CLEANING METHOD FOR SIMPLE FILTRATION SYSTEMS
First Claim
1. A method of cleaning a permeable, hollow membrane in an arrangement of the type wherein a pressure differential is applied across the wall of the permeable, hollow membrane immersed in a liquid suspension provided in a vessel, said liquid suspension being applied to the outer surface of the permeable hollow membrane to induce and sustain filtration through the membrane wall wherein:
- (a) some of the liquid suspension passes through the wall of the membrane to be drawn off as clarified liquid or permeate from the hollow membrane lumen, and(b) at least some of the solids are retained on, or in, the hollow membrane or otherwise as suspended solids within the liquid surrounding the membrane,the method of cleaning comprising the steps of;
(i) suspending said filtration;
while continuing to supply said liquid suspension to said vessel;
(ii) aerating the membrane by flowing gas into said vessel to produce a flow of gas bubbles around said membrane to dislodge at least some of the retained particulate material;
(iii) removing liquid containing dislodged particulate material from said vessel during said aerating step;
(iv) recommencing said filtration.
3 Assignments
0 Petitions
Accused Products
Abstract
A method of cleaning a permeable, hollow membrane (6) in an arrangement of the type wherein a pressure differential is applied across the wall of the permeable, hollow membrane (6) immersed in a liquid suspension provided in a vessel (5), said liquid suspension being applied to the outer surface of the permeable hollow membrane (6) to induce and sustain filtration through the membrane wall. The method of cleaning comprising the steps of: suspending the filtration process; while continuing to supply the liquid suspension to the vessel (5); aerating the membrane (6) by flowing gas into the vessel (5) to produce a flow of gas bubbles around the membrane (6) to dislodge at least some of the retained particulate material from the membrane surface; removing liquid containing dislodged particulate material from the vessel (5) during the aerating step and recommencing the filtration process.
135 Citations
14 Claims
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1. A method of cleaning a permeable, hollow membrane in an arrangement of the type wherein a pressure differential is applied across the wall of the permeable, hollow membrane immersed in a liquid suspension provided in a vessel, said liquid suspension being applied to the outer surface of the permeable hollow membrane to induce and sustain filtration through the membrane wall wherein:
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(a) some of the liquid suspension passes through the wall of the membrane to be drawn off as clarified liquid or permeate from the hollow membrane lumen, and (b) at least some of the solids are retained on, or in, the hollow membrane or otherwise as suspended solids within the liquid surrounding the membrane, the method of cleaning comprising the steps of; (i) suspending said filtration;
while continuing to supply said liquid suspension to said vessel;(ii) aerating the membrane by flowing gas into said vessel to produce a flow of gas bubbles around said membrane to dislodge at least some of the retained particulate material; (iii) removing liquid containing dislodged particulate material from said vessel during said aerating step; (iv) recommencing said filtration. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A membrane filtration system comprising a permeable, hollow membrane in an arrangement of the type having means for applying a pressure differential across the wall of the permeable, hollow membrane immersed in a liquid suspension provided in a vessel, said liquid suspension being applied to the outer surface of the permeable hollow membrane to induce and sustain filtration through the membrane wall wherein:
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(a) some of the liquid suspension passes through the wall of the membrane to be drawn off as clarified liquid or permeate from the hollow membrane lumen, and (b) at least some of the solids are retained on, or in, the hollow membrane or otherwise as suspended solids within the liquid surrounding the membrane, the filtration system comprising; (i) means for suspending said filtration;
while continuing to supply said liquid suspension to said vessel;(ii) aeration means for aerating the membrane by flowing gas into said vessel to produce a flow of gas bubbles around said membrane to dislodge at least some of the retained particulate material; (iii) means for removing liquid containing dislodged particulate material from said vessel during said aeration of the membrane; (iv) and means for recommencing said filtration. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification