Porosity Investigations of Fine-Grained Filter Cake

Abstract

Conventional filtration theory states that the filtrate flow rate depends on the porosity of the filter cake, so that its prediction requires advance knowledge of the porosity. A previous paper proposes a new theoretically supported approach to the prediction of the porosity of fine-grained filter cake. This approach considers the agglomeration phenomena in the filter cake determined by the adhesive forces between the particles on the one hand, and the disruption of the agglomerates by the drag force of filtrate flow on the other. The model is derived from the balance of forces and includes common filtration parameters (pressure difference, particle size and filter cake height) as well as the free specific surface energy of the particles as a measure of the agglomeration activity. In order to verify the model, porosity measurements were compared with porosity predictions. The results of this validation study are presented in this paper.