Flux enhancement in laminar crossflow microfiltration using a collapsible-tube pulsation generator

A 0.5 g/l suspension of silica particles (range 0.2–8.0 μm) in water was microfiltered in a Millipore 0.2 μm unbaffled tubular ceramic membrane. The crossflow was varied periodically at frequencies inducing fluid-dynamic unsteadiness using a collapsible-tube pulsation generator. The time-averaged Reynolds number at the membrane inlet was 1340. The time-averaged transmembrane pressure, P ̄ tm , was systematically varied from 70 to 180 kPa. With pulsation the filtrate flux reached a plateau faster than in steady flow at the same P ̄ tm and time-averaged crossflow velocity. The flux enhancement (pulsating-flow flux/steady-flow flux) increased with increasing P ̄ tm , reaching 450%.