Experimental study of colloidal flow in porous media at high velocities

Abstract

Latex colloidal particle deposition onto an engineered porous medium has been studied at high suspension velocities at conditions favorable for particle attachment. Low value of ratio between particle diameter and mean pore size ensured the absence of particle straining due to size exclusion. Particle deposition is accompanied by the formation and destruction of bridges at high flow velocities accompanied by a sudden increase in hydraulic resistance. Treatment of experimental permeability data with the Forchheimer equation shows that the formation damage coefficient is a function of the critical retained concentration and inverse function of fluid velocity. The inertia coefficient shows similar behavior at low velocities, although it remained almost constant at low surface coverage. Particle deposition at lower fluid velocities is accompanied by a significant increase of inertia coefficient and formation damage. This is explained by a partial formation of the external cake on the inlet surface of the filter. Deep bed filtration continues even at high surface coverage and is characterized by a high filtration coefficient at lower velocities.