Filtration System

• US 20080093297A1
• Filed: 01/13/2006
• Published: 04/24/2008
• Est. Priority Date: 01/14/2005
• Status: Abandoned Application

• Current Assignee: Siemens Industry Incorporated (Siemens AG)
• Original Assignee: Siemens Industry Incorporated (Siemens AG)
• Inventors: Butler, David, Gock, Kenneth
• Application Number:
  US11/813,936
• Publication Number:
  US 20080093297A1
• Time in Patent Office: Days
• US Class Current: 210/636
• CPC Class Codes: B01D 2313/06 External membrane module supporting or fixing means
• CPC Class Codes: B01D 2313/24 Specific pressurizing or depressurizing means
• CPC Class Codes: B01D 2315/02 Rotation or turning
• CPC Class Codes: B01D 2315/04 Reciprocation, oscillation or vibration
• CPC Class Codes: B01D 2315/06 Submerged-type; Immersion type
• CPC Class Codes: B01D 2321/04 Backflushing
• CPC Class Codes: B01D 2321/185 Aeration
• CPC Class Codes: B01D 2321/2058 by vibration of the membrane, e.g. with an actuator
• CPC Class Codes: B01D 61/14 Ultrafiltration; Microfiltration
• CPC Class Codes: B01D 61/18 Apparatus therefor
• CPC Class Codes: B01D 61/20 Accessories; Auxiliary operations
• CPC Class Codes: B01D 63/033 Specific distribution of fibres within one potting or tube-sheet
• CPC Class Codes: B01D 63/16 Rotary, reciprocated or vibrated modules
• CPC Class Codes: B01D 65/02 Membrane cleaning or sterilisation ; Membrane regeneration
• CPC Class Codes: C02F 1/444 by ultrafiltration or microfiltration

Abstract

A method and apparatus for cleaning a permeable, hollow membrane (7) in an arrangement of the type wherein a pressure differential is applied across the wall of the permeable, hollow membrane (7) immersed in a liquid suspension, the liquid suspension being applied to the outer surface of the permeable hollow membrane to induce and sustain filtration through the membrane wall, the method of cleaning comprising the step of producing mechanical agitation between the membrane and the liquid suspension to dislodge at least some of the solids retained in or on the membrane. Application of the pressure differential by force of gravity applied to the liquid is also disclosed.

Claims

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, 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) producing mechanical agitation between the membrane and the liquid suspension to dislodge at least some of the retained solids, and

wherein the method further includes removing, at least partially, liquid from the feed side of the membrane before and/or during the step of producing the mechanical agitation.

2. :

A method according to claim 1 wherein the mechanical agitation is produced by moving the membrane relative to the liquid suspension or vice versa.

3. :

A method according to claim 2 wherein the liquid suspension is held in a vessel and the agitation is produced by moving the vessel and the liquid suspension therein relative to the membrane or vice versa.

4. :

A method according to claim 2 wherein said movement includes one or more of the following types of movement;

rotation, lateral movement along an axis of the vessel, rocking movement.

5. :

A method according to claim 4 wherein the movement is oscillatory.

6. :

A method according to claim 1 further including the step of a liquid backwash of the membrane.

7. :

A method according to claim 1 further including the step of a chemical cleaning of the membrane using a cleaning agent.

8. :

A method of cleaning retained solids from the surface of a permeable hollow membrane used in a membrane filtration system including comprising the step of producing mechanical agitation between the membrane and liquid in which the membrane is immersed to dislodge at least some of the retained solids.

9. :

A method according to claim 8 wherein the mechanical agitation is produced by moving the membrane relative to the liquid or vice versa.

10. :

A method according to claim 9 wherein the liquid is held in a vessel and the agitation is produced by moving the vessel and the liquid therein relative to the membrane or vice versa.

11. :

A method according to claim 9 wherein said movement includes one or more of the following types of movement;

rotation, lateral movement along an axis of the vessel, rocking movement.

12. :

A method according to claim 11 wherein the movement is oscillatory.

13. :

A method according to claim 8 further including the step of a liquid backwash of the membrane.

14. :

A method according to claim 8 further including the step of a chemical cleaning of the membrane using a cleaning agent.

15. :

A method of treating a liquid suspension to remove particulate material using one or more permeable hollow membranes, the method comprising the steps of;

(a) applying a pressure differential across the walls of the permeable hollow membranes immersed in a liquid suspension, said liquid suspension being applied to the outer surface of the permeable hollow membranes to induce and sustain filtration through the membrane walls wherein;

(i) some of the liquid suspension passes through the walls of the membranes to be drawn off as clarified liquid or permeate from the hollow membrane lumens, and

(ii) at least some of the particulate material is retained on or in the hollow membranes or otherwise as suspended solids within the liquid surrounding the membranes;

wherein the pressure differential is produced by withdrawing liquid under force of gravity from the fibre lumens.

16. :

A method according to claim 15 wherein the liquid suspension is contained in a closed vessel and the liquid suspension is fed into the vessel under force of gravity such that pressure is applied on the feed side of the membranes by gravity feed of liquid into the vessel.

43. :

A method of treating a liquid suspension to remove particulate material according to claim 16 further including the step of producing mechanical agitation between the membranes and the liquid suspension to dislodge at least some of the retained particulate material.

17. :

A method of treating a liquid suspension to remove particulate material using one or more permeable hollow membranes, the method comprising the steps of;

(a) applying a pressure differential across the walls of the permeable, hollow membranes immersed in a liquid suspension, said liquid suspension being applied to the outer surface of the permeable hollow membranes to induce and sustain filtration through the membrane walls wherein;

(i) some of the liquid suspension passes through the walls of the membranes to be drawn off as clarified liquid or permeate from the hollow membrane lumens, and

(ii) at least some of the particulate material is retained on or in the hollow membranes, or otherwise as suspended solids within the liquid surrounding the membranes;

wherein the liquid suspension is contained in an open vessel and the pressure differential is produced by siphoning liquid from the membrane lumens.

19. :

A method according to claim 17 wherein the mechanical agitation is produced by moving the membrane relative to the liquid suspension or vice versa.

20. :

A method according to claim 19 wherein the liquid suspension is held in a vessel and the agitation is produced by moving the vessel and the liquid suspension therein relative to the membrane or vice versa.

21. :

A method according to claim 19 wherein said movement includes one or more of the following types of movement;

rotation, lateral movement along an axis of the vessel, rocking movement.

22. :

A method according to claim 21 wherein the movement is oscillatory.

23. :

A method according to claim 17 further including the step of a liquid backwash of the membrane.

24. :

A method according to claim 17 further including the step of a chemical cleaning of the membrane using a cleaning agent.

18. :

A method of treating a liquid suspension to remove particulate material using one or more permeable hollow membranes, the method comprising the steps of;

(a) applying a pressure differential across the walls of the permeable hollow membranes immersed in a liquid suspension, said liquid suspension being applied to the outer surface of the permeable hollow membranes to induce and sustain filtration through the membrane walls wherein;

(i) some of the liquid suspension passes through the walls of the membranes to be drawn off as clarified liquid or permeate from the hollow membrane lumens, and

(ii) at least some of the particulate material is retained on or in the hollow membranes, or otherwise as suspended solids within the liquid surrounding the membranes;

(b) suspending said filtration;

(c) producing mechanical agitation between the membranes and the liquid suspension to dislodge at least some of the retained particulate material;

(d) removing liquid containing dislodged particulate material;

(e) recommencing said filtration, and

wherein the method further includes the step of removing, at least partially, liquid from the feed side of the membrane before and/or during the step of producing the mechanical agitation.

25. :

A filtration system including 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, said liquid suspension being applied to the outer surface of the permeable hollow membrane to induce and sustain filtration through the membrane wall comprising;

(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,

wherein the system includes means for cleaning the membrane including means for producing mechanical agitation between the membrane and the liquid suspension to dislodge at least some of the retained solids.

26. :

A filtration system according to claim 25 wherein the mechanical agitation means includes means for moving the membrane relative to the liquid suspension or vice versa.

27. :

A filtration system according to claim 26 wherein the system includes a vessel for holding the liquid suspension and the agitation is produced by moving the vessel and the liquid therein relative to the membrane or vice versa.

28. :

A filtration system according to claim 26 wherein said movement includes one or more of the following types of movement;

rotation, lateral movement along an axis of the vessel, rocking movement.

29. :

A filtration system according to claim 28 wherein the movement is oscillatory.

30. :

A filtration system according to claim 27 wherein the vessel and/or membrane are fixed about an axis and said movement is relative to said axis.

37. :

A filtration system according to claim 25 wherein said mechanical agitation means includes motor driven means.

31. :

A membrane filtration system including one or more permeable, hollow membranes immersed in a liquid and means for cleaning from the surface of a permeable hollow membranes at least some of solids retained thereon during filtration, wherein said cleaning means includes means for producing mechanical agitation between the membrane and liquid in which the membranes are immersed to dislodge at least some of the retained solids.

32. :

A filtration system according to claim 31 wherein the mechanical agitation means includes means for moving the membrane relative to the liquid suspension or vice versa.

33. :

A filtration system according to claim 32 wherein the system includes a vessel for holding the liquid suspension and the agitation is produced by moving the vessel and the liquid therein relative to the membrane or vice versa.

34. :

A filtration system according to claim 32 wherein said movement includes one or more of the following types of movement;

rotation, lateral movement along an axis of the vessel, rocking movement.

35. :

A filtration system according to claim 34 wherein the movement is oscillatory.

36. :

A filtration system according to claim 33 wherein the vessel and/or membrane are fixed about an axis and said movement is relative to said axis.

38. :

Apparatus for treating a liquid suspension to remove particulate material therefrom using one or more permeable hollow membranes, the apparatus comprising;

(a) means for applying a pressure differential across the walls of the permeable hollow membranes immersed in a liquid suspension, said liquid suspension being applied to the outer surface of the permeable hollow membranes to induce and sustain filtration through the membrane walls wherein;

(i) some of the liquid suspension passes through the walls of the membranes to be drawn off as clarified liquid or permeate from the hollow membrane lumens, and

(ii) at least some of the particulate material is retained on or in the hollow membranes or otherwise as suspended solids within the liquid surrounding the membranes;

wherein the means for applying a pressure differential includes means for withdrawing liquid under force of gravity from the fibre lumens.

39. :

Apparatus according to claim 38 further including a closed vessel for containing the liquid suspension and means for feeding the liquid suspension into the vessel under force of gravity such that pressure is applied on the feed side of the membranes by gravity feed of liquid into the vessel.

40. :

Apparatus according to claim 38 further including means for producing mechanical agitation between the membranes and the liquid suspension to dislodge at least some of the retained particulate material.

41. :

Apparatus for treating a liquid suspension to remove particulate material therefrom using one or more permeable hollow membranes, the apparatus comprising;

(a) means for applying a pressure differential across the walls of the permeable, hollow membranes immersed in a liquid suspension contained in an open vessel, said liquid suspension being applied to the outer surface of the permeable hollow membranes to induce and sustain filtration through the membrane walls wherein;

(i) some of the liquid suspension passes through the walls of the membranes to be drawn off as clarified liquid or permeate from the hollow membrane lumens, and

(ii) at least some of the particulate material is retained on or in the hollow membranes, or otherwise as suspended solids within the liquid surrounding the membranes;

wherein the means for applying a pressure differential includes means for siphoning liquid from the membrane lumens.

42. :

Apparatus according to claim 41 further including means for producing mechanical agitation between the membranes and the liquid suspension to dislodge at least some of the retained particulate material.

44-45. -45. (canceled)