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N ATIONAL BUREAU OF STANDARDS REPORT

PERFORMANCE TEST OF A "DUSTFOE"

DISPOSABLE AIR FILTER

manufactured by

Mine Safety Appliances Company

Pittsburgh, Pennsylvania

Carl W. Coblentz and Paul R. Achenbach

General Services Administration

Public Buildings Service

Washington 25 > D. C.

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

7506

by

Report to
THE NATIONAL BUREAU OF STANDARDS

Functions and Activities

The functions of the National Bureau of Standards are set forth in the Act of Congress, March 3, 1901, as amended by Congress in Public Law 619, 1950. These include the development and maintenance of the national standards of measurement and the provision of means and methods for making measurements consistent

with these standards; the determination of physical constants and properties of materials; the development of methods and instruments for testing materials, devices, and structures; advisory services to government agencies on scientific and technical problems; invention and development of devices to serve special needs of the Government; and the development of standard practices, codes, and specifications. The work includes basic

and applied research, development, engineering, instrumentation, testing, evaluation, calibration services,

and various consultation and information services. Research projects are also performed for other government

Agencies when the work relates to and supplements the basic program of the Bureau or when the Bureau’s

unique competence is required. The scope of activities is suggested by the listing of divisions and sections on the inside of the back cover.

Publications

The results of the Bureau’s research are published either in the Bureau’s own series of publications or

in the journals of professional and scientific societies. The Bureau itself publishes three periodicals avail- able from the Government Printing Office: The Journal of Research, published in four separate sections,

presents complete scientific and technical papers; the Technical News Bulletin presents summary and pre- liminary reports on work in progress; and Basic Radio Propagation Predictions provides data for determining

the best frequencies to use for radio communications throughout the world. There are also five series of nonperiodical publications: Monographs, Applied Mathematics Series, Handbooks, Miscellaneous Publications,

and Technical Notes. A complete listing of the Bureau's publications can be found in National Bureau of Standards Circular

460, Publications of the National Bureau of Standards, 1901 to June 1947 (SI. 25), and the Supplement to National Bureau of Standards Circular 460, July 1947 to June 1957 ($1.50), and Miscellaneous Publication 240,

July 1957 to June 1960 (Includes Titles of Papers Published in Outside Journals 1950 to 1959) ($2.25); avail- able from the Superintendent of Documents, Government Printing Office, Washington 25, D. C.
NATIONAL BUREAU OF STANDARDS REPORT

NBS PROJECT NBS REPORT

1003-30-10630 May 16, 1962 7506

PERFORMANCE TEST OF A "DUSTFOE"

DISPOSABLE AIR FILTER

manufactured by

Mine Safety Appliances Company

Pittsburgh, Pennsylvania

by

Carl W, Coblentz and Paul R. Achenbach

Mechanical Systems Section

Building Research Division

to

General Services Administration

Public Buildings Service

Washington 25, D. C„

NATIONAL BUREAU OF STAND

Intended for use within the Gove

to additional evaluation and reviev listing of this Report, either In wl

the Office of the Director, Nation; however, by the Government ager

to reproduce additional copies foi

IMPORTANT NOTICE

Approved for public release by the

Director of the National Institute of

Standards and Technology (NIST)

on October 9, 201 5.

:ss accounting documents

f published it Is subjected

duction, or open-literature

s obtained in writing from

permission is not needed,

ired if that agency wishes

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
>
PERFORMANCE TEST OF A "DUSTFQE"

DISPOSABLE AIR FILTER

manufactured by

Mine Safety Appliances Company

Pittsburgh, Pennsylvania

by

Carl W, Coblentz and Paul R, Achenbach

1 . Introduction

At the request of the Federal Supply Service, General Services Administration, the performance characteristics of

^

sP° sable air filter manufactured by the Mine

, -y Appliances Company of Pittsburgh, Pennsylvania were

minatior^of th^

SC ° P

J

° f thlS examinatlon included the deterlaboratorS^i^ ^

restance of . the particulate matter in the air the pressure drop and the dust holding capacfm

f the tSSt specimen at the ra ted air flow rate of 1,000

2. Description of Test Specimen

The test specimen was manufactured and supplied for f-pqt

TMv!vanLthe^

lne fff Pennsyivania. The

y Appliances Company^mt^ur^ outside dxmenslons of the filter unit were

(about n‘i/?

U

?h

6 5

n

7/8 in ' deep ’ lts wel Sht was 5,355 g

aboufp^iy2!^8

' h

pleoes of hard fiber board, each

a °lcld

3

hoT'fip„

8’ UA "( wlde > and V1* m. thick formed

t

* lgla box frame with sheet metal angles as corners The fil ter media was arranged In 46 pleats that were supported by a box frIme

eW

°St f

Tde

1 medla was cemented to the Inside of the

matelv 7L ^

area of the filter media was approxl- ^J sc* ana consisted of a loose glass fiber paper

stiff"or

on

. stiff

both sldes by a 10-mesh webbing of a organic fiber thread which did not sustain combustion.

of 1 ooo Cff was operat ed at its rated air flow rate Based on a. gross face area of 3,75 sq ft, this low rate corresponded to a face velocity of 267 ft /min

in the f^nT* t0 the 75 Sq ft filter Ldla lLta^ed’

13 . 3

h

ft/mln?

t0 aVerage media face velocity of approximately

” 3 • Test Method and Procedure

the *'NBS ^st

S

Spot Method" ^escribe^in^^pape^by

1 ^

311 ^

6

Dill

actions' ' VoS/'^P? 379?193

f

8).

Alr FilterS " (ASHVE *ra —
-2

For test purposes, the filter element was installed in

the test apparatus and carefully sealed to prevent inward

leakage of air except through the measuring orifice. The

desired rate of air flow through the filter was established

and samples of air were drawn from the center points of the

test duct two feet upstream and eight feet downstream of the

test specimen at equal rates and passed through known areas

of Whatman No. 41 filter paper. The change of the opacity

of these areas was determined with a sensitive photometer

which measured the light transmission of the same spot on

each sampling paper before and after the test. The two sampling papers used for each test were selected to have the same

light transmission readings when clean.

All but one of the arrestance determinations were made

using the particulate matter in the laboratory air as the

aerosol. For these tests equal sampling areas were used for

the upstream and downstream samplers. A similar increase of

the opacity of the upstream and downstream filter papers was

obtained by passing the sampling air through the upstream

paper only part of the time while operating the downstream

sampler continuously. This was accomplished by installing

one solenoid valve in the upstream sampling line and another

one as a by-pass for the sampler and first solenoid valve.

The valves were operated by an electric timer and a relay so

that one was open while the other one was closed during any

desired percentage of the 5-minute timer cycle, reversing the

position of the two valves during the remainder of the cycle.

The arrestance, A (in percent), was then determined with the

following formula:

A = 100 - T x ~AU

where T is the percentage of time during which air was drawn

through the upstream sampler, AU and AD being the changes of

opacity of the sampling papers, as previously indicated.

For determining the arrestance of the filter, with Cottrell

precipitate as the test dust, different size areas of sampling

papers were used upstream and downstream of the filter in order

to obtain a similar increase of opacity on both sampling papers.

For each arrestance determination with Cottrell precipitate, the upstream sample of the aerosol was collected on one

filter paper for about half of the test period and on a second

filter paper during the remainder of the test period. The down-,

stream sampling paper collected the dust for the entire test.

This method was used to avoid too large differences in the dust

spots when determining Cottrell precipitate arrestance values
Table 1

PERFORMANCE OF A MINE SAFETY APPLIANCES COMPANY

"DUSTFOE" DISPOSABLE AIR FILTER

AT AN AIR FLOW RATE OF 1000 CFM

Dust Load Pressure Drop Arrestance

g in. W. Q. T~

0 0.415 85.0

0 0.417 84.6

15 0.437 98.9*

99 0.587 88.8

158 0.700 89.4

238 0.901 -- 257 0.989 92.2

257 1.20 94.1

*Cottrell precipitate was used hs the aerosol in this test*

all other arrestance determinations were made using the

particulate matter in the laboratory air as the aerosol.

-3-

on the order of 99 percent. The arrestance, A (in percent ),

was then calculated by the formula:

A = (l - Sp

SU

AD

AU1 + au2

x 100

where Sy and S D

are the upstream and downstream sampling areas

and AUp AU^, and AD the observed changes in the opacity of the

two upstream and one downstream sampling papers, respectively.

After making two arrestance determinations with the particulate matter in the laboratory air as the aerosol, one arrestance

determination was made with Cottrell precipitate. The specimen

was then loaded with Cottrell precipitate and lint at a rate of

1 gram of dust per 1,000 cu ft of air. Cotton lint was added

during the loading process in a ratio of 4 parts to every 96

parts by weight of Cottrell precipitate, including the amount

used for the one arrestance measurement. The Cottrell precipitate was previously sifted through a 100-mesh screen and the

lint was prepared by grinding No. 7 cotton linters in a Wiley

mill with a 4-millimeter screen.

Four more arrestance determinations were made at selected

intervals with the particulate matter in the laboratory air as

the aerosol. The pressure drop across the filter was recorded

at the beginning and at the end of each arrestance determination and also after introducing each increment of 20 grams

dust into the test apparatus. The test was terminated when the

pressure drop exceeded 1 in. W.G.

4. Test Results

The test results are summarized in Table 1 which shows the

pressure drop across the filter and the arrestance values determined at several dust load conditions.

The #, Dust Load** shown in this table is the weight of Cottrell

precipitate and lint received by the filter. It is the total

aerosols introduced into the test apparatus diminished by the

percentage of fallout upstream of the filter. This dust fallout

was determined at the conclusion of the test by sweeping out the

test duct on the approach side of the test specimen. The fallout amounted to 13 grams, or 4.8 percent of the total 270 g of

Cottrell precipitate and lint introduced into the test apparatus during the test.

It will be noted that the arrestance of the particulate

matter in the laboratory air increased from about 85 percent

to 94 percent while the filter received a dust load of 257
- 4-

grams. Only one arrestance determination was made with Cottrell

precipitate as the aerosol indicating almost 99 percent with a clean filter. The pressure drop of the clean filter was 0.415

in. W.G.

. i

'

1 /

"

• V

' ' •'

•

;

| v 11

Figure 1 presents a graph of the values shown in Table 1

with the pressure drop and the arrestance values plotted against

the dust load. Smooth curves were drawn through the plotted

points representing the observed data. This graph shows that

the pressure drop increased in almost direct proportion to the

dust load until more than 200 grams had been introduced and

then rose very sharply. This rise in pressure drop coincides

with a sudden rise of approximately 3 percent in the observed

arrestance. This sudden rise in pressure drop and increase in

arrestance occurred during a period of about 2 hours in which

an atmospheric arrestance determination was being made and no

additional Cottrell precipitate was added.

According to these graphs/ the dust load at 1.00 in. W.G.

pressure drop was 255 grams and the average arrestance approximately 89 percent.

USC0MM-NBS-DC
IFOmflTCE (CURVE^'^FOR

K PLOW

U. S. DEPARTMENT OF COMMERCE

Luther H. Hodges, Secretary

NATIONAL BUREAU OF STANDARDS

A. V. Astin, Director THE NATIONAL BUREAU OF STANDARDS

The scope of activities of the National Bureau of Standards at its major laboratories in Washington, D.C., and

Boulder, Colorado, is suggested in the following listing of the divisions and sections engaged in technical work.

In general, each section carries out specialized research, development, and engineering in the field indicated by

its title. A brief description of the activities, and of the resultant publications, appears on the inside of the

front cover. WASHINGTON, D. C.

Electricity. Resistance and Reactance. Electrochemistry. Electrical Instruments. Magnetic Measurements

Dielectrics. High Voltage.

Metrology. Photometry and Colorimetry. Refractometry. Photographic Research. Length. Engineering Metrology.

Mass and Scale. Volumetry and Densimetry.

Heat. Temperature Physics. Heat Measurements. Cryogenic Physics. Equation of State. Statistical Physics.

Radiation Physics. X-ray. Radioactivity. Radiation Theory. High Energy Radiation. Radiological Equipment.

Nucleonic Instrumentation. Neutron Physics.

Analytical and Inorganic Chemistry. Pure Substances. Spectrochemistry. Solution Chemistry. Standard Refer- ence Materials. Applied Analytical Research. Crystal Chemistry.

Mechanics. Sound. Pressure and Vacuum. Fluid Mechanics. Engineering Mechanics. Rheology. Combustion

Controls. Polymers, Macromolecules: Synthesis and Structure. Polymer Chemistry. Polymer Physics. Polymer Characterization. Polymer Evaluation and Testing. Applied Polymer Standards and Research- Dental Research.

Metallurgy. Engineering Metallurgy. Microscopy and Diffraction. Metal Reactions. Metal Physics. Electrolysis

and Metal Deposition.

Inorganic Solids. Engineering Ceramics. Glass. Solid State Chemistry. Crystal Growth. Physical Properties.

Crystallography.

Building Research. Structural Engineering. Fire Research. Mechanical Systems. Organic Building Materials. Codes and Safety Standards. Heat Transfer. Inorganic Building Materials. Metallic Building Materials. Applied Mathematics. Numerical Analysis. Computation. Statistical Engineering. Mathematical Physics. Operations Research. Data Processing Systems. Components and Techniques. Computer Technology. Measurements Automation.

Engineering Applications. Systems Analysis.

Atomic Physics, Spectroscopy. Infrared Spectroscopy. Solid State Physics. Electron Physics. Atomic Physics.

Instrumentation. Engineering Electronics. Electron Devices. Electronic Instrumentation. Mechanical Instru- ments. Basic Instrumentation. Physical Chemistry. Thermochemistry. Surface Chemistry. Organic Chemistry. Molecular Spectroscopy. Molecular Kinetics. Mass Spectrometry.

Office of Weights and Measures. BOULDER, COLO.

Cryogenic Engineering Laboratory. Cryogenic Equipment. Cryogenic Processes. Properties of Materials. Cryogenic Technical Services. CENTRAL RADIO PROPAGATION LABORATORY

Ionosphere Research and Propagation. Low Frequency and Very Low Frequency Research. Ionosphere Research. Prediction Services. Suit-Earth Relationships. Field Engineering. Radio Warning Services. Vertical Soundings Research.

Radio Propagation Engineering. Data Reduction Instrumentation. Radio Noise. Tropospheric Measurements.

Tropospheric Analysis. Propagation-Terrain Effects. Radio-Meteorology. Lower Atmosphere Physics.

Radio Systems. Applied Electromagnetic Theory. High Frequency and Very High Frequency Research. Modulalation Research. Antenna Research. Navigation Systems.

Upper Atmosphere and Space Physics. Upper Atmosphere and Plasma Physics. Ionosphere and Exosphere Scatter. Airglow and Aurora. Ionospheric Radio Astronomy.

RADIO STANDARDS LABORATORY

Radio Physics. Radio Broadcast Service. Radio and Microwave Materials. Atomic Frequency and Time-Interval

Standards. Millimeter- Wave Research.

Circuit Standards. High Frequency Electrical Standards. Microwave Circuit Standards. Electronic Calibration

Center.
MBS