Abstract
Membrane filters with a relatively low porosity have net-like or agglomerate-like structure and the internal flow field in these filters is so complicated that neither the channel model nor the single fiber model are directly applicable to predict its collection efficiency for aerosol filtration. The present work proposes a simple method for predicting collection efficiency of these membrane filters in diffusion-interception control regimes based on channel model , which employs an effective pore diameter calculated by the pressure drop and an adjustable parameter of dimensionless pore length. In order to determine diffusion-interception control regimes for particle collection, collection efficiency of a single pore was calculated in terms of interception parameter and Peclet number. Then, the measurements of collection efficiency of net- and agglomerate-like filters were conducted in the interception and diffusion control regime. The experimental particle penetrations were compared with those predicted by the present model. As a result, the proposed model gave a fairly good prediction for both net- and agglomerate-like filters by assuming a value of dimensionless pore length between 0.5 and 0.8.
