Chemical and Biomolecular Engineering Faculty Research


Unified Analysis of Compressive Packed Beds, Filter Cakes, and Thickeners

Document Type


Publication Date

Fall 8-29-1991


Fluid—particle systems are widely used throughout industry. Using an ad hoc approach to model a particular fluid—solid process lacks generality. A unified approach using continuum theory for multiphase systems is applied here to evaluate a packed bed, filter cake, and continuous gravity thickener. The unified approach has the advantage that the governing equations are obtained by simplifying the generalized continuum equations. The simplifying assumptions are obvious from the equations and do not require intuitive understanding as does the ad hoc approach. Also, for similar localized conditions the same constitutive relations can be applied when the same material is used in several processes. In the packed bed, filter cake, and thickener modeled here, a compressible solid matrix behavior is represented by a truncated Taylor series expansion for the solid phase stress. The packed bed and filter cake behaviors are evaluated for a range of pump powers and bed masses or cake heights. The thickener behavior is evaluated for a range of feed and sludge discharge concentrations.

Publication Title

Separation Science and Technology





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