NATIONAL BUREAU OF STANDARDS REPORT

PERFORMANCE TESTS OP A DOLLINGER

MODEL WKE-8 DRY PANEL FILTER

by

Henry E. Robinson

Thomas W. Watson

Report to

General Services Administration

Public Buildings Service

Washington 25, D. C.

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
U. S. DEPARTMENT OF COMMERCE

Sinclair Weeks, Secretary

NATIONAL BUREAU OF STANDARDS

A. V. Astin, Director

THE NATIONAL BUREAU OF STANDARDS

The scope of activities of the National Bureau of Standards is suggested in the following listing

of the divisions and sections engaged in technical work. In general, each section is engaged in

specialized research, development, and engineering in the field indicated hy its title. A brief

description of the activities, and of the resultant reports and publications, appears on the inside

of the back cover of this report.

Electricity and Electronics. Resistance and Reactance. Electron Tubes. Electrical Instru- ments. Magnetic Measurements. Process Technology. Engineering Electronics. Electronic

Instnunentation. Electrochemistry.

Optics and Metrology. Photometry and Colorimetry. Optical Instruments. Photographic

Technology. Length. Engineering Metrology.

Heat and Power. Temperature Measurements. Thermodynamics. Cryogenic Physics.

Engines and Lubrication. Engine Fuels.

Atomic and Radiation Physics. Spectroscopy. Radiometry. Mass Spectrometry. Solid

State Physics. Electron Physics. Atomic Physics. Nuclear Physics. Radioactivity. X-rays. Betatron. Nucleonic Instrumentation. Radiological Equipment. AEC Radiation Instruments. Chemistry. Organic Coatings. Surface Chemistry. Organic Chemistry. Analytical Chemistry.

Inorganic Chemistry. Electrodeposition. Gas Chemistry. Physical Chemistry. Thermochemistry. Spectrochemistry. Pure Substances.

Mechanics. Sound. Mechanical Instruments. Fluid Mechanics. Engineering Mechanics.

Mass and Scale. Capacity, Density, and Fluid Meters. Combustion Controls.

Organic and Fibrous Materials. Rubber. Textiles. Paper. Leather. Testing and Specifications. Polymer Structure. Organic Plastics. Dental Research.

Metallurgy. Thermal Metallurgy. Chemical Metallurgy. Mechanical Metallurgy. Corrosion.

Mineral Products. Porcelain and Pottery. Glass. Refractories. Enameled Metals. Concreting Materials. Constitution and Microstructure.

Building Technology. Structural Engineering. Fire Protection. Heating and Air Conditioning. Floor, Roof, and Wall Coverings. Codes and Specifications.

Applied Mathematics. Numerical Analysis. Computation. Statistical Engineering. Mathematical Physics.

Data Processing Systems. Components and Techniques. Digital Circuitry. Digital Systems.

Analogue Systems.

Cryogenic Engineering. Cryogenic Equipment. Cryogenic Processes. Properties of Materials.

Gas Liquefaction.

Radio Propagation Physics. Upper Atmosphere Research. Ionospheric Research. Regular

Propagation Services.

Radio Propagation Engineering. Frequency Utilization Research. Tropospheric Propagation

Research.

Radio Standards. High Frequency Standards. Microwave Standards. • Office of Basic Instrumentation • Office of Weights and Measures
NATIONAL BUREAU OF STANDARDS REPORT

NBS PROJECT NBS REPORT

1000-30-1^830 January 23, 1958 1)505

PERFORMANCE TESTS OP A DOLLINGER

MODEL WKE“8 dry PANEL FILTER

by

Henry E. Robinson

Thomas W. Watson

Heating and Air Conditioning Section

Building Technology Division

Tb

General Services Administration

Public Building Service

Washington 2'5, D. C.

<NBS>

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

The publication, re

unless permission l!

25, 0. C. Such per

cally prepared If t

Approved for public release by the

Director of the National Institute of

Standards and Technology (NIST)

on October 9, 201 5.

In part, Is prohibited

andards, Washington

port has been specifieport for its own use.

PERFORMANCE TESTS OF A DOLLINGER

MODEL WKE-8 dry PANEL FILTER

by

Henry E* Robinson and Thomas W. Watson

1

.

INTRODUCT ION*

At the request of the Public Buildings Service, General

Services Admli^l strati on, the performance characteristics of

dry-type air filters were determined to provide information

to assist in the preparation of new air filter specifications.

The test results presented herein were obtained on a

specimen dry-type air filter submitted by its manufacturer

at the request of the Public Buildings Service and included

determinations of dust arresting efficiency with two aerosols

(atmospheric air and Cottrell precipitate), pressure drop and

dirt load.

2

.

DESCRIPTION OF THE FILTER SPECIMEN

The filter was manufactured by the Dolllnger Corporation

of Rochester, New York, and was of the renewable media type,

identified as a "Model WKE-8 Dry Panel Filter". The filter

cell' and frame had overall dimensions of 2I4X2I4X8 3/8 inches

deep, and had six ply flameproofed Feltex paper filtering

media (6 PF), 26 Inches wide, arranged in vee-folds approximately 5 1/2 inches deep, supported downstream by a 14-mesh

wire retaining screen and held in place in the troughs by thin

retaining strips supported by the top or upstream section of

the frame. The upstream face of the filter was covered by an

8-mesh flat screen and had a net face area of 3*146 sq. ft.

The area of the medium effective for filtering was approximately 2i| sq, ft, and the length of paper medium required

for one filling of the frame was ll| ft. 2 in.

3.

TEST METHOD AND PROCEDURE

Efficiency determinations were made by the NBS "DustSpot Method" using the following aerosols; (a) outdoor atmospheric air drawn through the laboratory without addition

of other dust or contaminant; and (b) Cottrell precipitate.

*This report is submitted for information only, and is not

released for use in connection with advertising or sales

promotion.
tf

»?

:-7 ip:

1 '^ >'d’pv

flBWI. >- *''*» "Hfi' w

, \^*’ -:‘

mt ’)

vjf r

»'•.

I '•

r -.•:'» i#i;. ' i ,7

'

ui, ,'•

. Jli’ ^. «.« '• :..#4 •':<;<;» i -.^r

., .1 •’ •

:i '

I " t. ; f -'’>

. vvt:",'^!:i^ ;. ra- 1 ^ '?, ' ,.U

\,rt i«;K' r''l;Mr»i/

‘i.i >:g-’ » av

."o » '^;i‘r ^4^;. j

^ I ;

(Sf

' ' ,. -v.i.<tf _i <J ili.iM *.rf ''^•:' *v’5:''‘4'/? ^ '* wa;>*^ ?,

i. ^;.i'-;'»Wv.i*.'i ' •^i

) Tff' *4 *^'f4i,v’ H^vr .v^Hhfiii>4^

’ » *1*: vin C'f9it«f^.y’'.'i Jk Mi . . i'^

•:

i< \IA Xv -i;ri«ieV'-0 iurf ^;r-t-;'‘c: ,

' ' 4

’' ^ ^’ ••' '» .t'*'':^ < 3^U ai’4 fctnift

« ^ I «« ilft r. «

.* ’ . f^rti . 4. tf* Na

‘' 4Ti^t»'; ; .ii\A ? ’'^‘i ••>’',* .-^ .\ ^ tii 'fv/*»rt f*; ' "• ’ '(L‘ 'y>\: ' ‘"’''^’^'

1 ,y,iM^. ^ant' >! i'‘A't fci. , nj?:; ,,,, . ^

''* '"'n It Wan*.*/ •'-:: t.>4 M' .i!- • iif*JC4^‘&|^ ^

' %.* \ '{it , :»». / f '• ’Z"

'* •* ’ ‘-pw ^

’ !?

- <A'i ^/ifS I

. .

. itK

. v<<- .

‘ '

I <fi I r

,

ri: ,i V 7 > r j .- %.; .t r^ ; :,.> •.

• <' i >•.** *1' ia&M^' A ••^

M..' '

. . * J ^ • '•'* >-.w *^i4

* 'I f?'V *sw ••!

• ’

‘.t ^ /.

«5'’x-?'^ ' fpoa 7

,

i (..I'i '^:m

' (

*

•’ :ua r. t ''tM

. . '-J: ytj ".oA

j!
2

dispersed in the outdoor atmospheric air f « described in the paper "A Test

S, Dill (A6HVE Transact!

is

H. . ons

Method

Vol. L;ii,

The test method

for Air Filters" by

p. 379 , 1936).

For these tests, the filter was installed in the anoa

was

ratus and the desired rate of air flow through the cleaner

of the

established. Samples of air were drawn from the center test duct, at points one foot upstream and eieht feet

Whatman

passed through known areas of No. I4I filter paper. The areas of the filter oaner's used

air was

upstream and downstream and the times during whiorthF s^pled upstream and downstream were selected ex- perimentally so that the change in transmission of light

The filter efficiency was calculated by means of the formula

Efficiency, percent = 100

Al 0l

T1

T2

where A represents the dust spot area, 0 the change in

filter paper as measured before deposition of dust, and T the time during which

to the

the air sample was drawn. ^Subscripts 1 a^d Trefer upstream and downstream positions, respectively.

techniques or modifications based on the above formula were used, depending on the an parent emciency of the filter with’ the’^liffefen? Srosoh

SLted ir^Iblfl: N were used/arin"!’

chSractLlsti^®”’®?L°?-tt'’®^®"’®”°® constant transmission

stre^

racberistics. The filter papers used upstream and down were selected to have equal light tLnsmi^siSns^Shen

The efficiency of the filter in arresting particulate

testrof"the“r°®^*^i'^M°<.®^’’ <^®termined by means of two

described in Table 2, with clean. Following these, the effioiencv of the

meina'^of”two^M^t^"® means

Cottrell precipitate was measured by

cess

of two N-type tests, after which was begun the nrh

Of cotton

of loading the filter with a mixture of four percent lint and 96 percent of Cottrell prec^Ke! Sy
i \

riir4 ! VL

: v^

. 1

1

iga' I''.-

;,r- r.'

- </ ( > /l.t tf»- * i'

' ‘' I { ^^4SSr.rfp-'' - «' n.‘ £L'_ ‘

• .1 r .- a - .. iriq ....

*£0“ p-'3LLV *»-? .

't wv/A'-f^i ¥» - '. • :id[ai?iiiisi'lii'.-*'^ 'h,»^rU -r ,{ •'.'.''I '^•viw' (3 5i'tAci</ lc, , V ••. « .; »¥?rit i lf^ '

• f 'V

' ’lyn.H i»- • ^ f. «ijfi'''iittw '>X' ./' :'» ftbiil

i',»4>-7 ft, JU-li'CJ ?"V' .4- j.-:

' ,?^'i

>•' I

, ,t« ' >£l

' it .^

•*

‘ t;

,e V Vt... ^ fit. ,

’ .C‘Jt*i

,’ ..I

4 '.'

I ,

,*tf^r.f ' ,U 3, /, 9.

•¥'s»'ji.

, 1 f f I Vil ^

'v '>''«Cki'? --< «t''7

'' f-'/’y*-' -\dl';'-

-.,1' 'i .1 • .t :•’«'. « • ' '

• U

,t HJOX

t t •' *1 5> “ M'f ft- 1^-0 ?nl.? <* H0

r V!*!#

’* '>'• < ! t ^•‘ •»':.'U',' .ti '»'J 'iiv -,'!a

R .

»' ^-1; OrjrdJ»t «i Uj|¥,rA3J

i -.it'

r -ft'tt. •M*' '.*' ^ f

fr • t - ' • ‘.« I' jM ;|

^

i-.'ip_<‘f

' -,1'.* tv**j;*' r J^*. ' -

, «

•' ..'« .

.s

' *; : rn « :.« ii,.’. -tv-V ;. ^*,1 ' - yj^phiaiVi'^

,. - , i't; ' iJ> ' »; .> ‘ o . > » ? 1* fi \Uf I")*' ? , ''3 " I .l5>

>'i Xl ,V‘‘^

.>£

.' J'! .1 : .‘Cl TO ijTtii *'J'.

' I iKk : ^.» ,-
weight, separately dispersed in the air stream. The lint

used for this purpose was No. 7 cotton linters previously

ground in a Wiley mill with a I| -millimeter screen. At

suitable periods as the loading progressed, the efficiency

of the filter was determined using Cottrell precipitate in

outdoor air. Pressure drops were recorded at intervals

during the test. The dirt-loading was continued until the

pressure drop increased to approximately 0 . 5C incn W. G.

The efficiency was again determined with Cottrell precipitate and then with atmospheric air as the aerosols.

I) . TP3ST RESULTS

Table 1 presents data as to the pressure drop of the

clean filter at several rates of air flow.

The performance of the filter at 1000 cfm is summarized

in Table 2, for both aerosols A and C. The performance of

the filter in regard to aerosol C (Cottrell precipitate in

atmospheric air) is also shown graphically in Figure 1. The

efficiency of the filter in arresting aerosol A (atmospheric

particulate matter), both initially, and after its resistanc

had been increased to 0,5 inch W.G., is indicated in Table 2

Observation of the media at the end of the dirt-loading

test revealed that the greater part of the arrested dirt was

found uniformly distributed on the upstream face. The downstream face of the media was slightly darkened by dust. No

lint was visible on the downstream face of the media.

After the unit had been removed from the test duct,

the section of the duct five feet long downstream of the

unit and upstream of a ^/ii^-inch wood strip fastened flat

across the bottom of the test duct was carefully swept out

with a fine brush. The amount of material obtained from the

duct by this sweeping was 6.5 grams, consisting chiefly of

relatively large dust particles.

Cellophane tapes, stretched across the test duct downstream of the filter with the adhesive side facing upstream,

indicated upon visual and microscopic examination after exposure to the air stream that some particles up to approximately 80 microns In size had passed through the filter

during the dirt-loading tests. Particles smaller than five

microns were observed in quantity by microscopic examination

of the downstream filter papers obtained in tests with both

aerosols. No lint was observed on the tapes during these

tests.

- Il - observed in the test on atmospheric air followinp; the dirt-loading tests that some large dust particles up to

75 microns in size were cau^t on cellophane tapes exposed downstream of the filter. These particles had apparentlv been released from the dirt burden on the media. The atmos- pheric air efficiency, however, was nevertheless considerably greater than it was found to be initially with clean filter media.
•< S {. - I li' I-. ' 'M»jy
TABLE 1

PRESSURE DROP OP CLEAN FILTER

Air Air Velocity Pressur-e

Flow Through Media Drop

Cfltl fpm inch W.G

1200 50 0.130

1000 k2 .101

• 800 33 .071)

600 25 .051

TABLE 2

PERFOUl'u-U^iCE OF FILTER AT 1000 CFM

Aerosol (1)

Total

Dirt

Load (2)

Pressure

Drop

Eff. Meas,

Technique

(

3 ) Ef f Icienc;

gr ams inch Vh G. percent

A »• 0.109 111 - .107 I'!. 10

C 9 .113 N 80

19 .117 N 62

67 .II42 N 60

183 .199 N 89

279 ,262 N 87

395 • 355 N 86

912 . 1*95 N 86

522 .900 N 87

A 922 .507 M 26

(1) Aerosol A: Particulate matter in atmospheric air at NBS.

Aerosol C: Cottrell precipitate in atmospheric air

(1 gram per 1000 cf).

(2) Average mijcture: I4 .O percent lint, 9o.O percent Cottrell

precipitate by weigtit.

(3)

Efficiency measuring technique;

L: Air sampled at equal rates through equal areas;

upstream sampling time selected to yield approximately equal dust-spot opacities of the upstream

and downstream filter papers.

M: Air sampled at equal rates through equal areas for

equal times.

N: Air sampled at equal rates for equal times; downstream areas selected to yield approximiately equal

dust-spot opacities of the upstream and downstream

filter papers.
rij

i- U9U. i' V

•2'--0

' »Y< ?.V>y,r2’‘: :$J .

‘ '.11^ j||*t4j-fe 4,«. (IfaKt

ii

. «

':* V l “no li.;

. I

' <1...;,

:l

;f

ta.-f

t.. i\

.... ,^-Mr ; SVjS'

'^m

\

'

• -fe

Tv • M.rd rit v.* ~ rfutt p -i

if.i. -VI Vi, 4

, ( t a oof'i. ^n» ' F'irrr.

.. . ^' " :.y

i- ) ,!.,

Xc'Liridllv

•*~

»

• -

i?iUO.-< J ,

. r t ‘5 . ' •» ;

, , m I j i

I j,

. '

‘VVs4 -• ^

'

, l'*i i .^1 '. .» | • ' >>tj)||f.;

I »

<»•: , V, T(,o j «4'., . j .' ; art.i'; ts4

.fff-

./ f 1

*•, I

' - ‘>i(f t ' i) ,k.'^j*|l • ' ' 'J'iW /

•> "< ' isD

‘ -r *'t-‘ . .;c

' , >4», J

-' -1. / .
lN30y3d A0N3I0I333

o

100

200

300

400

500

600

LOAD

REACHING

FILTER,

GRAMS

FIG.

I

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. A major portion of the Bureau’s work is performed

for other Government Agencies, particularly the Department of Defense and the Atomic Energy

Commission. The scope of activities is suggested by the listing of divisions and sections on the

inside of the front cover.

Reports and Publications

The results of the Bureau’s work take the form of either actual equipment and devices or published papers and reports. Reports are issued to the sponsoring agency of a particular project

or program. Published papers appear either in the Bureau’s own series of publications or in the

journals of professional and scientific societies. The Bureau itself publishes three monthly periodicals, available from the Government Printing Office: The Journal of Research, which presents

complete papers reporting technical investigations; the Technical News Bulletin, which presents

summary and preliminary reports on work in progress; and Basic Radio Propagation Predictions,

which provides data for determining the best frequencies to use for radio communications throughout

the world. There are also five series of nonperiodical publications: The Applied Mathematics

Series, Circulars, Handbooks, Building Materials and Structures Reports, and Miscellaneous

Publications.

Information on the Bureau’s publications can be found in NBS Circular 460, Publications of

the National Bureau of Standards ($1.25) and its Supplement ($0.75), available from the Superintendent of Documents, Government Printing Office. Inquiries regarding the Bureau’s reports and

publications should be addressed to the Office of Scientific Publications, National Bureau of

Standards, Washington 25, D. C.