Analytical investigation of free surface flow in multi-layer porous media

In this paper, the free surface flow passing through a multi-layer porous medium is analyzed. An analytical model to describe the flow in multi-layer porous media driven by surface tension and vacuum pressure is proposed. The structure of the medium studied is modeled after those found in Rigid-Capillary-Press (RCP) dewatering devices. The capillary phenomenon is used in RCP to improve the water removal efficiency and the energy consumption in a paper making process. The porous medium is composed of six layers with complex woven fabric structures and pore sizes that range from 5 μm to 2 mm The dewatering performance predicted by the analytical model is compared to the pilot plant experiments with good agreements. The potential of the model to be applied as a parametric optimization tool for industrial RCP porous media design is discussed.