Method of cleaning membrane modules
First Claim
1. A method for cleaning a membrane filtration module, the module comprising at least one membrane located in a feed-containing vessel, the membrane comprising a permeable wall, the method comprising:
- conducting a filtration operation wherein a feed is applied to a first side of the permeable wall and a filtrate is withdrawn from a second side of the permeable wall;
suspending the filtration operation;
performing a cleaning process on the permeable wall to dislodge a contaminant therefrom into a liquid surrounding the membrane;
forming a gas-containing region on the first side of the permeable wall;
sealing the feed-containing vessel;
pressurizing a gas within the gas-containing region via a backwash operation;
opening a lower valve of the feed-containing vessel to atmosphere when a pressure on the first side of the membrane equals a pressure on the second side of the membrane to generate an instantaneous negative transmembrane pressure, whereby the gas-containing region expands and produces a high velocity sweep of the feed-containing vessel to remove the liquid containing the dislodged contaminant through the lower valve; and
suspending the backwash operation when the high velocity sweep of the feed-containing vessel is complete.
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Accused Products
Abstract
A method of cleaning a membrane filtration module (6), the module (6) including at least one membrane (8) located in a feed-containing vessel (7), the membrane (8) having a permeable wall which is subjected to a filtration operation wherein feed containing contaminant matter is applied to one side of the membrane wall and filtrate is withdrawn from the other side of the membrane wall. The method comprising the steps of: suspending the filtration operation; performing a cleaning process on the membrane wall to dislodge contaminant matter therefrom into liquid surrounding the membrane (8); performing a high velocity sweep of the feed-containing vessel (7) to remove the liquid containing the dislodged contaminant matter; and recommencing the filtration operation. An improved gas scouring method is also disclosed.
629 Citations
14 Claims
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1. A method for cleaning a membrane filtration module, the module comprising at least one membrane located in a feed-containing vessel, the membrane comprising a permeable wall, the method comprising:
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conducting a filtration operation wherein a feed is applied to a first side of the permeable wall and a filtrate is withdrawn from a second side of the permeable wall; suspending the filtration operation; performing a cleaning process on the permeable wall to dislodge a contaminant therefrom into a liquid surrounding the membrane; forming a gas-containing region on the first side of the permeable wall; sealing the feed-containing vessel; pressurizing a gas within the gas-containing region via a backwash operation; opening a lower valve of the feed-containing vessel to atmosphere when a pressure on the first side of the membrane equals a pressure on the second side of the membrane to generate an instantaneous negative transmembrane pressure, whereby the gas-containing region expands and produces a high velocity sweep of the feed-containing vessel to remove the liquid containing the dislodged contaminant through the lower valve; and suspending the backwash operation when the high velocity sweep of the feed-containing vessel is complete. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification