Apparatus and method for cleaning membrane filtration modules

• US 20030205519A1
• Filed: 05/01/2003
• Published: 11/06/2003
• Est. Priority Date: 09/25/1998
• Status: Active Grant

• Current Assignee: Evoqua Water Technologies LLC (Xylem, Inc.)
• Original Assignee: US Filter Wastewater Group Incorporated (Siemens AG)
• Inventors: Zha, Fufang, Jordan, Edward John
• Granted Patent: US 6,821,420 B2
• Time in Patent Office: Days
• US Class Current: 210/321.69
• CPC Class Codes: B01D 2313/26 Specific gas distributors or gas intakes
• CPC Class Codes: B01D 2315/06 Submerged-type; Immersion type
• CPC Class Codes: B01D 2321/04 Backflushing
• CPC Class Codes: B01D 2321/16 Use of chemical agents
• CPC Class Codes: B01D 2321/185 Aeration
• CPC Class Codes: B01D 63/031 Two or more types of hollow fibres within one bundle or within one potting or tube-sheet
• 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
• CPC Class Codes: C02F 3/1273 Submerged membrane bioreactors
• CPC Class Codes: Y02W 10/10 Biological treatment of water, waste water, or sewage

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.

Claims

1. 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.

2. The module according to claim 1, further comprising at least one partition, wherein the partition comprises a spacing between bundles.

3. The module according to claim 2, wherein at least one aeration opening is positioned to coincide with at least one partition.

4. The module according to claim 1, further comprising a plurality of partitions, wherein the partitions extend radially from a center of the module.

5. The module according to claim 1, further comprising a central longitudinal passage extending a length of the module between the potting heads.

6. The module according to claim 1, wherein at least one aeration opening comprises a slot or a row comprising a plurality of holes, and wherein a bundle is located in at least one of the potting heads adjacent to the slot or row.

7. The membrane module according to claim 6, wherein the slot or row is situated between two or more of the bundles.

8. The module according to claim 1, comprising at least two aeration openings, wherein a bundle is situated between the aeration openings.

9. The membrane module according to claim 1, wherein the fibers within the module have a packing density of between about 5 and about 70%.

10. The membrane module according to claim 9, wherein the packing density is between about 8 and about 55%.

11. The membrane module according to claim 1, wherein the aeration openings have a diameter or an equivalent diameter averaging between about 1 mm and about 40 mm.

12. The membrane module according to claim 11, wherein the aeration openings have a diameter or an equivalent diameter averaging between about 1.5 mm and about 25 mm.

13. The membrane module according to claim 1, wherein an inner diameter of the fibers averages between about 0.1 mm and about 5 mm.

14. The membrane module according to claim 1, wherein an inner diameter averages between about 0.25 mm and about 2 mm.

15. The membrane module according to claim 1, wherein a wall thickness of the fibers averages between about 0.05 and about 2 mm.

16. The membrane module according to claim 1, wherein a wall thickness averages between about 0.1 mm and about 1 mm.

17. 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.

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 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.