Modeling Approach to Mechanical Gas Dewatering of Filter Cakes With Non-Uniform Cake Height

Abstract

Gas dewatering of filter cakes with non-uniform cake height is investigated. Two-phase fluid flow is described in a continuum approach by conservation of mass and momentum of both phases. A priori measurements of capillary pressure and relative permeability allow to predict the impact of different cake geometries on the dewatering kinetics. Transient saturation and flow velocity fields within the filter cakes are calculated and discussed. No measurable effect on the mean saturation is observed in the investigated cases. However, the total flux, which needs to be handled by the vacuum pump to prevent a drop of the pressure difference during gas dewatering, is affected significantly by cake geometry. Model predictions are compared to experimental data from preceding publications and show reasonable agreement within the margin of error.