Publication Date |
1988 |
Personal Author |
Liu, B. Y. H.; Fardi, B. |
Page Count |
230 |
Abstract |
Characteristics of particulate air filters used in respiratory protective devices were studied. Efforts were made to determine the overall efficiency of the filters as a function of particle size and as a function of the velocity of air flow through the filter. A determination was also made of the resistance of the filter media to the flow of air. The report deals with the history of respirator development (types of respirators, types of hazardous particulates, respirator approval tests, and previous work on respirator filter testing); reviews electrostatic filtration; presents experimental work relating to the grant including a description of the test chamber, particle generation devices, particle size distribution measuring devices, test chamber performance and experimental procedure; and offered a theoretical study consisting of numerical calculations. An apparatus for testing respiratory air filters was designed. For all filters tested, a unique and well defined particle size was found at which the aerosol penetration through the filter was a maximum and the filter efficiency was a minimum. The particle size which had the most penetration varied between 0.1 and 0.4 micrometers with the corresponding efficiency ranging from 55 to 98.9%. Efficiency was dependent upon both the specific filter being studied and the flow rate through that filter. |
Keywords |
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Source Agency |
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NTIS Subject Category |
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Corporate Authors |
Minnesota Univ., Minneapolis. Particle Technology Lab.; National Inst. for Occupational Safety and Health, Cincinnati, OH. |
Supplemental Notes |
See also Volume 2, PB89-152912. Sponsored by National Inst. for Occupational Safety and Health, Cincinnati, OH. |
Document Type |
Technical Report |
Title Note |
Final rept. 1 Sep 84-31 Dec 87, |
NTIS Issue Number |
198911 |