Cross Flow Membrane Operations

Dead end filtration

Dead end filtration is when flow is applied perpendicular to the membrane surface. Particles smaller than the effective pore size pass through as filtrate, and particles that are larger build up as a cake layer on the membrane surface.

Cross flow filtration

Cross flow filtration is when the flow is applied tangentially across the membrane surface. As feed flows across the membrane surface, filtrate passes through while concentrate accumulates at the opposite end of the membrane. The tangential flow of the membrane creates a shearing effect on the surface of the membrane, which in turn reduces fouling.

Advantages of cross flow versus dead end

Because cross flow removes build up from the surface of the membrane, the permeate flux does not drop as fast when compared to dead end filtration. Cross flow technology also provides the benefit of an improved membrane lifespan by helping to prevent irreversible fouling.