A fundamental study of respiratory air filtration, volume 2.
Mechanical Engineering Department, University of Minnesota, Minneapolis, Minnesota 1988 Sep; :1-203
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 material from the final three chapters of the Grant Final Report. A numerical simulation model was designed and applied to the study of particle collection by electrically charged filter fibers. The results of dimensionless viscous drag calculations on rectangular fibers were presented along with information regarding single electret fiber capture efficiency results due to the Brownian diffusion, interception, or electrostatics. Single fiber capture efficiency was found to be proportional to 0.778, 0.54, and 0.15 powers of the solid volume fraction for the diffusion, interception, and Coulombic force interaction mechanisms, respectively, when an individual mechanism prevailed. The peak penetration of both solid monodisperse sodium- chloride particles and liquid DOP particles through respirator filters ranged from 1.2 to 30 percent at 16 liters per minute (lpm), from 3.5 to 37 percent at 28lpm, and from 6 to 45 percent at 48lpm.
NIOSH-Grant; Respirators; Personal-protective-equipment; Respiratory-protective-equipment; Filter-materials; Mathematical-models
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
University of Minnesota of Mnpls-St Paul, Minneapolis, Minnesota