Patent ID: 8652331

Claim:
A method of filtering solids from a liquid suspension in a filtration system comprising: performing a filtration process including providing a pressure differential across a wall of a permeable hollow membrane to induce and sustain filtration through the wall of the permeable hollow membrane; suspending the filtration process; and periodically backwashing pores of the permeable hollow membrane using permeate remaining in the filtration system after suspending the filtration process, the backwashing of the pores dislodging fouling materials therefrom, the backwashing of the pores including: measuring a characteristic of the permeable hollow membrane, the characteristic of the permeable hollow membrane being one of membrane permeability, membrane resistance, and an increase in membrane resistance over a filtration cycle; making a determination of a gas pressure at which to apply backwash gas to the permeate remaining in the filtration system after suspending the filtration process, the determination made responsive to the measured characteristic of the permeable hollow membrane, the gas pressure being one of a high gas pressure below the bubble point of the permeable hollow membrane and a low gas pressure below the bubble point of the permeable hollow membrane, the low gas pressure being lower than the high gas pressure; and applying the backwash gas at the determined gas pressure to the permeate remaining in the filtration system after suspending the filtration process.