Premium
A Mean Phi Model for Pressure Filtration of Fine and Colloidal Suspensions
Author(s) -
Raha Sasanka,
Khilar Kartic C.,
Kapur Pradip,
Kapur Prakash C.
Publication year - 2006
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450840112
Subject(s) - filter cake , volume fraction , filtration (mathematics) , colloid , dewatering , permeability (electromagnetism) , thermodynamics , chemistry , physics , chromatography , mathematics , membrane , engineering , biochemistry , statistics , geotechnical engineering
A working model for engineering analysis of pressure filtration is presented. Based on the filtration characteristics of fine and colloidal suspensions, the process was divided into two stages. A time‐invariant spatially uniform volume fraction of solids approximation is invoked in the growing filter cake stage (stage 1). A time‐dependent spatially uniform volume fraction of solids assumption is made in the cake consolidation stage (stage 2). The two models, named collectively as Mean Phi (M‐P) model, have a common physical basis, seamless continuity between the stages and internal consistency. The M‐P model has only three parameters: terminal or equilibrium volume fraction of solids in the filter cake that is related to its compressive yield stress, critical volume fraction of solids, which joins stage 1 and stage 2, and a permeability factor, which is common to stages 1 and 2. The model is validated with a large number of colloidal suspensions filtered under highly diverse physical‐chemical process conditions. A Pareto profile is identified that relates the timescale of filtration and the extent of dewatering achieved, the two most important performance indices of the process.