Constant pressure filtration of mono-dispersed deformable particle slurry

Constant pressure filtration experiments of Ca-alginate gel particle, Saccharomyces cerevisiae, and polymethyl methacrylate (PMMA) were conducted to study the local properties of cake layer formation by deformable particles. Effects of particle deformation due to frictional drag and cake mass on cake compression and contact area among particles were examined. The factors that lead to the increase in filtration resistance were discussed. The dynamic analysis proposed by Lu and Hwang in 1993 was modified to analyze formation and compression of cake during cake filtration of deformable particle slurry. A thin skin layer of low porosity and high resistance was formed next to the filter medium due to severe deformation, caused by frictional drag, of the first layer. The results of this study clearly indicate that neglecting the area-contact effect among particles will lead to an overestimate of cake porosity, and neglecting the transient effect of cake compression during gel layer formation will result in an underestimate of cake porosity. The characteristic values of filter cake obtained from dynamic analysis can be used to predict the performance of the filtration of slurries containing deformable particles.