MASS-TRANSFER ENHANCEMENT BY SUSPENSIONS IN A SHEAR-FLOW

Electrochemical measurement of mass transfer enhancement in a dilute suspension of particles, due to particle rotation in the presence of a shear flow, has been studied with a Couette cell. An effective diffusivity D(e) involving the Peclet number Pe of the particles and the molecular diffusivity D of the solute was obtained for low particle volume fraction-phi as D(e) = D(1 + 3.5-phi-Pe1/2). From steady-state and transient data, it was shown that aggregation may occur with alumina particles and that inertial effects due to centrifugation reveal a marginal layer free of particles near the rotating inner cylinder.