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NATIONAL BUREAU OF STANDARDS REPORT · PDF file 2016. 8. 10. · -/7fir" NATIONALBUREAUOFSTANDARDSREPORT NBSPROJECT NBSREPORT 1000-30-4^37 April26,1954 3259 PERFORMANCETESTSOFAWESTINGHOUSE

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  • NATIONAL BUREAU OF STANDARDS REPORT

    3259

    PERFORMANCE TESTS OF A WESTINGHOUSE PRECIPITRON ELECTRONIC AIR CLEANER

    Henry E 0 Robinson Thomas W„ Watson

    Report to General Services Administration

    Public Buildings Service Washington 25, D. C.

    0. 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 special- ized research, development, and engineering in the field indicated by 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. Resistance and Reactance Measurements. Electrical Instruments. Magnetic Measurements. 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. Cryogenic Engineering.

    Atomic and Radiation Physics. Spectroscopy. Radiometry. Mass Spectrometry. Solid State Physics. Electron Physics. Atomic Physics. Neutron Measurements. Infrared Spectros- copy. Nuclear Physics. Radioactivity. X-Ray. Betatron. Nucleonic Instrumentation. Radio- logical Equipment. Atomic Energy Commission Radiation Instruments Branch.

    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 Control.

    Organic and Fibrous Materials. Rubber. Textiles. Paper. Leather. Testing and Specifica- tions. 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 Condition- ing. Floor, Roof, and Wall Coverings. Codes and Specifications.

    Applied Mathematics. Numerical Analysis. Computation. Statistical Engineering.

    Electronics. Engineering Electronics. Electron Tubes. Electronic Computers. Electronic Instrumentation. Process Technology.

    Radio Propagation. Upper Atmosphere Research. Ionospheric Research. Regular Propagation Services. Frequency Utilization Research. Tropospheric Propagation Research. High Frequency Standards. Microwave Standards.

    ^Office of Basic Instrumentation ^Office of Weights and Measures.

  • -/7fi r"

    NATIONAL BUREAU OF STANDARDS REPORT NBS PROJECT NBS REPORT

    1000-30-4^37 April 26, 1954 3259

    PERFORMANCE TESTS OF A WESTINGHOUSE PRECIPITRON ELECTRONIC AIR CLEANER

    TYPE FA-22

    by Henry E. Robinson Thomas W. Watson

    Heating and Air Conditioning Section Building Technology Division

    to General Services Administration

    Public Buildings Service Washington 25, D. C.

    U. S. DEPARTMENT OF COMMERCE

    NATIONAL BUREAU OF STANDARDS

    The publication, reprlntl

    unless permission isobta

    25, D. C, Such permlssi

    cal ly prepared If that a

    a a c ii- i .1 rt, Is prohibitedApproved tor public release by theJ rds, Washington Director of the National Institute of

    „ a8 been speclfl .

    Standards and Technology (NIST) for its own U 3 e. on October 9, 20 1

    5

    .

  • PERFORMANCE TESTS OF A WESTINGHOUSE TYPE FA-22 PRECIPITRON ELECTRONIC AIR CLEANER

    lo INTRODUCTION

    At the request of the Public Buildings Service, General Services Administration, the performance character- istics of electrostatic air cleaners 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 electrostatic filter unit submitted by its manufacturer at the request of the Public Buildings Ser- vice and included determinations of dust arresting ef- ficiency with three aerosols (atmospheric air, kerosene lamp smoke, and Cottrell precipitate), pressure drop, specific dirt load and cleanability of the specimen,,

    The cleaner was manufactured by the Westinghouse Electric Corporation, Sturtevant Division, Hyde Park, Boston 36

    , Massachusetts, and was of the electrostatic

    type. It was identified as a Westinghouse Precipitron Type FA-22 with two type CA-12 cells, Style 15595&7, rated velocity 333 feet per minute (1332 CFM total). The power pack had the following nameplate data:

    The test unit had a housing with actual outside dimen- sions of 24x24 - 1/4 inches and was 26 -1/2 inches long, and was rated as having 4 sq. ft. of transverse area, i.e., 1332 CFM air delivery at 333 fpm velocity. The upstream and downstream faces had flanges 30 inches square matching those of the duct of the test apparatus. The face openings were 20x22-1/2 inches upstream and 20x20-1/2 inches downstream. The down- stream face was adapted to receive a nominal 24x24x1 inch after-filter, which for this unit was a 24x23 - 1/16x1 inch

    2. DESCRIPTION OF THE FILTER SPECIMEN

    Precipitron Power Pack

    Type M Volts 115 Cycles 60-50

    Style No. I 56O6OI .Amps 0.3 Watts 90 Phase 1

    Ionizer volts 12,300 Plate 5,500

  • - 2 -

    "A-Lum-O-Aire” aluminum wool (dry type) air filter manu- factured by the Carey Electronics Engineering Co® of Spring- field, Ohio„

    There were two similar filter cells in the housing, each having actual outside dimensions of 11-7/8 inches in height, 15 inches in length, and 22 inches in width, and each containing 61 aluminum plates spaced approximately 5./l6-inch apart, presenting a total surface area of approxi- mately 120 square feet for each cello The manufacturer supplied a piece of 0 o 025 inch aluminum angle 1-1/2x1/2x22 inches in size, which was inserted beneath and around the downstream bottom edge of the top cell, with the 1-1/4 inch dimension parallel to the direction of air flow, for the purpose of preventing oil blow-off from the upper plates

    ®

    The manufacturer furnished an adhesive (a water-emulsi- fying oil) designated as TfPrecipitron Adhesive T-675"

    , and

    an applicator for oiling the collecting plates of the cells by spraying them from the upstream face® In accordance with the request of the manufacturer’s representative, the ”A-Lum-O-Aire” after-filter was oiled in preparation for the test by immersing the filter in an oil and letting excess oil drain off with the filter standing on edge for 18 hours prior to the test® The adhesive supplied by Westinghouse for spraying the collecting plates was not sufficient in quantity for immersing the after-filter, so a suitable water-emulsifying oil was selected for this purpose from a group of oils that had been submitted by manufacturers for oiling viscid impingement air filters®

    The power pack, connected to a 115-volt 60-cycle supply, was adjusted by the manufacturer’s representative to recom- mended settings prior to the tests; the ionizer and plate voltages that resulted were measured by means of a high- resistance voltmeter which was compared with an accurate electrostatic voltmeter®

    3® TEST METHOD AND PROCEDURE

    Efficiency determinations were made by the NBS ”Dust- Spot Method” using the following aerosols: (a) outdoor air drawn through the laboratory without addition of other dust or contaminant; (b) kerosene lamp smoke; and (c) Cottrell precipitate® The test method is described in the paper

  • - 3 -

    TT A Test Method for Air Filters" by R. S. Dill (ASHVE Trans- actions, Vol. 44, Po 379, 193$) o The test duct and arrange- ment are shown in Figure 1. A baffle made of two 3-inch wide sl^tts wa^ located in the duct about 3-1/2 ft downstream of the test unit to intermix the air discharged from it.

    For these tests, the unit was installed in the test duct and carefully sealed to prevent inleakage of air. The desired rate of air flow through the air cleaner was established and samples of air were drawn from the center points of the test duct one foot upstream and eight feet downstream of the air cleaner at equal rates and passed through known areas of Whatman No. 41 filter paper. For the atmospheric air and oil lamp smoke tests, the samples were drawn at equal rates through equal areas of filter paper (3/4-inch diameter spots). The downstream sample was drawn continuously during the test; the upstream sample was drawn intermittently in a number of one-minute periods uniformly distributed over the duration of the test, aggregating one-tenth of the downstream sampling period. Under these conditions an efficiency of 90 percent would be indicated if the upstream and downstream dust-spots on the filter papers had the same opacity, as indicated by the change in the light transmissions of the dust-spot areas before and after the sample was drawn, which were determined by means of a photometer using transmitted light. The filter papers used in the upstream and downstream positions were selected to have the same light transmission readings when clean. If the opacities of the dust-spo