Ultrafiltration and microfiltration module and system

• US 20030057155A1
• Filed: 11/04/2002
• Published: 03/27/2003
• Est. Priority Date: 09/29/1999
• Status: Active Grant

• Current Assignee: Zenon Technology Partnership
• Original Assignee: Andreas Dreasner, Henry Behmann, Hidayat Husain, Michael Blair
• Inventors: Dreasner, Andreas, Behmann, Henry, Husain, Hidayat, Blair, Michael
• Granted Patent: US 6,814,861 B2
• Time in Patent Office: Days
• US Class Current: 210/636
• CPC Class Codes: B01D 2321/04 Backflushing
• CPC Class Codes: B01D 2321/10 Use of feed
• CPC Class Codes: B01D 2321/12 Use of permeate
• CPC Class Codes: B01D 2321/168 Use of other chemical agents
• CPC Class Codes: B01D 2321/2066 Pulsated flow
• CPC Class Codes: B01D 2321/2083 By reversing the flow
• CPC Class Codes: B01D 61/145 Ultrafiltration
• CPC Class Codes: B01D 61/147 Microfiltration
• CPC Class Codes: B01D 61/18 Apparatus therefor
• CPC Class Codes: B01D 63/024 with a single potted end
• 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 of purifying feedwater to remove impurities including suspended solids therefrom, the method suitable for using in-line water pressure to permeate water through hollow fiber membranes and to backflush the membranes to remove solids collected or deposited thereon.

Claims

1. A method of purifying feedwater to remove impurities including suspended solids therefrom, the method using water in-line pressure to permeate water through membranes and to backflush the membranes to remove solids collected thereon, the method comprising:

(a) providing a chamber defined by a wall having an inside and having;

(i) a first end and a second end;

(ii) membranes selected from ultrafiltration and microfiltration membranes extending between said first end and said second end; and

(iii) a feedwater entrance for connecting to a water line to introduce feedwater to said chamber at in-line pressure, a permeate water exit and a concentrate water exit;

(b) introducing feedwater through said entrance to said chamber;

(c) filtering said water in said chamber by using said in-line pressure to pass water through the membranes to provide permeate water inside said membranes and to concentrate suspended solids outside said membranes to provide concentrate water;

(d) collecting said permeate water from said membranes in a permeate collector and dispersing said permeate water for use;

(e) directing a portion of said permeate water to a pressure tank which collects permeate water under in-line water pressure, said pressure tank in liquid connection with said permeate collector; and

(f) periodically draining said chamber to remove concentrate water, concurrently therewith backflushing said membranes with permeate water from said pressure tank to remove solids from said membranes.

2. The method in accordance with claim 1 wherein said membranes are microfiltration membranes.

3. The method in accordance with claim 1 wherein said membranes are ultrafiltration membranes.

4. The method in accordance with claim 1 wherein said in-line water pressure is maintained in a range of 20 psi to 100 psi.

5. The method in accordance with claim 1 including backflushing said chamber with permeate water using 0.2 to 2 chamber volumes of permeate water.

6. The method in accordance with claim 1 including activating said draining and backflushing steps utilizing a single solenoid valve for opening and closing a drain pipe for draining said chamber and backflushing said membrane.

7. The method in accordance with claim 1 wherein said first end is a top of said chamber and said second end is a bottom for said chamber.

8. The method in accordance with claim 1 including continuing to pass feedwater through said chamber to flush concentrate water and solids from said chamber.

9. The method in accordance with claim 1 including periodically draining said chamber at least once every 24 hours.

10. The method in accordance with claim 1 including repeating step (f) immediately upon refilling said pressure tank to provide a double backwashing step.

11. A method of purifying feedwater to remove impurities including suspended solids therefrom, the method using in-line water pressure to permeate water through membranes and to backflush the membranes to remove solids collected thereon, the method comprising:

(a) providing a chamber defined by a wall having an inside and having;

(i) a top and bottom and an upper portion and a lower portion;

(ii) bundles of hollow fiber membranes selected from ultrafiltration and microfiltration membranes extending generally vertically between said top and said bottom; and

(iii) a feedwater entrance provided in said top for connecting to a water line thereto for introducing feedwater to said chamber, a permeate water exit and a concentrate water exit adjacent said bottom;

(b) introducing feedwater through said entrance to said chamber at an in-line water pressure of 20 to 100 psi;

(c) filtering said water in said chamber by using said in-line pressure to pass water through the hollow fiber membranes to provide permeate water inside said hollow fiber membranes and to concentrate suspended solids outside said hollow fiber membranes to provide concentrate water;

(d) collecting said permeate water from said hollow fiber membranes in a permeate collector located adjacent said bottom;

(e) directing a portion of said permeate water to a pressure tank in liquid communication with said collector, said pressure tank collecting permeate water under in-line water pressure; and

(f) periodically flushing said chamber to remove concentrate water, concurrently therewith;

(i) backwashing said hollow fiber membranes with permeate water from said pressure tank to remove solids from said membranes using one-half to two volumes of permeate water as measured by the volume of said chamber, and

(ii) continuing to pass feedwater through said chamber to remove said concentrate water and solids from said chamber.

12. A method of purifying feedwater to remove impurities including suspended solids therefrom, the method using in-line water pressure to permeate water through membranes and to backflush the membranes to remove solids collected thereon, the method comprising:

(a) providing a chamber having a top and bottom and an upper portion and a bottom portion, bundles of ultrafiltration or microfiltration membranes extending generally vertically between said top and said bottom, said hollow fiber membranes having lumens closed at said top and open at said bottom, said chamber having a feedwater entrance adapted for connecting a water line thereto, a permeate water exit adapted for connecting to permeate water distribution means, a concentrate water exit provided for connecting to a drain;

(b) introducing feedwater through said feedwater entrance to said chamber;

(c) filtering said water in said chamber by using said water in-line pressure to pass water through the hollow fiber membranes to provide permeate water in said lumens of said hollow fiber membranes and to concentrate suspended solids outside said hollow fiber membranes to provide concentrate water;

(d) collecting said permeate water from the lumens of said hollow fiber membranes in a permeate collector at in-line pressure;

(e) directing a portion of said permeate water to a diaphragm tank which collects permeate water under in-line pressure water, said diaphragm tank in liquid communication with said permeate collector;

(f) periodically flushing said chamber to remove concentrate water therefrom and concurrently therewith backwashing said hollow fiber membranes with permeate water from said diaphragm tank to remove solids from said membranes; and

(g) during said flushing, continuing to pass feedwater through said chamber to remove said concentrate water and solids from said chamber.

13. A method of purifying feedwater to remove impurities including suspended solids therefrom, the method using in-line water pressure to permeate water through membranes and to backflush the membranes to remove solids collected thereon, the method comprising:

(a) providing a chamber having a top and bottom and an upper portion and a lower portion, a feedwater entrance, a concentrate water exit and a permeate water exit;

(b) providing bundles of hollow fiber membranes selected from ultrafiltration and microfiltration membranes extending generally vertically between said top and said bottom;

(c) introducing feedwater to said chamber through said feedwater entrance;

(d) filtering said water in said chamber by using said in-line water pressure to pass water through the hollow fiber membranes to provide permeate water in lumens of said hollow fiber membranes and to concentrate suspended solids outside said hollow fiber membranes to provide concentrate water;

(e) collecting said permeate water from said hollow fiber membranes in a permeate collection tank located adjacent said bottom;

(f) directing a portion of said permeate water to a diaphragm tank which collects permeate water under in-line water pressure; and

(g) periodically flushing said chamber to remove concentrate water therefrom, concurrently with said flushing, backwashing said hollow fiber membranes with permeate water from said diaphragm tank to remove solids from said membranes.

14. The method in accordance with claim 13 including the steps of introducing a controlled amount of chlorine to said membranes with said backwashing.

17. The method in accordance with claim 13 including the step of treating said permeate water with activated carbon.

18. The method in accordance with claim 13 including repeating step (g) immediately upon re-filling the diaphragm tank to provide a double flushing and backwashing step.

15. A method of purifying feedwater to remove impurities including suspended solids therefrom, the method using in-line water pressure to permeate water through membranes and to backflush the membranes to remove solids collected thereon, the method comprising:

(a) providing a chamber having a top and bottom and an upper portion and a lower portion, a feedwater entrance, a concentrate water exit and a permeate water exit;

(b) providing bundles of membranes selected from ultrafiltration and microfiltration membranes extending generally vertically between said top and said bottom;

(c) introducing feedwater to said chamber through said feedwater entrance;

(d) filtering said water in said chamber by using said in-line water pressure to pass water through the membranes to provide permeate water and to concentrate suspended solids outside said membranes to provide concentrate water;

(e) collecting said permeate water from said membranes in a permeate collection tank located adjacent said bottom;

(f) directing a portion of said permeate water to a diaphragm tank which collects permeate water under in-line water pressure;

(g) periodically flushing said chamber to remove concentrate water therefrom, concurrently with said flushing, backwashing said membranes with permeate water from said diaphragm tank to remove solids from said membranes; and

(h) repeating step (g) at least once to provide multiple flushing and backwashing upon refilling said diaphragm tank.

16. A method of purifying feedwater to remove impurities including suspended solids therefrom, the method using water in-line pressure to permeate water through membranes and to backflush the membranes to remove solids collected thereon, the method comprising:

(a) providing a chamber defined by a wall having an inside and having;

(i) a first end and a second end;

(ii) bundles of membranes selected from ultrafiltration and microfiltration membranes extending between said first end and said second end; and

(iii) a feedwater entrance for connecting to a water line to introduce feedwater to said chamber at in-line pressure, a permeate water exit and a concentrate water exit;

(b) introducing feedwater through said entrance to said chamber;

(c) filtering said water in said chamber by using said in-line pressure to pass water through the membranes to provide permeate water inside said membranes and to concentrate suspended solids outside said membranes to provide concentrate water;

(d) collecting said permeate water from said membranes in a permeate collector and dispersing said permeate water for use;

(e) directing a portion of said permeate water to a pressure tank which collects permeate water under in-line water pressure, said pressure tank in liquid connection with said permeate collector;

(f) periodically draining said chamber to remove concentrate water, concurrently therewith backflushing said membranes with permeate water from said pressure tank to remove solids from said membranes; and

(g) introducing a controlled amount of chlorine to said permeate water used for backflushing said membranes, said chlorine dispersed into said permeate water from said pressure tank during said backflushing.

19. A method of purifying feedwater to remove impurities including suspended solids therefrom, the method using water in-line pressure to permeate water through membranes and to backflush the membranes to remove solids collected thereon, the method comprising:

(a) providing a chamber defined by a wall having an inside and having;

(i) a first end and a second end;

(ii) membranes selected from ultrafiltration and microfiltration membranes extending between said first end and said second end; and

(iii) a feedwater entrance for connecting to a water line to introduce feedwater to said chamber at in-line pressure, a permeate water exit and a concentrate water exit;

(b) introducing feedwater through said entrance to said chamber;

(c) filtering said water in said chamber by using said in-line pressure to pass water through the membranes to provide permeate water inside said membranes and to concentrate suspended solids outside said membranes to provide concentrate water;

(d) collecting said permeate water from said membranes in a permeate collector and dispersing said permeate water for use;

(e) directing a portion of said permeate water to a pressure tank which collects permeate water under in-line water pressure, said pressure tank in liquid connection with said permeate collector; and

(f) periodically draining said chamber to remove concentrate water therefrom.

20. A method of purifying feedwater to remove impurities including suspended solids therefrom, the method using water in-line pressure to permeate water through membranes and to backflush the membranes to remove solids collected thereon, the method comprising:

(a) providing a chamber defined by a wall having an inside and having;

(i) a first end and a second end;

(ii) membranes selected from ultrafiltration and microfiltration membranes extending between said first end and said second end; and

(iii) a feedwater entrance for connecting to a water line to introduce feedwater to said chamber at in-line pressure, a permeate water exit and a concentrate water exit;

(b) introducing feedwater through said entrance to said chamber;

(c) filtering said water in said chamber by using said in-line pressure to pass water through the membranes to provide permeate water inside said membranes and to concentrate suspended solids outside said membranes to provide concentrate water;

(d) collecting said permeate water from said membranes in a permeate collector and dispersing said permeate water for use;

(e) backwashing said membranes 1 to 6 times every 24 hours with permeate water using 0.2 to 2 chamber volumes of said permeate water; and

(f) draining said chamber to remove concentrate water therefrom during said backwashing.

21. A system for purifying feedwater to remove impurities including solids therefrom, the system for use with in-line water pressure to permeate water through membranes and to remove solids collected thereon, the system comprising:

(a) a chamber having a first end and a second end and a first region and a second region, a feedwater entrance for connecting to a feedwater line, a permeate water exit and a concentrate water exit;

(b) membranes provided in said chamber and adapted for permeating water therethrough to purify water to provide permeate water and to reject solids under in-line water pressure to provide concentrate water in said chamber;

(c) a permeate collector for collecting said permeate water through said permeate water exit for distribution;

(d) a pressure tank in fluid connection with said permeate water collector, said pressure tank adapted for storing permeate water at in-line water pressure, said pressure tank adapted for backflushing said membranes with permeate water; and

(e) means for periodically draining concentrate water from said chamber through said concentrate water exit and lowering the pressure in said chamber below in-line water pressure, and means for backwashing said membranes with permeate water from said pressure tank to dislodge solids from said membranes for removal with said concentrate water during said draining, said means for backwashing activated by said means for draining and lowering the pressure in said chamber.

22. The system in accordance with claim 21 wherein said membranes are hollow fiber membranes disposed between said first and said second end, said membranes in fluid connection with said permeate water exit and having dead-ends potted in a first header disposed in said first region of said chamber and second ends potted in a second header disposed in said second region of said chamber, said second ends of said membranes having lumens adapted to empty permeate water into said permeate collector.

23. The system in accordance with claim 21 wherein said membranes are ultrafiltration membranes.

24. The system in accordance with claim 21 wherein said membranes are microfiltration membranes.

25. The system in accordance with claim 21 including providing means for flushing said chamber with feedwater during activation of means for draining and backflushing.

26. The system in accordance with claim 21 wherein the pressure tank is disposed below said chamber.

27. The system in accordance with claim 21 wherein said bundles of membranes are arranged substantially vertically in said chamber and said concentrate water exit is located substantially below said membranes to facilitate draining.

28. A system for purifying feedwater to remove impurities including solids therefrom, the system adapted to use in-line water pressure to permeate water through membranes and to remove solids collected thereon, the system comprising:

(a) a chamber having a first end and a second end, a feedwater entrance in said chamber for connecting to a feedwater line and, a permeate water exit and a concentrate water exit;

(b) bundles of hollow fiber membranes selected from ultrafiltration and microfiltration membranes provided in said chamber and disposed between said first end and said second end, said hollow fiber membranes in fluid connection with said permeate water exit and adapted for permeating water from said chamber therethrough into lumens thereof to purify water and reject solids under in-line water pressure to provide concentrate water in said chamber;

(c) a permeate water collector adapted for removal of permeate water from said lumens for re-distribution;

(d) a pressure tank in liquid communication with said permeate water collector for storing permeate water in said pressure tank at in-line water pressure, said pressure tank adapted for backwashing said membranes with permeate water; and

(e) valve means for periodically draining concentrate water from said chamber through said concentrate water exit and for lowering the pressure in said chamber below in-line water pressure, said valve means by draining and lowering the pressure in said chamber,

(i) activating backwashing of said membranes with permeate water from said diaphragm tank to dislodge solids from said membranes for removal with said concentrate water during said draining, and

(ii) activating flushing of said chamber with feedwater during said periodically draining concentrate water and backwashing.

29. An assembly for purifying feedwater to remove impurities including solids therefrom, the assembly for use with in-line water pressure to permeate water through membranes and to remove solids collected thereon, the assembly comprised of:

(a) a chamber having a first end and a second end, a feedwater entrance located in said first end for connecting to a feedwater line, a permeate water exit and a concentrate water exit;

(b) bundles of hollow fiber membranes provided in said chamber and disposed between said first end and said second end, said hollow fiber membranes in fluid connection with said permeate water exit and adapted for permeating water from said chamber therethrough into lumens thereof to purify water and reject solids under in-line water pressure to provide concentrate water in said chamber;

(c) a permeate collector adapted for collecting water from said lumens for distribution;

(d) a pressure tank coupled to said permeate water collector, said pressure tank adapted for storing permeate water at in-line water pressure, said pressure tank arranged for backwashing said membranes with permeate water; and

(e) valve means arranged for periodically draining concentrate water from said chamber through said concentrate water exit and lowering the water pressure in said chamber below in-line water pressure, said valve means by draining and lowering pressure in said chamber, activating backwashing of said membranes with permeate water from said diaphragm tank to dislodge solids from said membranes for removal with said concentrate water during said draining.

30. An assembly for purifying feedwater to remove impurities including solids therefrom, the assembly for use with in-line water pressure to permeate water through membranes and to remove solids collected thereon, the assembly comprised of:

(a) a chamber having a first end and a second end, a feedwater entrance located in said first end for connecting to a feedwater line, a permeate water exit and a concentrate water exit;

(b) bundles of hollow fiber membranes provided in said chamber and disposed between said first end and said second end, said hollow fiber membranes in fluid connection with said permeate water exit and adapted for permeating water from said chamber therethrough into lumens thereof to purify water and reject solids under in-line water pressure to provide concentrate water in said chamber;

(c) a permeate collector adapted for collecting water from said lumens for distribution;

(d) a pressure tank in fluid connection with said permeate water collector, said pressure tank adapted for storing permeate water at in-line water pressure, said pressure tank adapted for backflushing said membranes with permeate water; and

(e) a controller arranged for periodically opening and closing a concentrate water exit valve to drain concentrate water from said chamber through said concentrate water exit and to lower the pressure in said chamber below in-line water pressure, and said pressure tank activated for backwashing said membranes with permeate water by lowering the pressure in said chamber.

31. A system for purifying feedwater to remove impurities including solids therefrom, the system for use with in-line water pressure to permeate water through membranes and to remove solids collected thereon, comprising:

(a) a chamber having a first end and a second end and a first region and a second region, a feedwater entrance for connecting to a feedwater line, a permeate water exit and a concentrate water exit;

(b) membranes provided in said chamber and adapted for permeating water therethrough to purify water to provide permeate water and to reject solids under in-line water pressure to provide concentrate water in said chamber;

(c) an activated carbon tank coupled to said permeate water exit for collecting permeate water and having a purified water exit for distribution of said purified water;

(d) a pressure tank in liquid communication with said activated carbon tank, said pressure tank adapted for storing permeate water at in-line water pressure, said pressure tank arranged for backwashing said membranes with permeate water; and

(e) valve means for periodically draining concentrate water from said chamber through said concentrate water exit and lowering the water pressure in said chamber below in-line water pressure, said valve means by draining and lowering pressure in said chamber, activating backwashing of said membranes with permeate water from said pressure tank to dislodge solids from said membranes for removal with said concentrate water.

32. The system in accordance with claim 31 wherein a source of chlorine is provided for introducing a controlled amount of chlorine to said hollow fiber membranes with said backwashing with permeate water.

33. A system for purifying feedwater to remove impurities including solids therefrom, the system adapted to use in-line water pressure to permeate water through membranes and to remove solids collected thereon, comprising:

(a) a chamber having a top and a bottom, a feedwater entrance in said chamber for connecting to a feedwater line and, a permeate water exit and a concentrate water exit;

(b) bundles of hollow fiber membranes selected from ultrafiltration and microfiltration membranes provided in said chamber and extending generally vertical between said top and said bottom, said hollow fiber membranes in fluid connection with said permeate water exit and adapted for permeating water from said chamber therethrough into lumens thereof to purify water and reject solids under in-line water pressure to provide concentrate water in said chamber;

(c) a permeate water collector adapted for receiving permeate water from said lumens for re-distribution;

(d) a pressure tank in liquid communication with said permeate water for storing permeate water in said pressure tank at in-line water pressure, said pressure tank adapted for backwashing said membranes with permeate water; and

(e) a controller arranged for periodically opening and closing a concentrate water exit valve to drain concentrate water from said chamber through said concentrate water exit and to lower the pressure in said chamber below in-line water pressure, said pressure tank activated for backwashing said membranes with permeate water by lowering the pressure in said chamber; and

(f) means for flushing said chamber with feedwater during draining said chamber and backwashing said membranes.

34. The system in accordance with claim 33 wherein said permeate water collector contains activated carbon.

35. The system in accordance with claim 33 wherein said pressure tank is disposed below said chamber.

36. A system for purifying feedwater to remove impurities including solids therefrom, the system for use with in-line water pressure to permeate water through membranes and to remove solids collected thereon, the system comprising:

(a) a chamber having a first end and a second end and a first region and a second region, a feedwater entrance for connecting to a feedwater line, a permeate water exit and a concentrate water exit;

(b) membranes provided in said chamber and adapted for permeating water therethrough to purify water to provide permeate water and to reject solids under in-line water pressure to provide concentrate water in said chamber;

(c) a permeate collector for collecting said permeate water through said permeate water exit for distribution;

(d) a pressure tank in fluid connection with said permeate water collector, said pressure tank adapted for storing permeate water at in-line water pressure, said pressure tank adapted for backflushing said membranes with permeate water;

(e) means for periodically draining concentrate water from said chamber through said concentrate water exit and lowering the pressure in said chamber below in-line water pressure, and means for backwashing said membranes with permeate water from said pressure tank to dislodge solids from said membranes for removal with said concentrate water during said draining, said means for backwashing activated by said means for draining and lowering the pressure in said chamber; and

(f) a chlorine dispenser disposed between said pressure tank and said permeate water collector, said dispenser comprising a flexible bladder containing a source of chlorine, said dispenser adapted for dispensing chlorine into permeate water used for backwashing said membranes.

37. The system in accordance with claim 36 wherein said chlorine dispenser is activated to dispense chlorine by permeate water flow during backwashing said membrane, said permeate water flow adapted for compressing said flexible bladder.

38. A system for purifying feedwater to remove impurities including solids therefrom, the system for use with in-line water pressure to permeate water through membranes and to remove solids collected thereon, comprising:

(a) a chamber having a first end and a second end and a first region and a second region, a feedwater entrance for connecting to a feedwater line, a permeate water exit and a concentrate water exit;

(b) membranes provided in said chamber and adapted for permeating water therethrough to purify water to provide permeate water and to reject solids under in-line water pressure to provide concentrate water in said chamber;

(c) an activated carbon tank coupled to said permeate water exit for collecting permeate water and having a purified water exit for distribution of said purified water;

(d) a chlorine dispenser disposed in said activated carbon tank, said dispenser comprising a bladder containing a source of chlorine, said dispenser adapted for dispensing chlorine into permeate water used for backwashing said membranes; and

(e) valve means for periodically draining concentrate water from said chamber through said concentrate water exit and lowering the water pressure in said chamber below in-line water pressure, said valve means by draining and lowering pressure in said chamber, activating backwashing of said membranes with permeate water from said pressure tank to dislodge solids from said membranes for removal with said concentrate water.

39. The system in accordance with claim 38 wherein said bladder is adapted for compression by permeate water flow during backwashing for purposes of said dispensing chlorine into permeate water for backwashing.