A Generalized Predictive Model for Displacement Washing of Partially Reslurried Filter Cakes

ABSTRACT

Displacement washing is a common process to increase product quality after cake filtration. During this process, impurities or valuable substances dissolved in the pore liquid are displaced by a wash liquid that is usually applied to the cake surface via nozzles, drip plates, or overflow channels. On impact of the wash liquid, the filter cake is partially reslurried, causing the wash liquid to be contaminated by dissolved impurities of the re‐dispersed filter cake surface. This contamination affects the washing process to a great extent. This article presents a generalized model to predict washing results of partially reslurried filter cakes on both discontinuous and continuous equipment. Model calculations are validated for different cases with experimental washing results. Partial cake reslurrying is identified as a new limiting effect for displacement washing.