AlllDl 11DSE3

NBS

PUBLICATIONS

NBSIR 82-2469

Effect of Ventilation on the Rates

of Heat, Smoke, and Carbon

Monoxide Production in A Typical

Jail Cell Fire

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Washington, DC 20234

March 1982

Sponsored in part by;

National Institute of Justice

. Department of Justice

shington, DC

6i-2m

1982

c. 2

/

NBSIR 82-2469

» f > EFFECT OF VENTILATION ON THE RATES

OF HEAT, SMOKE, AND CARBON

MONOXIDE PRODUCTION IN A TYPICAL

JAIL CELL FIRE

SATIOWAL

OF OTANDABU8

library

lAAY 17 1982

Ho L Co: ~ ‘f OCloo

. ioL (s>

B. T. Lee

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Washington, DC 20234

March 1982

Sponsored in part by:

National Institute of Justice

U.S. Department of Justice

Washington, DC

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

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

TABLE OF CONTENTS

Page

LIST OF FIGURES iv

LIST OF TABLES

Abstract 1

1. INTRODUCTION 2

1 . 1 Background 2 1.2 Measurement of Heat Release Rate and Heat Losses 3

2. EXPERIMENTAL 4

2.1 Prison Cell Fire Tests 4 2.2 Fire Load and Ignition Source 5

2.3 Instrumentation 6 2.4 Corrections for Measurement of Heat Release Rate

and Heat Outflow Rate 7 2.5 Heat Release Rates of Individual Items 1*^

3. RESULTS AND DISCUSSION 10

3.1 Heat Release H

3.2 Room Air Temperatures 13

3.3 Production of Smoke and Carbon Monoxide 14

3.4 Thermal Flux and Radiation 1^

4. SUMMARY 18

5. ACKNOWLEDGMENTS 2 0

6. REFERENCES 2 0

APPENDIX A 70

A.l Calculation of Heat Release Rate from Oxygen

Depletion Measurement 70

A. 2 Effective Value of Ah 1/2 for Two Vertically Displaced

Small Openings in a Room Fire 72

iii
LIST OF FIGURES

Page

Figure 1. General view of test cell-exhaust hood complex 29

Figure 2. Representative prison cell arrangement 30

Figure 3. Representative prison cell arrangement 31

Figure 4. Plan view of fire test cell room arrangement 32

Figure 5. Test cell fuel arrangement 33

Figure 6. Heating rate versus temperature rise in thermocouple grid . . 34

Figure 7. Heat release histories for mattress with bedding,

plywood bookcase, and cardboard box of paper files 35

Figure 8. Heat release history for fabric material 36

Figure 9. Heat release history for clothes 37

Figure 10. Heat release rate history for cell room test 1 38

Figure 11. Heat release rate history for cell room test 2 39

Figure 12. Heat release rate history for cell room test 3 40

Figure 13. Heat release rate history for cell room test 4 41

Figure 14. Heat outflow rate from cell room test 1 42

Figure 15. Heat outflow rate from cell room test 2 43

Figure 16. Heat outflow rate from cell room test 3 44

Figure 17. Heat outflow rate from cell room test 4 45

Figure 18. Doorway air temperature profiles for test 1 46

Figure 19. Doorway air temperature profiles for test 3 48

Figure 20. Doorway air temperature profiles for test 4 50

Figure 21. Doorway air temperature histories for test 1 52

Figure 22. Doorway air temperature histories for test 3 54

Figure 23. Doorway air temperature histories for test 4 56

Figure 24. Doorway air temperature histories for test 2. . . . 58

Figure 25. Interior air temperature histories for test 1 59

Figure 26. Interior air temperature histories for test 2 60

Figure 27. Interior air temperature histories for test 3 61

Figure 28. Interior air temperature histories for test 4 .

' 62

IV
LIST OF FIGURES (Continued)

Page

Figure 29. Smoke generation histories for tests 2, 3, and 4 63

Figure 30. Smoke extinction cross section versus time for

tests 2 and 4 64

Figure 31. Mass flow rate of carbon monoxide versus time for test 1. . . 65

Figure 32. Mass flow rate of carbon monoxide versus time for test 2. . .66

Figure 33. Mass flow rate of carbon monoxide versus time for test 3. . . 67

Figure 34. Mass flow rate of carbon monoxide versus time for test 4. . .68

Figure 35. Peak heat release rate versus doorway

ventilation parameter 69

V
LIST OF TABLES

Page

Table 1. Doorway dimensions and test conditions in prison

cell fire tests 22

Table 2. Fuel loading in prison cell fire tests 23

Table 3. Location of instrumentation 24

Table 4. Heat release rate measurements 25

Table 5. Fraction of heat release convected away from fire room

at time of peak heat release rate 26

Table 6. Other doorway and exhaust hood measurements 27

Table 7. Thermal flux measurements 28

VI
EFFECT OF VENTILATION ON THE RATES OF HEAT, SMOKE, AND

CARBON MONOXIDE PRODUCTION IN A TYPICAL JAIL CELL FIRE

B. T. Lee

Center for Fire Research

National Bureau of Standards

Washington, DC 20234

Abstract

The rates of heat release and smoke development

from a fire in a typical prison cell configuration were

examined under four doorway ventilation conditions. Peak

heat release rates varied from about 4500 kW for a 3.34 m^

doorway opening down to 340 kW for a 0.17 m^ opening.

However, the total and rate of smoke generation were

greater with the small opening. The peak carbon monoxide

production rate varied from 0.03 kg/s for the large opening to 0.01 kg/s for the smallest opening. The quantity

of carbon monoxide generated, however, was highest for

the smallest opening with 5.3 kg produced over the fire

duration of 1800 s. During the peak fire development

in the configuration with the larger openings, temperatures inside the room reached about 1000°C with roughly

two-thirds of the heat lost to the cell room boundaries.

Peak thermal fluxes inside the room generally exceeded

the ignition threshold value of about 20 kW/m^ for

clothing, bedding, and other light combustible fuel for

all of the tests.

Key words: Fire growth; fuel load; heat release rate;

prison cell fire; smoke

1
1 . INTRODUCTION

1 . 1 Background

The National Institute of Justice has asked the National Bureau of

Standards to prepare a fire safety evaluation system for prisons. One re- quirement of this system is an evaluation of the fire safety of multi-level

prison cells located in a large, closed building. In the event of fire in

such facilities, fans are used to purge the smoke and hot gases from the

building. There is presently little, if any, information available on the

heat release rate and production of smoke and combustion products from

typical prison cell fires. Such information is needed to help establish the

operational requirements for these fans. In addition, information is needed

on the effect of ventilation on the prison cell fire development to aid in

the design of more fire-safe cell rooms.

The heat release rate and production of smoke and combustion products

depend on cell room construction and configuration; the type, quantity, and

distribution of combustible materials in the cell; and, on the ventilation

conditions. The latter depends on the size and location of the openings and

on the location and capacity of any mechanical means of ventilating the

cell. In practice, cell openings vary from small cell-door windows to

barred, full wall openings.

The study presented here determined the rates of heat, smoke, and

carbon monoxide production of one representative prison cell construction,

configuration, and fire loading under four natural ventilation conditions.

The fire load arrangement chosen for this study was based on a survey of

some selected prison cells at the Maryland State Penitentiary. This survey

indicated that each of the cells usually had one two-tier cot with cotton

batting mattresses, wall-mounted shelves on the back wall, and one bookcase

or bureau or storage cabinet located opposite the cots. Boxes of personal

2
belongings were often stored under the lower cot. Sheets, woven goods (such

as blankets and towels) , and clothing were hung between the cots and wall

shelves and sometimes across the back wall. It is likely that fire initiating at either the bookcase or at the cots could spread along these combustible

materials to involve the entire cell.

1.2 Measurement of Heat Release Rate and Heat Losses

The rate of heat release is an important factor in determining the fire

hazard associated with combustible furnishings. There are two generally

recognized methods of measuring rate of heat release. One is the standard

textbook method of measuring the temperature rise of the combustion gases

and entrained air from the burning material. A problem with this technique

is heat loss to the measurement apparatus and to the surroundings. The

other method for measuring rate of heat release relies on a measurement of

the oxygen consumed in the fire. Both techniques for measuring rate of heat

were used here. In the method involving the measurement of oxygen consumption, about 13 megajoules is obtained from each kilogram of oxygen consumed

in the burning of materials normally used in the construction and furnishing

of rooms [1]^. Thus, the total rate of heat generation from burning furnishings in a room can be obtained by measuring the oxygen content and volume

flow rate of the gases discharged from the fire. This total rate, Q^, includes the heat released from flames extending beyond the doorway, if this

occurs, as well as the heat produced inside the room. The portion of the

heat actually generated within the room by the burning furnishings, Q^, could

be calculated from the oxygen and flow measurements at the doorway opening.

Part of the heat produced in the room is lost to the room surfaces. This

heat loss can be obtained by first calculating and then subtracting away

h^, the flux of heat leaving the room at the doorway. The quantity h^ can

be calculated from measurements of the volumetric flow rate and the temperature

^Numbers in brackets refer to the literature references listed at the end of

this report.

3
rise of the exhaust air at the doorway. The total flux of heat leaving the

room fire, h^ , includes the heat release from flames extending beyond the

doorway, in addition to the contribution from h^. The quantity h^ can be

based on the temperature rise of the mixture of combustion gases and entrained

air at, e.g., the inlet of the exhaust collection hood, as was done in this

study. The quantity h^ is equal to minus the heat loss to the room

boundaries and the heat loss to the surroundings between the room doorway

and the inlet of the exhaust collection system.

2 . EXPERIMENTAL

2 . 1 Prison Cell Fire Tests

Figure 1 shows a general view of the test cell-exhaust hood arrangement.

Interior dimensions of the compartment were 1.8-m wide, 2.7-m deep, and

2.4-m high. The back and two side walls were of concrete block construction.

The ceiling was fabricated from two layers of 25-mm thick calcium silicate

board supported along the rim of the block walls and attached to the underside of several steel joists spanning the side walls. The front wall with

the cell opening was constructed from a single layer of the calcium silicate

board. Four fire tests, each having a different cell opening size, were

conducted during this study. One of the tests had a small opening at the

1.37-m height and another small opening near the floor. The dimensions of

these cell openings are shown in Table 1. The test cell was located adjacent

to a large 3.66 x 4.88-m exhaust collector hood having an exhaust flow

capacity of about 3 m^/s.

4
2 . 2 Fire Load and Ignition Source

The fire load used for these tests was based on a survey of some

selected prison cells at the Maryland State Penitentiary. Figures 2 and 3

show some actual cells which had estimated combustible fire loads of about

34 kg/m^ of floor area. This compares with an average fire load of 23 kg/m^ for

for a recreation room in a single family home in the Washington, DC metropolitan area [2]. The total estimated mass of combustible material in a

cell room came to about 170 kg, with exposed clothing and miscellaneous

woven goods accounting for about 15 kg. Whenever possible, the room furnishings observed were duplicated for the fire tests. Used cotton-batting

innerspring mattresses (having fire-retardant-treated tickings) were obtained

from a federal prison, and used clothing was purchased. Wool blankets,

which do not burn readily [3], were excluded in order to reduce costs, and

cardboard boxes of disposable paper files were used to replace the estimated

90 kg of loosely-filled combustible materials in storage cases or boxes.

Typical clothing fabric materials were also used to simulate some clothing,

towels, and other woven goods. Furnishings used in this study are listed in

Table 2. Each test used the same arrangement of the cots, shelves, and

bookcase as indicated in Figures 4 and 5. The two 0.76 x 1.94 m cots were

located 0.5 and 1.5 m from the floor. A 1.52-m wide, 0.46-m deep, and 0.66-m

high cabinet having two open shelves was mounted on the back wall 0.46 m down

from the ceiling. One wood bookcase, 1.52-m wide, 0.46-m deep, and 0.91-m

high, having two shelves, was positioned on the opposite wall of the cell

from the cots. The cover sheet at the head end of the upper cot was permitted to drape down to the lower cot, and the cover sheet on the lower cot

was permitted to drape to the floor. Some of the clothes and fabric on the

top shelf of the bookcase were also permitted to drape over the paper files

on the lower shelf and to reach down to the floor. In all of the tests, the

fire was started with a match flame ignition of twelve pages of crumpled

5
newspaper located at the point indicated in Figure 4 where the bed sheet,

extending down to the floor, contacted the clothes and fabric hanging from

the bookcase.

2.3 Instrumentation

Location of all instrumentation in these cell room fire tests is indicated in Table 3 and Figure 4. Measurements of the vertical temperature

profile halfway between the cots and the bookcase, and the total incident

heat flux on the room surfaces were taken to characterize the thermal environment in the room. Thermal radiance was also measured at two positions on

both sides of the cell opening, flush with the exterior wall, to examine the

radiant heat transfer to adjacent cell rooms from flames emerging from the

fire room. Temperatures, velocities, and oxygen and carbon dioxide concentrations in the exhaust gases at the opening were monitored for calculation

of Q^, the rate of heat generation inside the room. The same measurements

were made in the stack to determine Q^, the total rate of heat production

by the fire. This total rate represented that heat produced inside the cell

plus the portion of the heat released by the flames outside the opening. As

mentioned in section 1.2, temperatures and velocities measured at the opening

can also be used to determine h^, the total flux of heat leaving the fire

test room, i.e., the rate of heat release by the fire Q^, minus the heat

losses to the room boundaries. An average temperature taken across the

inlet of the exhaust collection hood was used to calculate the rate of heat

release from individual items burning directly under the hood as well as to

measure h^ , the total flux of heat from the fire test cell, including the

heat from flames extending beyond the cell opening. Smoke was monitored in

the stack, and carbon monoxide was also monitored in the stack and at the

cell opening to help quantify these products of combustion from the cell

room fires.

6
The average temperature at the inlet of the hood was monitored with a

grid of 25 chromel-alumel thermocouples arranged in parallel. Each thermocouple was made from Brown and Sharpe 24-gauge (0.51-mm or 0.020-in) diameter

wire. Temperatures inside the room and at the cell opening were also measured

with chromel-alumel thermocouples, made mostly with 0.51-mm wire. Due to the

propensity of the large-size thermocouples for radiation error, thermocouples

fabricated from 0.05-mm chromel and alumel wires were also employed at a sufficient number of locations to assure that the temperature readings were

valid. Although the smaller wire thermocouples were more accurate, they

were also more difficult to prepare and were more vulnerable to breakage.

Heat flux was monitored with water-cooled total heat flux gauges of the

Garden type. Crumpled newspaper on top of the bookcase (0.91 m above the

floor) was also used to indicate if and when the irradiance was sufficient

to ignite such light combustible materials in the lower half of the room. Bidirectional velocity probes [4] were employed for measuring the air velocity

in the cell doorway and to note the occurrence of any flow reversal along

the doorway. The optical density of the smoke was determined by attenuation

of a light beam in the stack. Neutral optical density filters were used to

calibrate the light sensor over the range of optical densities from 0.04 to

3.0. The optical measurements, when calibrated in this manner, provide a useful measure of optical density. However, a more detailed calibration of

the optical system with smoke of known concentration would be required for

an accurate measurement of optical densities above about 1.5. Oxygen was

sensed directly with a paramagnetic-type instrument at the stack and with

chemical galvanic cells at the and cell opening. Non-dispersive infrared

analyzers were used to record the concentrations of carbon monoxide and

carbon dioxide at the stack and cell opening.

2.4 Corrections for Measurement of Heat Release Rate and Heat Outflow Rate

Diffusion-flame burner tests using propane were conducted inside the

cell to calibrate the exhaust stack measurement of the rate of heat release

7
from room fires based on the oxygen depletion in the gases exhausted from

the room. A heating rate of 485 kW was maintained for 300 s, and this was

immediately followed with a rate of 1290 kW for another 300 s. The above

calibration tests were then repeated with the burner positioned directly

under the hood. In the calibration test, CO

2 was first removed ahead of the

analyzer for the oxygen measurement. Then, the test was repeated with the

CO

2

allowed to flow through the oxygen analyzer in order to evaluate the

effect of CO

2

on such measurements. In the determination of heat release

rates with and without the removal of CO

2

, formulae given by Lawson et al

[5] were employed. These formulae are given in appendix A.l.

When the burner was operated directly under the stack, and the CO

2

was

removed, the values of the heat release rate calculated from oxygen consumption were 7 and 6 percent higher than those calculated from the actual low

and high burner flow rates employed, respectively. In the test where the

CO

2

was not removed, the values calculated from oxygen consumption were 6 and 7 percent higher, than the respective burner rates used. The flow rate,

oxygen depletion, and carbon dioxide data used to calculate the heat release

rates are shown at the end of appendix A.l. When the burner having the same

heating rates was located inside the burn room, no significant change occurred

in the oxygen consumption measured in the stack, compared with having the

burner under the stack. However, the mass flow through the stack based on

measurements taken at a single location in the stack appeared to have increased by 25 percent, and this apparent increase was carried over to the

calculation of the heat release rate. One plausible explanation for this

apparent increase in mass flow may be that when the exhaust from the room

entered the stack it clung to the inside surface closest to the room, re- sulting in highly non-uniform flow at the cross section of the duct where

the measurement was taken. The heat release rate values calculated from the

stack measurements were about 30 percent higher than those calculated from

the actual low and high fuel flow rates used.

8
Heat release rate calculations based on the flow and oxygen depletion

data at the doorway also averaged 30 percent higher than the actual burner

rates employed. Much of this difference was due to the use of velocities

taken at the vertical centerline of the doorway for calculating the mass flow

from the fire room. Quintiere and McCaffrey [6] and Tu and Babrauskas [7]

have found that calculations of mass based on outflow centerline velocities

could be 20 to 30 percent greater than the actual flow.

Based on the above findings with the calibration burner, the heat

release rates determined from measurements in the stack and cell opening for

the fire tests have been multiplied by 0.77 to obtain the corrected values.

The fact that both stack and doorway heat release rates need to be corrected

by the same factor of 0.77 is a coincidence. Only the corrected heat release

rates for and Q^, based on the stack and doorway measurements, respectively, are given in this report.

Accurate measurement of the rate of heat release based on the oxygen

depletion of the exhaust in the stack or in the cell opening becomes difficult when small fuel items are burning, as small changes in oxygen concentration cannot be measured reliably with the instrumentation. Measurement of

low heat release rates becomes more feasible when the burning item is directly

under the hood where heat losses to the surroundings are small. Then the

rate of heat release can be calculated from the temperature rise and mass

flow of the combustion products and entrained air from the burning item. The

temperature rise can be based on either the thermocouple in the stack or on

the grid of 25 thermocouples at the inlet or neck of the hood. The thermocouple grid gives a more accurate temperature measurement as it measures the

average temperature over the stack opening and minimizes the thermal losses

to the hood by measuring temperatures closer to the burning item. The thermocouple grid was then calibrated using propane as the fuel, with heating

rates of about 19, 58, 118, 234, and 447 kW. The results shown in Figure 6 indicated that the temperature rise of the air as measured by the thermocouple

9
grid varied linearly with the rate of heat release from the calibration

burner at about 4.66 kW/°C rise in air temperature. This calibrated thermocouple grid was also used to provide a rough estimate of h^, the total heat

outflow rate from the cell fire tests. The heat outflow rate at the opening

of the cell, h^, can be calculated from temperatures and mass flow measurements taken at the cell opening. As with the cell room heat release rate

measurements, the rates of heat outflow from the cell fire taken in the cell

opening were also multiplied by the correction factor of 0.77. Only the

corrected values for the rate of heat outflow, h^, are given in this report.

2 . 5 Heat Release Rates of Individual Items

Individual items such as the mattress and bedding, bookcase, loose paper

files, and piles of clothes and fabric materials were burned under the exhaust

hood to provide a rough indication of their free-burning behavior, and thus

provide some insight as to what to expect during the room fire tests with

these materials, as well as to generate additional heat release rate data

which could be used for predicting early room fire growth. The heat release

rate for each item was determined from the rise in temperature in the calibrated thermocouple grid discussed in the preceding section. These were

preliminary tests and were not intended to fully characterize the fire behavior of the individual items. A propane torch was used as the fire initiation source, and each item was ignited along one end. As a safety precaution,

only a one-third section of the bookcase was burned directly under the hood

to avoid potential damage to the hood and surroundings from a fire that could

be too severe. The data from these tests are given in Figures 7 to 9

.

3. RESULTS AND DISCUSSION

A summary of the heat release rate measurements for the four room fire

tests is given in Tables 4 and 5 and in Figures 10 to 17. Table 4 also sum- marizes the methods used to calculate the rate of heat release and heat

10
outflow rate from the cell room fire tests. Figures 18 to 28 present temperature profiles at various times, temperature histories at several locations

along the vertical centerline of the doorway, and the vertical distribution

of temperatures inside the test room. Table 6 gives the degree of fire

buildup, as indicated by the maximum temperature found in the doorway exhaust.

For each room fire, smoke production and the generation of CO in the fire

tests are also indicated in Table 6 and in Figures 29 to 34. Peak values of

thermal flux measured inside of the room and on the outside wall adjacent to

the doorway are shown in Table 7.

3.1 Heat Release

The rate of heat generation from the fire room was a strong function of

the ventilation conditions. The data from the exhaust stack in Table 4 shows

that the peak heat release rate increased from about 340 kW to over 4500 kW

as the doorway opening increased from 0.17 to 3.34 m^ . This would be expected for ventilation-controlled fires. Figure 35 shows that the peak heat

release rate increased linearly with the increasing doorway ventilation

1/2 parameter, AH , where A and H are the area and height of the doorway open1/2 ing, respectively. The parameter AH is usually used for single openings.

However, since prison cell doors can have two separate openings, an effective

AH^^^ must be used for this case. The effective value of AH^^^ for test 2 with the two openings was derived by W. Parker in appendix A. 2 and is shown

in Figure 35. The newspaper flashover indicator in tests 1, 3, and 4 ignited

at times of about 35, 45, and 100 s, respectively, with the likely attainment

of ventilation controlled conditions at the same times or shortly thereafter.

Test 2 appeared to have reached flashover or near flashover at about 780 s with room air temperatures reaching about 600°C. Flashover is defined here

as the room condition where the thermal radiation level becomes high enough

to ignite light combustible materials, such as newspaper, in the lower half

of the room. This corresponds to the room fire condition where the thermal

11
radiation to the floor reaches about 20 kW/ra^ and the air temperatures reach

600 to 650°C near the ceiling and 500 to 550°C at the top of the doorway.

Table 4 and Figure 35 show that the differences between heat release

rates measured in the stack and in the cell opening for the three fires with

the largest openings were as great as 23 percent. With the small opening in

test 2, there could have been considerable constriction or tunneling of the

flow out of the opening. This would have led to high centerline velocities

which, when used to calculate mass flow, could have led to errors exceeding

the 20 to 30 percent discussed in section 2.4. For test 2, the ratio of the

calculated mass flow out of the cell room to that into the room was much

higher than the ratios for the other three tests with the larger openings.

This, in turn, led to a calculated rate of heat release at the cell opening

for test 2 which was much too high. Consequently, the heat release rate

measured in the cell opening for test 2 was 65 percent higher than that

measured in the stack. For tests 1, 3, and 4 having the larger openings, the

stack values were expected to be somewhat higher than the doorway values,

since some of the fuel was being consumed outside of the room, as evidenced

by flames extending beyond the doorway. Apparently, the measurement limitations may have masked any difference between the rates measured in the stack

and cell opening. Figures 10 to 13 showed that the rates of heat release

measured in the stack and cell opening agreed well over the duration of the

fire. Averaged stack heat release rates over an 1800 s duration were 630,

230, 690, and 410 kW, corresponding to total heat release values of 1130,

410, 1240, and 740 MJ , for tests 1, 2, 3, and 4, respectively. The lower

average rate for test 4 may be due to a less severe room fire environment.

This may be inferred from the temperature of the air exhausting through the

opening (see Figures 21A, 22A, and 23A) . The temperature in test 4 decreased

to below 300 to 400°C much sooner than the doorway air temperatures for tests

1 and 3

.

12
The heat leaving the fire room is also given in Table 4 and Figures 14

to 17. Again, the stack values are close to the doorway values. Table 5

indicated that, on the average, only about one- third of the total heat re- leased by the fire during the peak fire development was convected out through

the doorway, with the remaining two-thirds of the heat lost to the room

boundaries. In the prison cell tests discussed in section 2.4, with the

calibration gas burner as the heat source, the heat outflow rate from the

cell accounted for about one-half of the heat released by the burner. The

flames from the burner extended across the ceiling to the doorway. No flames

touched the back and sides of the room. In the fire tests of the jail

furnishings, because of the distribution of fuel sources, the fire often contacted the walls as well as the ceiling. This could have resulted in a greater relative heat loss to the walls of the room itself. In addition, the

furnishing fires produce less transparent flames than propane fires, implying

greater flame radiation, with subsequent larger heat loss to the cell surfaces.

3 . 2 Room Air Temperatures

The air temperature in the upper part of the room is a good measure of

fire buildup [8]. Temperatures measured with the vertical thermocouple tree

inside the room can give a good but often approximate measure of the temperature environment in the upper part of the room. Local heating and flame

contact can give readings that are higher than average. The hot air inside

the room usually becomes well mixed by the time it is exhausted through the

doorway. Consequently, the peak doorway air temperature may be a more re- liable indicator of the fire buildup than the interior air temperature

measurement. Peak doorway air temperatures given in Table 6 varied from

867°C at 2110 s for test 2 to 1079°C at 380 s for test 3. While test 2 with

a very small opening of 0.17 m^ took over 2000 s to reach its peak doorway

temperature, the other tests with doorway openings greater than 1.0 m^ took

only about 500 s or less to reach the peak fire buildup.

13
Analysis of the vertical temperature profiles in the doorway (Figures 18

to 20) and the temperature histories at the doorway (Figures 21 to 24)

revealed that the monitoring of air temperatures with large junction thermocouples could lead to errors. When there was considerable thermal stratification, as in the doorway, the large junction thermocouples in the hot

upper zones behaved as thermal sources radiating to the outside and to the

cooler lower levels. The large size thermocouples in the cooler lower part

of the doorway acted as heat sinks for the radiation from the hot air, smoke,

and heated surfaces in the upper part of the room. Consequently, large

junction thermocouples registered temperatures which were too low in the hot

zone and too high in the cooler zone. Small junction thermocouples are less

prone to radiation errors, as the convective heat transfer component overwhelms the radiative heat transfer component when smaller size junctions are

used. The differences due to thermocouple size were particularly noticeable

in Figures 18A and 19A where errors of as much as 90, 230, and 100°C were

observed near the top, middle, and bottom part of the doorway opening.

Consequently, only the data with the small junction thermocouples were used

for the mass flow and heat release rate calculations at the doorway.

When the space is completely filled with flames and little thermal

stratification exists, large and small junction thermocouples indicate about

the same temperatures. This can be seen in the interior air temperature

histories in the upper part of the cell, shown in Figures 25 to 28, at times

following flashover.

3.3 Production of Smoke and Carbon Monoxide

The smoke production in the prison cell fire tests can be expressed by

the extinction cross section generated. This extinction cross section, E(m^),

is equal to the total mass of the smoke generated, M^(kg), times the specific

extinction coefficient, K(m2/kg). The relationship between E and the optical

density, O.D., is given below. The optical density is defined as

14
0.434 KML ( 1 )

where T is the percent transmission of the smoke meter, L(m) is its path

length, and M(kg/m^) is the mass concentration of the smoke. Thus, E is

given by

flow rate of the air through the doorway, and the quantity O.D./L change

during the test, E is determined by integrating over the duration of the

test, or

Equation (3) can also be related to measurements performed in the ASTM

E 662 test with the smoke density chamber [9]. The quantity E is equivalent

to the product of the specific optical density measured in that test and the

specimen surface area employed in the test. Equation (2) can be used to

estimate the average O.D. per meter beyond the room of fire origin if the

smoke is dispersed over a volume V, and the effect of smoke deposition and

coagulation is neglected.

If the total mass of smoke generated were also measured routinely during

some future room fire tests, then the average specific extinction coefficient

K could be determined (i.e., K = E/M^) . Since K is a property of the smoke

rather than a measure of its quantity, some insight might be gained into the

nature of the smoke. This might help relate O.D. to visibility and provide

an indication of its coagulation properties, since K is a function of par-

( 2 )

where V(m^) is the volume of the smoke produced. Since V(m^/s), the volume

(3)

tide diameter. If a functional dependence of K can be established for room

15
fires, it may be possible to utilize data on mass generation rates of smoke

from material tests to predict the optical density.

Peak smoke concentrations given in Table 6 showed that test 3 with the

3.34 m^ doorway opening and test 4 with the 2.23 m^ opening had peak O.D./L

values of 1.12 and 1.25 m respectively. These concentrations correspond

to extinction cross section per unit time values of 16.7 and 19.6 m^/s,

respectively. In contrast, test 2 had the smallest opening at 0.17 m^ and

experienced the lowest level of fire buildup, but generated the most smoke

with an O.D./L greater than 2.5 m~^, corresponding to an extinction cross

section per unit time value of greater than 24.7 m^/s. Values of O.D./L

above 2.5 m“ ^ are not very meaningful as this is the upper limit of the

instrumentation. Smoke generation histories for fire tests 2, 3, and 4 are

given in Figure 29. The light sensor used to measure smoke in test 3 malfunctioned at about 120 s; however, visual observation indicated that the

most heavy smoke production occurred prior to that time. No smoke data were

recorded for test 1 due to malfunctioning of the instrument. Equation (3)

was used to calculate the smoke production as a function of time from cell

fire tests 2 and 4, with the results shown in Figure 30. Calculation of the

extinction coefficient for test 2 in Figure 30 assumed that the peak O.D./L

value did not exceed 2.5 m“ ^ . This meant that the actual smoke production

was higher than that shown for test 2. Thus, the data in Figure 30 show that

over a duration of 1800 s, the fire in the cell with the small opening produced at least 30 percent more smoke than the fire in the cell having a large

opening

Peak concentrations of CO and the times at which they occur in the stack

and at 0.30 m down from the top of the cell opening are given ' ,j Table 6 for

the four prison cell fire tests. Concentration levels of CO at this cell

opening location ranged from 3.5 percent for test 1 to 8.2 per' -'nt for test

2. Stack concentrations of CO were an order of magnitude lowe due to the

dilution of the exhaust with entrained air. A more meaningful accounting of

16

h

*
CO is in terms of mass flow, based on the measurement of the mass flow rate

of the combustion gases and entrained air from the cell fire and on the

measurement of the CO concentration of this gas-air mixture. Figures 31-34

show the mass flow histories for CO for the room fire tests. Differences

between the doorway and stack measurements of the peak mass flow rate of

carbon monoxide exceeded the differences between the peak rates of heat

release taken at the same two locations for tests 1, 3 and 4. The reason for

these larger differences can be attributed to oxidation of the CO exhausting

from the doorway. Analysis of the ratio of CO to CO

2

showed that this ratio

was much lower in the stack than at the doorway during the peak fire development. The maximum mass flow of CO at the cell opening ranged from 0.017 kg/s

for test 2 to 0.064 kg/s for test 3. The peak mass flow at the stack varied

from 0.010 kg/s for test 2 to 0.033 kg/s for test 4. Test 2, however, produced the highest quantity of CO. The production of CO, as measured in the

stack, was 3.7, 5.3, 3.9 and 4.9 kg for cell fires 1, 2, 3, and 4, respectively, over the test period of 1800 s.

3.4 Thermal Flux and Radiation

Peak thermal flux measurements inside the room and on the outside wall

close to the doorway are reported in Table 7. The highest flux values were

recorded for test 3 with the largest doorway opening, and the lowest values

were found for test 2 having the smallest opening. The maximum flux values

for the ceiling and walls in the upper part of the room ranged from 22.6 to

121.8 kW/m^ for the cell room tests. Peak radiative fluxes to the floor in

tests 1, 3, and 4 exceeded 47 kW/m^ , a value larger than the 20 kW/m^ chosen

to represent threshold ignition conditions [10]. Test 2, however, had a peak

recorded flux of only 8.8 kW/m^ at the center of the floor. Test 2 did develop interior and doorway temperatures of over 800°C, which indicated that

flashover conditions were achieved. Fallen material from the bunks and

bureau could have been partially shielding the flux meter from the radiation

from the upper portion of the room.

17
At a height of 1.5 m alpng the exterior wall and 1.8 m away from the

doorway, peak flux levels of 2.0 to 9.1 kW/m^ were measured for tests 1, 3,

and 4. The flux meter at that location was not functioning properly during

test 2. At the same height along the outside wall, but 0.2 m away from the

other side of the opening, peak values of 19.3 to 23.8 kW/m^ were recorded in

tests 1, 3, and 4. These flux levels were reached as early as 40 s, as in

test 3, and were sufficiently high to result in the ignition of some adjacent

fuels had they been present. For test 2, exhaust from the fire room was primarily hot air and smoke, with a brief period at about 900 s where a little

extension of the flames occurred beyond the doorway opening. The plume from

the opening in test 2 was relatively small due to the restricted size of the

opening. Consequently, the peak thermal radiation from this plume reached

only about 0.7 kW/m^ at the wall location 0.2 m away from the doorway.

4 . SUMMARY

The total rates of heat, smoke, and carbon monoxide production were

measured during four fire tests in a 1.8-m by 2.7-m by 2.4-m high jail cell

having similar fire loads of 34 kg/m^ and a range of ventilation conditions.

The findings from this series of tests are given below. No additional tests

were performed to assess the repeatability of these results. However, in

another study of fully furnished room fires [11], good repeatability was

found between tests for measurements of interior temperatures, thermal fluxes,

and times to reach room flashover.

1. In those prison cell fire tests where the cell door openings were

1.1 m^ or greater and where a combustible fire load of 34 kg per m^

of floor area was employed, flashover occurred between 30 and 100 s.

Peak heat release rates between 1460 and 4510 kW occurred at times

from 80 to 396 s. Total heat generation ranged from 740 to 1240 .MJ

for a fire duration of 1800 s. Maximum tempers tures of the air

discharging from the cell reached about 1000°C.

18
2. With a doorway opening of 0.17 and the same fire load of 34 kg/m^

flashover or near-f lashover with accompanying interior temperatures

of about 600°C occurred at 780 s. The peak heat release rate of

about 340 kW did not occur until about 700 s. Peak temperature of

the exhaust from the room reached 867°C at 2110 s. However, the

reduction of ventilation due to the small opening resulted in a higher peak rate of smoke generation and at least 30 percent more

total smoke than that produced from a room fire with a larger

opening.

3. On the average, at the time of peak rate of heat release from

the fire, roughly two-thirds of the heat was lost to the cell

room walls, ceiling, and floor, with only one-third convected

away through the doorway.

4. Carbon monoxide reached peak levels of 0.013, 0.033, and

0.028 kg/s in the exhaust collection hood at times between

90 and 110 s for cell openings of 1.11, 2.23, and 3.34 m^

respectively. A maximum level of 0.010 kg/s was attained

at 680 s in test 2 with the small opening. Total generation

of carbon monoxide, over the test duration of 1800 s, was

highest for the small opening with 5.3 kg produced as compared

with 3.7, 4.9, and 3.9 kg for cell openings of 1.11, 2.23,

and 3.34 m^ , respectively.

5. Peak heat fluxes inside the room generally exceeded the 20 kW/m^

value which is an approximate threshold value for ignition of

light combustible fuel such as cotton bed sheets and upholstery

fabrics. Maximum fluxes at a height of 1.5 m on the outside

wall reached about 20 kW/m^ at about 0.2 m from one side of the

opening and dropped rapidly with increasing distance from the

doorway

19
6 . The cell fire having the small opening resulted in a lower

heat release rate, less total heat production, and lower air

temperatures than the fires having the larger openings.

However, total smoke generation and the total production of

carbon monoxide were greater with the small opening.

5 . ACKNOWLEDGMENTS

The work was partially supported by the National Institute of Justice.

Appreciation is expressed to Messrs. C. Veirtz, T. Maher, and 0. Owens who

built the test compartment, prepared the test arrangements, and performed

the actual testing; to Mr . J. N. Breese for the data reduction and preparation of most of the figures in the report; and, to Mr. J. Shibe and Dr. L.

Cooper for their help in establishing the prison cell test arrangements. The

author would also like to express his gratitude to Mr. W. J. Parker for

appendix A. 2 of this report and for contributing to the discussion in section

3.3 on the quantification of smoke from fire tests.

6 . REFERENCES

[ 1] Huggett, C., Estimation of Rate of Heat Release by Means of Oxygen Consumption Measurements, Fire and Materials, 4, 61-65, 1980.

[2] Fang, J. B., Fire Performance of Selected Residential Floor Constructions

Under Room Burnout Conditions, NBSIR 80-2134, Decen.ber 1980.

[3] Lee, B. T. and Parker, W. J., Naval Shipboard Fire Risk Criteria

Berthing Compartment Fire Study and Fire Performance Guidelines,

NBSIR 76-1052, September 1976.

[4] McCaffrey, B. J. and Heskestad, G., A Robust Bidirectional Low-Velocity

Probe for Flame and Fire Application, Combustion a id Flame, 26, 125-127

(1976) .

[5] Lawson, J. R. et al. Development of an Oxygen Consumption Calorimeter,

NBSIR in preparation.

[6] Quintiere, J. and McCaffrey, B., The Burning of Wood and Plastic Cribs

in an Enclosure, Vol. I, NBSIR 80-2054, November 1980.

20
[7] Tu, K. M. and Babrauskas, V., The Calibration of a Burn Room for Fire

Tests on Furnishings, NBS Technical Note 981, December 1978.

[8] Parker, W. J. and Lee, B. T., A Small-Scale Enclosure for Characterizing

the Fire Buildup Potential of a Room, NBSIR 75-710, June 1975.

[9] Standard Test Method for Smoke Generated by Solid Materials, ASTM E 662.

[10] Fang, J. B., Fire Buildup in a Room and the Role of Interior Finish

Materials, NBS Technical Note 879, June 1975.

[11] Fang, J. B., Repeatability of Large-Scale Room Fire Tests, Fire Technology,

Vol. 17, No. 1 (February 1981), pp. 5-16.

21
Table 1. Doorway dimensions and test conditions in prison cell fire tests

Test

Doorway Opening Dimensions Ambient Room Conditions

Height H

(m)

Width W

(m)

Area A

(m2)

ahJ-/

(m^ ^2

)

Temp

.

(°C)

Relative Humidity

Q,

*0

1 1.83 0.61 1.11 1.50 26 49

2

* * 0.17 0.30* 17 49

3 1.83 1.83 3.34 4 . 52 19 45

4 1.83 1.22 2.23 3.02 20 42

* A 0.305m X

1.37m, and

door. The

0.305m opening in the door, with the

a 0.102m high by 0.711m wide opening

effective value of Ah 1/2 was derived

lower ledge at a height of

along the bottom of the

by Parker in appendix A. 2.

22
Table 2. Fuel loading in prison cell fire tests

Combustible Weight in Kilograms

Fuel Item Test 1 Test 2 Test 3 Test 4

2 mattresses* 27.7 26.3 27.2 31.8

Bedding (2 pillows,

2 pillow cases,

4 sheets) 4.5 4.5 4.5 4.5

Loose paper files

and cardboard boxes

of paper files ** 90.8 90.8 90.8 90.8

Plywood bookcase 42.7 29.1 30.4 30.0

Clothes t 9.1 9.1 9.1 9.1

Fabric tt 5.4 5.4 5.4 5.4

Total Combustible

Fuel 180.2 165.2 167.4 171.6

* Mattress weight excluding weight of innersprings

.

** 45.4 kg of loose files in lower shelf of bookcase, three 9.1-kg boxes

of files under bed, and two 9.1-kg boxes of files in lower shelf of

wall cabinet.

t Consisted of 4 jackets, 10 pants and 10 shirts for a total of 9.1 kg.

1.8 kg of clothing in wall shelves, 5.4 kg in upper shelf of bookcase, and

1.8 kg suspended on wires in front of wall shelves and along the wall over

the bookcase.

tt 0.9 kg of fabric in upper wall shelves, 1.8 kg crumpled up in upper shelf

of bookcase, 1.4 kg hanging on wires in front of wall shelves, and another

1.4 kg used for privacy curtains hanging on wires alongside the cots.

80 percent of material was 0.12 kg/m^ fabric having a fiber blend of

65% polyester - 35% cotton, while 20 percent of the material was 0.24 kg/m^

fabric with a blend of 65% polyester - 35% rayon.

23
Table 3. Location of instrumentation

Type of Transducer

1 smoke meter

1 gas sample port {O

2

/ CO,

1 velocity probe

1 0.51-mm thermocouple

25 0.51-mm thermocouples

12 0.51-mm thermocouples

5 0.05-mm thermocouples

7 flux meters

11 0.51-mm thermocouples

5 0.05-mm thermocouples

3 gas sample ports

(0^, CO, CO

2

)

5 bi-directional velocity

probes

Location

Exhaust hood

CO

2

) Exhaust hood

Exhaust hood

Exhaust hood

Inlet area of exhaust hood

Following distances below the center

of the ceiling (m) : 0, 0.025, 0.10,

0.30, 0.60, 0.90, 1.20, 1.50, 1.80,

2.10, 2.34, 2.44

Following distances below the center

of the ceiling (m) : 0.10, 0.60, 1.20

1.80, 2.34

Center of ceiling and center of floor

0.30 and 0.76 m below ceiling on cot

side of wall and 0.76 m below ceiling

on bookcase side. 1.5 m above floor

level on exterior wall, 2.1 m to left

of right edge of doorway and 0.2 m to

right of right edge of doorway.

Following distances below the top of

the doorway (m) : 0.025, 0.10, 0.30,

0.50, 0.70, 0.90, 1.10, 1.30, 1.50,

1.70, 1.83

Following distances below the top of

the doorway (m) : 0.10, 0.50, 0.90,

1.30, 1.70

Following distance below the top of

the doorway (m) : 0.30, 0.70, 1.10

Following distance below the top of

the doorway (m) : 0.10, 0.50, 0.90,

1.30, 1.70

24
Table

4.

Heat

release

rate

measurements

Cr> C

rH C •H P

(1) *H Ti •H U C 'U c £ fd (UO 03 •H £ B a +J 5 03 03 0 o X 0 03 X > M 0 03 iH to X •rH

y-iH * X •rH O'

rH 0) ^ o O o U1 P X

p e s rH VO 03 (0 0 to

(d

U -H ^ V£) cn 00 E CO

u 03

(U Eh

—

rH (d fd o 03 £

a: c rH E to

X

•H 4-> IH P •H fd 4h fd T3 03 P > 0 'U E C a

a) ^ 0 fd 03 xi

X Jh TJ P P 03 a p x: VW c £ X

rH

w 0 X o

Cm rd TD • fH VD fd 03

Q> 03 ^ X VO

pp S (0 0 03 • 03 p

fd fd

X a 0

03 -P 04 E u H W 03 X 03

03 'O 0 X P 03 • 0 x: C P P 4J 4J 03 0 £ • (N O o o fd O' X fd (N (U'O w IT) rH o 03 C >1 u B — in rH rH X -H X fd S £

•H 0 X 0 0

03

W

X •H

X -p c £ X

X

X c 0 0 U

03 •H to 03 u) e Ti X to to ^ Q) 03 0) 03 fd fd

<d

w T3 P top E £

0) fd P D fd

X •H

CU 0)

HW

X •H 03 rH » o o O O U fd X X

>1 0) TSS VO VO 'sr o C 03 to fd

X 03

fd 'SJ*m CO in •P E •rH o CO 5 ^ rH m ro E to P 4-» P S X 03 0 £ 0 fd •H 0 *H X P U 0 d) rH X X to Q ac • ^ MH •o •rH rH X £ TJ

rH

WX 0 03 03 0) 03 X P o fd U T5 fd 0

rH E 03 1—1 X

rH *» 03 03 CO £ u

(U ^ X TJ

X (du fd

U ^ w

X C X

X

XX

o»o fd fd

B fd 03 03 to

u £ 0 -p M-l 'O c •H 0 P w 0 •H 0 •H to •H

U-l

W -H toX •H

X C QJ ^ o o o o C -P c •H o

4J -H e s o a^ C30 o\ •H 03 •rH

X 03

(d

M in ro 00 rH *•. •H P

CD TJ tH rH to 04 to 03 P

u: 0) 4J 03

X P 0 p -p C T3 £ •iH On U

MH D m 03 03

X £ 0 w 4J C X •H rfd “ C 03 c X £ r- X <D w 0 O' 0 X 03 • D S x: U >1 u 03 a o

rH

XO 0

Cm Cn 0 O' 03 C £ 03 X X

•H C •rH

X

X

X C 0 £ X 03 P P u >1 0 0 'O D E X 4J X 03 X 0 03 VO o O o CO P X T3

d)*Of

W o\ <7V 00 00 03 fd 03

X

X 03

B

m VO

X

X

X • •rH •H X X O' T3 X • X

Eh (0 £ 03 CT' O' a,

MH -H

X -H

X £ £ •H 0 0 £ U 0 -H X

(0 03 03 • P £ r—

03*0 03 Or > T3

X 03 £

0)

XX 0 £ -H

X a E ^ W fd fd 0 P 0

fd fdw

p • P XU cn £

0) (UO^ o O o o O'

X 03X 03 04 rH S VO rH o 03 C 03 03 X 03 X X 03

0) 0) rj* fO in rH to -H to o fd

X

U 03

X Di -P rH 'sr ro fd c fd 03 a 03 U o fd 03 03 03 03 X £ > 03

fd 4J Di

X Qj

X

X 0 £ 03 > p fd 03 0 03 X X o 0 X fd

c/3 <U P P 0 0 U

X

X

X rH

X E X rH X fd 03 P X

X -003

fd 03 fd

X 03 fd fd

X

X

03

U 03 to fdX 03

X

XX

X P X

X O' TJ fd >1 O' 03 £ £ £ X

fd c ^ rH ro 03

X 03 03 03 ^ 03 -H fd

15 -Hcg rH iH

m (N

XXX E XuX O' 03 P C E • • X X 03 X fd X P - > 0 03 iH O ro CM T3 P X fd TJO 0 a CO C to £ to CO to X • OX Q O •H 0 •H CO •rH •H u fd >4 fd 03 to «. C003 03 COX T3-H t0£ •O X •a B X X X tJ • O-H

in -p 03 • • w rH fN m 4J rH CN m in

(U 0

£h z

25
Table 5. Fraction of heat release convected away from fire room

at time of peak heat release rate

Test

Stack Flux of Heat t S tack Peak Heat Release Rate

Doorway Flux of Heat t Doorway Peak Heat Release Rate

hs/Qs

1 0.34 0.44

2 0.26 —

3 0.31 0.34

4 0.29 0.25

0.30 Average 0.34 Average

Note: Q , h , Qj, and h, are defined in Table 4.

s s d d

26
Table

6.

Other

doorway

and

exhaust

hood

measurements o e w 00

•H ' '

E-i o OO

OO

u

n

fa

(0 c o ^

fa oQ

UCou

Lnn

CM o

00m in

44U

(0 •Pcnc

•H

cueH

Eh

<NOO

ID

ID

Oo

44

(0

<u fa o ^ LO 00 CQ C 0,0 ro CM m 0 ^ • > • • u o o o O

VD

r-H m o o o

iH 00

rH 00

M

CM

>1

fO5uooQ

44

fO0

fa • u

Cuo e —

0) Eh oo

o^

00

<y\

>1 Cn

fO C — ^ -H ovj P C O OJ O Cu Q O e

<sj' 00

iH 00 CM O 00 CM

Section (m^/s) W 0) m g r- VO 0 1 • • • P Eh 1 VO o^ U CM iH iH P A C -H 0 c

•H D PU P

44 C O U H a

(0p P X

cn fa c

•H0 0

44 rH 0 fa e

cn o — H cn 44 Sh \ 1 00 ID 00

(0 4J ro 1 > • • (U CD g VO VO

fa

gd0>

(U 1 o o o g m 1 o 00 VO •H

Eh• g rvj LO u in rH CN C • 1 . • • 0 Q U • 1 CM rH (H O A

>1 Cn

cO C — rH ro S H rH ro (N P c g • • • • 0 0) — rH o ro CN 0 fa Q O p

cn pH CM ro

(U Eh

rH (N ro ^

27

*For

test

3,

the

peak

value

occurred

at

0.50 m

from

top

of

doorway.

In

tests

1,

2,

and

4,

peak

temperatures

occurred

at

0.10 m

from

top

of

doorway.
Table

7.

Thermal

flux

measurements

(U ^a w o o o o • H ' Eh CD \o

-p

X

cn C3 ^

<u rH CsJ o O' CO 00

E-i tu a • • • • ro CM

Peak (kW N*

mm

CD -- a cn o o o o

•H '—' CTi CO coc o

Eh r-H

ro

-PX

W ^3

—

0) C\l o N- cr» 00

Eh Cm a • • • • \ CO t—!

<T\ [S o CTv 00

CC3 a;

CD 1—1 e ^ o o o O a cn O O' 00 •H m 0^

Eh (—I

CM

-P

X

cn 3 —

(U rH CN Eh Cm a in 00 CD • • • • 1X1 00 cn (N n M

Q) p^

ro ro CN

(D ^ cx 00 o O a cn CN CD LD • H '—

Eh N- 1—1

-P

X

cn

b ^

(U rH CN CO CD rEh Pm £ • • • • \ CO o ^ s 'a’ CD cn fO

fOCD --

a, C C 0 0

CnC C

•H •H 1—1

rH C *H I—1

•H rH •H P CD rP Q} rH 1—1 0 O CO U fO •H 0

CD 1—1 > U cw 0 Mh 0 Mh

-H 0 -H

O

MH CMI CD CD c 0 0 n e t! CD 0 03 T3 *H p P a -p a -p

-p e CD cn cn

CO -p -P o CD O c C cn 4-> +J 0 Q) e • 0 • 0

P]

uu o u o u o o o

'cr IpCN

\D CD

KD cn CTi ID 1—1 O o o

r-- CD '3' 1

00 1—100 1—1

a\ cn

CN CN <—1 o o K cn kO CD 1—1

C' • • ro X o

roo CD 1

CN 1—1

cn

00 o cn 1—!

CN CTi LO 1

1

CM CM 0 C H a 0 Ip E 0 CD CD CD (—i > np e > CN Cn cn rP e • cn CD • t C cc3 fH CN X5 tP O CD p CD 1—1 P - p V -p •P CM 0 i-P -P 0 rP x:

CD

O 0 x: 0 rP cn

U rP cc3 Cn rp C^ ’p

CD CM 5 -H cc^-l 5 p ^ 'b P 0 -P d) P CD P CM iH cn > 0 CM >00 e 0 -P 0 0 -p

t! CD X5 P X! P -P

cn c3 CD -P >1 i3 CD x; >1 a CO -P CM cd -P cn CC3 u axes a X -P E5 CD ^ CD rP P (DPP 0 CD o in 0 • 0 •boo •COO O X! rP 0 -p T3 iP 0 -P T3 28

Data

unavailable
EXHAUST

HOOD

<DU

3

fcC

U-i

29

General

view

of

test

cell-exhaust

hood

complex
Figure 2. Representative prison cell arrangement

30
Figure 3. Representative prison cell arrangement

31
Scale:

LOCATION INSTRUMENTATION

1 DOORWAY THERMOCOUPLE TREE, VELOCITY PROBES,

GAS SAMPLE PORTS

2 ROOM THERMOCOUPLE TREE

3 FLOOR AND CEILING FLUX METERS

4,5 WALL FLUX METERS

6 NEWSPRINT FLASHOVER INDICATOR

7,8 FLUXMETERS FLUSH WITH EXTERIOR WALL AND

FACING AWAY FROM THE CELL

figure 4. Plan view of fire test cell room arrangement

32
33

Figure

5.

Test

cell

fuel

arrangement
MM 'im imm 1V3H mm\2

34

TEMPERATURE

RISE

IN

THERMOCOUPLE

GRID, C
OL

t/i oc

CM UJ

a. u.

-ac ec a» Lu

CO

00 g*-3

je O

CM

CO P— mI

00 :

_l O

M>l ‘3iV» 3SVJI3U 1V3H

35

Figure

7.

Heat

release

histories

for

mattress

with

bedding,

plywood

bookcase,

and

cardboard

box

of

paper

files
2.7kg

FABRIC

SUSPENDED

ALONG

5

PARALLEL

WIRES,

0.15m

APART,

1.5m

LONG

AND

0.9m

HIGH.

TORCH

IGNITION

OF

LOWER

CORNER

OF

FABRIC

HANGING

ON

MIDDLE

WIRE.

oo

CM

MM ‘iLVd 3SV313M iV3H

'rH

36

;ure

8.

Heat

release

history

for

fabric

inatcrial
4.5kg

CLOTHES

(2

JACKETS, 5

PANTS, 5

SHIRTS)

SUSPENDED

ALONG 3

PARALLEL

WIRES,

0.15m

APART,

1.5m

LONG

AND

0.9m

HIGH.

TORCH

IGNITION

OF

LOWER

CORNER

OF

CLOTHES

HANGING

ON

MIDDLE

WIRE.

37

Figure

9.

Heat

release

history

for

clothes
TIME

MIN

8

3IV«

o

o

oJ9 a o a

o o g o o o

M'l ••• 3SVn3a 1V3H jO

38

nCURE

10

-

HEAT

RELEASE

RATE

HISTORY

FOR

CELL

ROOM

TEST

1
TIME

•••

MIN o o o o o o o o o o o o a oo

00oo

inoao

O)ao

(Oaa

tn

«•

Ui2P

39

nCORE 11-

HEAT

RELEASE

RATE

HISTORY

FOR

CELL

ROOM

TEST 2
OOjg

i-I111I11^1\II1II^1^1i11111111»

OOOS MM ••• 3SVJ13a IV3H 30 31VM

40

FIGURE

12-

HEAT

RELEASE

RATE

HISTORY

FOR

CELL

ROOM

TEST 3
TIME

•••

MIN

O O O o o

o o o o o

1/3 'T rn CSI

</i

UJ2

M>l ••• 3SVJT3y 1V3H JO 3IVW

41

FIGURE

13

-

HEAT

RELEASE

RATE

HISTORY

FOR

CELL

ROOM

TEST

4
TIME

MIN

o

o

o

o

o

o

••• 31VM MOlJinO iV3H

42

nCURE

14

-

HEAT

OUTFLOW

RATE

FROM

CELL

ROOM

TEST

1
TIME

•••

MIN

o o a

o o o o a o o

UJ2

f=

MM ••• 3IVU MOnjIOO iV3H

43

FIGURE

15

-

HEAT

OUTFLOW

RATE

FROM

CELL

ROOM

TEST

2
TIME

MIN

o

o

o

a

o

o

M>t ••• 3iViJ MOUinO 1V'3H

44

FlGUf?E

16

-

HEAT

OUTFLOW

RATE

FROM

CELL

ROOM

TEST

3
Time

wiM

o

o

o

o

o

o

csj a CD ••• 3iva MO^Jlno 1V3H

tsj

45

FIGURE

17

-

HEAT

OUTFLOW

RATE

FROM

CELL

ROOM

TEST

4
lOQ

200

300

400

500

600

700

800

900

lOOD

1100

1200

o o uo a 3 • • • •

t I I I I Ui ••• AVMtiOOO iO dOi I^Odi iONViSlO

46

FIGURE

\5A

-

DOORWAY

AIR

TEMPERATURE

PROFILES

FOR

TEST

1
IQQ

200

300

400

500

600

700

800

900

1000

1100

1200

47

nCURE

1«.B -

DOORWAY

AIR

TEMPERATURE

PRORLES

FOR

TEST 1
100

200

300

400

500

600

700

BCG

900

1000

1100

1200

C> if> o lO o

I I

t t I a

CD

CM

a

o

o

o

o

CD

O

o

00

o

o o

UJ

a. §§in

o

o

o

o<n

O

a

CM

ao

o

o

o oI Ui «*«

to

AVMfciooa JO dOi mhd jonvisiq

o

CM

I

48

FIGURE

19.A

-

DOORWAY

AIR

TEMPERATURE

PROFILES

FOR

TEST

3
o m o uj o

I / I I ui ••• AVVidOOG JO dOi WOdJ SONVISIQ

49

nCURE

19.0

-

DOORWAY

AIR

TEMPERATURE

PROFILES

FOR

TEST

3
100

20C

3CO

400

5D0

600

700

803

903

IC03

I

1

33

1230

CM ... AVMdOOa JO dOi WOdJ 30NVISI0

50

FIGURE

20A

-

DOORWAY

AIR

TEMPERATURE

PROFILES

FOR

TEST

4
100

200

300

400

500

6CI]

7C:

8CC

9CC

1300

IICC

1200

o LO o U3 a • • • •

o

o

inot UJ ••I*

in

AVMbOOQ JO dOi WObJ lONViSIQ

a

Cii

I

51

nCURE

20.5

-

DOORWAY

AIR

TEMPERATURE

PROFILES

FOR

TEST

4
TtME

•••

MIN

oooaooooooooo o o

0 ••• 3ttniva3dW3i

52

FIGURE

21

.A

-

DOORWAY

AIR

TEMPERATURE

HISTORIES

FOR

TEST
TIME

MIN

a

a

o

o

a

tn

o

a

n a

’

on ui2

P

O

o

«D

ao<n

o

o

CM s s; § S 8 S S 8 8

m CM O

o

a

0 ••• 3anivy3dW3i

53

FIGURE

21. B

-

DOORWAY

AIR

TEMPERATURE

HISTORIES

FOR

TEST

1
T»^E

•••

MIN

o

o

a

o

o

Cl o o

3

F

IbOiVHSdiMIl

54

FIGURE

2Z.A

-

DOORWAY

AIR

TEMPERATURE

HISTORIES

FOR

TEST

3
TIME

MIN

a

<0

a

a

in

a

ocst

o

o

o

03

Oo

cn

n

•

UJ2

P

o

o

(M S 8 S § g 8 S 8 8 §

°

lO U3 P) OJ »

D ••• 3a01Vb3dW3i

53

FIGURE

21. B

-

DOORWAY

AIR

TEMPERATURE

HISTORIES

FOR

TEST

1
TBVtE

••••

MIN

0 •” 3hniva3diMi

54

FIGURE

22.A

-

DOORWAY

AIR

TEMPERATURE

HISTORIES

FOR

TEST

3
Time

MIN

o o o

o

00

o

o

m

o

oCM

§•

<n uj2

O

o

(O

o

o

tn

a a o o o o o a o o o o o o o o a o o o o o o

a 01 oo r* (O lO cn CVJ 0 ••• 3MniVb3dW3i

55

FIGURE

22Jd

-

DOORWAY

AIR

TEMPERATURE

HISTORIES

FOR

TEST

0
TIME

MIN

o o o

o o a o o o a o a a o o O

o o a o a o o o o o o o

CO —a ffi oo U5 m CM 0 ••• 3arayb3dW3i

56

FIGURE

23>

-

DOORWAY

AIR

TEMPERATURE

HISTORIES

FOR

TEST
o a o

0 ••• 3«OiVb3dW3l

57

FIGURE

23^

-

DOORWAY

AIR

TEMPERATURE

HISTORIES

FOR

TEST

4
003 [1III

1111 IIIIIiII1I—11111111—I1i1—I

0021 o o o o —I o I III

zzzz

oaaaa: 8888 QQQQ

oooo

aaq. a oo6o

oooo _I -J —I _J UlUlUiUI mmcmD E E E E ^ ^ tv OOCMCS dodo

UJUJUUJ acL^i

OOOO ooo oog „_33S Oo:q:q;q;

ZUlUiLklUi X X X T

CM E E E E ^ E E E E

0«-iO»- «n ^lOOiOO Kdddd Q.

J_J L_L oo 0 •- 3yniVh3dW3i

58

FIGURE

24-

DOORWAY

AIR

TEMPERATURE

HISTORIES

FOR

TEST 2
TIME

MIN

oooaoaoooaooo a o

ui2

0 ••• 38fUVb3dh3I

59

FIGURE

25

-

INTERIOR

AIR

TEMPERATURE

HISTORIES

FDR

TEST

1
1200 I1111—

111\111—I^11—

11111^1^11I

r—1

1200 o Qo oo 0 ••• 3ariiVb3dA3i

60

nCURE

26-

IN7ERK5R

AIR

TEMPERATURE

HISTORIES

FOR

TEST 2
TIME

MIN

0 ••• 38niVb3dW31

59

nCURE

25

-

INTERIOR

AIR

TEMPERATURE

HISTORIES

TOR

TEST

1
002tl—l II11IiIIIII1II11—I111—1111—I111—I

0021 T 0 ••• 3«niva3c)A3i

j.

60

FIGURE

26-

INTERIOR

AIR

TEMPERATURE

HISTORIES

FDR

TEST 2
TIME

•••

MIN

2

P

0 •- 3ynivb3di^3i

61

FIGURE

27

-

INTERIOR

AIR

TEMPERATURE

HISTORIES

FOR

TEST

3
Time

MIN

o o o

o a o o a o o o o o a o o o o o o a o o o o o o o

CSJ o oo (O U5 m CM 0 ••• 3yniyy3dW3i

62

FKWRE

28

-

INTERIOR

AIR

TEMPERATURE

HISTORIES

FOR

TEST

4
M

N

U7 O 1/5 O lO O

CM <M —• — O Q

M3I3W y3d AilSN3G nvOlidO

63

FIGURE

29

-

SMOKE

GENERATION

HISTORCS

FOR

TESTS

2.3

AND

4
riME

***

MHM

o

o

ot o

o a a

o o a a a

u) o o o a a

o o o o a O

o o o o a 40 o 40 in

CM o r- 40 esi « 3 'N0I1D3S SSOaO NOliONliXH 3M0WS

64

FIGURE

30

-

SMOKE

EXTINCTION

CROSS

SECTION

VERSUS

TIME

FDR

TESTS

2

AND
TIME

*•*

MIN

ooooooooo tDr^toiO'^cocs) — o

65

nCURE

31

-

MASS

FLOW

RATE

OF

CARBON

MONOXIDE

VERSUS

TIME

FOR

TEST

1
TIME

•••

MIN

I

I

CDO o

(Oo

HiD e

<no

CMo o

o

o

o o a O o a o o a

t/f>H ••• 1LV» MOTJ SSVW

66

nCURE

32

-

MASS

FLOW

RATE

OF

CARBON

MONOXIDE

VERSUS

TIME

FOR

TEST 2
TIME

*»•

MIN

QOO

r-o o o

00o

CMo

o

o

o

8/&M

o o

3iVy MOU ssvw

67

FIGURE

3:3

-

MASS

FLOW

RATE

OF

CARBON

MONOXIDE

VERSUS

TIME

FOR

TEST

3
Time

*'••

MIN

o o

lOo

iPo

cna Q

o

o

o o o

q/ 6>) ••• 3j_yy /ViOU SSVW

68

I

FIGURE

34

-

MASS

FLOW

RATE

OF

CARBON

MONOXIDE

VERSUS

TIME

FOR

TEST

4
O

STACK

ir»

MM ‘31VH 3SV313U 1V3H

69

Figure

35.

Peak

heat

release

rate

versus

doorway

ventilation

parameter
APPENDIX A

A. 1 Calculation of Heat Release Rate from Oxygen Depletion Measurement

The formulae given here are taken from a report by Lawson et al.* The

rate of heat release from a room fire can be expressed as:

Q = EXg^ m0

where

Q = Rate of heat released from the fire room, MW.

E = Heat per unit mass of oxygen consumed by the burning of materials

normally used in the construction and furnishing of rooms, MJ/kg.

A value of 13.2 MJ/kg was chosen based on a study by Huggett.**

Oxygen concentration in ambient air, moles oxygen/moles air.

I Mass flow rate of air from fire room, kg/s. •>.

W = Molecular weight of oxygen, kg.

W . = Molecular weight of air, kg. air / -r)

0 = Oxygen depletion of the air.

The oxygen depletion can be further defined as:

*Lawson, J. R. et al. The Development of an Oxygen Consumption Calorimeter,

NBSIR in preparation.

**Huggett, C., Estimation of Rate of Heat Release by Means of Oxygen Consumption Measurement, Fire and Materials, 4, 61-65, 1980.

70
is trapped ahead of the oxygen analyzer

when CO

2

is not trapped

where

Measured oxygen concentration with CO^ trapped out

Measured oxygen concentration when CO

2

is not trapped

Measured concentration of CO

2

As an example of the use of the above formulae, the following table

outlines the calculation of the rate of heat release in the case of the calij bration burner operating directly under the stack (refer to section 2.4 for

further details)

.

Heat

Input

from

Propane

Burner

-- (kW)

Flow Rate

Through Stack

(20°C , 1 atm.

)

(m^/s)

Ambient

^2

Cone

.

(%)

Measured

°2

Cone

.

(%)

Measured

CO

2 Cone

.

(%)

Oxygen

Depletion

(p

Rate of

Heat . Release Q

(kW)

C02 485 2.9 20.90 20.06 _ 0 . 0503 517

Removed 1290 2.7 20.90 18.47 - 0.1426 1365

CO

2

Not 485 2.9 20.90 19.93 0.66 0.0501 515

Removed 1290 2.7 20.90 18.08 1.93 0.1446 1384

Note: ,A value of 12 .75 MJ/kg or 16.96 MJ per m^ of oxygen at 20°C and 1 atm.

was used for propane

.

Example

:

Q = (16.96 MJ/m^) (0,.209) (2.9 mVs) (0.0503) = 0 .517 MJ/s or 517 kW

X"

CO,

71
1/2

A. 2 Effective Value of AH for Two Vertically Displaced Small Openings in

a Room Fire (by W. J. Parker)

Figure la Figure lb

Room having two opening

areas of A^^ and

Room having one opening

area of A

1/2 The effective value of the ventilation parameter AH is defined here as 1/2 the value of AH for a single rectangular opening which would provide the

same induced air inflow for a fully developed fire in a room having one opening near the floor and another opening at head level, as shown in Figure la.

It is assumed that for this case,

(1) there is a uniform temperature, T, in the room and outside the

room

;

(2) the air flows in through the lower opening and out through the

top opening; and.

72
( 3 ) the height of each opening in Figure la is small enough that the

velocity of the air passing through can be considered to be uniform

and equal to the value calculated at its center point.

The pressure gradient in the room is given by

where is the density of the ambient air; g is the acceleration due to

gravity; and X2 are the distances from the neutral density plane to the

center of the openings in Figure la; and and Z2 are the distances from

the neutral density plane to the bottom and top of the opening in Figure lb,

respectively. Then the differential pressure at the center of the openings

are 6x^ and 6X2- The corresponding velocities are

where p is the density of the air inside the room. The mass flows are

and

and

Since m^ = m2 and X2 = d - x^, the neutral plane height above the center of

the lower opening is found to be

73
and the mass inflow is given by

For the single doorway case in Figure lb,

Similarly

,

"2 = I

^ 2 w(h-zJ3/2

The mass balance requires that

so that.

Eg. (1)

74
Eq. (2)

The openings shown in Figures la and lb are equivalent if they have the

3/2 same mass inflow. Comparing equation (1) and (2) and solving for WH = 1/2 1 / 2 * AH we have the effective value AH for the room with the two' openings.

T

Thus, letting ^ have

= kA2d^/^

where

3

k =

2

\l/3 ^ 3/2

ITT

The air temperature in the room in test 2, aside from^that near the floor,

averaged about 425°C at times between 690 and 770 s, at which times the peak

rate of heat release occurred at the stack and cell opening, respectively.

Then,

T = 300 K

o

T = 698 K

A^ = 0.093 m2

A^ = 0.073 m2

d = 1.47 m

1/2* 5/2 Hence, k = 2.67 and AH = 0.30 m for test 2 with the two openings.

75
HBS»114A (REV» 2*80

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 82-2469

2. Performing Organ. Report No. 3. Publication Date March 1982

4. TITLE AND SUBTITLE

Effect of Ventilation on the Rates of Heat, Smoke, and Carbon Monoxide Production

in a Typical Jail Cell Fire

5. AUTHOR(S)

B. T. Lee

6. PERFORMING ORGANIZATION (If joint or other than NBS, see instructions)

national bureau of standards

DEPARTMENT OF COMMERCE

WASHINGTON, O.C. 29234

7. Contract/Grant No.

S. Type of Report & Period Covered

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City, State, ZIP)

Sponsored in part by: National Institute of Justice

U. S. Department of Justice

Washington, DC

10. SUPPLEMENTARY NOTES

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 significant

bibliography or literature survey, mention it here) The rates of heat release and smoke development from a fire in a typical prison cell

configuration were examined , under four doorway ventilation conditions. Peak heat

release rates varied from about 4500 kW for a 3.34 m^ doorway opening down to 340 kW

for a 0.17 m^ opening. However, the total and rate of smoke generation were greater

with the small opening. The peak carbon monoxide production rate varied from

0.03 kg/s for the large opening to 0.01 kg/s for the smallest opening. The quantity

of carbon monoxide generated, however, was highest for the smallest opening with

5.3 kg produced over the fire duration of 1800 s. During the peak fire development

in the configuration with the larger openings, temperatures inside the room reached

about 1000“C with roughly two-thirds of the heat lost to the cell room boundaries.

Peak thermal fluxes inside the room generally exceeded the ignition threshold value

of about 20 kW/m^ for clothing, bedding, and other light combustible fuel for all of

the tests.

12. <EY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons)

Fire growth; fuel load; heat release rate; prison cell fire; smoke

13. AVAILABILITY

Hn Unlimited

I I For Official Distribution. Do Not Release to NTIS

I I Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402.

Order From National Technical Information Service (NTlS), Springfield, VA, 22161

14, NO, OF

PRINTED PAGES

80

15. Price 10.50

USCOMM-OC 8O43-P80

I