Data analysis and modeling of constant pressure batch dewatering of fine particle suspensions

Abstract

The problems of data analysis and modeling of experimental constant pressure batch dewatering of materials forming compressible cakes are considered. Dewatering in these materials is typically completed in two stages, viz. cake formation and cake consolidation. A data representation method especially useful for determining the transition point between the filtration and consolidation stages, as well as for comparing accuracy of model predictions, is illustrated. It is shown that dewatering occurs via one of three qualitatively different pathways. A simplified model for engineering analysis of the process is presented. A time-invariant spatially uniform volume fraction of solids approximation is invoked in the cake formation stage. A time-dependent spatially uniform volume fraction of solids assumption is made in the cake consolidation stage. The two models contain four model parameters and have a common physical basis in Darcy's law. Interrelationships between key process parameters are determined and employed to predict the temporal evolution of dewatering in the cake consolidation stage as well as the end point of dewatering.