About AAQR

Aims and Scope

Articles online
For contributors
Call for Papers
Guideline for the
Special Issue Proposal
Subscription
Information

Advertising

Contact Us
 
Search for  in   Search  Advanced search  

 

Article in Press  PDF(681 KB)  Supplementary MaterialPDFPDF (207 KB)
doi: 10.4209/aaqr.2016.08.0375   

Evaluation of Respirator Filter Media under Inhalation-only Conditions

Qiang Wang, Laleh Golshahi, Da-Ren Chen

Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA

 

Highlights
  • The effects of breathing frequency and peak inhalation flowrate were studied.
  • Breathing frequency has its noticeable effect on particle penetration of filters.
  • The new ratio of peak particle penetration was introduced.
  • Semi-theoretical model was developed to find the peak penetration of filter media.

Abstract

 

Filter media for respirator applications are typically exposed to cyclic flow condition instead of constant flow adopted in the standard filter media tests. The objective of this study is thus to investigate the effects of breathing frequency (BF) and peak inhalation flow rate (PIFR) on the peak particle penetration of respirator filter media, especially for particles at the most penetration particle sizes under the constant flow condition having equivalent mean inhalation flowrate (MIFR). Five respirator filter media were evaluated under inhalation-only conditions. Three BFs and three PIFRs were selected for the testing. Our study evidenced that both BF and PIFR would increase the peak particle penetration under the cyclic inhalation-only conditions. It is further found that, for each filter media, the peak particle penetration at various PIFRs could be merged into one curve via the newly-defined peak penetration ratio (i.e., the ratio of peak particle penetration at cyclic flow condition to the penetration at the constant flow condition having the equivalent MIFR) and the curve is only a function of BF. The above observation indicates that the increase of peak particle penetration resulted from the increase of PIFR is simply because of the increase of MIFR. The effect of BF on the peak particle penetration is clearly observed using the defined penetration ratio. Based on our finding a semi-theoretical model was further proposed to estimate the peak particle penetration of respirator filter media under inhalation-only conditions.

 

 

Keywords: Breathing frequency (BF); Inhalation-only testing; Peak inhalation flowrate (PIFR); Respirator filter media.

 

 

Copyright © 2009-2014 AAQR All right reserved.