COMPUTER MODELING OF FILTER PRESSING AND CLOGGING IN A RANDOM TUBE NETWORK

During ceramic filtration processes fine particles can be carried along with the filtrate and deposited within the ceramic compact and/or the filter medium thereby clogging and reducing the permeabilities of the porous media. This in turn affects the growth rate of the compact as well as its density and microstructure uniformity. A computer model consisting of a network of tubes with a random size distribution has been developed to simulate the filtration process. The model accounts for porous media clogging due to: (1) fine particles depositing on the pore walls and gradually reducing the pore radii and (2) pores trapping particles larger than the pore openings. The network model shows that the permeability of the porous medium is dependent upon its pore size distribution rather than an average pore size. Minor changes in the pore size distribution due to clogging can cause a significant drop in the permeability of the compact.