Scale-up Procedures and Test Methods in Solid/LiquidSeparation

Publication Reference: 
25-02
Author Last Name: 
Wakeman
Authors: 
R J Wakeman
Report Type: 
ARR
Research Area: 
Wet Systems
Publication Year: 
1993
Publication Month: 
11
Country: 
United Kingdom

Abstract

Further data are reported on the formation of filter cakes, and data are analysed through the two consecutive mechaisms, filtration and consolidation. Process design parameters for each mechanism are obtained. The magnitude and dependence of the constitutive parameters on solid/liquid mixture properties and operating parameters are shown. It was found that increasing the proportion of finer particles in the feed increased both the cake specific resistance and the equilibrium voids ratio; flocculation at the correct dosage causes higher filtration rates and lower equilibrium voids ratios; an optimum liquid conductivity (and hence ionic strength) exists to maximise the filtration rate; increasing the filtration pressure causes an increase in specific cake resistances and a reduction in equilibrium voids ratios; and a minimum cake resistance (and maximum filtration rate) occurs at the isoelectric point of the suspension. Forms of equations have been developed to calculate equilibrium voids ratios and specific cake resistances of binary mixtures of particles, such as occurs when filter aid is used as a body feed.