AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Artifacts in Filter Penetration Measurements Associated with Multiple Charging of Particles
MEILU HE, Suresh Dhaniyala, Matthew Wagner, Clarkson University
Abstract Number: 284 Working Group: Control Technology
Abstract A critical characteristic of filter performance is its size-dependent particle capture efficiency. The capture efficiency of a filter is usually established by challenging the filter with mono-mobility particles from a differential mobility analyzer (DMA) and determining change in particle concentrations upstream and downstream of the filter. It's often assumed that the particles exiting the DMA are singly charged, and hence monodisperse in size. The contribution of multiply-charged particles to the filter efficiency measurements can, however, be important under some conditions. This is particularly the case when the test particles entering the DMA have a peak size larger than the most penetrating particle size of the test filter. Under such a test condition, even a small number of multiply-charged particles corresponding to a highly penetrating size can significantly skew filter particle capture results. In our presentation, we will highlight the role of multiple charging on filter penetration measurements and propose solutions to eliminate this problem and ensure accurate measurements.