Experimental study on mechanical dewatering and displacement washing of filter cakes with inhomogeneous cake geometry

Abstract

The influence of cake geometry on mechanical gas dewatering and displacement washing of filter cakes is investigated experimentally. For this purpose, five cake geometries are considered. The results show that the dewatering kinetics are independent of cake geometry within the limits of measurement accuracy. Further investigations demonstrate that an inhomogeneous cake geometry negatively influences displacement washing, which can be quantified in a wash diagram. Compared to flat filter cakes used as reference, non-uniform cake heights increase the needed amount of wash liquid to achieve the same cake purity in the dispersion and diffusion regime. This research underlines the importance of ensuring that filter cakes have homogeneous properties to maintain sustainability of industrial filtration processes.