Three-Dimensional Simulation of the Filtration Process of Polydisperse Particulate Matter by Fibrous Filter

Abstract

Fibrous filtration, which has a high capture efficiency for submicron particles, is widely used in coal-fired power plants, mining engineering, cement industries and indoor air purification. The mechanisms by which solid particles are collected include Brownian diffusion, interception, and inertial impaction, as well as mechanisms due to external forces such as electrostatic forces and gravity. Filter cloth is often used to remove the suspended and fine particles, with the cloth's fibers combined through different weaving methods (plain, twill and satin weaves); however, there are few studies on woven filter cloth, and few researchers have investigated the filtration process of polydisperse particles by fibrous filter. The filtration process is an unsteady state, and the growth of dendritic structure – dependant on the initial particle distribution and fiber arrangement – influences the capture efficiency and pressure drop. Gaining insight into the dynamic evolution of the capture efficiency, pressure drop, deposition pattern, and local porosity is very helpful in the design and optimization of filters. In this work, the unsteady filtration process of polydisperse and fine particles was simulated using the Lattice Boltzmann-Cellular Automata (LB-CA) probabilistic model. In addition the dynamic process of dendritic structure growth, and the dependence of the porosity of dendritic structures on the deposited particles, was also investigated.