AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Investigation of Breathing Frequency and Inhalation Flow Rate on the Performance of Respirator Filter Medium
QIANG WANG, Laleh Golshahi, Da-Ren Chen, Virginia Commonwealth University
Abstract Number: 117 Working Group: Control and Mitigation Technology
Abstract Filter media for respirator applications are typically exposed to cyclic flows, different from the constant flow adopted in standard testing for respirator filter media. To understand the actual performance of respirator filter media, it is necessary to study the particle penetration through respirator filter media under simulated cyclic flows. In this study, a new method was proposed to investigate the individual impacts of breathing frequency (BF) and peak inhalation flow rate (PIFR) on the performance of respirator filter media. Testing filter media were placed in a standard filter holder (47 mm in diameter) and challenged with DMA (differential mobility analyzer)-classified NaCl particles with the most penetration particle size (MPPS), which was measured at the equivalent-MIRF (mean inhalation flow rate) flow condition prior to the cyclic flow testing. Two CPCs (condensation particle counters) were applied to measure the particle concentration at the upstream and downstream of filter media. Filter penetration at selected DMA-classified particle sizes was derived as the ratio of downstream and upstream aerosol concentrations of test filter media. Experiments were performed under selected cyclic flows with three peak inhalation flow rates (PIFRs), i.e., 9.42, 13.6 and 18.14 LPM, and three breathing frequencies i.e., 6, 12, and 25 breaths per minute (BPM). Six filter media (including two composite media) were tested. The effect of BF and PIFR on the particle collection efficiency of respirator filter media was thus concluded for the collected. The detail of this study will be presented in the talk.