burning

rate are activated under elevated temperature circumstance.

5.2. Formation of smoke and gases

509
In this experiment the behaviour in smoke evolution is represented by

a light extinction coeffient (Cs) and an index of evolved smoke ( Ics ).

Results of Cs and Ics at 550°C and 850°C are shown in table 5? together with the ratio of Ico at 550°C and that at 850°C.

Cs is the resulted smoke density from a certain mass of a test sample,

which varies by sample as shown in tables 3 and 4. Ics is the con- version of Cs into that per unit burned mass.

By comparing the value of Ics with each other, a rating of plastic

material in terms of smoke-related characteristics could be assessed

on the nearly equivalent level of criterion.

Table 6 shows the values of Ico , Ico2 and Ico/lco2 measured at 550

°C and 850 °C , together with the amount of gases of HC1 and HCH evolved,

expressed in mg per 1 g

of burned mass of sample, and also with consumed oxygen (% by vol) during the test.

As seen in t aBle 6, in all cases decrease in oxygen concentration in

air were very slight within the range of decimal place, because of so large the capacity of the test chamber relative to the mass of test

portion in this method.

Pigs 10 and 11 are of Ico/lco2 and Ics indicated by bar graph for

various plastic materials.

6. Conclusion

At the present time relationship between circumference conditions of

burning and the burning behaviours of plastic materials, including

smoke and gases generated by combustion, can not be definitely explained. However, a rating of plastic material in terms of smoke-related

characteristics may be assessed from the values of Ics, Ico and

Ico/lco2 together with the knowledge of concentation of HCl ana HCN

(mg/g)

•

The effect of flame-retardants and reinforcing materials on the burning behaviours of plastic materials can also be estimated by these

510
measurements

.

Ax eievaxed temperature , some plastics generate much, more amount of

smoke and gases, while others less amount of smoke and gases. such

phenomena are inherent in natures of plastics and can he categorised

into two groups.

From a viewpoint of this test method being capable of rating and categorizing the plastics material in terms of burning behaviour, this method

could be considered useful as a measure as a measure of assessment of the

burning behaviour of plastic materials.

511
Table 1 Test results of preliminary experiments.

mass

of

until

flash burn- gasses resulted by burning

sample test

sample

[ 9)

ignition

time

(sec)

ing

time

(sec)

Ics

Ico Ico2 0,

(%/9 ) HCN(mg/g)

21 9 1 9 5 1 1 5 o .78 0.0 1 1 1 0.2 0 4 0. 2 0 6 —

P C

4.5 7 1 6 1 1 2 1 1—1 O Oj 0. 0 1 2 5 0.2 2 4 0.1 9 8 -

6. 8 6 1 5 9.3 1 5 7.5 l • 59 0. 0 1 2 4 0.2 1 4 0.2 2 3 -

0.4 1 0 3.6 1 9.0 1 .65 0.0 1 6 0 0.2 5 4 0.3 3 6 —

P S

( foam 1 . 89

)

0.8 6 4.6 3 5.6 0.015 3 0.3 3 3 0.2 4 5 —

1.2 0 9 0.5 3 9.0 !

!° 0 00 0.0 1 3 7 0.2 9 1 0.1 4 8 -

24 9 1 3 5.0 1 9 3.0 0.34 0. 0 0 5 1 0.2 7 8 0.3 2 7 2 7.8 P A

4.6 4 1 1 0.8 9 9.0 0.51 0. 0 0 5 3 0.2 7 6 0.3 2 9 1 9.3

7.0 0 1 1 7. 5 1 1 0.5 0 00 0.0 0 6 2 0.2 3 4 0.3 2 1 1 8.3

Table 2 Tested materials

Mo sample remarks

1 polycarbonate P C

2 polyacetal POM

3 rigid poly P VC

4 vinyl chloride PVC (r) fire

retardant

5 high impact

polystylene H I - P S

6 polystylene P S ( r) fire

retardant

7 A B S A B S

8 polystylene PS (f ) form

9 polyamide P A

1 0 unsaturated

polyester (fibre

reinforced

)

F R P

1 1 FRP (r) fire

retardant

1 2 polyethylene P E

1 3 polyurethane

(form)

PUR

1 4 PUR (r) fire

reta rdant

1 5 polypropylene P P

1 6 poly methyl

methacrylate P M M A

17 urea- formaldehyde U F

1 8 phenolf ormaldehyde P F

1 9 wood W

512
able 3

Test

results

(at

550

°C)

Table 4

Test

results

(at

8S0°C)

tt T3 o <T>

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5.8 ao

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3.9 6

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0.5 41.7 40.9 0 990

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0.27 1.0 2

1.5 6

0.28

0.6 04

0.7 14

burning time

(sec) 15

7.5 9

4.0 7

8.5 7

5.0 009 102.0 57.5 o

CM 8

0.5 in

xrCO 20

8.0 o

xrO 2

7.0

heated

for

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sec 8

2.5 in

xr cn

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for

600

sec

SIEI

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—

p 5 ^

-H cn -H

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u P <3 C

4J “ CH " 3 CP -H O 11

2.5 9

3.0 103.0 16

5.0 7

3.0 7

6.0 7

9.5 9

3.0 108.5 8

1.5 11

4.5 10

3.5 5

3.5 7

5.5 ~-o

CO

ao 29

7.5 27

1.0

"o

cn

_ CM CO CM o ao

_ , CO o m

OO ° P cn e

CM CO co’ co CM CM CO CO CO co" CO CO

d cri cm' co CO CM MO JZ <v ^ P C

(0 ^ c- o o in tx CO o CO in CO o in CO ao

m ao

O

O ° in O CO CM CO ao CM CO xr <n o cn fx r- xr MO <n VO ° e ^ CM co" CM CO CM d CM CM d d *"* c4 CM CM 1

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513
Table 5 Smoke evolution

No. sample c.3 •'CS Ics/

55 0°C 8 50°C 550°C 850°c -ics

1 PC 1 . 492 2 . 724 0 . 773 1 . 2 1 1 0 . 63

2 POM 0 . 002 0 . 010 0 . 001 0 . 004 0 . 25

3 PVC 4- 050 4- 124 1 . 710 1 . 589 1 . 08

4 PVC ( r

)

3 - 600 4. 400 1 . 319 1 . 352 0 . 98

5 HI - PS 3 • 1 80 O^ • 000 2 . 294 1 . 399 1 . 64

6 PS ( r

)

3 • 710 2 . 424 2 . 363 1 . 585 1 . 49

7 ABS 3 • 280 2 . 450 1 . 624 1 . 140 1 . 42

8 PS(f ) 0 . 262 0 . 900 1 . 637 0 . 923 1 . 77 i 9 PA 0 . 742 0 . 450 0 . 322 0 . 196 1 . 64

10 FRP 2 . 300 2 . 274 1 . l6l 0 . 936 1 . 2 4

1

1

FRP( r

)

2 . 880 3 • 100 1 . 220 1 . 040 1 . 17

12 PE 1 . 214 l . 100 0 . 664 0 . 579 1 . 15

13 PUR 0 . 568 0 . 364 1 • 422 0 . 347 4. 10

14 PUR ( r

)

0 . 668 0 . 600 1 . 759 0 . 545 3. 23

15 PP 1 . l 90 1 . 064 0 . 915 0 . 721 1 . 27

1

6

PMMA 0 . 728 0 . 400 0 . 294 0 . 186 1 . 58

17 UF 1 . 226 -- 0 . 434 — - --

1 8 PF 0 . 826 1 . 024 0 . 623 0. 682 0 . 91

19 wood 0 . 200 0 . 550 0 . 1 16 0 . 290 0 . 40

514
Table 6

Gasses

resulted

by

burning

515

Note :

"trace
Wet

ana

)

ysis

516

Fig.

1-1

Diagram

of

test

apparatus
amount

of

generated

amoke

per 1

g

of

the

teat

aample

mass of test sample (g)

Fig. 1 Relationship between burned mass

and mass of test sample.

burned mass ( ? ) Fig. 2 Relationship between the burned mass and the smoke density.

mass of sample (?)

Fig. 3 Relationship between the burning

rape and the amount of generated

smoke per lg of the test sample. mass and evolved amount of CO.

517
amount

of

evolved

CO

per

1

g

of

test

sample

1.8

fig- 7 Relationship between CO and C02*

Fig. 6 Relationship between the burned

mass and evolved amount of'COjFig. 8 Relationship between the burned, mass and consumed oxygen concentration.

518
ignition

time

(see)

and

burning

time

Fig. 10 Ico/lco2 and lea

mass of test sample (g)

Fig. 9 Relationship (between the ignition

time and binning time with various

mass of test samples.

Fig. 11 Ico/lco2 (at 550'C an

519

MEASUREMENT METHODS

Patrick Pagni

Session Chairman

521

CURRENT U. S. ADVANCES IN FIRE RESEARCH TECHNIQUES

Raymond Friedman

Factory Mutual Research Corporation

Norwood, Massachusetts 02062, U.S.A.

(For Seventh U.S. -Japan Natural Resources Panel

Meeting on Fire Research and Safety)

September 1983

Factory Mutual Research

1151 Boston- Providence Turnpike

Norwood, Massachusetts 02062

523
Scope

This review is limited to very recent U. S. progress in experimental

techniques applied to fire research. For the most part, work published before

1982 is not included. Work in progress is mentioned, insofar as the author is aware of it.

1. Measurement of Heat Release Rate

The largest accurate calorimeter used to date is described by Heskestad

(1.1) and Lee (1.2) of Factory Mutual Research. It consists of a vertical duct

10.5 m tall and 1.5 m in diameter, below which is a cone opening to 6.1 m diameter. Combustion products are drawn into the cone by an exhaust fan, at a rate up to 30 kg/s. After passage through a mixing orifice, the temperature

and composition of the gases are measured at a single point, yielding both the

convective portion of the heat release rate and the total heat release rate

inferred from oxygen consumption or carbon dioxide/carbon monoxide production.

The useful range for accurate work is from 100 kW to at least 4 MW.

Babrauskas et al., (1.3) used a large calorimeter to measure heat release

rates of furniture items, primarily upholstered chairs. The oxygen depletion

method was used to determine heat release rate. Ignition was with a 50 kW

natural gas burner for 200 s, intended to simulate a wastebasket fire. Peak

heat release rates up to 3.7 MW are reported; however, the capacity of this

apparatus is stated to be 2.5 MW.

Let us now consider heat release rate measurements on a smaller scale.

Babrauskas (1.4) measured several gaseous and horizontal polymethyl methacrylate samples with the Ohio State University apparatus using two different

techniques: 1) standard compensated thermopile measurement, and 2) oxygen

depletion. Results showed substantially complete combustion according to oxygen depletion, but a varying incompleteness in excess of 20% with the standard sensible enthalpy-based procedure. Furthermore, plastic samples burned

at a progressively increasing rate in the OSU apparatus, the rate doubling in

the interval between 100 and 500 s, while identical samples burned at a con- stant rate over this interval in a different apparatus. Babrauskas proposes

that, in the OSU apparatus, the external irradiance of the sample increases

throughout a test because of flame impingement on the reflector and other

nearby metalwork, instead of remaining close to the original nominal value.

524
Tordella and Twilley (1.5) have described development of a calorimeter

for simultaneously measuring heat release and mass loss rates. Their appara2 tus provides a radiant flux from 25 to 80 kW/m from gas-heated radiant panels

to vertical specimens 300 x 300 mm or horizontal specimens 150 x 300 mm. The

heat release rate is measured by the substitute gas burner technique. A problem was experienced on windy days — fluctuations in flow rate of gas to the

substitution burner caused by variable wind velocity at the top of the stack.

2 Gusts caused baseline variations up to 150 kW/m .

Babrauskas (1.6) has reported on a bench-scale heat release rate apparatus using a cone calorimeter. The specimen may be vertical or horizontal2 upward. Irradiance up to 100 kW/m is achievable. Oxygen depletion, product

gas flow, and sample weight loss are measured; heat release rate is calculated

by assuming 13,100 kJ released per Kg of oxygen consumed, which is valid

within ± 5% for most fuels.

2 . Measurements in Flames and Plumes

Continued refinements have been made on laboratory techniques to probe

small laminar flames. Colket et al. , (2.1) and Fristrom (2.2) have studied

reaction-quenching efficiency of small gas-sampling probes. Cattolica and

Schefer (2.3) and Lucht et al. , (2.4) have developed laser-fluorescence techniques for measuring hydroxyl radical concentration in flames. Knuth et al.

,

(2.5) has described molecular-beam sampling of methane-air flames being extinguished by dry chemicals. Hughey and Santavicca (2.6) have studied techniques

for reconstructing axisymmetric reacting flow fields from absorption measurements.

Turning now to turbulent flames and plumes, we find that Most et al.,

(2.7) have succeeded in measuring velocity profiles in a turbulent ethane diffusion flame burning close to a porous wall, by using laser-Doppler velocimetry. The flame was seeded with alumina particles. The method was based

on random sampling of velocities in the measuring volume. Ikioka et al (2.8)

have described a laser anemometer seeding technique for combustion flows with

multiple stream injection.

Markstein (2.9) has developed a fiber-optic absorption probe which measures infrared diode radiation at 0.96 micrometers across a gap of 60 mm. This probe has been inserted into turbulent diffusion flames up to 762 mm in

525
diameter, and local absorption measurements may be interpreted to yield the

spatial variations within the flame of absorption coefficient and correspond-

_6 ing soot volume fraction. Soot volume fractions as high as 1.9 x 10 have

been measured in a propylene flame.

Tamanini (2.10) has built an apparatus for quenching the reaction at any

desired height above the fuel surface for a turbulent pool fire. The principle is to draw the entire burning flow into a horizontal "catcher-quencher"

heat exchanger located a variable distance above the pool surface. The heat

exchanger is ccoled with hot water to prevent condensation. Chemical analysis of the quenched gases is performed, as well as a flow-rate measurement.

Analysis of propane data yields heat release rate and carbon-monoxide yield

versus height in the flame. The apparatus is limited in that: 1) data taken

with the heat exchanger very close to the pool surface are of doubtful significance; and 2) use with fuels much sootier than propane may be limited because

of plugging of the heat -exchanger openings. Except for these limitations, the

data appear to be reliable.

Rung (2.11) has described a method of measuring the convective heat flux

in a buoyant turbulent plume over a large pool fire. The method is based on

a limited number of temperature and velocity measurements at selected locations within the plume, and analysis involving curve-fitting to assumed

Gaussian profiles of temperature and velocity. Results are in good agreement

with those obtained by Heskestad’s calorimeter (2.11). While the calorimeter

is inherently more accurate, any given calorimeter will have a maximum capacity, while Kung’s method has no such limitation.

Zukoski et al., (2.12) have applied the Ricou- Spalding technique (1961)

to entrainment-rate rate measurements in 10 to 200 kW buoyant fire plumes of

0.1 to 0.5 m diameter. They find that small irregularities in the induced

air inflow can cause substantial increase in entrainment rate. Delichatsios

(2.13) is measuring entrainment by a similar technique, and is taking elaborate precautions to eliminate effects of flow irregularities on the results.

3 . Fires in Compartments

Fisher and Williamson (3.1) have described a proposed standard room fire

test method for evaluating interior finish materials (wall and/or ceiling materials). The test compartment is 2.4 m wide, 3.7 m long, and 2.4 m high,

526
with an open doorway. The ignition source is a propane-fired sand burner in one comer. The combustion products rising from the doorway are collected

and mixed in a stack, and heat release rate is deduced from oxygen depletion.

In addition, measurements are made of temperature 100 mm below the ceiling,

heat flux to the floor, and light transmission through the stack gases. In

a typical test leading to flashover, an average ceiling temperature of 600°C

is achieved in a few minutes, and flames appear outside the door one or two

minutes later (at which time the heat release rate is 750-950 kW) . More re- cent data (August 1983) show that times to flashover for plywood correlate

with moisture content and with presence of fire retardant.

Two papers have appeared which deal with techniques to study compartment

fires. Cooper (3.2) is concerned with the leakage of smoke through door assemblies, and also overall wall and floor assemblies. He evaluated the proposed ISO test method DP5925, Part 3 for door assemblies and found certain

problems with the method. After analyzing the reasons for lack of success,

the author proposes a new test configuration which would hopefully remove the

limitations and problems of the proposed ISO test method.

Steckler et al. , (3.3) have carried out probably the most complete and

accurate set of steady-state experiments conducted to measure the flow rate

induced through an opening in a compartment by a simulated pool fire in the

compartment. Movable bidirectional velocity probes and thermocouples were located on a grid of up to 144 points in the opening. A series of fire sizes

and fire locations were studied. The resulting flow rates were well corre- lated by a hydrostatic model which requires measurement of vertical distribution of temperature, but no velocity measurements. An accuracy of the order of ± seven percent is shown.

4. Droplets and Particulates

You and Symonds (4.1, 4.2) have used a unique instrument to measure water

drop-size in sprinkler sprays. This is a custom-made device constructed by

Particle Measurement Systems, Inc., Boulder, Colorado. A sheet of laser

light is projected across a 61-mm gap onto a linear array of 64 detectors.

A passing drop produces a shadow, the width and duration of which are measured. If the drop is known to be spherical, both the diameter and velocity

may be deduced. On the other hand, given a non-spherical drop moving with

527
known velocity, its cross-sectional shape is obtainable. The output is stored

in a computer and various statistical distribution functions may be displayed

on a screen. Data are obtainable for droplets from a few tenths of a mm diameter up to 6 mm diameter. As long as the total water flux is low enough (below

2 about 15 droplets/cm min), an accurate measure of total water flux is also

obtainable. At higher fluxes, some droplets are missed. However, tests with

polydisperse stainless steel balls have confirmed the probe’s ability to provide accurate particle distribution information, even at higher fluxes than

indicated above. The system has built-in modes for coincidence error rejection, depth-of-field rejection, and edge rejection.

Turning now to measurement of. smoke, Mulholland (4.3) has analyzed errors made by the widely used method of light extinction. What is measured is not

only the transmitted light but also the forward-scattered light, which depends

on the particulate diameter. Furthermore, the use of white light instead of

monochromatic light causes deviations from Bouguer’s law. Measurement errors

of the order of 25% will result from each of these effects. A potential method for calibrating extinction instruments is described.

Quintiere (4.4) has made an extensive review comparing full-scale fire

smoke data with laboratory test method results. In general, the correlations

are rather poor. The author attributes this primarily to the importance of

various physical factors affecting smoke formation rather than to faults of

the various test methods. The identified factors influencing smoke in a large

fire, which cannot be easily related to laboratory tests, are: 1) the variation of smoke production with time as the sample is heated; 2) the effect of

external radiant flux; 3) oxygen concentration; 4) scale; 5) orientation;

6) flaming vs. non-flaming decomposition.

5 . Toxicity

Toxicity is reviewed separately at this meeting so it will not be discussed here. However, two important papers, by Levin et al. , (5.1) and by

Williams and Clark (5.2) are noted. The former deals with development of a test protocol, while the latter shows that when polytetrafluorethylene is

heated with a methane flame the toxicity of the products is about three or- ders of magnitude less than when it is pyrolyzed under non-flaming conditions.

They propose that water which forms in the flame may act to hydrolyze and

528
deactivate the toxic species (the identity of which is uncertain). However,

these data also show that pyrolysis of PTFE in the absence of a flame at 850 °C

gives products a factor of 300 less toxic than for pyrolysis at 700 °C, suggesting that heat rather than water vapor deactivates the toxic species.

6 . Miscellaneous

Robertson (6.1) has described a gas-fired radiant heat source for use in

a fire test method. It can be operated at equivalent black-body temperatures

2 of about 930°C, allowing specimen irradiance levels of 5 W/ cm for substantial

2

periods, and could approach 7 W/cm for short periods. A heated surface of

270 x 480 mm, fired with natural gas, was made of commercially available re- fractory tiles.

Steel (6.2) has tested several pressure probes of types used in fire en- durance furnaces at room temperature and then compared in a furnace. It is

suggested that the total pressure be measured instead of static pressure and

that the most accurate probe is a small flush hole in the specimen.

de Ris (6.3) has proposed a concept for a new bench-scale test method to assess flammability of solid materials. It is based on the concept that the

radiant emission of a material’s own flame is a critically important property

in determining its large-scale burning rate and spread rate. A small sample

is electrically heated in an oven through which a nitrogen-ethylene mixture

flows. The effluent nitrogen-ethylene-pyrolysis gas mixture is discharged upward from an orifice to form a candle-like laminar diffusion flame. Depending

on flow rate and composition, this flame may be above its smoke point; i.e.,

releasing soot from the top. The flame height and soot formation are sensed

automatically. The nitrogen and ethylene flow rates are automatically adjusted so as to hold the flame height constant while simultaneously keeping

the flame just at its smoke point. The heat release rate is proportional to

the flame height. Accordingly, as combustible pyrolysis gas is generated,

ethylene flow must be reduced to maintain constant flame height. The ethylene

flow reduction is a measure of heat release rate. Now, if the generated pyrolysis gas had the same soot-forming propensity as ethylene, no further adjustment would be needed to maintain the flame just at the smoke point. However, for example if the pyrolysis gas had a greater soot-forming propensity

than ethylene, it would be necessary to increase the nitrogen flow suf f i c imt 1 .

529
to hold the flame at the marginal soot point. Thus, by proper interpretation

of the ethylene and nitrogen flow rates as pyrolysis occurs while flame height

and incipient soot formation are being held constant, one can deduce both

soot-forming tendency and heat release rate of the sample. Correlations exist between soot-forming tendency and fire radiative emission for a series of

hydrocarbons, but further data are needed for other combustibles. Also, the

applicability to situations where volatile chemical retardants must be ex- plored. Finally, the concept must be translated to practical hardware.

Kashiwagi and Kashiwagi (6.4) have used a high-speed, two-wave length

holographic interferometer to study transient ignition events (500 frames/

second) associated with high-flux CO^ laser irradiation of a flammable liquid

surface. This provides both temporally and spatially resolved temperatures

and species concentrations. In this apparatus, a helium-neon red laser

(632.8 nm) and an argon blue laser (688 nm) are used. The molar refractivities of the hydrocarbon vapor, oxygen and nitrogen at the two wavelengths are

known. Fringe analysis from laser holograms reveals the temperature and com- position information.

In another ignition study, Kashiwagi (6.5) explored the effects of sample

orientation on spontaneous ignition delay using either a CO^ laser or a gasfired radiant panel to heat PMMA or red oak. Ignition occurred sooner and at

lower minimum radiant flux with horizontal as contrasted with vertical samples. Sample size was also important. Although extensive discussion is provided, the full explanation for these effects is still not established. However, it is clear that auto-ignition of a surface is not uniquely determined

by the incident radiant flux and the ambient atmosphere.

530
REFERENCES

1.1 Heskestad, G., "A Fire Products Collector for Calorimetry into the MW Range,"

Factory Mutual Research Corporation, J.I. 0C2E1.RA, June 1981 (100 pp)

.

1.2 Lee, J. L. , "A Manual for Measuring the Convective and Radiative Heat Release Rates of Transformer Fluids Using the Fire Products Collector,"

Factory Mutual Research Corporation, J.I. 0G1E8.RA, February 1982 (23 pp)

.

1.3 Babrauskas, V., Lawson, J. R. , Walton, W. D. and Twilley, W. H. , "Upholstered Furniture Heat Release Rates Measured with a Furniture Calorimeter."

NBSIR 82-2604, December 1982 (73 pp)

.

1.4 Babrauskas, V., "Performance of the Ohio State University Rate of Heat Release Apparatus Using Polymethyl Methacrylate and Gaseous Fuels." Fire

Safety Journal 5_, No. 1, pp. 9-20 (1982) .

1.5 Tordella, J. and Twilley, W. H. , "Development of a Calorimeter for Simultaneously Measuring Heat Release and Mass Loss Rates." NBSIR 83-2708,

June 1983 (30 pp)

.

1.6 Babrauskas, V. , "Development of the Cone Calorimeter - A Bench-Scale Heat

Release Rate Apparatus Based on Oxygen Consumption," NBSIR 82-2611,

November 1982 (75 pp)

.

2.1 Colket, M. B., Chiappetta, L. , Guile, R. N., Zabielski, M. F. and

Seery, D. J. , "Internal Aerodynamics of Gas Sampling Probes," Combustion

and Flame 44^, 3-14 (1982)

.

2.2 Fristrom, R. M. , "Comments on Quenching Mechanisms in the Microprobe

Sampling of Flames," Combustion and Flame 5U, 239-242 (1983).

2.3 Cattolica, R. J. and Schefer, R. W. , "Laser Fluorescence. Measurements

of the OH Concentration in a Combustion Boundary Layer," Combustion

Science and Technology 30 , pp 205-212 (1983).

2.4 Lucht, R. P., Sweeney, D. W. and Laurendeau, N. A., "Laser-Saturated

Fluorescence Measurements of OH Concentration in Flames," Combustion

and Flame 50, pp 189-205 (1983).

2.5 Knuth, E. L., Ni, W. F. and Seeger, C., "Molecular-Beam Sampling Study

of Extinguishment of Methane-Air Flames by Dry Chemicals," Combustion

Science and Technology 2_8, pp 247-262 (1982).

531
2.6 Hughey, J. and Santavicca, D. A., "A Comparison of Techniques for Reconstructing Axisymmetric Reacting Flow Fields from Absorption Measurements,"

Combustion Science and Technology 29_ , pp 167-190 (1982).

2.7 Most, M., Sztal, B. and Delichatsios , M. A., "LDV Measurements in a Turbulent Wall Fire," FMRC-CNRS, report in preparation, 1983.

2.8 Ikioka, L. M. , Brum, R. D. and Samuelson, G. S. , "A Laser Anemometer

Seeding Technique for Combustion Flows with Multiple Stream Injection,"

Combustion and Flame 49^ pp 155-162 (1983).

2.9 Markstein, G. , "Measurements on Gaseous-Fuel Pool Fires with a FiberOptic Absorption Probe." Submitted to Combustion Science and Technology

(August 1983).

2.10 Tamanini, F. , "Direct Measurements of the Longitudinal Variation of Burning Rate and Product Yield in Turbulent Diffusion Flames ," Combustion and

Flame 51, pp 231-243 (1983).

2.11 Kung, H. C., "Buoyant Plumes of Large-Scale Pool Fires," Nineteenth Symposium (International) on Combustion, The Combustion Institute,

Pittsburgh, 1983, pp 905-912.

2.12 Zukoski, E. E., Kubota, T. and Cetegen, B., "Entrainment in Fire Plumes,"

Fire Safety Journal 3_, pp 107-121 (1981).

2.13 Delichatsios, M. , Factory Mutual Research Corporation, August 1983,

Private communication.

3.1 Fisher, F. L. and Williamson, R. B., "Intralaboratory Evaluation of a Room

Fire Test Method," NBS-GCR-83-421, January 1983.

3.2 Cooper, L. Y. , "Measuring the Leakage of Door Assemblies During Standard

Fire Exposures," Fire and Materials .5, No. 4, pp 163-174 (1981).

3.3 Steckler, K. D. , Quintiere, J. G. and Rinkinen, W. J., "Flow Induced by

Fire in a Compartment." Nineteenth Symposium (International) on Combustion, The Combustion Institute, Pittsburgh, Pennsylvania, 1983,

pp 913-920.

4.1 You, H. Z. and Symonds, A. P., "Sprinkler Drop-Size Measurement, Part I: An Investigation of the FMRC PMS Drop-Size Measuring System," Factory

Mutual Research Corporation, J.I. 0G1E7.RA, December 1982, (57 pp)

.

532
4.2 You, H. Z., "Sprinkler Drop-Size Measurement, Part II: An Investigation

of the Spray Patterns of Selected Commercial Sprinklers with the FMRC

PMS Droplet Measuring System," Factory Mutual Research Corporation,

J.I. 0G1E7.RA, May 1983 (95 pp)

.

4.3 Mulholland, G. W. , "How Well Are We Measuring Smoke?" Fire and

Materials 6^, No. 2, pp 65-67 (1982).

4.4 Quintiere, J. G. , "Smoke Measurements: An Assessment of Correlations

Between Laboratory and Full-Scale Experiments." Fire and Materials 6_, No. 3/4, pp 145-160 (1982).

5.1 Levin, B. C., Fowell, A. J., Birky, M. M. , Paabo, M. , Stolte, A. and

Malek, D., "Further Development of a Test Method for the Assessment of

the Acute Inhalation Toxicity of Combustion Products," NBSIR 82-2532,

June 1982 (143 pp) .

5.2 Williams, S. J. and Clarke, F. B. , "Combustion Product Toxicity: Dependence on the Mode of Product Generation," Fire and Materials 6_ , No. 3/4,

pp 161-162.

6.1 Robertson, A. F. , "Development of an Improved Radiant Heat Source for

Fire Testing," Fire and Materials 6_, No. 2, pp 68-71 (1982).

6.2 Steel, J. S., "Furnace Pressure Probe Investigation," NBSIR 81-2415

(28 pp) , November 1981.

6.3 de Ris, J. , "Flammability Testing: State of the Art." Submitted to Fire

and Materials, July 1983.

6.4 Kashiwagi, T and Kashiwagi, T., "A Study of the Radiative Ignition Mechanism of a Liquid Fuel Using High-Speed Holographic Interferometry,"

19th Symposium (International) on Combustion, The Combustion Institute,

Pittsburgh, 1983, pp 1511-1521.

6.5 Kashiwagi, T., "Effects of Sample Orientation on Radiative Ignition,"

Combustion and Flame 44_, pp 223-245 (1982).

533

Discussion After R. Friedman's Report on CURRENT U.S. ADVANCES IN FIRE RESEARCH

TECHNIQUES

JIN: I’d like to know more about the particular device which you sprayed water;

what particular equipment or systems you have. Do you use a regular sprinkler?

FRIEDMAN: No, and we could not use regular sprinklers because we do not have a ceiling over the fire to collect the heat. We have this collector which draws

the gases in an unnatural way into the duct. So we do an elaborate calculation

of the heat release and deduce when sprinklers would have opened if a ceiling

had actually been present. Then we apply water through small openings very

close to the top of the fuel so that all the water reaches the fuel. For real

sprinklers , only a portion of the water would have reached the fuel because the

fire plume would have deflected a lot of the water. We measure that process in

a separate set of experiments. Therefore, we separate the penetration problem

from the extinguishment problem and study each problem separately.

HIRANO: What was the size of the water particle?

FRIEDMAN: Very fine, very tiny, miniature spray nozzles. The water hits the

top of the carton and just becomes a sheet of water which runs over the sides;

so it is not a droplet.

HIRANO: One question pertains to the timing of actual start of sprinkling water

and then, of course, the volume of water. Suppose we have two major factors,

one is time, the other one is volume of water. Which one should be more crucial

than the other?

FRIEDMAN: Both.

HIRANO: Suppose you used the fixed volume of water, what time spent would you

like to apply. .. continuously at once or over a certain period?

FRIEDMAN: It would depend, of course, on what you were protecting. In the

problem we are concerned with, we have cardboard boxes containing, usually,

polystyrene foam insulating packing material and electronic products inside. If

you can control the fire before the cardboard has burned through, before the

polystyrene is involved, then this makes it much easier to control the fire.

HIRANO: What was actual sprinkling time in this particular case?

FRIEDMAN: We started one minute after ignition and continued a long time, but

you saw that the heat release was very low. The fire would probably never be

put out. It might still be burning a half hour later but people could come and

put it out. It would be a very small fire. The fire is underneath 7 meters of

goods on top, so it is very hard to completely extinguish it.

NELSON: How close are we to unlinking these phenomena to put them back together

in the model?

FRIEDMAN: A lot of progress. We have special people working on models.

NELSON: Have you got a fairly clear picture of the elements of the model?

FRIEDMAN: The model has a lot of empiricism in it at this point.

535
PAGNI: What was the ignition source?

FRIEDMAN: Ignition source was a half pint of alcohol (473 cc)

.

EMMONS: In the experiment, and I would expect in practice, all of the top

portion had been extinguished, the bottom portion is not extinguished. You

suggest that the lower portion is extinguished by hand. But how do you ensure

the safety of those who do it from collapse?

NELSON: Isn't the basic underwriting theory to stop it from going to another

pile, and actually it's acceptable if that pile burns out because the fire

fighters can' t reach it?

FRIEDMAN: I think the key thing is that that fire was reduced to less than 1/10

of a megawatt within half a minute. If the water had not been put on at that

time, that fire would have been more than 30 megawatts. The water couldn't do

anything once the styrene got going.

BEYREIS: The basic philosophy of commercial industrial sprinklers is to control

the fire. That's why it is a difficult problem to go from that to people

protection for residential hotel arrangement where the idea is to extinguish the

fire.

COOPER: Could you say anything about the question of configuration; for

example, what if you use shelves that are solid as compared to open.

FRIEDMAN: I said empirical which means all our modeling for that geometry.

This is a fairly standard rack storage study. Hopefully it's a worst case.

536
VARIOUS MEASURMENT METHODS ON FIRE RESEARCH

by

Shuzo Yamashika and Taro Yumoto

Fire Defence Agency

Ministry of Home Affairs

Seventh Joint Meeting

U.S. -Japan on Fire Research and Safety

UJNR 3 Washington, D.C. Oct . 24-28 , 1 9 8

3

537
VARIOUS MEASUREMENT METHODS ON FIRE RESEARCH

Shuzo Yamashika and Taro Yumoto

1 . INTRODUCTION

Burning rate of combustibles, temperatures of flame or hot plume,

radiation from flame, velocity of hot flow and the compositions of

combustion products are indispensable measuring items for fire research.

In this paper, the present status and problems of various measurement

techniques which have so far been used in studies on the fires of buildings

since 1979 in Japan will be described.

2. PRESENT STATUS ON BUILDING FIRE RESEARCH

2.1 Experiments of Full-Scale Building Fires

Kishitani et al.^ made an experiment on the fire of a, three-story,

2 wood frame construction two-family house of a total floor area of 89.02 m

measuring the temperatures of 118 places in the house and 48 places of

walls by 166 chrome 1 -alumel thermocouples, as well as the concentration of

smoke in 34 places in the house by 34 smoke density meters and radiant

heat from the firing house to the environment by means of radiation meters

and disk thermocouples. In addition, the concentrations of CO and 0^ in

the central part of the rooms were continuously analyzed by using CO and

0^ analyzers, and the behaviors of mice put in such atmospheres were

measured by the rotary behavior recorders.

In an experiment on the fire of a two -story light steel -frame house

2 21 of a total floor area of 104,16 m , which was conducted by Oguni et al. ,

in addition to similar measurements mentioned above, the surface temperature

of the house was measured by a thermo viewer. The pressures of 4 places in

rooms are measured by 4 fine differential pressure meters combined with each

Pitot-tube, and the states of fire were recorded by a 16 mm camera, still

538
photograph, and VTR.

3

"\ Yamashita } measured, in an experiment of the fire of 12 wooden tenement

houses, three-dimentional wind speeds at a level of 55 m above the ground and

in a place about 40 m apart from the end of burning region down the wind by

using a supersonic wind direction and speed meter provided with a large-size

crane.

41

Sato et al. also carried out a run on the fire of a single compartment

2 in conventional wooden house with a floor area of 9.94 m , in which 4 load

cells were placed on the compartment and weight loss by burning was measured

and the radiation of heat from the' firing compartment to the environment was

measured by 17 disk thermocouples and a radiation meter. The temperature of

the inside of the compartment was measured by chromel-alumel thermocouples,

the air current velocity at the openings was measured by 2 simple Pitot -tubes

each of which is combined with fine differential pressure meters and also the

concentrations of smoke at 4 places were measured by 4 suction type smoke

density meters. In addition, the concentrations of CO., and CO were continuously analyzed by the infrared analyzers, the concentration of 0

? was

measured by a dissolution type oxygen analyzer, and the behavior of mice

was by the rotary type behavior recorders.

Sato et al.*^ carried out an experiment of fire for a three -story wood2 based prefabricated house of a total floor area of 114,68 m and similar

measurements mentioned above were made.

Hayashi et al.^ measured a strong radiant heat around a house on fire,

in the experimental fire of a mortar -plastered house with a floor area of

2 40.5 m , by using a water-cooled type heat sink type heat flux meter and

2 obtained a radiation intensity of 70,000 kcal/m • h at a level of 1.5 m

above the ground and at a place 0.25 m from the outer wall.

2.2 Flow Behavior of Smoke in Full-Scale Building

In an experiment on the smoke filling in a single room with a floor

539
2 71 area of 13.65 ra and a height of 2.41 m»_ Mulholand et al. 1 measured the

temperatures of 12 vertical positions in the room by using 12 chromelalumel thermocouples and the smoke concentration of 5 vertical positions by

using 5 smoke density meters.

Handa et al. J conducted an experiment on the flow behavior of hot fire

products in a concrete corridor 150 m length, 3.3 m width, and 1.63 m height

in which the weight loss of wood as a fire source was measured by a load

cell. Velocity and temperature of the flow were measured by a smoke-wire

method and an array of thermocouples. The tuft system was also employed

for the demonstration of profiles and the estimation of velocity.

2.3 Burning Behavior of Furniture

91

Kawagoe et al. burned each kind of furniture, e.g., cabinet, bookshelf,

2 desk etc., in an experiment room with a floor area of 34.31 m and a height

of 3.0 m, and measured the weight loss rate of the furniture by a load cell,

the temperatures of 6 places inside the room by 6 thermocouples, the temperatures of 43 places in the rising hot plume by 43 thermocouples, and the

velocity along the center axis of the rising hot fire products by a combination of a bidirectional -pressure probe and a fine differential pressure

meter. Also, the smoke concentrations at 8 places were measured by 8 smoke

density meters and the smoke filling and the height of flame were recorded

visually and photographically.

Mizuno and his coworkers^^ burned urethane foam mats in the same

experimental room and similar measurements mentioned above were made.

2.4 Miscellaneous

Nakaya et al.*^ also investigated the degrees of the change in

temperatures in a 30 cm cube model room during fire, in which methanol and

PMMA plate were burned in the model room, the temperatures of 9 places on

the surface of ceiling and walls were measured by a 0.1 mm chromel -alumel

thermocouple, and the temperatures of the space of the room were measured

540
by a 0.03 nun platinum-13%Pt-Rh thermocouple.

121

Haserai and his coworker J obtained the radiation tolerance criterion

of man by a method in which the whole body of a man is heated by a Schwankburner 1.1 m in width and 1.8 m in height.

131

Kawagoe et al. investigated the shape and height of flame by the

contour line charts of flame on the basis of a set of photographs taken by

concurrently operating the shutters of two cameras set in parallel.

141 Tachibana also photographed flames of fire by a long-term exposure

method on a thought that what necessary for the calculation of radiant heat

of fire is not the instantaneous shape of flame but the average value within

a period of time.

Masuda and his coworkers'*^ made an experimental run of wind tunnel to

compare an usual L-type Pitot-tube with a simple Pitot-tube in which two

iron steel pipes whose tips are folded at right angles are combined in backto-back manner, which was manufactured by them, on a thought that a probe

to be used in the measurement of velocity of hot fire products during the

full-scale fire experiment should be desirably strong against heat and

impaction and also be inexpensive, and confirmed that the simple Pitot-tube

was usable actually.

3. PROBLEM OF MEASUREMENT TECHNIQUE

3.1 Measurement of Temperature

In the measurement of temperatures, thermocouples have been used in all

cases. In most cases, a 0.6 mm or 1.0 mm dia. of chrome 1 -a lumel thermocouple

is being employed, although there was an experiment'*''^ in which thermocouples

of both 0.03 mm and 0.1 mm diameters were used. A question is wire diameter

of thermocouples. Since the fire of buildings is in the unsteady-state burning in most cases, it is advisable to use a thermocouple of as much a small

size as possible in the measurement of the inside temperatures of room space

in particular from the standpoint of the responding speed of the thermocouples.

541
However, a too small thermocouple could not be used in an full-scale or largescale fire experiments from the strength point of view, even if it can be

used in small-scale experiment. For this reason, a method in which a 0.65

or 1.0 mm thermocouple wire is used till midway of a thermocouple and a 0.3

mm thermocouple wire is used by welding only for the portion near the hot

junction is under consideration, although slightly troublesome.

3.2

Measurement of Pressure

In the measurement of pressures, bidirectional pressure probe or simple

bidirectional pressure probe made of steel pipe have been used. The problems

of pressure measurement arise in differential pressure transducer but not in

the probes. As for fluids to be handled in studies on fire, the differential

pressure is several mm Aq at maximum because of its high temperature and small

density. In Japan at present, a transducer is capable of measuring the

pressures of ± 7 mm Aq in maximum, but the present situation is that ones

having one-figure degraded accuracy have been used because a set of the

foregoing transducer and an exclusive amplifier costs us about a million yen.

3.3

Measurement of Radiant Heat

The measurement of radiant heat have been used radiation meter on the

market and a disk thermocouple. Since the radiation meter on the market is

very expensive, or costs 350,000 yen a set, many manually made disk thermocouples have been used in most cases in full-scale fire experiments. The

question is the time constant of the disk thermocouples, as in the case of

temperature measurement. The time constant is about 19 seconds^ ^

.

Considering that the fire of buildings is the unsteady-state burning, it is

desirable to use ones of small time constants.

3.4

Measurement of Smoke Concentration

In the measurement of smoke concentration, smoke density meters have

been used in all cases. The problem of the meter is the adherence of smoke

particles to the lenses on the light pathway. Suzuki^) tried a method in

542
which hot air is flowed near the lenses to heat the lenses in such a way as

to prevent the adherence of smoke particles to the lenses and also to

interrupt the reach of the smoke particles to near the lenses by the flow

of air in order to prevent the adherence of the smoke particles.

3.5 Measurement of Gas Concentration

In the full-scale fire experiments, the continuous analysis of gases

is desired. At the present time, those which can be analyzed continuously

are only CO, CO^, and 0^. The present situation is that since analyzers

for CO, CO^, and 0^ are still high in price and the number of the meters is

limited, the concentrations of these gases in the central part of room have

been presumed to be the average one of the room.

4. REFERENCE

1) Koichi Kishitani et al. : Annual Meeting of Architectural Institute of

Japan, Sept. 1979, p.1833-1840

2) Katsuo Oguni et al. : Annual Meeting of Architectural Institute of Japan

Sept. 1980, p. 2125-2130

3) Kunihiro Yamashita: Ibidem, p.2161

4) Hiroshi Sato et al . : Annual Meeting of Japanese Association of Fire

Science and Engineering, May, 1981, p.85-100

5) Hiroshi Sato et al. : Annual Meeting of Architectural Institute of Japan,

Oct. 1982, p.2307-2316

6) Koji Hayashi et al. : Annual Meeting of Japanese Association of Fire

Science and Engineering, May, 1983, p.59

7) George Mulnoland et al. : Fire Science and Technology, Vol.l, 1981, p. )

8) Takashi Handa et al.

:

ibidem, p.45

9) Kunio Kawagoe et al .

:

Annual Meeting of Architectural Institute c:

Japan, Sept. 1979, p.1805

10)

Tomoyuki Mizuno et al.

:

Fire Science and Technology, Vol.l, 1981, p.33

543
11) Ichiro Nakaya et al. : Bulletin of Japanese Association of Fire Scienc

and Engineering, Vol.31, No. 2, 1981, p.33

12) Yuji. Hasemi et al. : Bulletin of Japanese Association of Fire Science

and Engineering, Vol. 31, No.l, 1981, p.7

13) Kunio Kawagoe et al. : Annual Meeting of Architectural Institute of

Japan, Sept. 1980, p.2093

14) Fusao Tachibana: J. of Japan Society for Safety Engineering, Vol. 21,

No. 3, 1982, p. 15S

15) Hideaki Masuda et al. : Annual Meeting of Architectural Institute of

Japan, Sept. 1979, p.1829

16) Takayoshi Tanaka et al.

:

Annual Report of the Building Research

Institute, 1980, p.134

17) Hiroaki Suzuki: Annual Report of the Building Research Institute,

1981, p. 178

544
Discussion After T. Jin’s Report on VARIOUS MEASUREMENT METHODS ON FIRE RESEARCH

QUINTIERE: I think the price of the heat flux meter is too high. There are companies in the United States that will sell a thermopile- type of heat flux

meter or so-called Gardon-type meter for less than $500. However, you mentioned

radiometer, a radiant heat flux meter. Do you really mean a sensor only to measure radiation? If so, would you explain the type of radiant heat flux sensor that you are talking about? I realize that you are not the author of the

paper.

JIN: This test actually tried to measure the radiant heat externally, from

outside the building. If you are asking us whether or not we are also taking

the convection into consideration besides radiation, that is not the case in the

test because we have only tried to measure the radiation externally.

DAVIS: A comment about smoke measurement and soot deposition. If you use pitot

tubes, and pass air into those tubes, you keep soot away from the optical

system.

JIN: Yes, the study has dealt with this method, but I have used the method

myself.

DeRIS: I would like to comment on the radiometer question. At Factory Mutual,

we make a lot of radiation measurements using a little sensor which is the size

of a transistor which has a microcircuit thermopile inside the sensor. It costs

approximately $120. We have various optical mirrors or angles, holes, etc. to

make a very accurate radiation reading with extremely well-defined geometry.

545
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October 27, 1983

NEW DEVELOPMENTS IN FIRE PROTECTION -

EVOLUTION TO THE SYSTEMS APPROACH

PRESENTATION TO

U.S. -JAPAN PANEL ON FIRE RESEARCH AND SAFETY

by J. R. Beyreis*

INTRODUCTION:

In earlier times, the outbreak of fire frequently led to the

destruction of entire communities. Over the ages, fire

regulations have developed which have made such occurrences

largely a thing of the past. The earliest of these regulations

was, perhaps, the banning of commonly used combustible materials

such as thatched roofing. Efforts at suppression developed. At

first, this involved hastily arranged bucket brigades which later

led to organized fire companies of more modern times. In the

last century, automatic sprinkler systems were introduced. By

the early part of this century, the focus turned to the effort to

* - Managing Engineer, Fire Protection Department,

Underwriters Laboratories Inc., Northbrook, Illinois

547
contain fire to a single building by fire separation walls

between buildings and later to the objective of confining fire to

a single floor or single compartment within a building.

Attention was also given to the objective of limiting rapid fire

spread involving combustible materials in places of assembly such

as theaters and night clubs.

In the last decade or two, the evolution in fire protection

has tended to focus on eliminating or controlling fire in the

compartment or region of its origin, or mitigating its effects.

This has to a large extent been oriented toward providing for

improved life safety protection for building occupants, that is,

to keep fire and smoke away from people. The major symptoms of

this phase of the evolution in fire protection has been a focus

on understanding fire as a system involving the integration of

many factors. In turn, this has resulted in the need for more

performance characteristics information for the wide range of

products involved in or related to fire protection.

This evolution in fire protection has been accompanied by

the development of construction code documents describing

acceptable construction practices. These code documents,

together with various standardized test methods, form the basic

framework within which developments in the art and science of

fire, find their way into producing improvements in fire

548
protection in the human living environment. Within the context

of these documents, it is evident that each aspect of fire

protection - prevention, detection, suppression, limitation of

growth and containment - has had its place.

Underwriters Laboratories Inc. (UL) conducts fire related

testing for manufacturers who are required to provide fire

performance information to authorities having jurisdiction as a condition of use of the product or material the manufacturer

produces. Based on the activities at UL, it is becoming evident

that an increasing integration of the individual elements of fire

protection is taking place. More and more material, product and

system data and information is being made available from testing.

This information is gradually leading to the use of rational

design processes that recognize the interaction of the fire

protection elements. The availability of computers, to assist in

collecting and analyzing test data, and to assist in the use of

data for such purposes as mathematical fire modeling, are an

important part of this evolution.

549
In order to more closely examine the evolution of fire

protection, discussion of the elements of fire development and

treatment in buildings is in order at this point. These include

ignition, early fire growth, detection, suppression and

containment

.

IGNITION:

If the conditions required to produce an ignition are

absent, then all other concerns relative to fire protection

become moot. A major thrust of the activities of Underwriters

Laboratories over the years has been to reduce the likelihood of

an ignition to a reasonable minimum. This chiefly concerns

energy using or producing appliances and devices, such as

electrical appliances and equipment, and fuel consuming devices

such as furnaces, kerosene heaters, and wood heating appliances.

Developing technology has produced changes in many of these

products requiring the recognition of new hazards. For example,

the use of microprocessors in many appliances to control various

functions including safety functions, creates new problems in

assessing reliability of such appliances. For example, will the

550
software embedded on a chip reliably interrupt power when a sensor tells it that temperature limits are being exceeded?

These and other problems posed by new developments in such

products produce new challenges to the objective of reducing the

likelihood of ignition.

But, despite the level of safety that may be built into

various products, ignition can occur as a result of accidents,

misuse of uncontrollable sources of ignition such as matches and

smoking materials, or abuse and misuse of products which may

otherwise be used safely. The entire field of fire protection

encompassing ignition resistance, detection, suppression, growth

limitation, and containment are all predicated on the expectation

that unwanted ignition will occur from time to time, regardless

of precautions taken.

EARLY FIRE GROWTH :

Building contents, including interior finish are recognized

as having an important impact on early fire development.

Furnishings and similar contents of buildings have not generally

been regulated, except in a few applications such as decorations

551
in places of assembly, cubicle curtains in hospitals, carpets,

and mattresses. However, furnishings and similar contents do

provide the bulk of the fire load in most buildings and have been

identified as a major element as the first item ignited in many

major fires.

Fire Protection Department Engineers at UL are currently

working closely with manufacturers of furniture in a fire

evaluation program for building contents. Tests have been

conducted with mattresses and upholstered furniture.

The present thinking is that Classification programs could

be established on finished furniture, including consideration of

the fire performance of specific components and growth

characteristics such as total time dependent heat release rate

produced under varying ignition scenarios. Such information

would be developed using various ignition levels and positions on

representative furniture articles to determine time dependent

growth characteristics including heat release rate. Research

experimentation on mattresses and furniture pieces by Babraskus

at the National Bureau of Standards and other work set a pattern

for the development of testing of these products at UL. Basic

combustibility and ignition characteristics are also of

increasing interest.

552
Room tests have been used for more than a decade in

developing information on simulated actual installation

configurations for interior finish materials. These tests have

primarily involved measurements of gross phenomena such as

determination of whether or not flashover occurred under

specified ignition conditions, or extent of flame propagation and

material damage. Limited instrumentation provided information on

the velocity of gases flowing into and out of room openings, and

on smoke development. Such information has been used for

information purposes and has not been used in regulation.

More recently, the use of collection hoods has been

introduced which provides for gathering additional information

such as mass flow and other characteristics such as heat release

rate, smoke development, and to a limited extent, combustion

products composition. Efforts have been undertaken to develop

reduced physical scale models of these room tests. The important

role of heat release rate for materials has been recognized by

the introduction of various heat release rate methods. UL

operates an Ohio State University heat release apparatus to

provide supplementary information on material characteristics.

553
As attention is being focused on fire phenomena in a more

detailed fashion, including the relationship of gross heat

release rate to room flashover, the interest in the use of

mathematical models has grown. While mathematical models for

room fire growth have not as yet found direct application in

regulation, mathematical models are being studied with the

objective of making information developed in tests more broadly

useful. These are also being studied to assist in identifying

proper tests to supply input to mathematical models.

DETECTION:

UL's Burglary Protection and Signaling Department has

provided Certification Services for commercial burglary alarm

installers for many years. These systems have provided important

protection to banks and various commercial properties. More

recently, UL has been asked to develop requirements for

residential alarm systems. These systems are being integrated

with other technical developments such as the rapid expansion of

cable TV. The most recent developments provide recognition for

fire monitoring elements of such systems. To a large extent this

is made possible by the ready availability of relatively

inexpensive microprocessor systems. The experience UL has gained

in the investigation of sophisticated security systems using

554
advanced electronic components and voice communication channels

has afforded considerable experience in developing performance

requirements for these integrated cable systems. Such systems

are investigated for fire and shock risks, in addition to

reliability.

The conduct of investigations on such products involves

knowledge of diverse fields, ranging from computer bas^d

communication systems, to fiber optics, and radio transmission

methods

.

SUPPRESSION:

Automatic fire suppression has been a major element of fire

protection for more than a century. Until recently, the use of

automatic fire sprinklers has been almost entirely limited to

commercial and industrial occupancies. The primary emphasis has

been to provide fire control, in order to limit fire size and

reduce potential property damage.

555
Mew materials, warehousing methods, innovative building

designs, water supply considerations and other changes have

precipitated extensive testing and research of automatic fire

sprinklers. As knowledge is gained that permits more rational

design of automatic suppression for such environments, a need has

developed for sprinkler hardware having specifically identified

operating characteristics.

Development of this knowledge will further assist in

defining proper application and use of such sprinklers.

Sprinklers have been tested which have capability for extended

coverage or rapid response and operation in the event of fire.

Increasingly, testing of sprinklers is oriented toward developing

operating characteristics information for individual sprinklers.

This information is intended to be made available to sprinkler

system designers, who can take into consideration the specific

details of the premises to be protected. These rational design

processes will require close cooperation between researchers,

product testers and applicable code bodies if they are to evolve

to a practical procedure.

556
In the last decade, sprinkler hardware and systems have been

developed for residential occupancies. Such sprinklers are

intended to react quickly to fire, with the intent that fires

will not only be controlled, but actually be extinguished in

their incipient stage. Because the water supply to residences is

typically much more limited than that supplied to commercial and

industrial occupancies, innovative supplemental water supply

systems have been considered. These have included pressurized

tanks and similar equipment.

In commercial and industrial occupancies, the potential

property loss provides economic incentive for installation of

sprinklers. In residential occupancies, the potential property

loss is smaller. To make automatic sprinkler systems

economically more attractive, alternate materials have been the

subject of evaluation. These include steel pipe with lesser wall

thicknesses and plastic pipe.

CONTAINMENT:

When all other elements of the fire protection system have

entered the system and a fully developed fire still occurs,

containment, or as it is most commonly referred, fire resistance,

must be included in building design.

557
The basic concepts of containment have been in place for

many years. To a great extent, the concepts remain unchanged.

These concepts are to contain the fire and its products,

including heat, smoke and gases, and to protect the integrity of

the building structural system.

Over the years, hundreds of fire resistance tests have been

conducted on floors, walls, and columns. These tests have served

to establish the basic fire resistance characteristics for a wide

range of building construction systems and materials. While new

materials and structural approaches continue to expand this data

base, there are other aspects of fire resistance which are

receiving a greater focus. Firstly, the need for fire testing

specific assemblies has continued to decrease, as the expanding

data base permits system variations to be evaluated on the basis

of study of existing data. The costly large-scale tests can also

frequently be avoided by developing supplemental information on

building components using small-scale furnaces for fire

resistance tests. The number of tests conducted in such furnaces

has increased dramatically in recent years.

558
Individual elements of construction which have the potential

for disrupting the integrity of a fire resistive assembly, have

also increasingly been the subject of evaluation. This has

produced large numbers of tests of cable penetration protection

systems, electrical fitting tests, plumbing components testing,

and similar testing.

As a part of the continuing effort to extract an ever

growing amount of information from available test data, new

calculation methods are being introduced. These include such

methods as the Fire Analysis of Steel Building Systems (FASBUS)

model for calculating the response of a steel structural system

under the conditions of steel member temperature increase

produced by fire exposure. At present, such programs require the

availability of test data in order to provide temperature time

histories for structural members as input information.

Development of computer programs such as Fire Response of

Structures - Thermal Three (FIRES T3) have promise for replacing

at least a part of the need for test data, by providing

calculation methods for developing temperature time histories for

protected structural elements. These approaches to calculating

temperature rise and calculating structural response can be

supplemented by room fire growth models which can serve to

predict actual time temperature history to be used in specific

environments. This three element computational approach has

559
important implications for the future, and should be the subject

of continuing efforts. While details such as penetrations,

protruding electrical devices, and other discontinuities in fire

resistive assemblies represent particular challenges, they should

not be beyond the potential for solution by mathematical means.

For many years, the appropriateness of the temperature time

curve typically described in such fire test methods as ASTM E119,

has been questioned as to whether it is representative of actual

fire conditions. It is widely acknowledged that the conditions

in any individual fire are likely different than the specific

conditions in many other fire scenarios. While the standard

time-temperature curve has proven to be an effective broad

representation, there are circumstances where specific exposure

conditions are preferred. One such area is the protection of

structural support systems in petrochemical plants. In such

facilities, a common exposure condition is the ignition of

flammable liquid spills. In such fires, there tends to be a rapid temperature rise and associated developments of velocities

and flux composition peculiar to flammable fuel fires. A fire

test method has been developed for such exposures, and fire

560
resistance ratings are being developed for such circumstances.

Since such materials are commonly found in severe outdoor

exposures, fire performance for such materials are determined not

only on material in its newly installed condition, but also after

it has been exposed to representative solvents and extremes of

temperature, humidity, and water.

As the need to provide protection to specific building

elements broadens, the importance of protecting electrical wiring

systems has also been recognized. In many cases, electrical

control cables are installed in locations where there is

typically little other combustible loading. Such materials are

frequently required to meet minimum fire performance requirements

such as ignition resistance and limited flame propagation

requirements. In the past, such considerations led to the

conclusion that fire resistance protection was not necessary.

Several devastating fires have shown such assumptions to be

unfounded, and as a result many fire tests have been conducted on

such systems.

Within buildings, the long standing discussion over the

importance of pressures in building fires is giving rise to

conduct of tests under varying pressure conditions. In this

context, tests have been conducted to develop information on

leakage resistance of doors and dampers intended to be installed

561
in buildings. At present, such evaluations are conducted

primarily under room temperature conditions. Ratings developed

on doors and dampers under these conditions are intended to

facilitate the design of smoke control systems in buildings.

Such systems are intended to assure that the products of

combustion from a fire are contained so that building occupants

are not exposed to them.

SUMMARY:

This brief review of fire protection has attempted to

identify changes of recent times. In addressing the respective

elements of fire protection, it should be evident that the

distinction between the relevance of these individual elements:

ignition resistance, detection, suppression, limitation of growth

and containment, are becoming less clear. The interdependence of

these elements is being recognized and directed towards evolution

to a systems approach. Each of these elements are individually

subject to further development? the further development of

mathematical models will aid in many ways in this evolutionary

process. A major element of this overall development is the

562
availability of the computer over the last five years. The

computer enhances the ability to extract additional information

from individual tests, as well as to enhance the ability to use

such information in an overall design process. With these

continuing efforts, the evolution of fire protection toward

improved property protection and life safety will continue at a more rapid pace.

563

A measurement of Doorway Flow

Induced by Propane Fire

I. Nakaya, T-. Tanaka, and M. Yoshida

Building Research Institute

Ministry of Construction

Seventh Joint Meeting

UJNR Panel on Fire Research and Safety

Washington, U.S.A., October 24-28, 1933

565
1. INTRODUCTION

It will be one of the most important subject to measure exact

mass flow rate (inflow and outflow) through an opening for

analyzing various aspects of fire.

In strict way, this rate can be obtained by measuring the

local gas velocities whole over the opening and integrating

them. But this is too complex and tedious in most cases. When

gas temperature in a room is nearly uniform like in the fully

3 4 developed fire, it was shown by Kawagoe and Thomas that an

opening mass flow rate can be easily calculated applying

Bernoulli's relation and this relation was reduced to a simple

equation,

M ^AH 1 / 2

(1)

.

a Where M , A and H are mass inflow rate of air, opening area,

ci and opening height respectively. This equation is known to be

powerful enough to show good approximation. But no simple

relations have not been found when temperature in a fire room

is not uniform.

Recently, Steckler intensively studied the relationship

between the mass flow rates obtained from the local gas

velocities measurement using bidirectional pressure probes and

those calculated from the vertical gas temperature profile in

and out of the room of origin applying Bernoulli's equation.

From the results, he revealed the buoyancy driven flow modeL

was also useful for small fire and proposed orifice constant

(C) to be 0.73.

The burner used in his experiments did not have enough

capacity to attain high temperatures (above 300°C) and the

566
opening of the burning room faced directly to the open space.

In real fire, gas temperature becomes higher than 300 °C and

the doorway usually faces to a corridor. The objective of this

study is to examine whether the method previously proposed by

Steckler holds for the conditions in which fire is more

intense and a different structure. So in this study, we used a high-calorie burner and an apparatus having two rooms (a

burning room and an adjacent one.)

2. Description of experiment.

The structure used in this experiment had two rooms

(3.45x3.45x2.17 m and 3.55x3.45x2.12 m) as shown in Fig.l. The

concrete walls, ceiling and floors of the burning room were

covered with calciumsilicate boards.

The burner used was rectangular of 60x60 cm and fuel gas was

emitted through a porous plate.

With eleventh couples of movable bidirectional pressure probes

and bare-wire thermocouples, the pressures and temperatures of

the opening flows within the doorway between the burning and

the adjacent rooms were measured at eight or ten positions,

which is depending on the width of the opening.

Another set of seventeen bare-wire thermocouples measured the

doorway temperature between the adjacent room and the ambient

along the center line as shown in Figs. 2 and 3.

And room gas temperatures were measured by the aspirated

thermocouples at the following three positions,

1) in the front of the burning room,

2) in the rear of the adjacent room,

567
3) in the front of the adjacent room,

as also in Figs. 2 and 3. At a each position, seventeen

thermocouples were set.

The measurements were started after near-steady conditions

were established. The board used has high enough insulation

performance to establish near-steady in about 30 minutes from

the ignition of the burner. The fuel gas supplied to the

burner is commercial propane gas (mixture of butane and

propane .

)

Experiments were conducted under the following six different

conditions

:

A) fuel flow rate(V^=100 liter/min) , opening width (W=0. 59

m) ,

B) V

f

=200 , W=59,

C) V

f=100, W=89

,

D) V

f

=200 , W=89

,

E) V

f

=] 90 , W=8 9

,

F) V

f

=240 , W=8 9

,

Measurement were repeated by the five second interval and two

hundred times at one position of the movable probe.

3. Experimental results

The temperatures of hot gas layer in the burning room were

200-450°C. These were larger than the Steckler's, which were

about 300°C at their maximum.

The temperatures of hot gas layer in the burning room were

200-450°C and those in the adjacent room were 130-250°C. These

568
were larger than the Steckler's, which were about 300°C at

their maximum.

The mass flow rate through the opening was determined byintegrating the local mass flow velocities (pv) over the area

of the opening either above or below the zero-velocity level

(neutral plane) . The local velocity (v) was obtained from the

bidirectional probe data and the local density (p) was

established from the opening temperature data and ideal gas

law. Horizontally averaged representative temperature profile

data (fuel flow rate=200 liter/min, W=59 cm) are illustrated

in Figs. 4 and 5. The temperature differences between large

diameter wire thermocouples (0.65 mm in dia.) and fine ones

(0.1 mm in dia.) is not small. This difference will cause 5-10

% error in the flow rate evaluation. So, this means radiative

emission and absorbtion is not negligible.

Furthermore, temperature profiles in the burning room, in the

connected one and at the openings are in Fig. 6. The

temperature profiles indicate that the space in the room can

clearly separate into two fairly homogeneous layers (hot and

cold) as is observed in Steckler's experiments.

4. Flow through the opening

The temperature difference between the room (T^_) and its

surroundings (T ) induces a pressure difference which causes

the flow at the opening. The application of Bernoulli's

equation leads to the following formulation for the rate of

mass flow from the burning room (M )

.

569
M ( 2 ) g

=Wp T C.

oo co 2.

H

N {(2g/T ) / (1/T -1/T )dZ' }

1/2 dZ 3 IN 3 IT

and into the room (M )

,

3

N

M =Wp T C I

A

( 2g/T ) a

K oo oo o 0 ^ a

N

/

z (l/T

a

-l/T

r )dZ'} 1/2 dz (3)

where

p^: ambient gas density,

T^: ambient gas temperature,

C.,C : in- and out-flow coefficients,

l o

N: neutral plane height from the sill,

Z: height from the sill,

g: gravity constant,

T , T : adjacent and burning room gas temperatures.

Figures 7 and 8 present the opening flow rates obtained from

the experiments versus ' (=M^/C^) and ' (=M /C

q

) . The slopes

of the lines represent the out- and in-flow coefficients.

C =0.68 (4) 0

C . =0 . 6 8 (5) 1

As a little of trouble were observed in pressure transducer

for experiments C and D, the unreliable data were replaced by

interpolated values. So, experiments C and D have a slight

problem in its reliability. This value of C is the close to

that suggested by the water-kerosen analog experiments of

7 5 Prahl and Emmons and a bit smaller than Steckler's .

5 . Summary

570
An experimental study for the rate of the flows induced by a

propane gas fire in a structure composed of two rooms has been

conducted. The characteristics of the measured opening flow

rates can be explained by a simple hydrostatic model based on

temperature distribution. Indeed, a good correlation between

the measured and the calculated flow rates, which is obtained

from idealized flows, taking into account the vertical

temperature distribution, has been demonstrated even in the

high temperature (200-450) and 2 room configuration, as

previously shown by Steckler et al for the single compartment

and for the temperature lower than 300 °C.

6 . Acknowledgement

We are greatly appreciate to Dr. Kennith D. Steckler for his

advice about the arrangements of probes and his intensive

assist for computer programings and calculations.

7. References

1. Hugget, C., Estimation of Rate of Heat Release by Method of

Oxygen Consumption Measurements, Fire and Materials, Vol.4, 61

(1980) .

2. Nakaya, I., An Evaluation Method for CO, C0

2

, 0

2 Concentrations Under Turbulent Fire Conditions In a Compartment, Annual Meeting of Architectual Institute of Japan

(1983) .

3. Kawagoe, K., Fire Behavior in Rooms, Report No. 27, Building

Research Institute, Japan (1958).

571
4. Thomas, P.H., Heselden, A.J.M. and Law, M. , Fully-Developed

Compartment Fires —Two kinds of Behavior, Technical Paper

No. 18, Fire Research Station, England (1967).

5. Steckler, K. D., Flow Induced by Fire in a Compartment,

NBSIR 82-2520 (1982) .

6. Quintiere, J. G. and DenBraven , K . , Some Theoretical Aspects

of Fire Induced Flows Through Doorways in a Room-Corridor

Scale Model, NBSIR 78-1512, National Bureau of Standards, USA

(1978) .

7. Prahl, J. and Emmons, H. W. , Fire Induced Flows Through an

Opening, Combustion and Flame Vol.25, 369 (1975).

572
573
W,

ZW/77/tf/7$7a^77777ftZ/7y/Sy/.yy?(

//

0.17

0.17

<

0,17

CO

^

CO

LU CO UJ

rJ S§

=3O

51 ^

55 Cl

<_> o o u

^

Cd

^ ST- o —3

^

LXJ ^ CO

fg!3 CE

^

o •

574

Fig.

2

Probes

Arrangement

(Vertical

View)
Q

CO CO

UJ

O

ocu> o

CO

LU

OQOcc

Cl

LU

CC

S cc CO

§ UJ CO

1 I 1 1-1—

J

1— DC

r~ a_

0 &

575

Fig,

3

Probes

Arrangement

(Horizontal

View;
1H9I3H

c

1H9I3H

576

Fig.^

Velocity

profile

at

an

opening

Fig,

5

Temperature

profile

at

an

open!
CEILING

?

CEILING

1H9I3H

577

Fig.6

TeniDerature

profiles
OPEN

SPACE

1H9I3H

r" *

578

Temper

tu

re

profiles

(Continued)
(S/D>|)3i\ft) HOld SSVW 0NlN3dO

579

flow

model

(

Inf

low)
(S/6>i)31W MOld SSVW 9NIN3dO

580

flow

model

(outflow)
Plota I Full sacle fire test room.

581

Discussion After T. Tanaka's Report on A MEASUREMENT OF DOORWAY FLOW INDUCED BY

PROPANE FIRE

UANDA: We are not in fire, but with respect to the environmental issue, we have

to later calculate the pollutant. When we have certain features which create

the temperature difference over, say, 15°C, due to the particulate then at the

doorway we have to have three-dimensional measurements. We usually use an ultrasonic device to measure it. We also have certain regulations. For

instance, the time run should be less than 1 second. We once tested burning

alcohol in the room and then we applied the ultrasonic tester which can scan the

temperature as high as 200°. I clearly detected a three-dimensional flow.

Because of the result I have detected, I've been wondering how, in the test just

discussed, the mass flow rate is accurately captured?

WAKAMATSU: First, I'd like to know how you made your mass flow rate. Have you

measured by velocity, for instance?

TANAKA: Yes, I have measured the doorway by measuring the pressure caused by

the flow and then the temperature. By moving the measuring point gradually, we integrated the result, the velocity and temperature, moving this measuring point

all the way around along the frame of the door. Assuming that the action has

stayed stable during the time of measurement, this is assuming that the burning

condition in the burning room remains steady. This is basically the routine

procedure we have been applying in the area of fire study. There is one important point I believe I have omitted in my presentation. We have confirmed

that the equation obtained by Mr. Steckler can be applicable to the cases where

the existence of two chambers in the one building, you have to have the height

temperature layer of mass in two conditions. This is the condition where we found that his formula can be applicable.

PAGNI: Why are your temperatures so much higher than Steckler' s temperatures?

TANAKA: I think it is the mass of fuel we have burned in the room.

QUINTIERE: Another three-dimensional effect is the alignment of the velocity at

the plane of the doorway. The alignment of the probe in the doorway is

important. We have done some work and I think his was installed in a proper

way. One indirect proof that it is correct is that after the measurement is

taken, if the inflow befalls the outflow, then you might suspect that there was

no substantial deviation to the premise that the "probe is aligned." Has anyone

thought further about the measurement of species in that it might be useful to

determine the profile of the species concentration and it might be related to

the profile of the temperature or velocity concentration?

HIRANO: You're asking whether anyone has actually probed.

QUINTIERE: Yes, has anyone measured species concentration profile so that it

could be combined with the measurements?

HIRANO: I'd like to respond to the previous question with respect to the

velocity of the flow in the doorway. In case of fire study, especially the

probe coefficient obtained by the study of Mr. Tanaka, I think that is

determined by convergence of the flow occurring at the doorway. In general, I think in the area of hydrodynamics, when the flow moves from a wider area to the

583
narrow area, there is a tendency to curve at the corner. If you are to obtain

integrated results, if the pressure changes in the beginning, that may not cause

too much difference. However, it has to be assumed that the flow around the

door must be somewhat compressed and we assume that velocity might be slightly

increased at the point.

HANDA: Yes, you're right, the effect of the narrow flow. Please understand, I do not try to criticize the technique of the previous report, but I really

believe that if we can obtain the result by measuring temperature, it would be a very good idea.

TANAKA: It seems like this doorway acts like a giant orifice. It seems like

the coefficient he got was about .68, the orifice coefficient is about .62. Is

that just the orifice effect we see here or is that actually some fire test?

STECKLER: Yes, we are treating the doorway as an orifice. As you said, the

orifice coefficient in hydraulics is taken as .61, .62. That is for a unidirectional flow, but at the doorway we have concurrent flows. These

experiments show that there is an added effect, as you point out, due to the

concurrent flows or the three-dimensionality of the flows or the viscous

effects. All of those effects are lumped into the flow coefficient and there seems to be a 10 percent difference.

584
FLAMMABILITY TESTING

STATE-OF-THE-ART

by

John de Ris

Factory Mutual Research Corporation

Norwood, Massachusetts 02062

585
ABSTRACT

Traditional material flammability tests are discussed in terms of their

empirical foundation and oversimplified interpretation of fire phenomena.

More recent rate-of-heat-release tests overcome some of these problems by

measuring a material's response to different levels of fire exposure.

However, no existing small-scale tests are sensitive to the radiant emission

from the material's own flames. This radiant emission controls large-scale

fire hazards. As a result, existing flammability tests cannot be expected to

adequately characterize large-scale hazards. Some new approaches to this

problem are discussed and a specific bench-scale test method is suggested

which may overcome the identified problems of existing test methods.

586
I

BACKGROUND

Traditionally, the flammability of a building material has been evaluated

by measuring its: 1) ease of piloted ignition; 2) ability to propagate a small creeping flame in the presence of an external radiant source; and/or 3)

ability to propagate a larger under-ceiling fire as measured by the ASTM-E84

"tunnel test" which exposes a 25 ft (7.62 m) long sample to a sizeable propane

ignition source. This latter test is legally recognized by most building

codes. Since the piloted ignition and creeping flame spread phenomena are closely related and depend on similar material properties they are often

jointly evaluated by the ASTM-E162 test apparatus which measures the creeping

spread rate and extent of maximum flame travel under conditions of a spatially

decreasing external radiant flux.

These tests were developed about thirty years ago at a tine when building

materials where based primarily on cellulose which has a limited range of

flame properties. Also, at that time, lacking a basic understanding of fire

behavior, it was implicitly assumed that all materials could be ranked on a single flammability scale based on some standard test which subjects a material to a single representative fire environment. In view of the need for some flammability assessment procedure and the absence of obviously contradictory

full-scale (or loss) data this oversimplified approach appeared justified at

its time. This traditional philosophy has now outlived its usefulness.

587
II

FULL-SCALE TESTING

Around 1970, after experiencing unexpectedly severe losses involving newly

introduced fire retarded plastics, various full-scale corner tests were run to

check their flammability rankings suggested by the ASTM-E84 test (Castino,

1975) . A lack of correlation was observed which was particularly troublesome

for those flame-resistant insulation materials having a flame spread rating

less than 25. The ASTM-E84 ranking is based primarily on the extent of flame

travel normalized so that red-oak has a rating of 100 and cement-board a rating of zero. Apparently some modern polymeric materials and especially

flame-resistant foam insulations do not properly fit on this ranking scale.

This lack of correlation has lead to a wide-spread mistrust of current

standard flammability tests and the reluctant suggestion that one can only

rely on full-scale tests for flammability assessment. Consistent with this

full-scale test philosophy, ASTM and more recently, ISO (International

Standards Organization) are developing a "Proposed Method for Testing Wall and

Ceiling Materials and Assemblies" (ASTM, 1982) ^ which exposes a material to a large 176 kW propane burner flame placed in a lower corner of an 8 ft x 12 ft x 8 ft high (2.4 x 3.6 x 2.4 m) room whose wall and ceilings are lined with

the material. The outcome of these corner/ room tests is strongly dependent on

the rather arbitrarily chosen heat release rate of the ignition source. For

exposure heating rates above some (material dependent) critical value the fire

will undergo a dramatic transition to flashover when the heat release rate

from the burning wall material becomes comparable to the exposure fire heat

release rate. Exposure fires smaller than this critical value are insufficient to initiate flashover and usually cause only local damage. Test

engineers welcome such clear-cut go/no go tests because they have an indisputable outcome. However, a result from a single test run with a given exposure

is relatively uninformative to a potential user interested in the outcome

involving other levels of exposure. A potential user should probably wish to

rank materials according to the exposure which will just cause run-away

ignition (e.g. flashover) of the material. Unfortunately, at present, it is

not possible to determine this critical exposure for a given material from a single full-scale test.

588
Full-scale tests are usually very expensive, difficult to reproduce, and

require such large quantities of sample materials that they cannot be considered for screening new materials under development. Finally full-scale tests,

being empirical, give little guidance for assessing hazards in related situations. Often small changes in geometric details have a profound effect on the

outcome of a fire. In conclusion, full-scale tests should generally be

regarded as essential for validating the general claims of standard flammability test methods, but cannot serve as a substitute because of their

complexity, cost and large material requirements.

589
Ill

FIRE PHENOMENA

It is now generally recognized that various materials can have markedly

different flammability rankings in different situations depending on such

factors as: 1) fire scale; 2) imposed heat flux levels; 3) geometric arrangement; 4) the presence of other nearby materials, and 5) the temperature,

pressure and degree of vitiation of the surrounding atmosphere. Fires generally involve synergistic couplings between a material and its environment.

Also, different fire scenarios are often governed by qualitatively different

burning mechanisms which in turn are controlled by different combinations of

material properties. It is important to understand these differences in

burning mechanisms when interpreting flammability test results. In particular, it is important to appreciate the effects of fire-scale, if one wishes to

infer full-scale fire behavior from small standard flammability tests.

3.1 SMALL-SCALE

The steady (constant area) burning rate of a small-scale fire is controlled by the convective heat transfer from the flames. Small-scale flames are

not thick enough to emit significant radiation. As a result fuel mass transfer rates are primarily controlled by the heat required to vaporize unit mass

of fuel. The overall heat release per unit area is given by the product of

the fuel mass transfer rate and the heat of combustion of the fuel

volatiles. Other factors controlling peak small-scale burning rates depend

only on geometry for typical organic fuels burning by natural convection in

air at atmospheric pressure. The important fuel property - namely the heat

required to vaporize unit mass of fuel - can be directly measured by

Tewarson's (Tewarson, 1980)^ well known "FM Flammability Apparatus" which

measures the fuel-mass-loss-rate and heat-release-rate under different applied

radiant exposures.

Flame-retardants acting by inhibiting gas-phase reactions can significantly reduce, or even prevent, burning at small-scale. The effectiveness of such

retardants has often been inferred from the LOI (Limiting Oxygen Index) test

which measures the critical ambient oxygen concentration that is just sufficient to permit downward creeping flame-spread on a small sample. Because this

test is convenient and requires only a very small test sample, it is widely

590
used in the chemical industry during material development. Unfortunately, the

test results can be very misleading because large-hazardous-scale-fires are

not significantly influenced by such gas-phase flame retardants (because

large-scale flow times are so much longer than reaction times).. Innumerable

disappointments have occurred in recent years when supposedly non-flammable

fire-retardant polymers burned vigorously in large-scale tests. For example,

PVC plastics which usually have an excellent LOI rating burn more rapidly at

large-scales than acrylics which generally have a poor LOI rating. Unfortunately the flame-retardants encouraged by this test often tend to significantly

increase the smoke output and toxicity of the fire gases.

Fire-retardants which act by encouraging char-formation in the solid-phase

can be very effective at all fire scales. By preventing transfer of carbon to

the gas-phase they are triply effective by: 1) providing a thermal insulating

char layer; 2) reducing the gas-phase heat-release-rate and resulting flame

heights; and 3) reducing the flame luminosity and consequent radiant heat

transfer which is of dominant importance at large-scales. It is speculated

that some of these retardants act by encouraging the polymerization of the

fuel vapors as they flow through the chemically active char layer (Parker,

1982)^5 The eff ec tiveness of these char-enhancing retardants can be evaluated

by a rate-of-heat-release (RHR) apparatus which measures the transient combustion heat release per unit area of a material subjected to a controlled

radiant flux. Tewarson's ”FM Flammability Apparatus"^ and Smith's "Ohio

State Apparatus"!^ are well known examples of such RHR tests. Tewarson uses a 10 cm diameter sample and Smith uses a 25 x 25 cm square sample. In both

cases the material requirements are small enough to permit testing at a variety of imposed flux levels. However, neither test explicitly measures the

flame luminosity or radiated fraction of the heat release. As a result, one should not directly extrapolate the test results to large-scales where radiation from the flames is a controlling factor.

Many modern polymeric materials are retarded by the simple addition of

inert fillers which increase the heat required for fuel gasification and often

leave a porous char-like insulating residue. These effects can be measured by

the above mentioned RHR tests. In addition, some fillers incorporate a significant amount of water of hydration, which upon vaporization may possibly

reduce soot formation and flame radiation. Unfortunately, the current lack of a flame radiation test has prevented measurement of how effective this water

of hydration is in reducing the flame radiation.

591
The RHR test is particularly useful for examining charring flame-retarded

materials such as polyurethane or PVC foams. Such materials can have a distinctly non-linear response to an imposed heat flux. Figure 1 shows the

peak response of various polyurethane foams (NFPA Handbook, 15th Ed., pg. 4-

7)H. Notice the changes in rankings for various imposed heat fluxes. At

very low flux levels the material surface temperature does not increase

sufficiently for significant gasification. Above some critical flux level

gasification occurs at a rate sufficient to support piloted ignition. Once

ignition occurs the sample receives heat both from the external radiant source

and the flames themselves. The added heat transfer from the flames typically

decreases with increasing rates of gasification leading to a less than linear

increase of heat release rate with increasing imposed flux.

A RHR test has the advantage of providing several important flammability

parameters from a single test run versus time. Figures 2a and 2b show a typical RHR test arrangement and results (Ostman, 1982). The sample receives

a uniform radiant heat flux. Measurement of oxygen depletion in the exhaust

is now typically used to infer the rate-of-heat-release (Huggett, 1980). The

initial time delay prior to gasification provides a measure of the ease of

ignition. The rapid increase to the peak heat-release-rate is controlled by

the material's heat of gasification. The subsequent decrease in heat-releaserate is due to increasing char insulation; while the final secondary peak

results from acceleration of the pyrolysis wave as it approaches the thermally

insulated back-surface of the sample or possibly the increased exposed area as the speciman breaks up. Figure 2b shows curves for several externally imposed

fluxes. It simulates the effects of flame radiation in much larger fires.

The heat flux actually received by the solid is augmented by the heat transfer

from the flames produced by the sample itself. All of the above transient

phenomena are being actively studied by various fire research groups (e.g.,

Delichatsios and de Ris, 1983)^. A possible criticism of most current RHR

tests is their external radiant heat source. Gas panel radiant heat sources provide heat over a typical infrared wavelength range but their flux levels

are often too low for realistic view factors; whereas quartz heaters provide

plenty of heat but at unrealistically short wavelengths. Solid fuel response

times are known to be quite sensitive to the imposed wavelength (Welker,

1969)^. improved infrared gas fired radiant heaters using newly available

high temperature ceramics may resolve this problem.

592
Except for the characterization of flame radiation, it is now generally

believed that the rate-of-heat-release measurement will provide the most

meaningful characterization of large-scale flammability. Upward fire spread

hazards can be assessed from the time to piloted ignition and RHR both of

which can be measured in the same RHR apparatus.

Before closing this discussion of small-scale fire phenomena, one should

mention the wide body of research on the creeping flame spread associated with

downward and horizontally propagating fires. This phenomenon is reasonably

well understood for both flame-retarded and non-retarded materials having a smooth surface. It is addressed in part by the LOI test. Also Quintiere, in

a series of studies, has shown that the ASTM-E162 flammability apparatus can

be used to evaluate downward creeping flame spread rates under the influence

of external radiation (Quintiere, et al, 1982)^. In particular, one can measure the minimum external flux required to sustain propagation. A similar

apparatus and technique is now widely used for evaluating carpet flammability. Such tests point out materials capable of propagating creeping flames

with low levels of external radiation. For example nitrocellulose lacquer

paint can propagate a creeping flame with a minimal overall rate-of-heatrelease. However, such circumstances are now relatively rare. While these

advances are significant for the general flammability problem, the creeping

fire spread phenomenon is not of central importance to most large-scale fire

hazards. The marginal creeping flame-spread is governed by local chemical

kinetics, gas phase diffusion and solid conduction, whereas the critical

condition for large-scale upward fire spread is governed by solid ignition,

the duration and intensity of rate-of-heat-release and the flame radiative

heat feed-back. The associated phenomena are quite different and should not

be expected to correlate.

3.2 LARGE-SCALE

As the scale of a fire increases , the flames become thicker increase in

volume and involve more matter which can radiate. In general, the radiative

heat transfer from flames to adjacent surfaces exceeds convective heat transfer for flame heights exceeding 30 centimeters (Orloff, de Ris, Markstein,

1975) 1. For organic fuels this radiation comes primarily from soot in the

flames which makes them appear brightly luminous. Generally, the pyrolysis

vapors from man-made polymeric materials are high in carbon content and

593
produce more soot than cellulosic fuels whose pyrolysis vapors have a significant amount of oxygen already bound to the carbon atoms. Fuels which generate

copious amounts of smoke tend to have highly radiative flames and have higher

large-scale burning rates. The black smoke is thought to arise- from the

flames losing so much heat by radiation that they are extinguished locally by

this radiant loss.

All present day small-scale flammability tests attempt to simulate largescale fire environments by imposing an independently controlled external

radiative flux onto the fuel sample. This external flux generally dominates

the radiation from the sample's own flames; so that the measured result?, are insensitive to the sample's own flame radiation and cannot be expected to

provide a complete evaluation of the material flammability at large-scales.

This insensitivity is advantageous insofar as it can yield a clear picture of

the solid response to a controlled external environment. But it leaves out

the essential ingredient ~ namely the flame radiation which typically represents 80% of the heat feedback at large-scales (Orloff, Modak, Alpert,

1977

)

13

. How should we cope with these problems? Clearly we cannot do away with

standard flammability tests. If possible, we should have tests which require

relatively small samples - say 30 cm square or even less - to encourage

testing by industry involved in developing new materials. Of course results

from such tests must be corroborated at full-scale for a selection of representative fuels. These problems appear surmountable as will be described

below.

Rate-of-heat-release tests are clearly essential and several such tests

are under development at various fire research institutions. The test

measures the rate of combustion energy released per unit sample area versus

time when subjected to various levels of externally supplied radiation. It is

essential to evaluate material at various levels of irradiance because many

materials have a strong non-linear response. Also, because charring materials

typically have a strongly decreasing transient heat release subsequent to

ignition, one should evaluate both the peak rate of heat release, maximum

average rate-of-heat-release over selected time intervals (say 1, 2, 3 and 5

minutes) as well as the cumulative heat release. Results from these rate-ofheat-release tests can be directly used for estimating the evolved transient

heat release rate and corresponding flame heights for the material when

594
subjected to a known source fire in different practical situations of

interest.

Knowledge of the rate-of-heat-release leads directly to estimates of flame

heights. In general, both laminar and turbulent flame heights are controlled

only by the fire geometry and the actual heat release rates and not by other

fuel properties such as its stoichiometric requirements (Masliyah and Steward,

1

8

1970; Schug, Manheimer-Timnat , Yaccarino and Glassman, 1980) . To evaluate whether the evolved flames are powerful enough to significantly add to the exposure heat flux, and thereby induce a self-propagating

wall or corner fire, one must evaluate the radiative properties of the

flames. These properties are the effective flame radiation temperature T^ and

the absorption-emission coefficient which is essentially proportional to

the amount of soot per unit volume. The radiation emitted per unit volume is

4

equal to 4 a k^T^ where a is the classical Stefan-Boltzmann constant.

The accompanying Figure 3 shows a scientific flammability apparatus being

constructed at FMRC to evaluate these flame radiative properties for fireretardant charring wall materials. The charring material on the left is

subjected to an externally controlled radiant flux. The transient rate of

heat release is measured by chemically sampling the gases leaving the top of

the enclosure. A water-cooled heat transfer plate measures the total (radiative plus convective) heat feedback from the flames. It is shielded from the

radiant heat source by a series of radiation baffles, so that it measures only

the heat flux from the flames. In addition, we have built a dual radiometer

which looks through the flames from the side in order to simultaneously

measure both the effective flame radiation temperature Tf and absorptionemission coefficient kf.

This apparatus is not intended as a standard flammability test. It is

clearly too sophisticated for widespread use. It is a scientific apparatus

intended to provide an in-depth analysis of the radiative properties of a few

selected fire-retardant fuels; so that we can provide a rigorous scientific

foundation for a subsequent simplified standard material flammability measuring apparatus. It also is intended to provide the basic flame property data

needed for the development of mathematical models predicting corner and room flashover. In addition, provision has been made for providing vitiated air to

the enclosure for studying the effects of oxygen depletion on flame

radiation. This apparatus is the outcome of a long-range research program

595
aimed at providing a basic scientific understanding of flame radiation in

fires.

NBS is currently developing a similar but simpler test apparatus which

measures the total radiative-convective heat feedback flux from the upper

flames. While it is not placed within an enclosure and consequently is not

suitable for evaluating the effects of vitiation, it may eventually lead to a standard test method.

596
IV

A SUGGESTED BENCH-SCALE FLAMMABILITY TEST

As discussed above, flammability (or fire hazard) of a material at largescale is governed by three principle factors: 1) its piloted ignition time in

response to an imposed heat flux; 2) the subsequent rate-of-heat-release of

its pyrolysis vapors in response to the imposed heat flux; and 3) the radiant

emission from the flames resulting from the burning of these pyrolysis

vapors. Knowledge of the above factors should be sufficient, in principle, to

predict both peak burning rates and upward fire growth rates involving simple

fuel arrangements.

We have already discussed several test devices which can evaluate the

rate-of-heat-release and ignitability of a material. Here we discuss a proposed test concept which in addition may evaluate the radiant emission.

The suggested apparatus is also sufficiently compact to be placed on a laboratory bench.

As shown in Figure 4, the test examines a buoyant laminar (candle-like)

diffusion flame produced by the pyrolysis vapors emerging from the heated test

sample. As explained later, the ignition and rate-of-heat-release measurements are directly inferred from the resultant flame height and should produce

results similar to existing test methods with the advantage of decoupling the

flame heat-feedback from the pyrolysis process.

Of greater significance the test concept allows one to infer the expected

radiant emission from material flames at large-scale. It does this by measuring the fuel’s so-called "smoke-point". Recent research at FMRC shows there

is a close correlation between large-scale flame radiation and the smoke-point

for various hydrocarbon fuels*. The smoke-point is conventionally defined as the maximum height a buoyant laminar flame can attain without releasing soot

(i.e. smoke). The aircraft industry has traditionally used the smoke-point of

commercial liquid fuels as a measure of their relative smokiness and as well

as their radiant output. Standard test methods exist for evaluating the

*Specifically the peak soot absorption coefficient in a 50 kW pool fire and

the radiative fraction from a buoyant turbulent fuel jet ranging over 10-

50 kW are both tightly correlated with the fuel smoke- point (Markstein,

1983)

597
smoke-point of liquid and gaseous fuels (Schalla and Hibbard, 1957)^. The

present concept extends these methods to solid fuels.

It is well-known that the radiation from both large- and small-scale

diffusion flames comes principally from their luminous soot. This soot is

both formed and oxidized within the flames. Fuels which produce more soot

radiate more intensely. The radiative heat loss cools the flames and, if

given enough time, can induce local radiative extinguishment accompanied by

release of cold soot in the form of visible smoke. By increasing the fuel

supply to a small candle-like flame, one increases its flame height and

residence flow time, resulting in an increased fractional radiative heat

loss. A sooty fuel such as propylene can maintain only a relatively short

buoyant flame (2.9 cm high) without release of visible smoke; where as a less

sooty fuel like propane can support a much taller (16.2 cm) diffusion flame

without smoke emission (Shug, et al, 1980) . These candle-like flames at

their smoke-points release approximately one fifth of their chemical energy in

the form of radiation. In the case of hydrocarbon fuels, this heat loss

reduces the flame tip temperature to about 1550°K at which temperature soot

oxidation rates are significantly reduced (Markstein, 1983) . Smoke-point

heights are easily measured because the flame undergoes a sudden transition to

sooting and release of smoke. Measured smoke-points are independent of

apparatus details provided the fuel is supplied at a given temperature and

provided the buoyant flame is: well ventilated, shielded from stray laboratory air currents by a chimney, and not subjected to excessive induced forced

ventilation (Schalla and Hibbard, 1957)^.

The accompanying figure shows the suggested measuring apparatus for solid

fuels. A patent disclosure has been submitted. It is intended to simultaneously measure both the transient heat-release-rate and sootiness of the

pyrolysis vapors emerging from a test sample (say 4-6 cm in diameter) placed

in an oven at the start of a test run. Auxilliary supplies of fuel and inert

gases are added to the pyrolysis vapors under feedback control to maintain

both a constant overall heat-release-rate and degree of flame sootiness. In

general, for organic fuels, the heat-release-rate of a laminar buoyant

diffusion flame is directly proportional to its height, regardless of the fuel

chemical composition or presence of added inert gas (Shug et al, 1980)^.

Consequently, as the rate-of-heat-release from the pyroylysis vapors

increases, the excess fuel controller will reduce the excess fuel supply while

598
maintaining a constant flame height as seen by the radiometer. This reduction

in excess fuel supply provides a direct measurement of the sample's instantaneous heat-release-rate. The substitution technique should be both rapid and

precise.

Similarly, the flame can be maintained in its marginal smoke-point state

by a smoke detector which increases the supply of inert gas (say as the

pyrolysis vapors increase in sootiness. An increase in inert gas flow

suppresses soot formation without influencing the flame height (Shug et al

,

1980)^. The added inert flow provides an instantaneous measure of pyrolysis

vapor sootiness. The respective heat-release-rate and sootiness measurements

are presumably independent of one another and can be performed simultaneously

throughout the test run. Certainly the heat release measurement should be

independent of the simultaneous soot-point measurements. Recently Calcote and

Manos (1983) showed that the relative ranking of hydrocarbon fuels in terms of

their sootiness in diffusion flames is not particularly sensitive to the

measurement technique. This suggests that the relative sootiness of fuels

will not depend importantly on the sample size, or the base point supply rates

of excess fuel and nitrogen.

At present, the suggested test concept is in its early stages of development. Further data is needed for relating large-scale radiant fluxes in

various fire situations in terms of measured fuel smoke-points. So far we have only used hydrocarbon fuels for evaluating the test concept. We do not

know whether the principles can be extended to fuels having gas-phase chemical

retardants. Also considerable effort will be required to develop a standard

test method.

In spite of these caveats, one has little choice but to further investigate this suggested flammability test; because there are no other suggested

alternative small-scale tests designed to assess flame radiative properties.

Its bench-scale size and minimal material requirements should make it very

attractive to the chemical industry; thereby eliminating the principal impediment to the development of truly fire-resistive materials.

599
REFERENCES

1. ASTM, "Proposed Method for Room Fire Test of Wall and Ceiling Materials

and Assemblies," ASTM Subcommittee E-5 , 1982 ASTM Book of Standards,

Part 18, pp. 1618-38.

2. Calcote, H.F. and Manos, D.M. , "Effect of Molecular Structure on Incipient

Soot Formation," Combustion and Flame , Vol. 49 , No. 1-3, 1983.

3. Castino, G.T., Beyreis, J.R. and Metes, W.S., "Flammability Studies of

Cellular Plastics and Other Building Materials Used for Interior

Finishes," Underwriters Labs, Subject 723, 1975.

4. Delichatsios , M.A. and de Ris, J., "An Analytical Model for the Pyrolysis

of Charring Materials," presented at the CIB-14 Meeting, Boras, Sweden

(May, 1983).

5. Fisher, F.L. and Williamson, R.B., "Intralaboratory Evaluation of a Room

Fire Test Method," UCB-FRG 82-1, University of California, Berkeley, 1982.

6. Huggett, C. , "Estimation of Rate of Heat Release by Means of Oxygen

Consumption Measurements," Fire and Materials , Vol. 4 , No. 2, pp. 61-65,

1980.

7. Markstein, G.H. , "Measurements on Gaseous-Fuel Pool Fires with a FiberOptic Absorption Probe," FMRC Technical Report 83-BT-l, March 1983.

8. Markstein, G.H. , "Soot Formation, Radiant Emission and Absorption in

Laminar Ethylene and Propylene Diffusion," FMRC Technical Report in

preparation, July 1983.

9. Markstein, G.H., "Buoyant Plume Radiation," work in progress.

10. Masliyah, J.H. and Steward, F.R., "Radiative Heat Transfer from a Turbulent Diffusion Buoyant Flame with Mixing Controlled Combustion,

Combustion and Flame , Vol. 13 , pp. 613-625, 1969.

11. NFPA Fire Protection Handbook, 15th Edition, pp. 4-7, 1981.

12. Orloff, L., de Ris, J. and Markstein, G.H., "Upward Turbulent Fire Spread

and Burning of Fuel Surfaces," Fifteenth Symposium (International) on Combustion , The Combustion Institute, pp. 1285-1294 (1975).

13. Orloff, L. , Modak, A.T. and Alpert, R.L. , "Burning of Large-Scale Vertical

Surfaces," Sixteenth Symposium (International) on Combustion , The

Combustion Institute, pp. 1345-1354, 1979.

14. Ostman, B., "Rate of Heat Release from Building Materials," FoU-Brand

1981/1982, Fire Research and Development News, Sweden.

600
15. Parker, J.A. and Kourtides, D. , "Optimization of Fire Blocking Layers for

Aircraft Seating," 7th International Conference on Fire Safety, 1982.

16. Quintiere, J.G. , Harkleroad, M. and Walton, W. , "Measurement of Material

Flame Spread Properties," NBSIR 82-2557, National Bureau of _ Standards

,

August 1982.

17. Schalla, R.L. and Hibbard, R.R., " Smoke and Coke Formation in the

Combustion of Hydrocarbon-Air Mixture," Basic Considerations in the

Combustion of Hydrocarbon Fuels with Air , Chapter IX, Report 1300, NACA,

1957.

18. Schug, K.P., Manheimer-Timnat , Y. , Yaccarino, P. and Glassman, I.,

"Sooting Behavior of Gaseous Hydrocarbon Diffusion Flames and the

Influence of Additives," Combustion Science and Technology , Vol. 22 , PP . 235-250, 1980.

19. Smith, E.E., "Heat Release Rate of Building Materials," Ignition, Heat

Release, and Noncombustibility of Materials , Ed. A.F. Robertson, ASTM

Technical Publication 502, (1971).

20. Tewarson, A., "Heat Release Rate in Fires," Fire and Materials , Vol. A , pp. 185-191, 1980.

21. Welker, J.R., Wesson, H.R. , Sliepcevich, G.M. , "Ignition of AlphaCellulose and Cotton Fabric by Flame Radiation," Fire Technology , Vol. 5 , pp. 59-66, (1969).

601
CjWO/m) 31Vd 3SV3T3d 1V3H

602

FIGURE

1:

Heat

Release

Rate

of

Some

Fire

-Reta

rded

Polyurethanes

(Coded

According

to

Castino

et

al,

1975).
THERMOCOUPLE

603

FIGURE

2A:

Typical

Rate-of

-Heat-Release

Apparatus

(Ostman,

1982)
604

FIGURE

2B:

Typical

Rate

-of

-Heat

-Re

lease

Curves

versus

Time

for

Charring

Fuels

(Ostman,

1982).
Gas

Samplin

605

FIGURE

3:

Material

Flammability

Apparatus

of

Measuring

Flame

Radiation

in

a

Vitiated

Atmosphere.
GLASS CHIMNEY

y

> SMOKE DETECTOR

SOOT POINT

CONTROL LOOP

DOOR

CONTROL

VALVES

ELECTRONIC

FLOW METERS

MATERIAL FLAMMABILITY TEST

FIGURE 4: Suggested Bench-Scale Material Flammability Apparatus

for Measuring Both Rate -of -Heat -Release and Flame Radiation.

606
Discussion After J. deRis' Report on FLAMMABILITY TESTING: STATE -OF -THE -ART

MITLER: In that last apparatus, of course, the flame is visible to the central

part of the sample above the optic axis. I suppose you might block that in some

way or perhaps cut a hole in the sample.

DeRIS: My answer is that Henri is a perfectionist. I am also.

PAGNI: Earlier you showed on a slide of chi versus soot point with a variation

from 40 percent to 20 percent for various fuels, and then Latnr we saw a slide

that showed that at the soot point, chi was always 30 percent. I'm a little

confused about what the meaning of the first chi is when I see the second slide.

DeRIS: A turbulent diffusion flame has a certain micro-scale at which the

combustion takes place. This micro-scale turns out to be very insensitive to the overall flame height. It corresponds to a dimension such as 2 or 3 cm. This micro-scale is controlled by the turbulent convection but it does not

change with the fire size which can be shown by calculation. It is this microscale that defines or corresponds to a certain laminar flame height. The fuel,

however, may have a soot point which is above or below this corresponding

laminar flame height. Therefore, the actual radiant fraction from a turbulent

flame depends on the ratio of this characteristic micro-scale flame height and

the soot point flame height in the laminr case. This explanation leaves me

quite comfortable, but it may not leave you comfortable, and it certainly has

not been mathematically proven.

PAGNI: We need to change the scale of the answer in proportion tc the size of

the question.

HIRANO: My question might be related to the previous question. I think my

method of radiation can be ultimately determined by three factors: soot point,

type of fuel, and size of flame. Assuming that is correct, the burning

condition is one factor. Earlier from your presentation, the soot point has

been described as function of performance can be quite clear. But I believe

that flame height, especially in various conditions, must play a big role but

how do you concede the performance of flame sizing, the one that measured

de terminant

.

DeRIS: When we perform many experiments for larger fires, the tendency is one models the fluid mechanics, the rate exactly, then the radiant fraction tends to

not change once the fire is fully turbulent. However, this comment does not

apply for very large fires.

607
.

.
COMBUSTION TOXICITY

609
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;

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. v~, ... " •; -• <V'

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Discussion After Y. Tsuchiya's Report on U. S

. -CANADA-JAPAN COOPERATIVE RESEARCH

ON EVALUATION OF COMBUSTION GAS TOXICITY

(NOTE: No paper was submitted for the proceedings.)

LEVIN: The values that you use for your incapacitation and lethality values

,

are those values for 30 minutes?

TSUCHIYA: The data is from the literature and this is one of the examples. I showed the difference at the bottom. I can’t tell if it's 30 minutes or not.

These are lethal concentrations.

LEVIN: So you’re not sure what the time frame would be for these values.

TSUCHIYA: Yes, about 30 minutes.

LEVIN: How many liters of gas does your MS/MS instrument use?

TSUCHIYA: We can operate the machine from .5-10 liters per minute.

GANN: In your plots of CO/CO2 versus oxygen depletion, the large scale data

that you use, is that taken from within the burn room?

TSUCHIYA: Yes, for the large scale. . .inside the burn room.

GANN: In the vicinity of the burning fuel of interest?

TSUCHIYA: I'm not sure.

GANN: Obviously there will be a difference between the upper layer and lower

layer.

TSUCHIYA: Well, it depends upon the people who do the design.

GANN: In your OSU experiments, where was the gas measurement made?

TSUCHIYA: We take the gas off the top of the stack.

GANN: What we need to be very careful of is that it is the conditions in the

vicinity of the burning material that we replicate. In both the large scale

data that you reported from other people and the OSU data plus any other

toxicity apparatus, there is always going to be a region where fresh air enters

and an exhaust region where some average value of combustion products exists.

Those conditions will always be apparatus or burn dependent. What we need to

preserve is the conditions at the burning material.

TSUCHIYA: You’re suggesting closer to the sample?

GANN: Close to the sample, yes.

TSUCHIYA: In that case, the action isn't complete.

611
GANN: But that's where the oxygen depletion measurement is important, even if

the CO to CO2 ratio isn't yet resolved. The alternative to sampling in the

combustion environment is to have an extremely well defined air flow past the

sample. This exists in, for instance, the cone calorimeter or perhaps in

Dr. Yusa's apparatus, but that does not exist in the Smith machine.

TSUCHIYA: This was easily obtained at that time.

GANN: Yes, we have such a machine and it is sitting in the corner of the

laboratory also unused.

SUZUKI: You mentioned that sometimes you don't need to use animal models, you

can predict whether the animals will be killed or not killed. Don't you need to

take into consideration interfering gas?

TSUCHIYA: With different types of materials you get several kinds of gases,

pure gas and other types of gases.

SUZUKI: It is my opinion that at this stage, synergism is talked about very

much by many people. If there is synergism shown by experiment, quantitively we can adopt that information for our expression. In environmental inhalation

toxicity, this synergism has been talked about but there is no quantitative data

so far. Until quantitative data is presented, we can limit its effect.

LEVIN: I would like to add that we are now starting to do experiments with

combinations of carbon monoxide and hydrogen cyanide and carbon dioxide and are seeing the effect of one gas upon the other.

TSUCHIYA: Southwest Research Institute mentioned the effect of combination

gases many years ago.

LEVIN: I think a lot depends on the definition of synergism and additivity, but

we find that with CO and HCN we can take half the LC^q of each and arrive at a concentration that kills the animal.

TSUCHIYA: Combination of CO and HCN has been studied by many groups: a study

was done by a Japanese group which was published in a Japanese forensic

journal. This is a very good experiment.

LEVIN: There is data in the literature which shows there is synergism and there

is data which shows there is not synergism. I've had papers I can show you that

present both aspects.

TSUCHIYA: There is such data showing the synergistic effect but similar

experiments have been done by others. If there are two toxic components, a and

b, shown this way, and the synergistic effect is p and b, this value is very

high compared to others.

612
STUDY ON EVALUATION OF TOXICITY

BY GAS USING PURE GAS

Yoichi NISHIMARU M.D. et al

Department of Legal Medicine

Yokohama City University

School of Medicine

Yokohama, JAPAN

1) Y. NISHIMARU and Y. TSUDA

2 ) T . SAKURAI

3) N. NAGAMURA, Y. KUCHINOMACHI , 0. KASHIDA,

I. HIEDA and M. YAMAMURA

4) T. JIN and T. YAMADA

613
Study on Evaluation of Toxicity by Gas Using Pure Gas.

Four research proups are now doing research of the subject

above; each group is reseaching a different aspect of the

subject. We are now in the midst of the research and have

not got final results. The method of our research and a part

of the results are reported as follows.

( 1 ) Study of Physiological Disorders in Animals Caused

by Pure Gas.

1. Summary

a) To investigate whether or not we can get a definite

interrelational expression between physiological disorder

and gas density by using five toxic gases — CO, C0

2

, HCN,

HCL and NO^ — or the mixture of them and measuring disorders

in animals in each gas orgases and gas density in their blood.

b) To investigate whether or not we can get an definite

interrelational expression between each degree of heat burn

and gas density in blood by collecting blood from dead bodies

found on the scene of fire or in similar cases and measuring

gas density.

2 . Experimental Method

Condition

1) Animals ; Rats ( mainly ) , mice, rabbits.

2) Exposure chamber : 0.5 x 0.5 x 0.5 m..

It should have a fan and a heater and the temperature and the humidity in it should be controlled.

It should be a perfect air-tight box and have an

alarm.

3) Gases : CO, C0

2

, HCN, HCL, N0

2

4) Temperature ; Normal temperature, 30°C, 40°C,50°C

and 60 °C to observe the differences of heat burn

at each temperature.

5) Multiple meterological record equipment : Observed

the state of the change of respiration, E.E.G.,

and E.C.G. under each condition.

614
6) Analysis of gas density in blood : Measure the gas

density and the pH value in blood of animals after

finishing the inhalation of a gas or gases.

Procedure

1) Examine the respiration, E.E.G. and E.C.G. of

experimental animals in a normal condition, analyze

gas or gases in blood, and measure the pH value in it.

2) Analyze the changes of respiration, E.E.G. and E.C.G.

in animals caused by changes of temperature

normal temperature, 30°C, 40°C, 50°C and 60°C.

Analyze the changes of respiration, E.E.G. and

E.C.G. after making experimental animals inhale

each single gas whose density is varied at normal

temperature

.

4) Analyze the gas and measure the pH value in the

blood of animals, after finishing the experiment

of gas inhalation.

( 2 ) Study on Evaluation of Toxicity of Gas Using Pure Gas

.

1. Summary

This report describes the test results of investigation

on relation between concentration of toxic gas and incapacitation time of mouse in the gas/air mixture. The tests

were carried out with regard to 5 types of toxic gas ( CO,

C0

2

, N0

2

, NH

3

and HCL ).

2. Test Method

Toxic gas ( high purity ) was sipplyea and diluted in

a test chamber of combustion gas toxicity test apparatus

through a gas control system. The concentration of the

toxic gas was controled by controling the gas flow rate

and duration of supplying to the test chamber, and it was

monitored with gas concentration analyzer at each test.

8 rotating bastets with a mouse in each of them were set

up in the test chamber immediately before supplying gas

and a type of toxic gas was supplyed in the chamber.

Movement of the mice and gas concentration were observe:.

615
At tests for CO concentration was kept on about

21% by supplying 0

2

into the chamber so as to eliminate

the effect of hypoxia.

The mice for the tests were 5 weeks old female Jcl ICR

type and their weight was 18-20g..

3 . Appratus

Outline of the test chamber and gas control system is

shown in Fig. 1.

Gas Method of Analysis Type of Analyzer

CO

CO.

NH.

Infrared Gas Analyzer

N0

2

(NO)

( with N0

2

NO converter )

ZAL BG 152-11

(Fuji Electric Co. Ltd.)

ZAL DL 952-10

(ZAL ZJ 052-10

(ZAL pb 252-11

( O.

HCL

Magnetic Oxygen gas Analyzer

ZAJ IC 02

Ion- elect lode

(ZBV

)

(

4. Test Results

Fig.2--Fig.6 show the test results. The incapacitation

time of mouse is the time when themouse seases moving for

more than 3 minutes after the time. In the figure, gas

concentration is plotted by average incapacitation time

of 8 mice for each test.

Fig . 1, 2, 3, 4, 5, 6

616
Mixer

()1

C -*-> K N C

C >, D & ~ cc C X

O C X HC Lu 4 A

617

FIr.
CD

TIME iwzru ) Fig. 2

0 5 10 15 20 S 30 35 40 45 50 55 60 TIME (sin.)

Fig. 3

TIME tain.

)

Fig. 4

TIME Cain. I Fig. 5

1.4

1.2

1

s'3* S.B

HCL

o

® Vi •

©

N

© 9 © © Ga © \

1 © O ©

s & \

©

O

e

o £» -© \. a B 'n

* © ^ >

L

®D

ra

TIME tain.

}

Fig. 6

618
( 3 ) The Effect of Toxic Gas Upon Short Term Memory of Rats.

1. Introduction

The inhalation of CO or C0

2

concentrated air often

causes the severe disturbance of consiousness and leads

to the retrograde amnesia. This symptom is good for the

measurement of these kinds of toxic gases.

In the present report, thr effect of CO concentrated

air on the short term memory of rats was examined by the

use of the one-trial aversive learning situation.

2. Method and Procedure

The subjects were 18 male albino-rats of about 10 weeks

old. They were tamed enough and got familiar with learning apparatus. The apparatus consisted of an open-field

and small dark box which were connected with small

entrance. The floor of the box was brass grid to be

charged with alternate current for aversive shock.

The rats have a habit avoiding the bright open-field

and prefering to the dark small place, therefore, the

rats put down at the center of the open-field soon go to

the small box and enter in it.

Each rat was allowed five times to enter the small box,

and at each trial, the period between the moment the rat

wasleft in the open-field and the moment he entered the

small box was measured. This period indicates the intensity of dark box preference of each rat.

Then the rats were devided into three groups homogeneously on the preference intensity.

On the 6th trial the rat entered the box, its entrance

was shut and the grid floor was charged with electric

current of 100 V, 50 Hz for 10 seconds. The rats showed

a violent emotionality, and learned to avoide the small

box in spite of their preferance with only one time of

experience

.

One minute after the shock experience, the rat was put

619
into the gas chamber and exposed to CO concentrated air

for five minutes. CO concentrations were 0.75%, 0.50%

and 0.25% respectively. Concentration of 0^ was kept

constantly at 20%. Concentrations of CO and 0^ were

continously monitered by the gas analyzer.

The next day, rats were tested if they showed a retrograde amnesia or not, leaving again in the open-field

and being observed their behaviors.

3. Results and Discussion

Three rats were excluded from considerration , because

the one was given the misoperation of gas exposure and

the others misoperation of electric shock.

Table 1 shows the numbers of rats entered the small box

in test trial.

Table 2 shows the mean number of entrance and the mean

duration ' stayed in the box. In Table 2, there was not

found the statistically significant difference between

the group of 0.75% and the group of 0.5% CO concentration.

Five minutes exposure to 0.25% CO have no effect on

short term memory. The threshold may exist between

0.25% and 0.75% CO concentration.

Other conditions, such as poor oxygen air, CO

2

concentrated air or HCN are further investigating here.

Table 1. Number of rats entered in

the small box

group

concentration

CO N Number of rats

entered

( % )

1 0.75 4 3

2 0.50 6 3

3 0.25 5 0

620
Table 2. Mean number of entrance and

mean duration stayed in the box

Measure 1

Group

2 3

number of

entrance 2.5 1.5 0

duration 23.0 sec. 27.6 sec. 0 sec.

( 4 ) Study of the Psychological Effects on the Occupants

by the Smoke Generated in Early Stage of Fire

The main purpose of this study is to grasp the psychological and physiological effects on the occupants by

the smoke generated in early stage of fire.

In the first fiscal year, we have a plan to measure

the properties of the smoke generated from various

interior materials, furnitures, etc., i.e., the density

of smoke, size of smoke particles and the composition

of stimulous gases.

Particularly the relation between smoke density and

the mass rate of the stimulous gases are our concern,

so we make an experimental studies with various materials

and burning rates.

621

Discussion After Y. Nishimaru's Report on STUDY ON EVALUATION OF TOXICITY BY GAS

USING PURE GAS

TSUCHIYA: When you use HC1, what part of the rat was exposed to HC1?

NISHIMARU: The whole body. In this test we used mice, not rats, and the whole

body was exposed in the chamber.

TSUCHIYA: I thought it was only the nose that was exposed.

NISHIMARU: We knew the tradition, but we decided to expose the whole body of

the mouse because in case of fire, the whole body would be exposed. So, at the

first step we are using the whole body exposure due to hydrochloric acid being

produced from HC1.

623
• r | t#

.
GENERAL DISCUSSION

SAITO: We would like to ask Dr. Sumi to give us a very brief review of his

study because his study is related to the work in Group 1.

SUMI: We are building a room parameter. It will be used for surface lining

materials and building contents, such as furniture and furnishings. We are following the proposed method of ASTM for room fire tests and wall and ceiling

material. The method involves a fire in a standard room. If the room has an open doorway and products of combustion are sent into a hood connected to an exhaustor, measurements of rate of heat release, smoke and fire gases can be

made in that time. The rate of heat release will be measured by the oxygen

content method. Provision is made for exhaustor flow so that all the products

of the combustion will go through. The instrumentation in the room, I think,

initially was for very limited input, so we will have thermocouples in the room,

heat flux gauges, load cells for measuring mass burning rate, and gas analysis

will be carried out at the doorway. This is for monitoring CO, and C02* Oxygen

and grab samples will be collected for analysis of hydrogen cyanide, nitrogen

oxides, and aldehydes. I think it should be coming very clear to many of us that aldehydes are very important; very small concentrations could interfere

with the escape of occupants from fire. The instrumentation in the duct was in

the thermocouple, velocity probe, two types of smoke meters, and gas analysis,

again, for monitoring CO and CO2

. We also intend to collect grab samples

there. We hope to get information on possible loss of certain performance

during migration. We initially intend to do three types of wood cribs, 30, 60,

and 120 kilograms. The 60 kilogram size may be sufficient to reach flashover in

the room. Other materials considered are polyurethane, polystyrene, nylon,

polyethelene, polypropylene. With this heat release apparatus, it is convenient

to compare rates of heat release and others for wall and ceiling lining

materials. We can compare certain coating components, for instance, mattress

versus mattress. I am in favor of standardizing ignition sources so that

results obtained by different people in different laboratories can be

compared. We are receptive to any suggestions in this direction.

SAITO: We would like to exchange our information with each concerned with the

research done by Dr. Sumi.

NISHIMARU: I also feel it's not very good. I thought that we had suggested to

expose the whole body to HC1. The one reason we decided to expose the whole

body is that in a fire, the whole body would be exposed. You know that HC1

liquefies easily, that’s why we heated the two and the place where the HC1 will

be mixed so that the HC1 will not be liquefied. That’s how HC1 was set into the

chamber.

LEVIN: I have one question for Dr. Nishimaru. On these figures, is each point

one animal or is each point the average of the three?

NISHIMARU: In this test we have eight mice in one exposure. Therefore, one point is the mean value of eight mice.

TSUCHIYA: My question, Prof. Nishimaru, can you continue this kind of research

for other types of toxic gases, including ether?

625
NISHIMARU: I was supposed to give a talk on this subject in April next year,

and I’m very exasperated as I'm behind schedule. I have to collect more data

before the next lecture.

TSUCHIYA: You plotted your data on linear scale. It should be plotted on log

scale.

NISHIMARU: We also have it plotted in log scales; if you like, we will supply

that data.

TSUCHIYA: You can easily draw a straight line on the data?

NISHIMARU: It's okay for CO but it's not okay for the others.

GANN : Good data is independent of the axes

.

626
OPEN TECHNICAL SESSION

Takao Wakamatsu

Session Chairman

627

ANALYSIS OF THE FIRE PROTECTION COST INDEX

H. Nakamura, Y. Yashiro

Planning Division

The Research Institute of

SHIMIZU CONSTRUCTION CO., LTD.

4-17, Etchujima 3-chome

Koto-ku, Tokyo, Japan

629
ANALYSIS OF THE FIRE PROTECTION COST INDEX

(as the ratio of felectrical and mechanical works

in the whole estimation cost)

H. Nakamura, Y. Yashio

1. INTRODUCTION

This report presents the analysis of the costs of fire protection

in the "electrical and mechanical" works. The purpose of this research

is to evaluate an optimal cost for carrying out the fire safety, and to

contribute to working out a rational design method of fire safety.

It is commonly believed that the costs relating to fire protection

are usually unduly large in comparison with the entire construction cost

of a building. Yet, on the other hand, detailed researches into the exact

costs of fire protection do not seem to have been made. There are difficulties in such researches: many fire protection items are not merely

made for the single purpose of fire fighting, but are multi-functional.

For example, fire wall, stair case, safety zone etc. Under these circumstances, designers tend to take an easy way out and plan the fire protection only according to the relevant laws and regulations, instead of working out a fire protection plan which would be truly suitable and efficient

for the characteristics of building that they designed.

In this report, being well aware of the situations described above, we must nevertheless start where we can: the "fire protection costs"

included in our past estimates as such will be first extracted from the

record of estimation, and will be analysed in relation to the characteristics of the buildings in which such items were used.

630
2. DATA BASE AND ITEMS TO BE ANALYSED

SHIMIZU CONSTRUCTION CO., LTD. has kept a systematic record of estimation of every building work they have undertaken since 1977. For each

building the estimators enter their estimation results in the coding sheets

according to the entry manual. A set of the coding sheets has about 2,000

different items, as shown in Table 1, for which 13,000 bytes are used in

computer as random file. It is possible to search for any desired record,

and the data of any item can be obtained by appointing the field number of

random file. Now the data base has about 3,000 records, from which costs

of electrical and mechanical works of 1,290 were extracted to analyze the

fire protection cost index.

Table 1 The number of items for each occupancy

bui Iding works electrical works mechanical works

specification of

building

61 electric power 100 environment of

air conditionning

108

construction

costs

67 information, fire

safety equipment

128 sanitation, fire

extinguishment

119

areas

( floor, public

space, etc )

621

transportation,

others 444

air conditionning,

venti lation 159

costs, quantities 81 costs, quantities

l

1

103 1

1

631
Table

2

Items

for

fire

protection

U

*H -K

4-1 fs

d)

*H d) 4-i O

a o nj 00 G u-j c (d oj •H Li U C d 3 d O

Li CO id *H •H <TJ VJ • d d ^IflTtnJ^-rllDU

(TJ S u aj a> ai ^ a)

vj li li d o li O -H i-4 0) H rl

d. tM 4-i V-i co 4-4

d U

idM 0)

id ^

o

a) I d X

d a) o

u uo

a) u >, u

cl d ^ d

•rl jd ai a «J D. d 0 D. M

fl) £ 3 -o d w to to >, O -H X i-l Li 3 Li 0) 00 0) 0) 4-> C AJ Li cd *h td *H £ 4-4 £ 4-1

B CL

d

<U -H m x

o

li a> QJMPDrH i-4 <U 0J C ^ '-M X T3 O d U *H

. . . . ^ -H g d <D 4J (nucM(d<uv4 U exato.oLii-43 HdJ0CO4-4"O4-llO

4-1 -H3

a) oo

xj d

<u

ctLi *

3 AJ o d

CO 0)a u a tJ oo

00 • d CL

i-l 0) u T3

5S 4-1 u d

d ai

at g

00 CL U *H

<D 3 B cr

dt 0)

at5 3

o cr

CL 0) >> oo o d

d *H * a) d

oo LJ u x ' a) oo

1 0 -H i

tn id 5s -X

to cd

at

at

S o

at a aj at

(0 5-J 5S

(0 5sa

oo d

d at a

rl 00 d) C L u

U <D CO 5 a >>

Dr d) to

Li 4-i

a> oo

4J d

to CL 1-1 5s a d

<i» to <d M

a h nj h d 5 o o at > *H T3 d)

4-> 1-t 00

5s O 5s Cd 3

a u a a oo ^

d

at a

oo d) d -h cd

5s a)

CJ rH d .-i a) <u _ d). o_ 00 3 CL rH at 00 LI

Li g (d 4-1

<3J B O CO CO _ CO cd 5s 0

d) CO S 5s .. ... atcoatoatoococucj a

d at

d) > Li BOO a u 4-i

d) *h td

Li 4J 3

d) 1) O

aj cl at d

4-1 Cd AJ o

3 U O *H X CO Li 4-1 to at cl d

00

oo d co d d -h o *H d V4 •H d d) *H o u 01 HH J

o

d) d)

d) cu d) cl -X

Li Li Li CO O

i-4 -H *H 3 0

4-1 4-1 44 CO CO

H L4 4J 4J ecu d) O O > O O

X>

a) at

at O O LI B B *r-< CO CO 4-1

cd cl x 4J O rl X> d u d

a) 5s co <d a u 3

4J d x at m at 0 o

td oo o td CL Li O 4-1 a i) d li - a o 3

O 0) d co CL 4-1 0

iJ 0) 4-4 O 4-1

o aj at Li at a) *h

*—I 0) U AJ U 4-J *r4 o 4-1 cd d cd o o d cd a o cl li cd

<U CO CO CJ CO a. 4-1

oo oo o

d d Li

i-4 cd i-l d li td

4-t d

d o

at 1-4 B aj CL (J •h at 3 4-1 cr o

at LiCL

LiO 0)

632
In the design of fire safety, there are many fire protection items

to be taken into consideration, as shown in Table 2. In our data base,

most of their quantities are counted in terms of number or area, but

their costs are stored in terms of more general categories of works. For

example, the cost of a fire door is included in that of the fittings. For

this reason it is not always possible to pick up the exact cost of each

and every item. This is particularly so in case of the building structure.

On the other hand, it is relatively easy to determine the costs relating

to fire protection in case of the ’’electrical and mechanical" items. (1)

In this report, therefore, only the fire protection costs extracted

from "electrical and mechanical" works were used.

3. ANALYSIS

Table 3 and Fig. 1 show the fire protection cost index for each

occupancy

.

The mean values of the indices for all occupancies except for the

hotels are higher than the median values. Fig. 1 shows that the fire

protection cost index has a wide range particularly in shop and industry.

Table 4 shows the correlation coefficient between the number of

stories, gross floor area and the fire protection cost index for each

occupancy.

Fig. 2 and 3, for example, show the scatter plot between the number

of stories, gross floor area and the fire protection cost index of shop

and business building respectively.

No correlation is found between the number of stories, gross floor

area and the fire protection cost index in any occupancy.

(1) These are the items shown in the column of "system or equipment

for fire protection" in Table 2, except for those with symbol "*".

633
Fig.l Box and whisker display of fire protection cost index for each occupancy.

634
Table 3 A v a r a e e ol the lire pretecllon cost Indices and other values

occupancy

attract of

•tori it

uinii ol iron Moor

arta* (*)

attract ol Mr* proltc1 1 o n coal

Indies* (X)

*d 1 a n o

1

Mr* prolac11 on coal Indicts (X)

nuibtr ol

data

uni l pr let

I'lO

3

! an/* 2

)

detached home 2.07 309 0.64 0.24 81 220

flat 4.92 2804 1.68 1.44 246 180

business build. 4.12 2229 1.86 1.59 403 160

shop 3.62 597 1 3.26 2.53 66 130

restaurant 4.20 1386 2.79 2.49 15 2 1

0

1 ndus try 2.35 703 1 3.18 2.29 144 130

store 2.44 3867 2.53 1.79 90 100

hotel 4. 85 3288. 2.43 2.44 40 200

hospl tal 3.65 1870 2.57 2.30 86 170

education 3.26 4157 2.34 1.92 89 180

gy nnas 1 UD 2.43 2593 3.08 2.27 30 140

635
Table 4. Correlation coefficient between the niiaber of

stories, gross floor areas and the fire protection cost indices.

occupancy

corr. c o e f f

.

between stories and lln pr eo tec 1 1 on coat lndax

corr. coaff. bataaan cross Moor

area and flra pro- tection cost Index

detached hone 0.317 0.273

flat 0.234 0.202

business building 0.209 0.283

shop 0.115 0.379

restaurant 0.031 0.130

industry -0.033 -0. 100

store -0.120 0.033

hotel 0.488 -0.040

hospi tal 0.102 0.260

educat i on 0.078 0.097

gy anas i un L0.218 -0.041

1

636
fire

protection

cost

index

1.00 :.oo 3.00 5.90 4.00 7.00 3.00 0.00 10.00 11.00 ~ 3.3- « 1.50- - 3.25- 3.90- 7.3-

7.30- 7.5-

7.00- 4.3-

4.50-

4.23-

4.90-

5.75-

3.50-

^ '3-

3.30-

i. 75- 1.50- 1.3-

1.90-

'3.75- 3.50- 3.35-

3.00- 2.3-

2.30- 2.25-

1.50- 1.3-

1 . 00- 0.3-

9.29- 0.3-

0 . 00-

IEGEND

o J

« 2

• I

3.3

3.50

3.35 3.00 7.3

7.50

7.33 7.00 4.3

4.50

4.35

•4.00 5.75 3.50

5.35 5.00 1.3

1.50 1.23

1.00

3.75 3.50

2.25 3.00

2.75

2.50

2.25 2.00

1.75

1.30

1.25 1.00 0.3

0.20

0.25 0.00

2.30 5.50 1.00 3.90 4.30 7.J0 3.20 '.20 10.20 11.25 the nuiber of stories

9.00 1000.00 3000.00 12000.00 14000.00 20000.00 21000.00 23000.00 32000.00 26000.00 10009.00 ~ 3.3-

*« 3.20- - 3.33- - 3.99- ? 7.3- - 7.29-

- i-25- £

>.20-

2 230- = = ”

-r’.oo

3 1 . 3-

1 . 50 -

1. 22- uo3.3-

3 . 50-

3.23-

3 . 30- 2.3-

3.3

0.20

3.25

3.00 7.3

7.30

7.22

7.30 4.3

4.30 ).3

4.00 5.3

5.50

5.23 3.00 1.3

1.30

1.25 1.00 3.3

3.50

3.23 3.20

230

2.29- r.oo

r. 39- •

r.3o-g 1.3-"

1.50- •i.23—

0. 00- •

LEGEND

o 3

’ 2

•

1

1.30

1.20

>.20 >..3 9.00

1.00 1000.00 3000.30 12000.00 16000.90 20000.90 21000.90 22000.90 32000.00 34000.90 10000.00

Cross floor a r ea ( 1 1 1

Fig. 2 Scatter plot between the nuaber of stories, cross floor ar*e

and fire protection cost index of shop

637
l.oo :.oo 3.00 1.00 5.00 t.00 8.00 ?.00 10.00 11.00

9.75 8.50

8.35

3.00

7.75

7.00

8.75 8.50

6.00

5.00

1.75

1.30

1.25 1.00

3.25

3.00

2.50

2.00

1.75 1.50

1.23 1.00 0.75

i'.h 0.OO

the number of stories

0.00 1000.00 3000.00 12000.00 14000.00 20000.00 21000.00 23000.00 32000.00 38000.00 10000.00

3.75-

3.50- 3.25-

•3.00-

i . ij7.00- 4.75-

6.5')- '

j.25- 5.00- 3..J7.50- ’

2 . 00- 1.75- 1.30- °

LEGEND O*

C

" 5 O 'O O 5 O 4 o 3

• 2

3.75 3.50

3.00

7.30

* .»j 7.00

3.00

1.75

1.50 1.25

1.00

3.75 3.50

3.00

2.50

2.00

1.75

1.00 0.75 0.50 0.25

0.00

0.00 1000.00 3000.00 12000.00 14000.00 20000.00 21000.00 28000.00 32000.00 34000.00 10000.00

gross floor area (

Fit- 3 Scatter plot between the nunber of stories, gross floor area

and tire protection cost index ol business building.

638
4. CONCLUSION

The foregoing analysis may be summarized as follows:

• The fire protection cost index has a wide range particularly in shop and

industry.

• No correlation is found between the number of stories, gross floor area

and the fire protection cost index in any occupancy.

• In our estimation, total fire protection cost of an entire building would

generally be about 30 percent higher.

The reason why the fire protection cost index has such a wide range

may be that different fire protection plans and fire protection items are rather randomly installed in different buildings, and possibly thac there

are unnecessary or duplicated installations in many cases. In order to

look into this problem further, it would be necessary to extend the scone

of our analysis to cover not only the items extracted from the "electrical

and mechanical" works, but also all other items which have fire protection

functions in some way or other, and to know what kind of fire protection

functions are installed in a building and how many. It is thus our next

task, to carry out such extended analysis with regard to the types of

buildings and also to the functions and possible alternatives of various

fire protection methods.

REFERENCE

1. H. Nakamura, Analysis of the fire protection cost index (as the

ratio of electrical and mechanical works in the whole estimation

cost). The Geneva Association Seminar, 23/24, March, 1983.

639

Discussion After H. Nakamura's Report on ANALYSIS OF THE FIRE PROTECTION COST

INDEX

EMMONS: Is the index that you give the percentage of the cost of the building

that is used for fire purposes. . .percentage of building cost?

NAKAMURA: Yes, it is.

EMMONS: Do I understand then, from your Figure 1, that some industries have a building with 17 percent of the cost of the building?

NAKAMURA: This is, of course, limited to one specified group of buildings,

planned industrial and other purposes. That type of building can be constructed

relatively cheap for the entire structure.

SEKIZAWA: My question is related. Let's take your conclusion on page 10. In

part of your conclusion, you say that total fire protection cost of the building

would generally be about 30 percent or higher. How can I relate this rather big

figure to the figures we find in Figure 1?

NAKAMURA: The figure in Conclusions is inflated by 30 percent to what I had

summarized in Figure 1.

HIRANO: I'd like to know, there must be a costing cost but we can probably

divide it into two categories. One area of cost is mandatory, like regulatory

policy, and the owner may have some additional costs due to some kind of work on fire protection. How do you divide, what is the ratio between the legal cost

and the added cost?

NAKAMARA: To be honest, we cannot obtain a very accurate figure yet. The

figure we have enumerated in this Figure 1 is actually for the type of fire

protection our company standard requires. Of course, our company standard

follows the requirement of the Japanese building code.

HIRANO: I'll add a follow-up to my previous question. I'd like to invite any

comment from anybody here because I regard all of you here as authorities in

this area. I'd like to know if anybody has some new idea what the ratio between

the amount of cost to you and cost because of regulatory requirements and the

requirements for older buildings.

NAKAMURA: I might say the amount we spend, because it is required by regulatory

law, is close to 100 percent. This can be for buildings constructed under very

strict and strong government regulatory requirements.

LEVINE: I was told once that the British Fire Research Station had studied the

fraction of the building cost that was due to requirements for fire protection

and came up with a number of about 5 percent. This was many years ago. I think

this is very important work because if we are to convince people to use engineering methods of obtaining fire protection rather than codes that tell us exactly what should be put into a building, we must convince them that it is

cheaper to use engineering methods.

641
KAWAGOE: An association has been studying very strenuously for several years to

learn what’s the correlation between the damage incurred by the fire and then

the amount we invested in it to prevent the damage. I believe that as many as

11 nations in the EEC are still conducting this study. I have worked out a figure for monthly investment, but this is an average figure among EEC nations

which is about 1 percent of GNP. The types of damage are: direct loss and

indirect loss, and then expense for the fire department maintenance, the

construction investment in the area of fire protection, premium for fire

insurance. The total cost in the fire insurance industry and in human cost and

in research cost are the major areas covered by the EEC study. Among these

items, the one that is the most difficult to estimate is the construction

investment. Incidentally, at the Association's last symposium the very first

award was given to Mr. Nakamura.

642
AN EXAMPLE OF HUMAN BEHAVIOR IN A HOTEL FIRE

Soichiro Okishio

Takashi Handa

Kunio Kawagoe

Professor

School of Architecture

Faculty of Engineering

Science University of Tokyo

3, Kagurazaka 1-chome, Shinjukuku, Tokyo, 162

643
AN EXAMPLE OF HUMAN BEHAVIOR IN A HOTEL FIRE

So i chi ro Okishio

1. INTRODUCTION

Monday morning, February 8, 1982, a hotel located in downtown Tokyo caught

f i re.

The fire incident was detected by a member of the front desk staff of the

hotel as an odor of smoke in the nineth floor elevator hall. He noticed smoke

issuing from an aperture of a guest room door in the nineth floor corridor. He

and his colleagues tried to suppress the fire but their efforts were in vain.

The facility has about 500 guests rooms and about 350 guests were registered at the time of the fire incident. The ten story and two basement

building of steel framed reinforced concrete construction was erected in 1960.

The guest rooms of the hotel had no sprinkler systems. Automatic fire alarm

systems of the hotel were switched off at the time of the fire to avoid false

alarms. The report to the fire brigade was delayed considerably after the first

detection of the fire. Because of those bad conditions, the fire caused the

deaths of 33 persons. The time when the fire brigade received telephone

notification of the fire was 03.39 a.m.

The headquarters investigating the fire heard the testimonies of the

hotel’s guests who had been registered at that time and produced a detailed

written record. The written accounts were collected from 256 of the registered

guests just after the fire incident.

The contents of the written accounts include the responses of the guests

from awakening to evacuation, their observations of the other guests and of

the fire, their movements within the building, and so on.

Those documented accounts were transfered to Individual Behavior Cards as shown in Table 1

.

First, the sequence. of fire and smoke propagation and of the actions of

the hotel staff, guests and firemen were infered from the studies of the

mutual relation of the individual behaviors shown in those Individual Behavior

Cards. Second, the behavior of the guests in the hotel was examined by utilizing

those cards. This behavior study made reference to the papers on the Human

Behavior in the Fire at the MGM Grand Hotel by Dr. John L. Bryan. *1,*2 The

data presented in this paper are limited to the latter behavior study.

On the nineth floor where the fire originated, 40 of the 46 guests whose

Dehavior was recorded on the Individual Behavior Cards left the room through

:he window. On the tenth floor, 9 of the 25 guests recorded also left the room

:hrough the window. The behavior of those guests was quite different from the

>ehavior of the guests who evacuated through the corridor. Consequently, those

uests who left through the window were excluded from the study population in

644
Table 1. An Example of Individual Behavior Cards

Time Flame Smoke Information

Aware- ness

Leading

Behavior Rescue Note

Smoke in

Room

Saw Flame

Reflected «- on Ajacent

Bldg.

Window

Awakened

Smoke

Sme 1 1 ed

by

Became

Aware of

Fire

Less Smoke*-

in Corridor

3.57-8

Attempted to

Phone

i

Looked out

of Window

No Answer

Turned Light on

i I Notified Roommate

i

Dressed

Packed up Traps

Opened Door —Left Koom

J i

Went ^to Emergency Exit

Went Down Stairs

to 2rjd Floor

Attempted to . Open Exit Door

1 Went to

Elavator Hal 1

1

Pushed

Elevator Button

Remembered

Danger of

Elevator at Fire

i

Went to Exit

Again

Door

Cha i ned

I Heard

-» Woman’

s

Shrieking

Left -lotel

- Fireman

Unchained

Door

Looked at Watch

Degree of Drinking : Undetermined

Recognition of Emergency Exit : Recognized

7th FI. Name National ity Age Sex Room No. INDIVIDUAL BEHAVIOR CARD

.M F.

645
this paper. Two guests on the fourth floor and one on the eighth floor were out

of the hotel at the time of the fire. Those guests were also excluded from the

study population. Table 2 shows the number of the study population classified

by floor level.

Table 2. Number of Study Population Classified by Floor Level

Floor 4 5 6 7 8 9 10 Total

Number of Individual Behavior Cards 25 14 44 47 55 46 25 256

Number of Study Population 23 14 44 47 54 6 16 204

The items examined and analyzed in this paper were as follows:

the guests’ recognition of emergency exits ; the guests’ means of awakening ; the first three actions of the guests following their awakening ; the guests’ means of becoming aware of the fire ; the first five actions of the guests

following their recognition of the fire incident.

The first five actions of the guests following their recognition of the

fire incident were examined in the manner presented in the papers of the MGM

Grand Hotel Fire. Besides those actions, the first three actions of the guests

following their awakening were also examined. Figure 1 shows the classification

of guests’ actions in this study.

Figure 1. Classification of Guests’ Actions

2. RECOGNITION OF EMERGENCY EXITS

Table 3 presents the analysis of the guests’ recognition of emergency exits

A total of 138 members of the study population indicated their recognition or unrecognition of emergency exits prior to the fire incident. Figure 2 shows a percentage breakdown by sex, age, national origin and room type, of those 138

guests who recognized emergency exits prior to the fire incident. Figure 2 indicates that the older study population shows the higher percentage of

previous recognition of emergency exits. It is assumed that the older guests

were more careful than the younger guests in preparing for an emergency.

646
Table 3. Recognition of Emergency Exits

i i

1 Recognized 1

1 Fire Exit 1 Unrecogn i zedFire Exit —Un determined

1 - 1

1 Total 1

1 Male 33 1 64 38 1 135 1

1 Female 17 1 24 28 1 69 1

1 Age 10-19 3 1 10 8 1 21 i

1 20-29 6 1 13 9 1 28 1

1 30-39 6 1 26 7 1 39 !

1 40-49 11 1 17 17 1 45 1

1 50-59 8 1 12 12 1 32 1

1 60-69 11 1 8 10 1 29 1

1 70-79 4 1 1 3 1 8 I

1 Japanese 32 1 58 48 1 138 1

1 Foreigner 18 1 30 18 1 66 1

1 S i ng 1

e

20 1 39 18 1 77 1

1 Tuin, Tatam 1 30 1 49 48 1 127 1

1 Total 1 50 1 88 66 1 1 204 i

i 1 i . . i. J i i

3. MEANS OF AWAKENING

The means by which the study population were awoken are presented in Table

4. It should be noted that no one was awoken by fire apparatus such as a fire

alarm or an emergency speaker system. The most frequent means of awakening cited

was “Awakened by Roommate” , which was listed by approximately 24 percent of

the study population.

Figure 3 presents the percentage of the study population guests who were awoken by the five most frequent means of awakening excluding 10 persons who were awake at the time of the fire and 49 persons who were awoken by a roommate.

647
Table 4. Means of Awakening

1 Means

H

1 Number

i

1 * 1 1

1 4F 1i 5FI 6F 1 7F 1i 8F 1 9F I10F 1

Peopl e Yelling 1 12 1 5.9 1 1 1

1

1

1

51 4 1 0 1 0 1 1

1

Noise of Uindou Broken 1 32 1 15.7 1

1

31 4 1 81 31 11

1

0 1 31 ditto 8. People Yelling 1 6 1 2.9 1

1

1 1 0 1 21 0 1 21 0 1 1 1 Voice & Noise in Corridor 1 4 1 2.0 1

1

01 01 0 1 21 0 1 1 1 1 l Auakened by Roommate 1 49 1 24.0 1

1

61 21 121 91 151 1 1 4 1 Heard Noise 1 7 ! 3.4 1

1

1

1

0! 31 1 1 21 0 1 0 1 Sound of Explosion 1 5 1 2.5 1

1

1 1 01 01 1 1 0 1 0 1 31 People Shrieking t 6 1 2.9 1

1

01 01 1 1 21 21 0 1 1 1 Smelled Smoke 1 19 1 9.3 1

1

1 1 1 1 1 1 51 91 1 1 1 1 Noise & Yelling 1 1 1 0.5 1

1

01 01 01 01 1 1 0 1 0 1 Auake 1 10 1 4.9 1

1

31 1 1 21 21 21 0 1 0 1 Stifled 1 15 1 7.4 1

1

01 1 1 21 61 31 21 1 1 Smoke & Yell ing 1 4 1 2.0 1

1

01 1 1 01 1

1

1 1 1 1 0 1 Siren of Fire-engine I 2 1 1.0 1

1

1 1 01 01 0 1 1

1

0 1 0 1 Knock on Door 1 24 1 11.8 1

1

51 1 1 71 81 31 0 1 0 1 Telephon Ringing I 3 1 1.5 1

1

01 01 01 21 1 1 0 1 0 1 Others 1 5 1 2.5 1

1

01 21 1 1 1

1

1 1 0 1 0 1

8i. Total 1 204

i. .

i ioo

i . _

1 1 -1 L231

j- 14 1, i 44 1. —-i. 471

* 54 1i 61

. L. 161 1 5 10 15 20 25%

(D Noise of Window Broken 23% t=== = = =a © Knock on Door 17%

© Smelled Smoke 14%

® Stifled 10.8

© People Veiling 8.6

Figure 3. Means of Awakening excluding the Means of “Awakened by Roommate

and “ Awoke

4. MEANS OF FIRE AWARENESS

A total of 197 members of the study population indicated the means by

which they became aware of the fire in the hotel. Table 5 presents the analysis

of the means of fire awareness for this group. The most frequent means of awareness cited was “Saw Flame Outside” , which was listed by approximately

Table 5. Means of Fire Awareness

Means Number I V. |

Saw Flame Outside 79

1 1

1 40.1 1 81

1 21 181 21 1 221i 0 11 81 Sau Smoke Outside 6 1 3.0 1 0 1 0 1 21 0 1 2 1 0 1 21 Saw Smoke in Corridor 34 1 17.3 1 31 4 1 61 61 71 4 1 41 Smoke in Room 43 1 21.8 1 21 4 1 71 141 14 1 1 1 1 1 Told by Other Occupant 28 1 14.2 1 71 4 1 81 31 4 1 1 1 1 1 Smelled Smoke 3 1 1.5 1 1 1 0 1 1

1

0 1 1 1 0 1 01 Smoke & Yell ing 1 1 0.5 1 0 1 01 1

1

01 0 1 01 01 Yell of ' F ire

'

1 1 0.5 1 01 01 01 01 1 1 0 1 0 1 Sau Alarm Lamp 1 1 0.5 1 1 1 0 1 01 01 01 0 1 0 1 Sau Fire-engine 1 1 0.5 1 0 1 0 1 01 1 1 0 1 0 1 0 1

Tota 1 197 i ioo i _i i 221

A- 141i 431

, 1 451

i.. 51 1i 61 161

4F I 5FI 6FI 7FI 8F I 9FI10FI

648
40 percent of 197 members of the study population. The floor plan of the hotel

is shaped like a combination of 3-Ys as shown in Table 1. It is assumed that

the shape of the plan helped the guests to see flame or smoke emitted from the

opposite side of the hotel.

An examination of the means of fire awareness presented in Table 5 indicates that the physical fire-generated cues used as a means of awareness

were the phenomena of “ Saw Flame Outside "

, “ Saw Smoke Outside ”

, “ Saw

Smoke in Corridor "

, “Smoke in Room ” and “Smelled Smoke ”

. These cues were the means of awareness of the fire for approximately 33.7 percent of 197

members of the study population.

5. ACTIONS OF THE GUESTS (1 ) - ACTIONS FOLLOWING AWAKENING

Table 6 presents the first three actions of the guests following their

awakening until they became aware of the fire. 48 guests of the 197 study

population became aware of the fire incident at the time of their awakening.

The number of actions by which the 197 study population became aware of the

fire incident are presented in Figure 3.

Table 6. First Three Actions of the Guests Following Their Awakening till

Their Fire Awareness

Actions

V

1 1st

T- 2nd 1 3rd

“1 1 1

1 ITotal 1

« »

Looked at Uatch 1 1 2 1 0 1

1

3 1 Looked out of Uindou 1 73 24 1 6 1

1

103 1 Opened Door 1 29 14 1 8 1

1

51 1 Dressed 1 5 5 1 1 1

1

11 1 Turned Light on 1 22 2 1 0 < i 24 1 Packed up Traps 1 1 1 1 1 1

1

3 1 Uent to Emergency Exit 1 0 0 1 1 1

1

1 1 Notified Roommates 1 9 6 1 0 1

1

15 1 Notified Others/Other Rm 1 0 1 1 0 1

1

1 1 Attempted to Phone 1 3 1 t 0 1

1

4 1 Examined in Room 1 6 2 1 0 1

1

8 1 Uent to Bath Room 1 0 1 1 0 1

1

1 1«

Total 1 149

1 ...-1 59 1

. A. 17 1

Became Aware of Fire 0 10 20 30 40%

when they awakened 24%

by their 1st action 46%

by their 2nd action 21%

by their 3rd action or later 9%

Figure 3. Number of Actions by which the Guests became aware of the Fire

An examination of the first three actions of the guests following their

awakening as presented in Table 6 indicates that the predominant first actions

of the guests were “ information seeking actions "

, which were listed by

approximately 74.5 percent of the first-action population, 70 percent of the

second-action population and 82 percent of the third-action population. These

649
behaviors involved the actions of “ Looked out of Window” , “Opened Door "

, “ Attempted to Phone” and “ Examined in Room” . Approximately 19 per cent of the

first-action population and 15 percent of the second-action population were

involved in “preparatory actions ”

, including the actions of “Looked at

Watch ”

, “ Dressed " and “ Turned Light on ”

. Approximately 6 per cent of the

first-action population and 12 percent of the second-action population

were “ not i fying actions ".including “ Notified Roommates " and “Notified

Others /Other Rooms ” (Table 7 ) .

Table 7. Classification of First Three Actions of the Guests Following Their

Awakening till Their Fire Awareness

Actions First Second Third

(D Preparatory Actions 28 19% 9 15% 1 6%

© Information Seeking Actions 111 74.5 41 70 14 82

© Notifying Actions 9 6 7 12 0 0 (D Miscellaneous Actions 1 0.5 2 3 2 12

Total 149 100 59 100 17 100

6. ACTIONS OF THE GUESTS (2 ) — ACTIONS FOLLOWING FIRE AWARENESS

Table 8 and Table 9 present the first five actions of the study population

following their fire awareness. The predominant first and second actions of the

guests were preparatory for evacuation: “Dressed "

, “Notified Roommates’ , Packed up Traps ” and “Went to Bath Room ”

. The guests in the first-action

Table 8. First Five Actions Following Fire Awareness (Number of Persons )

1 Actions 1st 6 2nd 1 3rd 1 4th 1 5th 1 1 Total 1

Lookod at Watch

Umm. ~

91 0 1 0 i i 0 1

1

10 Looked out of Window 6 i 1 1 3 0 1 0 1

1

10

i Opened Door 10 i 1 1 0 1 1 0 1

1

12 Dressed 65 t 43 1 8 1 1 3 u 120

Tu>— ed Light on 10 i 2 1 0 0 1 0 1

1

12 Packed up Traps 26 i 40 1 21 5 1 3 1

1

95 Went to Elevator Hail 11 i 10 1 16 7 1 1 1

1

45

Looked for Emergency Exit' 1 i 12 1 10 11 1 2 1

1

36 Went to Emergency Exit 10 i 28 1 48 55 1 36 1

1

177 Notified Roommates 24 i 7 1 1 1 1 0 1

1

33 Wet Towels - Face 1 i 3 1 3 0 1 0 1

1

7 Yelled Fire' 2 i 0 1 1 0 1 0 1 ! 3 Opened Window 0 i 1 1 1 1 I 0 1 1 3 Pushed Alarm Button 0 i 1 1 0 1 f 0 1 1 2 Notified Others/Other Rm 5 i 4 1 9 4 1 0 1 1 22 Entered Room 2 i 4 I 4 4 1 0 1 1 14 Broke Window 0 i 0 1 1 0 1 0 1 1 1 Attemped to Phone 10 i 3 1 1 2 I 0 1 1 16

! Went Down in Elevator 0 i 3 1 0 2 1 2 1 1 7 Put Towels Around Door 0 i 2 1 1 0 1 0 1 1 3 Followed Other Guests 2 i 7 1 14 6 1 0 I 1 29

Wai«-»d & Asked for Help 0 i 0 1 0 0 1 1 1 1 1 Led to Safety 2 i 10 1 12 6 1 4 1 1 34 Went to Bath Room 1 • 1 1 0 0 1 0 1 1 2

" Went to Emergency Ladder 0 1 2 1 A2 1 1

. -1 0 1 1 —J L

5

—«

i i 1 1— i —i

1

I Total I 197 I 185 I 156 I 109 I 52 I

i -1 i i .i i

650
population also appeared to be greatly concerned with actions involving investigation of fire awareness cues in an attempt to obtain additional information to

evaluate the threat of the fire as indicated by their actions of “Opened Door

"

, ‘ Looked out of Window "

, “ Attempted to Phone ” and “ Looked at Watch ” ( Table 10) .

Table 9. First Five Actions Following Fire Awareness (Percent )

I Actions I 1st I 2nd I 3rd 4th I 5th I

r Looked at Uatch 1

j—

55s 1 Ok i

» 0* 1 15s 1 05C

1 Looked out of Window 1 3% 1 lk i 2k i Ok i 05C Opened Door 1 5* 1 lk l Ok i lk l 05s Dressed 1 335s 1 22k 1 4 k 1 1% l 25c Turned Light on 1 55s 1 lk l Ok 1 Ok i 05C Pecked up Traps 1 135c 1 20k l 115S 1 3k l 25C Went to Elevator Hoi 1 1 6k 1 5k 1 8k l 45c l 15C Looked for Emergency Exit 1 lk l 6k l 5k l 6k l 15C Went to Emergency Exit 1 55S | 145s 1 2455 1 28* 1 185s Notified Roommates 1 12k I 4 34 1 lk 1 lk l 0?c Uet Towels - Face 1 1?S 1 2k 1 2k 1 OX 1 05c Yelled 'Fire' 1 lk i Ok I lk l 0* 1 0>S Opened Window 1 OX 1 lk 1 lk l 15C 1 05S Pushed Alarm Button 1 Ok 1 lk 1 Ok l 15s 1 05C Notified Others-Other Rm 1 3k 1 2k l 5k l 25c ! 05C Entered Room 1 lk 1 2k 1 2k l 25c 1 05C Broke Window 1 0% 1 Ok 1 lk l 05c 1 05c Attemped to Phone 1 55c 1 25s 1 15s 1 15C 1 05c Went Down in Elevator 1 Ok 1 2k 1 0% 1 15C 1 15C Put towels Around Door 1 Ok 1 lk 1 lk l 05c 1 05C Followed Other Guests 1 15s 1 4k 1 75s 1 35c 1 05C Waited & Asked for Help 1 Ok l Ok l Ok 1 05C 1 15C Led to Safety 1 lk l 5k 1 6k l 35c 1 25c Went to Bath Room 1 15s I lk i 0k \ 05C 1 05C Went to Emergency Ladder 1 Ok 1 lk l lk l 15c 1 05C

1 Total 1 100* I 94*1

« 79* 11 55*1

« 265C !

Table 10. Classification of First Five Actions Following Fire Awareness

Actions First Second Third Fourth Fifth

(D Information 35 18% 5 3% 4 3% 4 4% - - Seeking Actions

© Preparatory 127 65% 102 57% 42 28% 13 13% 10 20%

Actions for Evacu

© Notifying

at ion

r 3% 5 3% 10 7% 5 5% - - Actions

(D Actions of 1 1% 6 3% 6 4% 1 1% - Self-protection

© Actions of 14 7% 29 16% 40 26% 24 23% 3 6%

Attempting Evacua

© Evacuation

tion

11 6% 32 18% 48 32% 57 54% 38 74%

Actions

Total 195 100 179 100 150 100 104 100 51 100

An examination of the fourth- act ion shown in Table 10 indicates that

the previous behavior periods of preparation for evacuation (©) and

information gathering to structure the seriousness of the threat ((D) have

651
passed, and the guests are now involved in evacuation (©) or attempting

evacuation (©) . This tendency is similar to the case of MGM Hotel fire.

Table 11 and Table 12 present the first five actions that the guests

took after their fire awareness in relation to their recognition of

emergency exits.

Table 11. Five Actions of the Guests who Recognized Emergency Exits

r1 Actions

y T

1 1st 1

r 2nd 1 — ~ i 3rd 1

' -1 4th 1

i i i 5th 1 ITotal 1

i r

1 Looked at Uatch

T 2 t

1 1 0 1 0 —r—

1 i

1

I 0 1

1

3 1

1 Looked out of Uindow 2 1 0 1 1 i 0 1 0 1

1

3 1

t Opened Door 1 1 1 1 0 i 0 1 0 1

1

2 1

1 Dressed 12 1 8 1 2 i 0 1 2 1

1

24 1

1 Turned Light on 2 1 1 1 0 i 0 1 0 1

1

3 1

1 Packed up Traps 8 1 7 1 4 i 1 1 3 1

1

23 1

1 Went to Elevator Hall 3 1 2 I 1 i 1 1 0 1

1

7 1

1 Looked for Emergency Exit 0 1 1 1 1 i 1 1 0 1

1

3 1

1 Went to Emergency Exit 4 1 13 1 13 i 8 1 6 1

1

44 1

1 Notified Roommates 8 1 1 1 0 i 1 1 0 1

1

10 1

1 Uet Touels - Face 0 1 1 1 2 i 0 1 0 1

1

3 1

1 Yelled ' F ire' 1 1 0 1 1 i 0 1 0 1

1

2 1

1 Notified Others/Other Rm 1 1 1 1 4 i 1 1 0 1

1

7 1

1 Entered Room J 1 1 1 1 i 3 l 0 1

1

6 1

1 Attemped to Phone 3 1 1 1 0 i 1 1 0 1

1

5 1

1 Put Touels Around Door 0 1 0 1 1 i 0 1 0 1

1

1 1

1 Followed Other Guests 0 1 0 1 0 i 1 1 0 1

1

1 1

1 Led to Safety 0 1 5 1 1 i 0 1 0 1

1

6 1

1 Went to Emergency Ladder

» 1 0 1 1 1* 0 1 —i

0 1 0 1

1

1 1

1

i

1

1 - i i i i

I Total I 48 I 44 I 32 I 19 I 11 I

l

- I J 1 1 A—<

Table 12. Five Actions of the Guests who Unrecognized Emergency Exits

1

1 Actions

r i

1 1st 1

1 i 2nd 1

i 3rd 1r 4th l« 1

‘ 1 » 5th 1 iTota 1 1

0“ —y

Looked at Uatch

lln ' " 1 4 0 1 0 1 ———1

0

" ‘ 0

1 1

1 1

1 4 1 Looked out of Uindou 4 0 1 1 1 0 0 1 1 5 1 Opened Door 6 0 1 0 1 0 0 1 1 6 1 Dressed 38 17 I 4 1 1 0 1 1 60 1 Turned Light on 1 1 1 0 1 0 0 1 1 2 1 Packed up Traps 8 26 1 12 1 0 0 1 1 46 1 Uent to Elevator Hall 4 6 1 8 1 5 1 1 1 24 1 Looked for Emergency Exit 0 6 1 7 1 8 1 1 1 22 1 Uent to Emergency Exit 3 6 1 21 1 25 20 1 1 75 1 Notified Roommates 8 3 1 0 1 0 0 1 1 11 1 Uet Towels - Face 0 2 1 1 1 0 0 1 1 3 1 Opened Uindou 0 0 1 1 1 1 0 1 1 2 1 Pushed Alarm Button 0 0 1 0 1 1 0 1 1 1 1

i Notified Others/Other Rm 2 1 1 4 1 2 0 1 1 9 1 Entered Room 1 2 1 0 1 1 0 1 1 4 1 Broke Uindow 0 0 1 1 1 0 0 1 1 1 1 Attemped to Phone 4 1 1 0 1 1 0 1 1 6 1 Uent Oown in Elevator 0 2 1 0 1 1 2 1 1 5 1 Put Towels Around Door 0 2 1 0 1 0 0 1 1 2 1 Followed Other Guests 2 3 1 10 1 4 0 1 1 19 1 Uaited & Asked Help 0 0 1 0 1 0 1 1 1 1 1 Uent to Bath Room 0 3 1 4 1 3 3 1 1 13 1 u Uent to Emergency Ladder 1 1 1

1

0 1* 0 0 k__ 1 1

1 1 2 1

*

1

1 l r~ i i .

I Total I 86 I 82 I 74 I 53 I 28 I

* * » * *

Figure 4 presents the number of actions by which the study population

evacuated successfuly in relation to their recognition of emergency exits. An

examination of Figure 4 indicates that those individuals who recognized emergen652
cy exits prior to the fire incident evacuated successfully in a lesser number

of actions than those who unrecognized emergency exits prior to the fire.

Evacuated Successfully

by their 1st Action

by their 2nd Action

by their 3rd Action

by their 4th Action

by their 5th Action

or later

Emergency Exits

Recognized 10%

Unrecognized 5%

Recognized 23%

Unrecognized 9%

Recognized 27%

Unrecognized 24%

Recognized 17%

Unrecognized 29%

Recognized 23%

Unrecognized 33%

20 30 40%

Figure 4. Number of Actions by which the Study Population Evacuated

Successfully in relation to Their Recognition of Emergency Exits

7. SUMMARY

It appears that the actions and behavior of the guest study population

following their awakening were primarily concerned with obtaining information.

The actions of the study population following their fire awareness were

initially primarily concerned with preparations for evacuation and obtaining

information about the fire threat. The actions then progressed to evacuation

actions. This tendency is similar to the case of MGM Hotel fire reported by

Dr. John L. Bryan. *1, *2

It also appears that the individuals who recognized emergency exits prior

to the fire evacuated successfully in a lesser number of actions than those

who unrecognized emergency exits prior to the fire. An examination of this

study indicates that the older guests show the higher percentage of previous

recognition of emergency exits.

ACKNOWLEDGEMENT

The study was completed only through the cooperation of the following

persons : Professor Takao Uehara, Kazuo Kumai, Mikio Tsukada, Atsuyuki

Ishibashi and Toshiyuki Fujino. Their cooperation is greatefully acknowledged.

REFERENCES

1. John L. Bryan: Human Behavior in the MGM Grand Hotel Fire ; Fire Journal

(19B2.3) , p.37-48.

2. John L. Bryan: A Review of the Examination and Analysis of the Dynamics

of Human Behavior in the Fire at the MGM Grand Hotel, Clark County, Nevada,

as Determined from a Selected Questionnaire Population: Fire Safety Journal,

5 (1983) , p.233-240.

653

Discussion After S. Okishio, T. Handa, and K. Kawagoe’s Report on AN EXAMPLE OF

HUMAN BEHAVIOR IN A HOTEL FIRE

QUINTIERE: Have you done subsequent analysis, such as what intervention action

might have been done so that you can then decide how many people would have been

saved or how the fire may have been limited? Have you had such thoughts or done

such an analysis?

HANDA: Well, since this case is at trial, and as the chief investigator, I cannot comment on an ongoing case.

SNELL: In the U.S. we have the same problem as data from very careful

reconstruction often does not become available for subsequent analysis and

answering such questions. We are seeking means to alter this so that we get the

benefit of the valuable data collected for the court sessions.

HANDA: I have frequently mentioned that we would greatly benefit.

LEVINE: Last month at a meeting in Washington of the Society for Fire

Protection Engineers, the speaker recommended that U.S. hotels remove the signs

that tell guests where to find the emergency exits and to put up signs to tell

them to stay in the room with the door closed until they are rescued. What is

your opinion on this?

HANDA: You see, Japan is plagued with earthquakes, but most hotels have steel

doors.

655

PANEL DISCUSSION ON CAPABILITIES OF FIRE GROWTH PREDICTION

QUINTIERE: The intent of this panel should be to try to address the

capabilities of current fire modeling. I request that we restrict our interests

only to predictions dealing with the burning rate. Of course, by this it is

meant that we include flame spread, ignition, pyrolysis, etc. I ask that the

panelists give their opinions briefly, without extensive elaboration, because we

do not have sufficient time. However, in giving their opinions, let us consider

the full spectrum of fire conditions that can affect the burning rate. I will

try to structure the discussion in terms of various scenarios and for each

scenario panelists should think if that problem has been solved, if it can be

solved, or if it cannot be solved with current knowledge. Especially where it

cannot be solved, panelists should try to say why. Next slide. I indicate the

scenarios here and by the arrows that is the sequence that we should discuss

these. In the first scenario we are addressing flame spread on solids and their

subsequent burn rate. I will now turn to the panelists and ask them to please,

when they speak, identify themselves, and so I solicit their comments on the

capabilities to predict flame spread, burning rate on solid materials. All

panelists should not feel that they have to say something about every scenario,

but I will request that we begin with Dr. Hirano.

HIRANO: My comment, a very simple spread of flame. Let’s just say a few words

on all the solved problems. We are in a position to make a prediction on the

horizontal spread and sometimes upward spread. I think most specialists here

understand violent conditions clearly. In these areas, I have a feeling we can solve both in the very, very near future. Given a clear, initial condition, the

upward spread of the flame area, we might be able to solve soon. Or the theory

for spread, to estimate the burning rate where the spread has already taken

place. I would like to touch upon other specific cases of flame spread. I think that the area is becoming gradually clearer now. The areas which we cannot solve problems, such as fire pyrolysis involving the critical condition

change, unless that factor is known to us. I do not think we can solve the

problem; we cannot make predictions. Also properties of certain materials in

terms of heat increase or chemical analysis, if that is unknown, again we cannot

solve the problem. Of course, some of the materials we don’t have to worry

about but this is a categorical problem.

PAGNI : I agree with Prof. Hirano, in especially the first two cases. I would

put those in the category "has been solved," that is horizontal spread and

vertical up and down spread, based primarily on the work of Prof. Hirano and the

work of Prof. Fernandez-Pello as described in the recent review at the August

conference. The next category of a piece of furniture in a compartment, I think, is in the second category of a "can be solved" problem. I think it's

important to add to the fire conditions spectrum, a material spectrum. Simple

materials can be understood theoretically, but composite and charring and

strangely behaving materials which require a much more detailed study represent

a much greater level of difficulty.

QUINTIERE: I'll ask a point on the first scenario, dealing with flame spread

and the burning of material. Are there any predictions that are capable of

predicting the transient aspects of the problem?

657
EMMONS: I would like first to note that we should define what we mean by

solution. If one of the major uses for such solutions would be use in a fire

model, as such, the really useful solution will have to be non-steady prediction

of fire spread burning rate, composition of gases, and so forth. From this

point of view, we have an empirical solution. We can have a solution that

depends upon growth from pneumatic properties using measured properties of the

materials. The ultimate solution would be to have enough knowledge of chemistry

to be able to predict from the first principles merely specifying the molecular

composition. The last is, at present, impossible and in view of its complexity

will remain so for many, many years. For pure materials, we are approaching the

point at which, given a measure of the properties of the pure materials, we can calculate the spread rate in both of the first two items. At present, I do not

believe we have quite reached the point at which the measurement of properties

of a new material would permit us to calculate with sufficient confidence. An

empirical solution, of course, is possible at present, but it is only available

for a limited number of materials.

QUINTIERE: In view of the time, perhaps we can move on to burning within a compartment and let us consider the next two scenarios together in which we have

the burning of a single item and then, perhaps, the possibility of the

involvement of the second item. Would Dr. Tanaka like to present some views.

TANAKA: Last night at the dinner table I was given this table by Mr. Nelson.

There are two teams on both ends, one is the design team, the other research

team. What Mr. Nelson is interested in is the building of a bridge to join two

groups with different languages. I also recognize that there is a big gap

between the design people and the research people, but actually if you look more

closely at the research group, among them I also find a certain gap. It is not

quite as big as between the two teams. I think one type of study or school is

very fundamental to people like us. On the other hand, a person like me who is

a design person uses the other approach. We have more results of damage rate at

the very last stage of the scenario where the actual victims, where the property

damage occurs , we like to protect it , so that it is usually the starting point

in our thinking tree. We really go backward because we, by all means, try to

estimate property and human damage; but to understand that, we probably have to

go back one stage if it doesn’t give use enough or we may have to go back to the

origin. In this kind of a mental or technical approach, when we come back to

the very origin of where we have to think about flame spread or burning time, we

tend to look for some kind of solution. Every year Japan introduces about 500 new materials to the market. To extract the burning mechanism among those

materials, I think in the beginning it's necessary to take the simply structured

material first. It might be too presumptious to say this but, at this moment, I would like to limit myself to a study at that simple state where we can really

have a sure hold of the subject matter.

QUINTIERE: In view of the time, I would just like to solicit some comments on

the next to the last scenario which in the diagram is intended to mean postflashover conditions. By postf lashover we mean that flames are leaving the

window and flames fill the enclosure. I would like to ask the panelists within

the current level of fire modeling can we predict the production of fuel vapor

for all possible fire conditions?

658
EMMONS: There are, I believe, two cases to be considered. One in which we can deem are ventilation limited, and another in which vigorous flames come out the

door, but we still have indentifiable individual items burning. I believe we

are very close to understanding how to handle correctly the second situation.

The ventilation limited case has not, to my knowledge, had adequate research. I believe the ventilation limited case can be solved by computing merely the air

that gets into the room through the vent. The oxygen which enters the room

would then, I believe, bum in the excess fuel vapor inside and a determinable

but not yet known fraction of the heat would be used to pyrolyze the solids.

This would make it unnecessary to consider where inside the various material

patterns could be. This is what I believe will work, but clearly I’m only

guessing in view of the absence of any clear experimental data.

HIRANO: I'd like to comment on the very last portion of Dr. Quintiere's

presentation. I think this is an area which is a total study and in explaining

it, it might take longer to reach a conclusion. One possible experiment or study along these lines is what Mr. Takeda is conducting right here.

QUINTIERE: I would like to ask a question on the last point Prof. Emmons

made. Could you further elaborate on what is needed in making the step between

the assumed fraction of heat that goes into heat transfer to the fuels and then

the subsequent pyrolysis rate? What is needed to describe this transfer

process?

EMMONS: Briefly, I believe this will depend upon the nature of the fuel that is

in the room. If, for example, it is a liquid fuel with a boiling point, then

one would have heat transfer to that surface. It would boil through; you would

have a known fluid temperature. If, as is more likely, you have many charring

fuels, then I believe we will need various empirically determined, overall

chemical reaction rates for the pyrolysis process. I believe the first thing

that needs to be done, however, is to run experiments on such rooms with careful

measurements of temperature, composition, and conservation. I suspect that no matter how much logic we put in ahead of the experiment, the observations will

redirect our thinking.

659

CLOSING SESSION

661

Chairmen's Report of Technical Session

Fire Hazard/Risk Management Methods

J. Bryan and K. Kawagoe , Chairmen

Dr. rakao Takamatsu, Building Research Institute, presented a comprehensive

paper entitled, "Development of Design System for Building Fire Safety," the

Mini 7 of Construction's five year project, initiated in April 1982 and

p

' s reported at the 6th UJNR. The objective of this design system is to

provide a rational and total design for building fire safety by systematizing

the knowledge established in fire research. A total of seven committees and six

working groups have provided input to the system.

The framework of the design system consists of four subsystems:

(1) The outbreak and growth of fire subsystem,

(2) The smoke control subsystem,

(3) The evacuation subsystem,

(4) The fire protection of the building subsystem.

The subsystems will be used to predict the performance of the various models.

By the end of 1983 they expect to complete the design framework of the system

and the subsystems, develop a data bank, and the fire growth prediction model.

Dr. John Keating, University of Washington, presented his report on the behavior

of occupants during residential occupancy fires, entitled: "Human Reaction

During Residential Fires: Establishing a Data Bank." The data was collected

from 118 occupants in residential fires in Seattle and 240 occupants in New York

City. The study utilized an interview technique with a narrative mode and an interrogatory mode. Contingency analyses were utilized to analyze the

behavioral episodes of the occupants. The New York City interviews were conducted by twelve members of the emergency response staff of the American Red

Cross, with the development of this data bank continuing. Planned improvements

include placing burn victim information into the data bank, improving the

contingency analysis, and the formulation of probability models of human

responses.

Dr. Ai Sekizawa, Fire Defense Agency, presented the paper entitled: "A Study on Fire Risk Analysis Method of Multi-Use Buildings." This is a five year project

initiated in 1982 to prepare an assessment manual for the fire service which

assists in the diagnosis of the fire risk of multi-use buildings. The total

program of the Fire Risk Analysis Method involves

:

(1) Fundamental studies on the contents of the fire risk in multi-use buildings,

(2) Studies on evaluation methods of building fire safety,

(3) Studies on the framework of the system and subsystems,

(4) Studies on the elements and construction of each system with theories and

statistical data,

(5) Improvement of the fire risk analysis method to multi-use buildings,

(6) Preparation of the fire risk assessment method for the fire service,

(7) Development of the fire risk assessment method for use in the planning of new multi-use buildings.

663
This method evaluates three variables in the building fire risk:

(1) Fire outbreak probability

(2) Fire spread risk, and

(3) Evacuation difficulty.

An outline of the existing data base consisting of 11,150 building fires from

1979 to 1981 was presented. It is currently planned to present a report on the

completed form of this fire risk assessment method at the 8th UJNR.

Dr. Tadahisa Jin, Fire Defense Agency, presented the final paper on the Fire

Safety Evaluation Method developed by the Tokyo Fire Department. The purpose of

the method is to diagnose the fire safety of the building with a scoring system

to identify problems and advise personnel on the improvements for fire safety.

The 34 items and 102 components in the method were obtained from matrix analysis

and event tree analysis of 134 fires. Counter measure scores for the categories

of fire prevention, fire outbreak control, fire growth control, fire spread

controls, and evacuation-escape are established. Total score for fire safety

evaluation of the building involves a range from excellent to definitely

unacceptable. The method has resulted in the development of a building owners manual for the application of the method to their building.

664
Chairmen's Report of Technical Session

Fire Growth Prediction

R. Friedman and T. Hirano, Chairmen

The morning session consisted of two summarizing progress reports, by Prof.

Emmons for the U.S. and by Dr. Wakamatsu for Japan, as well as six lectures,

three from the U.S. and three from Japan.

Prof. Emmons limited his review to recent U.S. research on fire spread

mechanisms. He reviewed work by Prof. Tien, Prof. Carrier, Dr. Fendell, and

Prof. Fernandez-Pello on the laminar flame spread problem involving wind. He

reviewed in some detail the work of two of his recent graduate students: Dr. A.

Atreya's study of spread on horizontal wood surfaces and Dr. C. Tan's study of

spread on a series of cellular plastics.

A paper by Dr. Wakamatsu and Dr. Tanaka on fire growth modeling in Japan was presented by the former. Thirteen works were referred to including fire spread

over materials, compartment fire phenomena, doorway flow, smoke movement, and a smoke-filling study of a new wrestling arena.

Dr. Quintiere, Mr. Steckler, and Mr. Corley assessed the prediction of vent

flows into compartments containing fire. Dr. Quintiere presented a comparison

of data with models prediction assuming two layers with no mixing gave vent

flows and layer positions always within 50 percent of measured values. The

discrepancy is due to vent mixing, primarily. Wall boundary layer flows are considered.

Dr. Takeda described a study of pre-flashover and flashover fire behavior. He

compared a simple model with small-scale experiments using a slab of PMMA in a 0.4 meter cubic enclosure, with varying window size. He divided h^s solutions

into three classes, depending on values of F(= fuel surface area/Lz

) and of the

ratio A / H/L , where L is 0.4 meters. It is predicted that flashover will not occur in one of these three regions.

Prof. Zukoski gave a progress report of his current work with Prof. Kubota on a flame and plume interacting with a hot layer and a ceiling. Correlations for

the free plume have been developed, but the interactions with the ceiling are still under active study.

In the afternoon, the presentation by Dr. Tanaka was concerned with models which

have presently been developed in Japan for establishing a reliable fire safety

design method. Detailed ideas of the evacuation/smoke control design method

were carefully explained.

The topics presented by Dr. Jones were of future directions for modeling the

spread of fire, smoke, and toxic gases. The interesting facts revealed by him

include the smoke layer growth in a room far from the fire room and the smoke

movement in various types of compartments.

Prof. Tsujimoto presented the results of theoretical prediction of smoke

movement in a long corridor or inclined stairway and compared them with

experimentally obtained ones. The discussion was mainly on the characteristics

of the smoke flows.

665
Two additional topics were presented by using a video system. One was of the

results performed by Dr. Saito on a box model fire test. The box was 0.84m

wide, 0.84m high, and 1.68m long with an opening of 0.3m wide and 0.67m high.

The inside walls are of plywood (3mm thick) covered by iron foil (0.25mm thick)

and a crib was burned inside it. Intense flashover-like phenomena could be

observed repeatedly. The other was presented by Dr. Takeda on a model compartment

fire. The compartment was of a 0.44m cube with an opening of 0.16m (h) x 0.11m

(w). The fuel burned in it was a 0.16m x 0.16m x 0.025m PMMA plate. It could

be observed that at about 10 minutes after ignition oscillation started, and at

about 12 minutes complete extinction occurred.

666
Chairmen's Report of Technical Session

Materials Fire Properties and Test Methods

T. Handa and H. Nelson

The session on fire properties and test methods included two progress reports

and five papers. All of the presentations were relevant to the measurement and

data for fire properties of materials in fire growth models. There was also a consistent emphasis on the need to provide accurate and appropriate data on rate

of heat and/or mass release information to the models. The several papers

viewed the state of the science and the problem from different aspects. It was

clear, however, that there is a need for an appropriate combination of

fundamental property data and sound tests for measurement of fire phenomological

parameters, some of which may be unique to the models.

The progress report by Prof. Pagni and Dr. Suzuki both provided overviews and a basic list of the types and items of property information that appears essential

to predictive modeling. Professor Pagni also proposed an ultimate target of

developing models on the basis of properties common across the scope of science

rather than unique fire phenomena measurements.

The first paper, "Identification of Fire Properties Relevant to the Prediction

of Fire Growth," by A. Tewarson reviewed the concept of material property

measurement and proposed a system of fire phenomena parameters based on types of

calculations typical to modeling and ratios or scaling factors useful in

converting test data to predictive models.

The second paper, "Concepts on Fire Spread Testing," by Prof. Hirano presented

an excellent statement of the critical consideration and properties involved in

developing test information that can predict the spread of fire on a surface.

As pointed out by Prof. Hirano, current flame spread tests do not meet all of

the necessary objectives and development of a fully comprehensive test will be

necessary to properly support the fire growth model.

The third paper, "A Methodology of the Sensitivity Analysis of Building

Properties on the Occurrence of Flashover," by Dr. Hasemi presented a mathematical analysis approach to predicting the probability of flashover based

on the sensitivity of the environment to parameters related to fire size, space

size, and ventilation opening. Dr. Hasemi presented advanced prediction

concepts involving calculation of the stability limit of the equilibrium

solution to zone models. Dr. Hasemi uses an iterative approach involving

successive searches of the optimum of an augmented Lagrange function.

The fourth paper, "Fire Engineering Tests Development: Bench-Scale Tests to

Predict Full-Scale Behavior," by Dr. Babrauskas reviewed the development of fire

phenomology tests of furniture type fuel packages as undertaken by

Dr. Babrauskas and his colleagues. Dr. Babrauskas proposes the development of

fire phenomology parameter measurements, particularly of rate of energy or mass release per unit mass or per unit area of exposed surface. Dr. Babrauskas also

presented a concept of relating full-scale furniture calorimeter test data to

bench-scale cone calorimeter results. The transition involved a conversion

equation that includes adjustment factors for the mass, type of furniture frame,

and the specific configuration of the furniture item.

667
The fifth paper, "Material Fire Properties and Test Methods to be Developed," by

Dr. Suzuki covered both the subject material and a review of the sub-system of

the Japanese design system for building fire safety that will relate to design

methods for prevention of outbreak and growth of fire. Dr. Suzuki pointed out

the need for data that can reasonably reflect a real world condition and the

need for a family of new and proper fire tests that will provide parametric data

demanded by the models within the design methods. The exact tests and data to

be dictated by the model as it develops. Dr. Suzuki, however, listed needs for

information on ignitability , latent heat, thermal decomposition products, heat

released by thermal decomposition, and heat transfer in complex elements.

668
Chairmen's Report of Technical Session

Combustion Toxicity

and

2nd Expert Meeting of the U. S. -Japan-Canada Cooperative

Research Group on Toxicity of Combustion Products from

Building Materials and Interior Goods

R. Gann, K. Kishitani , F. Saito

The three sessions included three progress reports and six technical papers.

They covered a range of topics from determining the conditions for small-scale

measurement to the science behind toxic product generation from burning

materials

.

In his progress report, Dr. Gann described the current U.S. activity, showed the

evolution of our thinking from toxicity to toxic hazard, and listed critical

areas for future research. Dr. Saito presented the Japanese plan for developing

a realistic small-scale measurement method. This involves three, programs: one

to determine the appropriate fire conditions , the second to develop a smallscale apparatus, and the third to develop the animal models for such a test.

Dr. Tsuchiya presented the Canadian approach to fire toxicology which is based

on an analytical approach with no animals. It includes combustion experiments

generally using a modified OSU apparatus and detailed analysis of combustion

products using novel techniques such as MS/MS.

Dr. Yusa, Mr. Furuya, and Prof. Alarie presented descriptions of their devices

for measuring toxic effects on laboratory animals. The former two apparatuses

are relatively new, and the first data was presented. There are excellent

design features in each. Dr. Alarie' s apparatus is more mature, and he

presented a variety of results useful in explaining the lethality of the

combustion gases.

Dr. Levin discussed her investigation of the generation of HCN from flexible

polyurethane foam. Her results indicate that the simple combustion exposures

developed in the past may not be sufficient to get a true toxicological measure

of fire gases.

Dr. Tanaka and Mr. Mizuno presented theoretical and experimental aspects of

full-scale Japanese studies to determine the fire conditions to be used in

small-scale measurement. Burning chairs in a double room arrangement, they have

obtained information on mass burning rates, radiative fluxes, and doorway flows.

Dr. Hartzell was unable to attend. However, his paper on toxic gas measurement

from fires in full-scale furnished rooms was distributed. Results were obtained

regarding hazards in the burn room, in an adjacent corridor, and in a second

room down the hall.

Dr. Nishimaru discussed his studies on the physiological effects resulting from

the exposure of rodents to five different toxic gases and their combinations.

Incapacitation and memory loss were the two effects reported.

The "U.S. -Japan-Canada Coopertive Research Group on Toxicity of Combustion

Products from Building Materials and Interior Goods" has agreed to meet again,

probably in about one year's time. We will investigate holding that meeting in

Canada.

669
The papers in these sessions reflect advanced thinking and increased laboratory

capability from the last UJNR meeting. It is anticipated that at least equal

progress will be reported at the 8th Panel Meeting.

670
Chairman's Report of Techni^'il Session

Measurement Methods

P. Pagni

The measurement methods session was held Thursday morning in Building 224. Much

of the tour of the laboratories in that building during the afternoon also was

related to measurement techniques. The following speakers addressed this

session:

(1) Dr. Friedman, Factory Mutual Research Corporation, "Current U.S. Advances in

Fire Research Techniques."

This paper briefly reviewed 33 recent reports related to measurement techniques,

including a review on toxicity by Clarke in the Fire Journal, September 1983

issue, which is not in the written paper. Dr. Friedman then described a very

large scale extinguishment test at Factory Mutual. The apparatus is essentially

a Tewarson system of 6m diameter. Stacked cartons filled with polystyrene

packing and electrical components were ignited and the fire suppressed by water

spray. The timing of water initiation was shown to be critical. The extended

discussion which followed emphasized the difference between warehouses where

fire confinement suffices for property safety and homes where full extinction is

required for life safety.

(2) Dr. Jin, Fire Research Institute, "Various Measurement Methods on Fire

Research.

Dr. Jin presented a very interesting review of a wide range of measurement

systems used in Japan for fire research. The radiation detection problems

stimulated much discussion. The ideas of using heated air to keep optics clear

is clever. Dr. deRis described a microthermopile sensor in use at Factory

Mutual

.

(3) Mr. Beyreis, Underwriters Laboratories, "Developments in Fire Tests Related

to Regulation."

The evolution of fire research techniques from large-scale tests to small-scale

tests and then to mathematical models was traced. It was indicated that

Underwriters Laboratories is now doing less large-scale testing and looking

forward to interacting more with researchers on mathematical models in the

future.

(4) Dr. Tanaka, Building Research Institute, "A Measurement of Doorway Flow

Induced by Propane Fire."

Dr. Tanaka described detailed experimental results for flows between two rooms

and into the surroundings. It was found that a flow coefficient of 0.68

sufficed for inflow and outflow both between the rooms and out of the last room. It also was found that fine thermocouples were needed to accurately track

the temperature profile. The Steckler technique worked well in generating an equivalent two layer temperature. Three dimensional effects at the doorway were

shown to be negligible In the informative discussion which followed.

671
(5) Dr. deRis, Factory i'u'cual Research Corporation, "Flammability Testing:

State-of-the-Art .

Dr. deRis departed from his written report to present some exciting recent FMRC

results relating x > the radiative fraction of heat release rates in turbulent

flames to i , the soot-point of laminar flames. The soot-point is defined as the flame height at which unburnt soot first appears at the tip of the flame.

It was found that x decreases as l increased approximately as

X = 0.42 - 0.G20?/25cm

with x f° r ethane **20 percent, propane ^-30 percent, and a maximum x^2 percent

for very sooty flames. The peak absorption coefficient also decreased

as i increased. The soot-point temperature and x appear to be constant for most

hydrocarbons at 1200°C + 30°C and 30 percent respectively. This discussion

demonstrated the strong connection between flame radiation and soot-point.

Based on these observations, a small-scale test which measures the soot-point

the heat release rate for real charring fuels was developed. This test was described in detail by Dr. deRis. He urges its adoption by the fire research

community and was pleased by the great interest shown it at this session.

672
RESOLUTIONS

KAMIMURA: According to the tradition, which means that this is to be read by

both Japanese and American Resolution Committee Members, we will proceed

accordingly. I ask Prof. Emmons to read the resolution.

EMMONS: The resolutions have been prepared by a committee of four. They met a number of times, making changes as either side had altered a proposal. The

present draft is suggested as the final draft. For a point of information,

should I just read all of it?

KAMIMURA: Yes, please.

EMMONS: The final draft is subject, of course, to correction by the whole

committee. The resolutions the panel members of the UJNR Panel on Fire Research

and Safety are very happy with the results of the Seventh Joint Meeting held in

Gaithersburg, MD. , October 24-28, 1983. The workshop on special topics proved

to be especially valuable for all participants and so were the combustion

toxicity sessions, held jointly with the meeting of the committee, Japan-United

States-Canada Cooperative Research on Toxicity of Combustion Products of

Building Materials and Interiors. The panel members herewith resolve:

1. The objectives of the meetings of this panel are to exchange information and

to promote cooperative research on fire science and its application to building

fire problems. For this purpose, the panel members are encouraged to:

(a) Make clear the contributions of fire science and engineering studies to

building fire safety by making fire safety design more quantitative, leading

eventually to performance fire codes;

(b) Develop the means to predict the growth of fire in compartments and

facilities, the generation and distribution of smoke and toxic gases resulting

from such fires, the time of automatic detection of fire, the evaluation of

hazard associated with such potential fires;

(c) Exchange information through reports and video tapes and illustrative

information;

(d) Do cooperative research on scientifically based models of fire

phenomena, determinations of the relevant fire properties of materials and

furnishings, the fire science and technology of measurement methods and the

associated test methods to be used to determine the relevant data for fire

models.

2. The 8th Meeting of the UJNR Panel on Fire Research and Safety for advancing

the above objectives, especially the application of fire science to building

fire safety, be held in Tsukuba, Japan in May or September 1985.

3. The format of the meeting should be as follows: The discussion of each of

these topics should include information on the validation of the research

results and their application to building fire safety to the degree that these

are possible:

673
(a) The first few days be devoted to workshops on:

(1) fire hazard, risk analysis methods,

(2) fire growth prediction,

(3) materials fire properties and test methods and fire research

measurement methods,

(4) evacuation and smoke control,

(5) combustion toxicity,

(6) modeling of fire detection and extinguishing, and

(b) These sessions to be held simultaneously as appropriate. The joint

session with the Japan-United States-Canada Cooperative Research on Toxicity of

Combustion Products of Building Materials and Interiors were especially

valuable. The combustion toxicity session of the 8th UJNR Meetings should, if

possible, again be joint with the meeting of that committee, and

(c) At the opening of each session and workshops progress overviews on each

field between meetings be reported by both Japan and the United States with

sufficient time allotted to permit some discussion.

4. Several cooperative fire research program should be started. These will be

especially valuable where the facilities are somewhat different in our two

countries. To be specific, it is suggested that joint research programs be

organized on:

(a) wall burn,

(b) smoke movement and its validation tests.

5. The working personnel exchange be pursued more vigorously. One NBS

employee, Mr. Steckler, spent a valuable two months in Japan. Dr. Hirata, of

FFPRI, Dr. Hasemi of BRI, Dr. Takeda of Tokyo University, and Dr. Morita of

Tokyo Science University, would stay in the United States to complete and/or

conduct valuable cooperative research.

6. The panel members be encouraged to exchange information of interest through

the respective chairmen between meetings. To accomplish significant exchanges

between panel meetings, all research reports issued in each country should be

exchanged every three months, January, April, July, and October. The titles of

these reports could, in each country, be sent to all panel members who could

check the ones they would like to receive. The desired reports could then be

reproduced and distributed by the chairman.

7. All the relevant reports for the panel meetings be sent in time to be

received in the other country in at least one month before the 8th Meeting.

KAMIMURA: Thank you very much, Prof. Emmons.

674
CLOSING ADDRESSES

KAMIMURA: I'd like to ask the American side to give us the closing remarks.

SNELL: The technical committee reports and the final resolutions of the

conference reflect the significance of this meeting. We have heard of

interesting and exciting new technical results and have seen in the formal

papers and informal discussions many evidences of effective collaboration. We

are all inspired by the continuing, outstanding work of the pioneering

researchers in this field such as Drs. Kawagoe and Handa, as well as the

exciting new ideas of the younger and newer members of the delegation. Dr.

Karaimura, you and your delegation are commended. It has been our intention to

create an atmosphere conducive to breeding close professional and personal

relationships. The record of accomplishment of this panel, I believe, attests

to steady progress in this regard. Change Is as inevitable as the seasons and

so it is in our human affairs. There have been numerous suggestions for making

the possibility for more discussion and free time in our deliberations and

these, I give, are welcome. We encourage their consideration for future

meetings of our panels. Each of us has, before us a little bag, on this it

says, tricks or treats, this is none but a treat. In the United States this is an important season. The harvest is in. This weekend our children will

celebrate Halloween and next month is our national holiday of Thanksgiving.

Therefore, I view it appropriate as this UJNR on Fire Safety and Research draws

to a close, that we share with you this small token Halloween treat, our heartfelt thanksgiving for the opportunity this collaboration has created; we wish you all a safe journey home.

KAMIMURA: I would like to say a few words on behalf of the Japanese on this

event. Dr. Snell and all of my friends and colleagues from the United States

and Japan, on behalf of all of the friends of the Japanese panel, I feel very

grateful and happy that the UJNR Fire Research and Safety Panel has successfully

concluded its session here today. I feel that we owe a great deal and we feel

very grateful for the scrupulous preparation and the very appropriate operation

of American Fire Research and Safety members , particularly the chairmen of the

American panel, Drs. Snell, Gann, and Kashiwagi in this effort. So I would like

to express my heartfelt thanks and gratitude to everyone, particularly

Drs. Lyons and Kramer and people of the National Bureau of Standards. The panel

has lasted for five days and we have gained a great deal from the five day

session and this result will help further in the future for both United States

and Japanese researchers. My thanks also go to the people who prepared data and

also made the arrangements for the meeting rooms and for the operation of the

conference and for the interpreters. We also have received a very warm welcome

and we appreciate the arrangements made for us when we went on a tour of the NBS

facilities and sightseeing in Washington, D.C. I would like to express my

thanks for all of those events. Thank you very, very much for your very warm

welcome and heartfelt hospitality which was shown at the reception held at Dr.

Snell's residence, the formal luncheons, the dinners we had at the Cracked Claw

Restaurant and at Blackie' s House of Beef and also the very enjoyable parties at

Dr. Gann's house and Dr. Quintiere's house. Several of the Japanese members

already have left Gaithersburg for home yesterday or the day before yesterday.

The remaining 15 of us will leave Washington for home either tomorrow or the day

after tomorrow with happy memories and useful information. The next, the 8th

UJNR Cooperative Panel, in accordance with the resolutions, will be held In

675
Japan in the city of Tsukuba, either in May or September of 1985. Upon our

return, we would like to embark upon preparations for that cooperative panel

meeting as soon as possible. Last, but not least, we will be looking forward to

seeing all of you at the next 8th UJNR Cooperative Panel. I hope that you will

be successful in your future research and you will maintain your good health and we would like to say, really, thank you very much for all the American members

and also finally we would like to express our thanks to the interpreters. Thank

you.

676
Participant’s Index

Alarie 445, 446, 469, 470, 487, 489, 503, 504

Babrauskas 369, 391, 401, 402

Beyreis 536, 547

Cooper 17, 29, 90, 91, 289, 536

Davis 545

deRis 545, 585, 607

Emmons 29, 89, 95, 189, 271, 285, 287, 288, 289, 299,

658, 659, 673

Friedman 523, 535, 536

Gann 39, 87, 89, 288, 309, 323, 399 , 405 , 411, 445,

Handa 89, 402, 583, 584, 655

Ha semi 341, 367, 368, 402

Hirano 287, 325, 391, 535, 583, 607 ; 641, 657, 659

Jin 51, _53, 87, 391 , 535, 545

Jones 209, 271, 272

Kamimura 673, 674, 675

Kawagoe 40, 288, 642

Keating 41 , 51, 87, 89

Kishitani 13, 91

Levin 447, 469, 470, 611, 612, 625

Levine 151, 190, 641, 655

Mi tier 151, 272, 287, 288, 323, 607

Mizuno 445, 446

Morita 272

536, 641,

612, 626

underscored number indicates author’s report

677
Nelson 7_, 39, 77, 87 , 89, 90, 91, 287, 401, 402, 535, 536

Nishimaru 504, 613, 623, 625 , 626

Pagni 77 , 87, 177 , 189, 190, 271, 285, 287, 293, 299, 391, 402,

503, 536, 583, 607 , 657

Quintiere 121, 151, 189, 271 , 285, 287, 288, 299, 367, 368, 545, 583,

655, 657, 658, 659

Robertson 411

Rockett 190, 288, 289

Salto 323, 401, 413, 625

Sekizawa 53, 77, 91, 641

Snell 655, 675

Steckler 151, 445, 584

Sum! 625

Suzuki j301_, 309, 393, 399 , Ml, 612

Takeda 153, 177, 288, 289

Tanaka 191, 287, 288, 401 , 419, 445, 565, 583, 584, 658

Tewarson 311, 323

Tsuchiya 445, 469, 503, 504 , 611, 612, 623, 625, 626

Tsuj iraoto 273, 285

Wakamatsu 29 , 3l_y 39 , 40 , 90 , 91, 109, 288, 583

Yusa 411, 471, 487

Zukosici 151, 179, 189, 190 , 271, 285, 288, 289, 299, 367

678
NBS -1 1 4 A [REV. 2-80) U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 85-3118

2. Performing Organ. Report No, 3. Publication Date

March 1985

4. TITLE AND SUBTITLE

7th Joint Panel Meeting of the UJNR Panel on Fire Research and Safety

Proceedings

5. AUTHOR(S)

Nora H. Jason and Karen Davis, Editors

6. PERFORMING ORGANIZATION (If joint or other than NBS, see in struction s)

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

8 . Type of Report & Period Covered

9.

SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State, ZIP)

10.

SUPPLEMENTARY NOTES

J Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11.

ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a si gn i fi cant

bi bl iography or literature survey, mention it here)

The 7th Joint Panel Meeting of the United States-Japan Panel on Fire Research

and Safety was held jointly with the Combustion Toxicity and 2nd Expert Meeting

of the U. S .-Japan-Canada Cooperative Research Group on Toxicity of Combustion

Products from Building Materials and Interior Goods at the National Bureau of

Standards, Gaithersburg, Maryland, October 24-28, 1983. Technical sessions

were in the areas of: Fire Hazard/Risk Management Methods; Fire Growth

Prediction; Materials Fire Properties and Test Methods; Measurement Methods;

Combustion Toxicity. Progress reports were presented in each area, in

addition to state-of-the-art papers. The next conference will be held in

Japan in May 1985.

12.

KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by s< • <

' • v

1 building fires; fire growth; fire hazards; fire models; fire test methods;

human behavior; material properties; toxicity test methods.

13. AVAILABILITY

pC | Uni imited

[ | For Official Distribution. Do Not Release to NTIS

[~n Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402. K I Order From National Technical Information Service (NTIS), Springfield. VA. 22161

14. NO. OF

PRINTED PAGES

648

15. Price

$44 . 50

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