Methods of running and washing spiral wound membrane module

• US 6,432,310 B1
• Filed: 01/20/2000
• Issued: 08/13/2002
• Est. Priority Date: 01/22/1999
• Status: Expired due to Term

• Current Assignee: Nitto Denko Corporation
• Original Assignee: Nitto Denko Corporation
• Inventors: Ohara, Tomomi, Andou, Masaaki, Kawada, Ichirou, Hisada, Hajimu
• Primary Examiner(s): FORTUNA, ANA M
• Application Number:
  US09/488,633
• Time in Patent Office: 936 Days
• Field of Search: 210/636, 210/321.74, 210/650, 210/333.1, 210/333.01, 210/321.83
• US Class Current: 210/636
• CPC Class Codes: B01D 2311/04 Specific process operations in the feed stream; Feed pretreatment
• CPC Class Codes: B01D 2311/12 Addition of chemical agents
• CPC Class Codes: B01D 2321/04 Backflushing
• CPC Class Codes: B01D 2321/185 Aeration
• CPC Class Codes: B01D 61/025 Reverse osmosis; Hyperfiltration
• CPC Class Codes: B01D 61/026 comprising multiple reverse osmosis steps
• CPC Class Codes: B01D 61/04 Feed pretreatment
• CPC Class Codes: B01D 61/12 Controlling or regulating
• CPC Class Codes: B01D 61/145 Ultrafiltration
• CPC Class Codes: B01D 61/147 Microfiltration
• CPC Class Codes: B01D 61/16 Feed pretreatment
• CPC Class Codes: B01D 63/107 Specific properties of the central tube or the permeate channel
• CPC Class Codes: B01D 63/12 comprising multiple spiral-wound assemblies
• CPC Class Codes: B01D 63/16 Rotary, reciprocated or vibrated modules
• CPC Class Codes: B01D 65/00 Accessories or auxiliary operations, in general, for separation processes or apparatus using semi-permeable membranes
• 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 spiral wound membrane element is formed by covering a spiral membrane component prepared by winding a plurality of independent or continuous envelope-like membranes around the outer peripheral surface of a water collection pipe through raw water spacers with a separation membrane and further covering the same with an outer peripheral passage forming material. In washing, permeate containing a chemical is introduced from an opening end of the water collection pipe while the permeate derived from the outer peripheral surface of the water collection pipe is discharged from at least the outer peripheral side of the spiral wound type membrane element and raw water is axially fed along the outer peripheral portion of the spiral wound type membrane element. In filtration running, the raw water in which bubbles are diffused by an air diffuser may be supplied to the spiral wound membrane element stored in a pressure vessel. Alternatively, filtration running may be temporarily stopped for holding the spiral wound type membrane element for a prescribed time in a state sealing the raw water and the permeate in the pressure vessel.

Claims

1. A method of running a spiral wound membrane element for dead-end filtration,

said spiral wound membrane element comprising a spiral membrane component including a perforated hollow pipe, a plurality of independent or continuous envelope-like membranes wound around the outer peripheral surface of said perforated hollow pipe and a raw liquid passage forming member interposed between said plurality of envelope-like membranes, a liquid-permeable membrane covering the outer peripheral portion of said spiral membrane component and an outer peripheral passage forming member entirely or partially covering the outer peripheral surface of said liquid-permeable membrane,

said method comprising steps of:

supplying a raw liquid containing an amount of contaminants and a chemical having a function of separating contaminants or a bactericidal action, from at least an outer peripheral side of said spiral wound membrane element;

flowing the raw liquid through the outer peripheral passage forming member to the outer peripheral portion of the spiral membrane component;

separating contaminants from the raw liquid with the spiral membrane component by dead-end filtration, thereby producing a captured contaminants component and a permeate liquid;

routing the permeate liquid from the spiral membrane component to the perforated hollow pipe; and

removing the permeate liquid from at least one opening end of said perforated hollow pipe.

2. The method of running a spiral wound membrane element according to claim 1, wherein

said chemical is sodium hypochlorite, chloramine, hydrogen peroxide, peracetic acid or ozone.

3. The method of running a spiral wound membrane element according to claim 1, wherein

said raw liquid contains a flocculant.

4. The method of running a spiral wound membrane element, according to claim 1, further comprising a step of introducing a washing liquid containing a chemical having a function of separating contaminants or a bactericidal action from at least one opening end of said perforated hollow pipe and discharging said washing liquid derived from the outer peripheral surface of said perforated hollow pipe through at least the outer peripheral portion of said spiral wound membrane element in washing.

5. The method of running a spiral wound membrane element according to claim 4, wherein

said washing liquid is said permeated liquid.

6. A method of washing a spiral wound membrane element for dead end filtration,

said spiral wound membrane element comprising a spiral membrane component including a perforated hollow pipe, a plurality of independent or continuous envelope-like membranes wound around the outer peripheral surface of said perforated hollow pipe and a raw liquid passage forming member interposed between said plurality of envelope-like membranes, a liquid-permeable membrane covering the outer peripheral portion of said spiral membrane component and an outer peripheral passage forming member entirely or partially covering the outer peripheral surface of said liquid-permeable membrane,

said method comprising steps of:

supplying a raw liquid containing an amount of contaminants from at least an outer peripheral side of said spiral wound membrane element;

flowing the raw liquid through the outer peripheral passage forming member to the outer peripheral portion of the spiral membrane component;

separating contaminants from the raw liquid with the spiral membrane component by dead-end filtration, thereby producing a captured contaminants component and a permeate liquid;

routing the permeate liquid from the spiral membrane component to the perforated hollow pipe; and

removing the permeate liquid from at least one opening end of said perforated hollow pipe;

supplying a washing liquid containing a chemical having a function of separating contaminants or a bactericidal action from at least one opening end of said perforated hollow pipe; and

discharging said washing liquid derived from the outer peripheral surface of said perforated hollow pipe from at least the outer peripheral portion of said spiral wound membrane element.

7. The method of washing a spiral wound membrane element according to claim 6, wherein

said discharging step further comprises a step of dipping said spiral wound membrane element in said washing liquid containing said chemical.

8. The method of washing a spiral wound membrane element according to claim 6, wherein

said chemical is sodium hypochlorite, chloramine, hydrogen peroxide, sulfuric acid, hydrochloric acid, sodium hydroxide, peracetic acid, isopropyl alcohol, oxalic acid or citric acid.

9. The method of washing a spiral wound membrane element according to claim 6, wherein

said discharging step further comprises a step of discharging said washing liquid from at least the outer peripheral portion of said spiral wound membrane element and thereafter axially feeding a raw liquid along the outer peripheral portion of said spiral wound membrane element.

10. The method of washing a spiral wound membrane element according to claim 6, wherein

said discharging step further comprises a step of axially feeding a raw liquid along the outer peripheral portion of said spiral wound membrane element before introducing said washing liquid from at least one opening end of said perforated hollow pipe.

11. The method of washing a spiral wound membrane element according to claim 6, wherein

said discharging step further comprises a step of regularly or periodically feeding a raw liquid axially along the outer peripheral portion of said spiral wound membrane element in parallel with introduction of said washing liquid from at least one opening end of said perforated hollow cylindrical pipe.

12. A method of running a spiral wound membrane module for dead-end filtration comprising a pressure vessel having a raw liquid inlet and one or a plurality of spiral wound membrane elements stored in said pressure vessel,

said spiral wound membrane element comprising a spiral membrane component including a perforated hollow pipe, a plurality of independent or continuous envelope-like membranes wound around the outer peripheral surface of said perforated hollow pipe and a raw liquid passage forming member interposed between said plurality of envelope-like membranes, a liquid-permeable membrane covering the outer peripheral portion of said spiral membrane component and an outer peripheral passage forming member entirely or partially covering the outer peripheral surface of said liquid-permeable membrane,

said method comprising steps of:

supplying a raw liquid containing an amount of contaminants and a chemical having a function of separating contaminants or a bactericidal action, from at least the outer peripheral side of said spiral wound membrane element through said raw water inlet of said pressure vessel;

flowing the raw liquid through the outer peripheral passage forming member to the outer peripheral portion of the spiral membrane component;

separating contaminants from the raw liquid with the spiral membrane component by dead-end filtration, thereby producing a captured contaminants component and a permeate liquid;

routing the permeate liquid from the spiral membrane component to the perforated hollow pipe; and

removing the permeate liquid from at least one opening end of said perforated hollow pipe.

13. A method of washing a spiral wound membrane module comprising a pressure vessel and one or a plurality of spiral wound membrane elements stored in said pressure vessel,

said spiral wound membrane element comprising a spiral membrane component including a perforated hollow pipe, a plurality of independent or continuous envelope-like membranes wound around the outer peripheral surface of said perforated hollow pipe and a raw liquid passage forming member interposed between said plurality of envelope-like membranes, a liquid-permeable membrane covering the outer peripheral portion of said spiral membrane component and an outer peripheral passage forming member entirely or partially covering the outer peripheral surface of said liquid-permeable membrane,

said method comprising steps of:

supplying a raw liquid containing an amount of contaminants from at least an outer peripheral side of said spiral wound membrane element;

flowing raw liquid through the outer peripheral forming member to the outer peripheral portion of the spiral membrane component;

separating contaminants from the raw liquid with the spiral membrane component by dead-end filtration, thereby producing a captured contaminants component and a permeate liquid;

routing the permeate liquid from the spiral membrane component to the perforated hollow pipe;

removing the permeate liquid from at least one opening end of said perforated hollow pipe;

supplying a washing liquid containing a chemical having a function of separating contaminants or a bactericidal action from at least one opening end of said perforated hollow pipe; and

discharging said washing liquid derived from the outer peripheral surface of said perforated hollow pipe through at least the outer peripheral portion of said spiral wound membrane element for taking out said washing liquid from said pressure vessel.

14. A method of running a spiral wound membrane element,

said spiral wound membrane element comprising a spiral membrane component including a perforated hollow pipe, a plurality of independent or continuous envelope-like membranes wound around the outer peripheral surface of said perforated hollow pipe and a raw liquid passage forming member interposed between said plurality of envelope-like membranes, a liquid-permeable membrane covering the outer peripheral portion of said spiral membrane component and an outer peripheral passage forming member entirely or partially covering the outer peripheral surface of said liquid-permeable membrane,

said method comprising steps of:

supplying a raw liquid containing an amount of contaminants from at least an outer peripheral side of said spiral wound membrane element;

flowing the raw liquid through the outer peripheral passage forming member to the outer peripheral portion of the spiral membrane component;

separating contaminants from the raw liquid with the spiral membrane component by dead-end filtration, thereby producing a captured contaminants component and a permeate liquid;

routing the permeate liquid from the spiral membrane component to the perforated hollow pipe; and

removing the permeate liquid from at least one opening end of said perforated hollow pipe; and

diffusing bubbles continuously or intermittently in a liquid coming into contact with the outer peripheral portion of said spiral membrane component.

15. A method of running a spiral wound membrane element,

said spiral wound membrane element comprising a spiral membrane component including a perforated hollow pipe, a plurality of independent or continuous envelope-like membranes wound around the outer peripheral surface of said perforated hollow pipe and a raw liquid passage forming member interposed between said plurality of envelope-like membranes, a liquid-permeable membrane covering the outer peripheral portion of said spiral membrane component and an outer peripheral passage forming member entirely or partially covering the outer peripheral surface of said liquid-permeable membrane,

said method comprising steps of:

supplying a raw liquid containing an amount of contaminants from at least an outer peripheral side of said spiral wound membrane element;

flowing the raw liquid through the outer peripheral passage forming member to the outer peripheral portion of the spiral membrane component;

separating contaminants from the raw liquid with the spiral membrane component by dead-end filtration, thereby producing a captured contaminants component and a permeate liquid;

routing the permeate liquid from the spiral membrane component to the perforated hollow pipe; and

removing the permeate liquid from at least one opening end of said perforated hollow pipe; and

applying ultrasonic vibration continuously or intermittently to a liquid coming into contact with the outer peripheral portion of said spiral membrane component.

16. A method of running a spiral wound membrane module comprising a pressure vessel and one or a plurality of spiral wound membrane elements stored in said pressure vessel,

said spiral wound membrane element comprising a spiral membrane component including a perforated hollow pipe, a plurality of independent or continuous envelope-like membranes wound around the outer peripheral surface of said perforated hollow pipe and a raw liquid passage forming member interposed between said plurality of envelope-like membranes, a liquid permeable material covering the outer peripheral portion of said spiral membrane component and an outer peripheral passage forming member entirely or partially covering the outer peripheral surface of said liquid-permeable material,

said method comprising steps of:

supplying a raw liquid containing an amount of contaminants from at least an outer peripheral side of said spiral wound membrane element;

flowing the raw liquid through the outer peripheral passage forming member to the outer peripheral portion of the spiral membrane component;

separating contaminants from the raw liquid with the spiral membrane component by dead-end filtration, thereby producing a captured contaminants component and a permeate liquid;

routing the permeate liquid from the spiral membrane component to the perforated hollow pipe; and

removing the permeate liquid from at least one opening end of said perforated hollow pipe; and

diffusing bubbles continuously or intermittently in a liquid stored in said pressure vessel.

17. The method of running a spiral wound membrane module according to claim 16, wherein

said step of diffusing bubbles includes a step of supplying a raw liquid from at least the outer peripheral side of said spiral wound membrane element while diffusing bubbles in said raw liquid and a permeate liquid from at least one opening end of said perforated hollow pipe in filtration running.

18. The method of running a spiral wound membrane module according to claim 17, wherein

said supplying step further comprises a step of continuously or intermittently feeding a partial raw liquid axially along the outer peripheral portion of said spiral wound membrane element and removing said partial raw liquid from said pressure vessel in filtration running.

19. The method of running a spiral wound membrane module according to claim 18, wherein

said supplying step further comprises a step of returning said raw liquid removed from said pressure vessel to a supply side of the spiral wound membrane element.

20. The method of running a spiral wound membrane module according to claim 16, wherein

said step of diffusing bubbles further comprises a step of introducing a washing liquid from at least one opening end of said perforated hollow pipe and discharging said washing liquid derived from the outer peripheral surface of said perforated hollow pipe through at least the outer peripheral portion of said spiral wound membrane element while diffusing bubbles in said washing liquid in washing.

21. The method of running a spiral wound membrane module according to claim 16, wherein

said step of diffusing bubbles further comprises a step of axially feeding a raw liquid or a washing liquid along the outer peripheral portion of said spiral wound membrane element while diffusing bubbles in said raw liquid or said washing liquid in flushing.

22. The method of running a spiral wound membrane module according to claim 16, wherein

said step of diffusing bubbles further comprises a step of diffusing bubbles in a raw liquid or a washing liquid stored in said pressure vessel when stopping running.

23. A method of running a spiral wound membrane module comprising a pressure vessel and one or a plurality of spiral wound membrane elements stored in said pressure vessel,

said spiral wound membrane element comprising a spiral membrane component including a perforated hollow pipe, a plurality of independent or continuous envelope-like membranes wound around the outer peripheral surface of said perforated hollow pipe and a raw liquid passage forming member interposed between said plurality of envelope-like membranes, a liquid-permeable membrane covering the outer peripheral portion of said spiral membrane component and an outer peripheral passage forming member entirely or partially covering the outer peripheral surface of said liquid-permeable membrane,

said method comprising steps of:

supplying a raw liquid containing an amount of contaminants from at least an outer peripheral side of said spiral wound membrane element;

flowing the raw liquid through the outer peripheral passage forming member to the outer peripheral portion of the spiral membrane component;

separating contaminants from the raw liquid with the spiral membrane component by dead-end filtration, thereby producing a captured contaminants component and a permeate liquid;

routing the permeate liquid from the spiral membrane component to the perforated hollow pipe; and

removing the permeate liquid from at least one opening end of said perforated hollow pipe; and

applying ultrasonic vibration continuously or intermittently to a liquid stored in said pressure vessel.

24. The method of running a spiral wound membrane module according to claim 23, wherein

said applying step includes a step of supplying a raw liquid from at least the outer peripheral side of said spiral wound membrane while applying ultrasonic vibration to said raw liquid and removing the permeate liquid from at least one opening end of said perforated hollow pipe in filtration running.

25. The method of running a spiral wound membrane module according to claim 23, wherein

said applying step further comprises a step of introducing a washing liquid from at least one opening end of said perforated hollow pipe and applying ultrasonic vibration to said washing liquid while discharging said washing liquid derived from the outer peripheral surface of said perforated hollow pipe from at least the outer peripheral portion of said spiral wound membrane element in washing.

26. The method of running a spiral wound membrane module according to claim 23, wherein

said applying step further comprises a step of axially feeding a raw liquid or a washing liquid along the outer peripheral portion of said spiral wound membrane element and applying ultrasonic vibration to said raw liquid or said washing liquid in flushing.

27. The method of running a spiral wound membrane module according to claim 23, wherein

said applying step further comprises a step of applying ultrasonic vibration to a raw liquid or a washing liquid stored in said pressure vessel when stopping running.

28. The method of running a spiral wound membrane module according to claim 23, wherein

said applying step further comprises a step of continuously or intermittently feeding a partial raw liquid axially along the outer peripheral portion of said spiral wound membrane element and removing said partial raw liquid from said pressure vessel in filtration running.

29. The method of running a spiral wound membrane module according to claim 28, wherein

said applying step further comprises a step of returning said raw liquid removed from the pressure vessel to the supply side of said spiral wound membrane element.

30. A method of running a spiral wound membrane element,

said spiral wound membrane element comprising a spiral membrane component including a perforated hollow pipe, a plurality of independent or continuous envelope-like membranes wound around the outer peripheral surface of said perforated hollow pipe and a raw liquid passage forming member interposed between said plurality of envelope-like membranes, a liquid-permeable membrane covering the outer peripheral portion of said spiral membrane component and an outer peripheral passage forming member entirely or partially covering the outer peripheral surface of said liquid-permeable membrane,

said method comprising steps of:

supplying a raw liquid containing an amount of contaminants from at least an outer peripheral side of said spiral wound membrane element;

flowing the raw liquid through the outer peripheral passage forming member to the outer peripheral portion of the spiral membrane component;

separating contaminants from the raw liquid with the spiral membrane component by dead-end filtration, thereby producing a captured contaminants component and a permeate liquid;

routing the permeate liquid from the spiral membrane component to the perforated hollow pipe; and

removing the permeate liquid from at least one opening end of said perforated hollow pipe; and

stopping running for a prescribed time period and holding said spiral wound membrane element in a state dipped in a liquid for the prescribed time during a running period.

31. The method of running a spiral wound membrane element according to claim 30, wherein

said holding step further comprises a step of supplying a raw liquid from at least the outer peripheral side of said spiral wound membrane element while removing the permeate liquid from at least one opening end of said perforated hollow pipe during filtration running in said running period and stopping said filtration running for holding said spiral wound membrane element in said state dipped in said liquid for the prescribed time.

32. The method of running a spiral wound membrane element according to claim 31, wherein

said holding step further comprises a step of introducing a washing liquid from at least one opening end of said perforated hollow pipe while discharging said washing liquid derived from the outer peripheral surface of said perforated hollow pipe through at least the outer peripheral portion of said spiral wound membrane element in back wash reverse filtration during said running period and stopping said back wash reverse filtration for holding said spiral wound membrane element said state dipped in said liquid for the prescribed time.

33. The method of running a spiral wound membrane element according to claim 32, further comprising a step of restarting said back wash reverse filtration after holding said spiral wound membrane element in said state dipped in said liquid for the prescribed time.

34. The method of running a spiral wound membrane element according to claim 32, further comprising a step of performing filtration running by supplying a raw liquid from at least the outer peripheral side of said spiral wound membrane element while removing a permeated liquid from at least one opening end of said perforated hollow pipe after holding said spiral wound membrane element in said state dipped in said liquid for the prescribed time.

35. The method of running a spiral wound membrane element according to claim 32, further comprising a step of performing flushing by axially feeding a raw liquid along the outer peripheral portion of said spiral wound membrane element after holding said spiral wound membrane element in said state dipped in said liquid for the prescribed time.

36. The method of running a spiral wound membrane element according to claim 32, further comprising a step of supplying a liquid containing a chemical having a bactericidal action or a function of separating contaminants to said spiral wound membrane element and dipping said spiral wound membrane element in said liquid containing said chemical after holding said spiral wound membrane element in said state dipped in said liquid for the prescribed time.

37. The method of running a spiral wound membrane element according to claim 31, further comprising a step of restarting said filtration running after holding said spiral wound membrane element in said state dipped in said liquid for the prescribed time.

38. The method of running a spiral wound membrane element according to claim 31, further comprising a step of performing back wash reverse filtration by introducing a washing liquid from at least one opening end of said perforated hollow pipe while discharging said washing liquid derived from the outer peripheral surface of said perforated hollow pipe through at least the outer peripheral portion of said spiral wound membrane element after holding said spiral wound membrane element in said state dipped in said liquid for the prescribed time.

39. The method of running a spiral wound membrane element according to claim 31, further comprising a step of performing flushing by axially feeding a raw liquid along the outer peripheral portion of said spiral wound membrane element after holding said spiral wound membrane element in said state dipped in said liquid for the prescribed time.

40. The method of running a spiral wound membrane element according to claim 31, further comprising a step of supplying a liquid containing a chemical having a bactericidal action or a function of separating contaminants to said spiral wound membrane element and dipping said spiral wound membrane element in said liquid containing said chemical after holding said spiral wound membrane element in said state dipped in said liquid for the prescribed time.

41. A method of running a spiral wound membrane module comprising a pressure vessel having a raw liquid inlet and one or a plurality of spiral wound membrane elements stored in said pressure vessel,

said spiral wound membrane element comprising a spiral membrane component including a perforated hollow pipe, a plurality of independent or continuous envelope-like membranes wound around the outer peripheral surface of said perforated hollow pipe and a raw liquid passage forming member interposed between said plurality of envelope-like membranes, a liquid-permeable membrane covering the outer peripheral portion of said spiral membrane component and an outer peripheral passage forming member entirely or partially covering the outer peripheral surface of said liquid-permeable membrane,

said method comprising steps of:

supplying a raw liquid containing an amount of contaminants from at least an outer peripheral side of said spiral wound membrane element;

flowing the raw liquid through the outer peripheral passage forming member to the outer peripheral portion of the spiral membrane component;

separating contaminants from the raw liquid with the spiral membrane component by dead-end filtration, thereby producing a captured contaminants component and a permeate liquid;

routing the permeate liquid from the spiral membrane component to the perforated hollow pipe; and

removing the permeate liquid from at least one opening end of said perforated hollow pipe; and

stopping running for a prescribed time period and holding said spiral wound membrane module in a state sealing a liquid in said pressure vessel for the prescribed time period.