Fluid mechanics of membrane-coated ceramic filters

Analytical models are formulated for evaluating the fluid mechanics of membrane-coated, dead-end ceramic filters. The models are applicable to forward flow as in the filtration mode and reverse flow as in the back-pulse cleaning mode. General criteria are derived to size the filter passages from considerations of Darcy pressure drop, friction pressure drop, and the dynamic head. These criteria together with Reynolds numbers are shown to provide measures of nonuniformities in face velocity and pressure that develop in the filter passages for atmospheric and high-pressure applications. A methodology is presented for optimizing the venturi geometry from the standpoint of minimizing pulse gas usage and controlling the thermal load imposed on the filter assembly.