Aeration method

• US 20050139538A1
• Filed: 02/16/2005
• Published: 06/30/2005
• Est. Priority Date: 08/21/2002
• Status: Active Grant

• Current Assignee: Evoqua Water Technologies LLC
• Original Assignee: Siemen Water Technologies Corporation (Siemens AG)
• Inventors: Lazaredes, Huw Alexander
• Granted Patent: US 7,361,274 B2
• Time in Patent Office: Days
• US Class Current: 210/321.690
• CPC Class Codes: B01D 2201/087 using gas bubbles, e.g. air
• CPC Class Codes: B01D 2313/26 Specific gas distributors or gas intakes
• CPC Class Codes: B01D 2321/185 Aeration
• CPC Class Codes: B01D 29/114 arranged for inward flow filtration B01D29/15, B01D29/33 take precedence
• CPC Class Codes: B01D 29/62 Regenerating the filter material in the filter devices for taking out of action one or more units of multi-unit filters, e.g. for regeneration, B01D35/12
• CPC Class Codes: B01D 29/6438 nozzles
• CPC Class Codes: B01D 63/026 Wafer type modules or flat-surface type modules
• CPC Class Codes: B01D 65/02 Membrane cleaning or sterilisation ; Membrane regeneration
• CPC Class Codes: B01D 65/08 Prevention of membrane fouling or of concentration polarisation

Abstract

A method and filtration module (5) for providing gas bubbles within an array of vertically disposed porous hollow membranes (6) to clean the outer surfaces of said membranes (6) when the array is immersed in a liquid by feeding (10) the gas bubbles into the array transversely of the vertical axis of the array. In one preferred form, the gas bubbles are retained within the array using a sleeve (11) surrounding the array (6) at least along part of its length.

Claims

1. A method of cleaning outer surfaces of membranes for use in filtering a liquid, the method comprising the steps of:

providing an array of vertically disposed porous hollow membranes immersed in the liquid; and

feeding gas bubbles into the array transversely of a vertical axis of the array, whereby the outer surfaces of the membranes are cleaned.

2. The method according to claim 1, wherein the method further comprises the step of:

retaining the gas bubbles within the array using a sleeve surrounding the array along at least a part of a length of the array.

3. A membrane filtration module comprising a plurality of vertically disposed porous hollow membranes and a gas feeder configured, when in use, to feed gas bubbles into the array transversely of the vertical axis of said array.

4. The membrane filtration module according to claim 3, wherein the module further comprises a sleeve surrounding the array along at least a part of a length of the array, wherein the sleeve, when in use, retains the gas bubbles within the array.

5. The membrane filtration module according to claim 4, wherein the sleeve extends along about 17% or greater of the length of the array.

6. The membrane filtration module according to claim 4, wherein the sleeve extends along a major portion of a length of the membranes.

7. The membrane filtration module according to claim 4, wherein the sleeve is situated adjacent to the gas feeder and above the gas feeder.

8. The membrane filtration module according to claim 3, wherein said porous hollow membranes comprise hollow fibre membranes.

9. The membrane filtration module according to claim 8, wherein the membranes are arrayed in a generally cylindrical bundle.

10. The membrane filtration module according to claim 3, wherein the gas feeder comprises a tube configured to extend around the periphery of the array, the tube comprising a plurality of openings in the inner surface of the tube adjacent to the array of membranes configured to feed gas into the array during use.

11. The membrane filtration module according to claim 10, wherein the openings in the tube comprise extensions, the extensions comprising tubes extending into the array.

12. A membrane filtration module according to claim 3, wherein a plurality of gas feeders are provided along a length of the array.

14. The membrane filtration module according to claim 3, wherein the module further comprises a sleeve surrounding the array along at least a part of a length of the array, wherein the sleeve, when in use, retains the gas bubbles within the array.

15. The membrane filtration module according to claim 4, wherein the sleeve extends along about 17% or greater of the length of the array.

16. The membrane filtration module according to claim 4, wherein the sleeve extends along a major portion of a length of the membranes.

17. The membrane filtration module according to claim 4, wherein the sleeve is situated adjacent to the gas feeding means and above the gas feeding means.

18. The membrane filtration module according to claim 3, wherein said porous hollow membranes comprise hollow fibre membranes.

19. The membrane filtration module according to claim 8, wherein the membranes are arrayed in a generally cylindrical bundle.

20. A membrane filtration module according to claim 3, wherein a plurality of gas feeding means are provided along a length of the array.

13. A membrane filtration module comprising a plurality of vertically disposed porous hollow membranes and gas feeding means to feed gas bubbles into the array transversely of the vertical axis of said array.