NIOSHTIC-2 Publications Search
A fundamental study of respiratory air filtration, volume 1.
Mechanical Engineering Department, University of Minnesota, Minneapolis, Minnesota, Particle Technology Laboratory Publication No. 680 1988 Sep; :1-219
The purpose of this grant was to study characteristics of particulate air filters used in respiratory protective devices. In particular, 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. This specific report contained the first four chapters of the full report and dealt with the history of respirator development (types of respirators, types of hazardous particulates, respirator approval tests, and previous work on respirator filter testing); reviewed electrostatic filtration; presented experimental work relating to this 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 percent. Efficiency was dependent upon both the specific filter being studied and the flow rate through that filter.
NIOSH-Grant; Respirators; Personal-protective-equipment; Respiratory-protective-equipment; Filter-materials
Mechanical Engineering University of Minnesota 111 Church Street, S E Minneapolis, Minn 55455
Final Grant Report
NTIS Accession No.
Mechanical Engineering Department, University of Minnesota, Minneapolis, Minnesota, Particle Technology Laboratory Publication No. 680
University of Minnesota of Mnpls-St Paul, Minneapolis, Minnesota
Page last reviewed: May 5, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division