Pressure and Porosity Profiles During Filtration–Expression Process

Abstract—This study presents a numerical model for pressure deliquoring of compressible solids, covering both filtration and expression. A simple and easy-to-solve model for the solid/liquid system is obtained by formulating the basic flux and continuity equations for both solid and liquid phases, the momentum balance for the liquid phase (Darcy’s law) and the momentum for the solid phase (Hooke’s law). Kaolin suspension is used as a product model having elastic behaviour. A computer model was developed to simulate cake formation and cake characteristics during filtration at an individual particle level. The model was shown to be able to generate structural information and quantify the cake thickness, cake solidosity, filtrate volume, filtrate flow rate for constant pressure filtration or pressure drop across the filter unit for constant rate filtration as a function of filtration time. The numerical model of the filtration–expression process seems promising to further improvement of the understanding and control of dewatering of solid/liquid suspensions.