3D air filtration modeling for nanofiber based filters in the ultrafine particle size range

Abstract

In this work, 3D filtration modeling utilizing realistic SEM image-based 3D structure model, transition/free molecular flow regime, Brownian diffusion, particle-fiber interactions, aerodynamic slip and sieve has been proposed and used for different polyurethane nanofiber-based filters. For the model validation purposes, two polyurethane nanofiber layers prepared by the electrospinning process (having identical average fiber diameter, 120. nm, but different average pore sizes) were combined to form two pairs of nanofiber-based filters; each pair consists of two filters having comparable mass area and thickness. Filtration characteristics of prepared filters were determined experimentally in the ultrafine particle size range (20-400. nm). It has been found that the proposed model is able to reasonably predict the measured filtration efficiency, pressure drop and quality factor for all tested filter samples.