Apparatus and method for cleaning membrane filtration modules
First Claim
1. A method of scrubbing a membrane surface using a liquid medium with a plurality of gas bubbles entrained therein, including the steps of:
- entraining a plurality of gas bubbles into a liquid medium by flow of the liquid medium and a gas into a junction, wherein the liquid medium comprises a cleaning chemical; and
flowing the gas bubbles and liquid medium along a membrane surface to dislodge fouling materials therefrom.
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Accused Products
Abstract
A method and apparatus for cleaning a membrane module, the membrane module having a plurality of porous membranes, the membranes being arranged in close proximity to one another and mounted to prevent excessive movement therebetween and means for providing, from within the module, by means other than gas passing through the pores of the membranes, gas bubbles entrained in a liquid flow such that, in use, the liquid and bubbles entrained therein move past the surfaces of the membranes to dislodge fouling materials therefrom, the gas bubbles being entrained in the liquid by flowing the liquid past a source of gas to draw the gas into the liquid flow. The gas bubbles are preferably entrained into the liquid using a venturi type device. The membranes are preferably partitioned into discrete groups to assist cleaning while maintaining high packing density.
64 Citations
39 Claims
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1. A method of scrubbing a membrane surface using a liquid medium with a plurality of gas bubbles entrained therein, including the steps of:
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entraining a plurality of gas bubbles into a liquid medium by flow of the liquid medium and a gas into a junction, wherein the liquid medium comprises a cleaning chemical; and
flowing the gas bubbles and liquid medium along a membrane surface to dislodge fouling materials therefrom. - View Dependent Claims (2, 3, 4)
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- 5. A membrane module comprising a plurality of porous membranes, the membranes having a plurality of pores, the membranes being arranged in close proximity to one another and mounted to prevent excessive movement therebetween, and a junction connected to a header, a source of gas, and a source of a cleaning chemical for providing, from within the module, a plurality of gas bubbles entrained in a liquid flow, the liquid flow comprising the cleaning chemical, such that, in use, the liquid flow and bubbles entrained therein move past outer surfaces of the membranes to dislodge fouling materials therefrom.
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9. A method of removing fouling materials from the surface of a plurality of porous hollow fiber membranes, the method comprising:
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providing a membrane module comprising a plurality of porous hollow fiber membranes, the membranes mounted and extending longitudinally in an array to form a membrane module, the membranes having a plurality of pores, the membranes being arranged in close proximity to one another and mounted to prevent excessive movement therebetween; and
providing, from within the array, a plurality of gas bubbles entrained in a substantially uniform distribution in a liquid flow, the liquid flow comprising a cleaning chemical, the gas bubbles being entrained in the liquid flow by flowing a gas and a liquid comprising a cleaning chemical into a junction connected to a header so as to cause the gas to be mixed into the liquid, the distribution being such that the gas bubbles pass substantially uniformly between each membrane in the array to, in combination with the liquid flow, scour outer surfaces of the membranes and remove accumulated solids from within the membrane module. - View Dependent Claims (10, 11)
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12. A membrane module, the membrane module comprising:
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a source of a cleaning liquid, the cleaning liquid comprising a cleaning chemical;
a source of a gas;
a first header, the first header having one or more holes formed therein through which the gas and the liquid are introduced;
a second header;
a plurality of porous hollow fiber membranes, the porous hollow fiber membranes being arranged in close proximity and mounted to prevent excessive movement therebetween, the porous hollow fiber membranes being fixed at a first end in the first header and at a second end in the second header; and
a junction, wherein the junction is connected to the first header, the source of the gas, and the source of the cleaning liquid. - View Dependent Claims (13, 14, 16)
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17. A membrane module comprising a plurality of porous hollow fiber membranes and a junction connected to a first header and a source of a cleaning liquid, the cleaning liquid comprising a cleaning chemical, the fiber membranes being arranged in close proximity to one another to form a bundle and mounted to prevent excessive movement therebetween, the fiber membranes being fixed at a first end in the first header and at a second end in a second header, the first header having one or more holes formed therein through which a gas and the cleaning liquid are introduced, and the bundle having a central longitudinal passage extending a length of the bundle between the headers.
- 18. A membrane module comprising a plurality of porous hollow membrane fibers mounted at a first end to a first potting head and at a second end to a second potting head and extending longitudinally between the potting heads, the membranes having a plurality of pores, the membrane fibers being arranged in close proximity to one another and mounted to prevent excessive movement therebetween, the fibers being partitioned into one or more bundles at least at or adjacent to one of the potting heads so as to form a space therebetween, at least one of the potting heads having an array and a connection to a junction, wherein the junction is connected to a gas source and a source of a liquid comprising a cleaning chemical, the junction providing within the module, through a plurality of aeration openings formed in the array, a plurality of gas bubbles entrained within the liquid, such that, in use, the gas bubbles move past outer surfaces of the membrane fibers to dislodge fouling materials therefrom.
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31. A membrane bioreactor comprising:
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a source of a cleaning liquid comprising a cleaning chemical;
a source of a gas;
a membrane module, the membrane module comprising a first header, the first header having one or more holes formed therein through which the gas and the liquid are introduced;
a second header; and
a plurality of porous hollow fiber membranes, the porous hollow fiber membranes being arranged in close proximity and mounted to prevent excessive movement therebetween, the porous hollow fiber membranes being fixed at a first end in the first header and at a second end in the second header, the membrane module provided with means for withdrawing a filtrate from at least one end of the fiber membranes;
a junction, wherein the junction is connected to the first header of the membrane module, the source of the gas, and the source of the cleaning liquid;
a tank having means for introducing the cleaning liquid, wherein the membrane module is positioned within the tank so as to be immersed in an activated sludge; and
means for forming the activated sludge within the tank.
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32. A method of operating a membrane bioreactor, the method comprising the steps of:
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providing a membrane module comprising a plurality of porous hollow membrane fibers mounted at a first end to a first potting head and at a second end to a second potting head and extending longitudinally between the potting heads, the membranes having a plurality of pores, the membrane fibers being arranged in close proximity to one another and mounted to prevent excessive movement therebetween, the fibers being partitioned into one or more bundles at least at or adjacent to one of the potting heads so as to form a space therebetween, at least one of the potting heads having an array and a connection to a junction, wherein the junction is connected to a gas source and a source of a liquid comprising a cleaning chemical, the junction providing within the module, through a plurality of aeration openings formed in the array, a plurality of gas bubbles entrained within the liquid, such that, in use, the gas bubbles move past outer surfaces of the membrane fibers to dislodge fouling materials therefrom;
providing a tank, wherein the membrane module is at least partially immersed in the tank;
introducing a feed to the tank; and
applying a vacuum to the fibers to withdraw a filtrate therefrom while periodically or continuously supplying a plurality of gas bubbles through the aeration openings to within the module such that, in use, the gas bubbles move past the outer surfaces of the membrane fibers to dislodge fouling materials therefrom. - View Dependent Claims (33, 34, 35)
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36. A membrane bioreactor comprising:
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a tank having a feed inlet;
a source of oxygen for forming an activated sludge within the tank;
a source of a gas; and
a membrane module, the membrane module comprising a first header, the first header having one or more holes formed therein through which the gas and the liquid are introduced;
a second header; and
a plurality of porous hollow fiber membranes, the porous hollow fiber membranes being arranged in close proximity and mounted to prevent excessive movement therebetween, the porous hollow fiber membranes being fixed at a first end in the first header and at a second end in the second header;
a junction, wherein the junction is connected to the first header, the source of the gas, and the source of the cleaning liquid;
the membrane module positioned within the tank so as to be immersed in the sludge, and the membrane module provided with a pump for withdrawing a filtrate from at least one end of the fiber membranes.
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37. A membrane module comprising a plurality of porous hollow membrane fibers mounted at a first end to a first potting head and at a second end to a second potting head and extending longitudinally between the potting heads, the membranes having a plurality of pores, the membrane fibers being arranged in close proximity to one another and mounted to prevent excessive movement therebetween, the fibers being partitioned into three or more bundles at least at or adjacent to one of the potting heads so as to form a space therebetween, at least one of the potting heads having a plurality of aeration openings formed in an array, wherein the bundles comprise a wedge-shaped cross section, and wherein the bundles are arranged in an configuration comprising a circular cross section.
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38. A membrane module comprising a plurality of porous hollow membrane fibers mounted at a first end to a first potting head and at a second end to a second potting head and extending longitudinally between the potting heads, the membranes having a plurality of pores, the membrane fibers being arranged in close proximity to one another and mounted to prevent excessive movement therebetween, the fibers being partitioned into two or more bundles at least at or adjacent to one of the potting heads so as to form one or more spaces therebetween, at least one of the potting heads having a plurality of aeration openings formed in an array, wherein each space comprises a cross section comprising two parallel sides.
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39. A membrane module comprising a plurality of porous hollow membrane fibers mounted at a first end to a first potting head and at a second end to a second potting head and extending longitudinally between the potting heads, the membranes having a plurality of pores, the membrane fibers being arranged in close proximity to one another and mounted to prevent excessive movement therebetween, the fibers being partitioned into two or more bundles at least at or adjacent to one of the potting heads so as to form a space therebetween, at least one of the potting heads having a plurality of aeration openings formed in an array, wherein the bundles comprise a circular cross section.
Specification