Patent ID: 8784662

Claim:
A filtration process comprising providing a membrane module including a membrane defining opposing permeate and retentate sides, an inlet and an outlet, a feed stream flowing from the inlet to the outlet axially along the retentate side of the membrane, a permeate stream flowing axially from the inlet to the outlet along the permeate side of the membrane, and a permeate recirculation loop for providing co-current permeate recirculation flow to the module; adjusting the flow rate or pressure on the permeate or retentate side of the membrane to provide baseline pressures at the inlet and the outlet on the permeate and retentate sides of the membrane such that the difference in baseline pressures between the permeate and retentate sides of the membrane is substantially the same at the inlet and the outlet, wherein the baseline pressure on the permeate side of the membrane is greater at the inlet than the baseline pressure at the outlet and the baseline pressure on the retentate side of the membrane is greater at the inlet than the baseline pressure at the outlet; and periodically performing a reverse uniform transmembrane pressure (rUTMP) process by either increasing the permeate pressure or decreasing the retentate pressure, resulting in a controllable overpressurization on the permeate side of the membrane in comparison with the pressure on the retentate side of the membrane to provide backflow across the membrane while axial flow is maintained from the inlet to the outlet on both sides of the membrane, wherein the difference in pressures between the permeate and retentate sides of the membrane is substantially the same at the inlet and the outlet during said rUTMP process.