Volume 13, No. 1, February 2013, Pages 162-171 PDF(389 KB)
Factors Affecting Filter Penetration and Quality Factor of Particulate Respirators
Sheng-Hsiu Huang1, Chun-Wan Chen2, Yu-Mei Kuo3, Chane-Yu Lai4, Roy McKay5, Chih-Chieh Chen1
1 National Taiwan University, Taipei 10617, Taiwan
2 Institute of Occupational Safety and Health, New Taipei City 22143, Taiwan
3 Chung Hwa University of Medical Technology, Tainan 71703, Taiwan
4 Chung Shan Medical University, Taichung 40201, Taiwan
5 University of Cincinnati, Cincinnati, Ohio 45221, USA
In the present study, a theoretical model was used to examine factors affecting the filtration characteristics of filters used for respiratory protection. This work was designed to support the particulate filter test requirements established in 1996. The major operating parameters examined in this work include face velocity, fiber diameter, packing density, filter thickness, and fiber charge density. Characteristics of the most penetrating particle size were also modeled with the same operating parameters.
The results showed that aerosol penetration through electret filter media increases with increasing face velocity and increasing fiber diameter, and decreases as packing density, filter thickness or fiber charge density increase. Face velocity and fiber charge density have more significant effects on filter quality than the other factors. Filter quality increases with decreasing face velocity or increasing fiber charge density. For electret filters, (1) the most penetrating particle size increases with increasing fiber diameter; (2) an increase in packing density, thickness, or fiber charge density would cause the most penetrating particle size to decrease, and (3) the most penetrating particle size through electret filters increases with increasing face velocity and decreasing filter thickness. On the other hand, for non-electret filter media, the most penetrating particle size increases with decreasing face velocity, and the filter quality factor is not affected by filter thickness.
Respirator; Filter; Filtration model.