AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Performance of Respirator Filter Media under Breathing Flow Condition
PENG WANG, Da-Ren Chen, Virginia Commonwealth University
Abstract Number: 303 Working Group: Control and Mitigation Technology
Abstract Respirator filter media in applications typically experience the flow in cyclic patterns due to the nature of human breathing, which is very different from the constant flow used in the NIOSH standard testing method. It is thus necessary to evaluate particulate respirator filter media under simulated human breathing conditions, i.e., at cyclic flow, in order to study the performance of media in practical applications. In this study, a new testing setup was proposed to investigate the performance of respirator filter media under breathing flow condition. In the setup, a special filter holder, integrating the mulit-point sampling probe and make-up air injection probe, was designed. A breathing flow simulator was connected to the filter holder to create the cyclic flow patterns. A condensation monodisperse aerosol generator was used to generate either liquid or solid sub-micro monodisperse particles in high concentration for testing. Two CPCs were used to measure the up- and down- stream number concentrations of test particles, from which the time-dependent particle penetration of filter media could be derived by taking the ratio of measured downstream to upstream concentrations. Because of the 0.1-second sampling time of CPCs, the new testing setup was able to measure close-to-instantaneous particle penetration through respirator filter media. This testing was performed under the inhalation and exhalation condition. Via the new testing method, individual effects of breathing frequency (BF) and peak inhalation flow rate (PIFR) on the collection efficiency of respirator filter media was studied. The performance of respirator filter media under equivalent constant flowrate (MIFR: Mean Inhalation Flow Rate) was also measured to compare with that under cyclic flow condition. The detail of data collected in this study will be presented in the conference.