Modeling of Cross-Flow Across an Electrostatically Charged Monolith Filter

Abstract

The flow field and filtration efficiency of electrostatically charged micro-channel filters under cross-flow conditions were modeled. In our simulations, the fluid flows tangentially to the filter face (cross-flow). Particles with diameters larger than 2 μm were considered in this study, hence, the effects of Brownian motion were not included in the simulations. The influence of particle size, pressure drop, and electrostatic charge on the filtration efficiency was investigated. Measurements from performing electrostatic force microscopy (EFM) on the monolith sample confirmed the presence of charge and gave a qualitative measurement of the charge distribution. Results from the flow simulations indicate that the electrostatic forces increased the particle capture efficiency only at lower pressure drop. At higher pressure drops, electrostatic forces did not significantly increase the capture efficiency of the particles. Also, the capture efficiency of relatively small particles is found to be more dependent on the pressure drop across the filter than that of larger particles.