The origin of high hydraulic resistance for filter cakes of deformable particles: cell-bed deformation or surface- layer effect?

This study reports a numerical approach for modeling the hydraulic resistance of a filter cake of deformable cells. First, a mechanical and osmotic model that describes the volume fraction of solids in a bed of yeast cells as a function of the compressive pressure it experiences is presented. The effects of pressure on the compressibility of yeast cells beds were further investigated both by filtration experiments and by centrifugal experiments based on the multiple speed equilibrium sediment height technique. When comparing the latter measurements with compression model calculations, we observed that the method based on centrifugal experiments suffers from rapid relaxation of the compressed bed. Concerning the filtration experiments, ∗ Corresponding author. Tel. +33 561 55 8162; fax: +33 561 88 6139 E-mail address: [email protected] (M. Meireles) ha l-0 03 23 04 3, v er si on 1 22 S ep 2 00 8 Author manuscript, published in "Chemical Engineering Science 59, 24 (2004) 5819-5829" DOI : 10.1016/j.ces.2004.06.040