Patent ID: 8790515

Claim:
A method of filtering solids from a liquid suspension in a membrane filtration vessel comprising the steps of: promoting filtration of the liquid suspension through membrane walls of permeable, hollow membranes in the vessel, the permeable, hollow membranes including lumens and outer surfaces; drawing off permeate from the hollow membrane lumens; retaining at least some solids on or in the membranes or within the liquid suspension; suspending a flow of the liquid suspension to the vessel; reducing a volume of liquid suspension within the vessel to a predetermined volume by injecting aeration gas from an aeration gas line into the vessel on a feed side of the membranes while the flow of liquid suspension to the vessel is suspended, forcing filtration to continue until the predetermined volume is achieved; suspending the filtration process when the volume of liquid suspension within the vessel has been reduced to the predetermined volume, the injection of the aeration gas continuing while the filtration process is suspended; dislodging at least some of the solids retained on or in the membranes; and removing the liquid suspension containing the dislodged solids from the vessel.