Dual head pump driven filtration system

• US 7,297,268 B2
• Filed: 01/16/2004
• Issued: 11/20/2007
• Est. Priority Date: 05/25/1999
• Status: Expired due to Fees

• Current Assignee: Miox Corporation (Industrie De Nora S.p.A)
• Original Assignee: Miox Corporation (Industrie De Nora S.p.A)
• Inventors: Herrington, Rodney E., Hand, Frank R.
• Primary Examiner(s): Menon; Krishnan S.
• Application Number:
  US10/759,753
• Publication Number:
  US 20040178145A1
• Time in Patent Office: 1,404 Days
• Field of Search: None
• US Class Current: 210/321.66
• CPC Class Codes: B01D 2311/04 Specific process operations in the feed stream; Feed pretreatment
• CPC Class Codes: B01D 2311/16 Flow or flux control
• CPC Class Codes: B01D 2321/2016 Static mixers; Turbulence generators
• CPC Class Codes: B01D 61/025 Reverse osmosis; Hyperfiltration
• CPC Class Codes: B01D 61/04 Feed pretreatment
• CPC Class Codes: B01D 61/06 Energy recovery
• CPC Class Codes: B01D 61/08 Apparatus therefor
• CPC Class Codes: B01D 61/10 Accessories; Auxiliary operations
• CPC Class Codes: B01D 61/12 Controlling or regulating
• CPC Class Codes: B01D 63/10 Spiral-wound membrane modules
• CPC Class Codes: B01D 65/08 Prevention of membrane fouling or of concentration polarisation
• CPC Class Codes: B01D 67/0088 Physical treatment with compounds, e.g. swelling, coating or impregnation
• CPC Class Codes: B01D 69/00 Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
• CPC Class Codes: B01D 69/02 characterised by their properties
• CPC Class Codes: B01D 69/141 Heterogeneous membranes, e.g. containing dispersed material; Mixed matrix membranes
• CPC Class Codes: B29C 41/20 incorporating preformed parts or layers, e.g. moulding inserts or for coating articles
• CPC Class Codes: B41J 3/407 for marking on special material
• CPC Class Codes: C02F 1/001 Processes for the treatment of water whereby the filtration technique is of importance C02F1/44 takes precedence; construction of filters in general B01D24/00 - B01D41/00
• CPC Class Codes: C02F 1/44 by dialysis, osmosis or reverse osmosis general membrane separation processes B01D61/00, membrane modules B01D63/00, electrodialysis C02F1/4693, combination of membrane modules and bioreactors C02F3/1268
• CPC Class Codes: C02F 1/441 by reverse osmosis
• CPC Class Codes: C02F 1/46104 : Devices therefor; Their operating or servicing
• CPC Class Codes: C02F 1/4674 : with halogen or compound of halogens, e.g. chlorine, bromine
• CPC Class Codes: C02F 2001/46119 : Cleaning the electrodes
• CPC Class Codes: C02F 2001/46128 : Bipolar electrodes
• CPC Class Codes: C02F 2001/46142 : Catalytic coating
• CPC Class Codes: C02F 2103/08 : Seawater, e.g. for desalination
• CPC Class Codes: C02F 2201/4611 : Fluid flow
• CPC Class Codes: C02F 2201/4612 : Controlling or monitoring
• CPC Class Codes: C02F 2201/4615 : Time
• CPC Class Codes: C02F 2201/46165 : Special power supply, e.g. solar energy or batteries
• CPC Class Codes: C02F 2201/4618 : Supplying or removing reactants or electrolyte
• CPC Class Codes: C02F 2209/04 : Oxidation reduction potential [ORP]
• CPC Class Codes: C02F 2209/10 : Solids, e.g. total solids [TS], total suspended solids [TSS] or volatile solids [VS]
• CPC Class Codes: C02F 2303/04 : Disinfection
• CPC Class Codes: C02F 9/00 : Multistage treatment of water, waste water or sewage
• CPC Class Codes: C02F 9/20 : Portable or detachable small-scale multistage treatment devices, e.g. point of use or laboratory water purification systems
• CPC Class Codes: F04B 43/04 : Pumps having electric drive
• CPC Class Codes: F04B 43/073 : the actuating fluid being controlled by at least one valve
• CPC Class Codes: F04B 9/107 : rectilinear movement of the pumping member in the working direction being obtained by a single-acting liquid motor, e.g. actuated in the other direction by gravity or a spring
• CPC Class Codes: F04B 9/14 : Pumps characterised by muscle-power operation hand-held spraying or dispensing apparatus using pumps or bulbs B05B11/00
• CPC Class Codes: Y02A 20/131 : Reverse-osmosis
• CPC Class Codes: Y02A 20/144 : Wave energy
• CPC Class Codes: Y02P 70/10 : Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working

Abstract

Improvements in product water throughput from a reverse osmosis (RO) membrane achieved by thinner feed spacers in the RO element (22), enhanced recovery (ratio of permeate to feed), pressure recovery of the retentate fluid pressure opposing the feed water pressure, and fluid pulsing of the RO element feed stream. These features are preferably combined to optimize the performance and cost per unit volume of water produced. The system of the invention preferably comprises a dual head reciprocating pump (20), an RO element (22) with a housing, and a differential pressure activated (“DPA”) valve (24). The DPA valve (24), in combination with offsetting fluid pressures on the two pump heads (28, 30), generate energy recovery. The frequency and amplitude of the reciprocating pump (20) create a pulse wave in the RO element (22) that improves permeate quality and throughput. A control system preferably monitors system parameters to optimize the reciprocating pump (20) speed and amplitude to tune the optimal frequency and amplitude required for maximum throughput and permeate quality from any given RO element (22) configuration.

Claims

1. A filtration system comprising:

a dual head pump comprising a single primary feed head and a single secondary retentate head separate from said primary feed head;

a hydraulically actuated differential pressure activated (DPA) valve; and

a filtration element;

wherein a front side of said primary feed head comprises a different swept volume than a front side of said secondary retentate head; and

wherein said DPA valve comprises;

a single piston slideably disposed in a single chamber, said chamber comprising a feed inlet port, a retentate inlet port, and a retentate discharge port; and

said piston comprising a feed side and a retentate side;

wherein an area of said feed side is larger than an area of said retentate side for keeping said retentate inlet port sealed during a compression stroke of said pump.

2. The filtration system of claim 1 wherein said pump is a diaphragm pump.

3. The filtration system of claim 1 wherein said two heads provide a fixed recovery.

4. The filtration system of claim 1 wherein said two heads comprise diaphragms of differing radii.

5. The filtration system of claim 1 wherein said secondary retentate head is smaller than said primary feed head.

6. The filtration system of claim 1 further comprising a connection between said two heads.

7. The filtration system of claim 6 wherein said connection is mechanical.

8. The filtration system of claim 7 wherein said connection is a shaft.

9. The filtration system of claim 6 wherein a force on said secondary retentate head offsets a force on said primary feed head.

10. The filtration system of claim 1 wherein said valve seals a discharge port of said retentate head when a feed pressure exceeds a retentate pressure.

11. The filtration system of claim 10 wherein said valve is hydraulically activated.

12. The filtration system of claim 10 wherein said connection and said valve provide a pressure recovery to said filtration system.

13. The filtration system of claim 12 wherein said pressure recovery reduces energy required to operate said filtration system.

14. The filtration system of claim 1 wherein said filtration element comprises a reverse osmosis element.

15. The filtration system of claim 14 wherein said reverse osmosis element comprises a spiral wrapped element.

16. The filtration system of claim 15 wherein said spiral wrapped element comprises:

at least one membrane; and

at least one thin feed spacer.

17. The filtration element of claim 16 wherein said at least one thin feed spacer comprises a plastic web mesh.

18. The filtration system of claim 16 wherein said at least one thin feed spacer is less than approximately 0.025 inches thick.

19. The filtration system of claim 16 wherein said at least one thin feed spacer is less than approximately 0.011 inches thick.

20. The filtration system of claim 16 wherein said at least one thin feed spacer provides for a reduction in an amount of total dissolved solids at a surface of said membrane.

21. The filtration system of claim 1 wherein at least one parameter of an optimized pulsed fluid flow produced by said pump is determined by a configuration of said filter element.

22. The filtration system of claim 21 wherein said parameter is selected from the group consisting of pulse frequency and pulse amplitude.

23. The filtration system of claim 21 further comprising at least one control to vary said at least one parameter.

24. The filtration system of claim 23 wherein said control is manual.

25. The filtration system of claim 23 wherein said control is automatic.

26. The filtration system of claim 23 further comprising at least one permeate quality monitoring device.

27. The filtration system of claim 26 wherein said at least one permeate quality monitoring device comprises a flow meter.

28. The filtration system of claim 26 wherein said at least one permeate quality monitoring device measures total dissolved solids.

29. The filtration system of claim 28 wherein said at least one permeate quality monitoring device comprises a conductivity meter.

30. The filtration system of claim 26 further comprising a feedback loop, wherein said control is varied to optimize a quality of permeate as determined by said permeate quality monitoring device.

31. The filtration system of claim 30 further comprising an electrical measurement device, wherein said electrical measurement device measures an amperage load on said system.

32. The filtration system of claim 31 wherein said control is varied additionally to minimize said amperage load on said system.

33. A method for filtering a substance comprising the steps of:

providing at least one filtration element;

providing a dual head pump which pumps a pulsed flow of the substance to the filtration element, the dual head pump comprising a single primary feed head and a single secondary retentate head separate from said primary feed head, wherein a front side of said primary feed head comprises a different swept volume than a front side of said secondary retentate head;

sealing a discharge port of a retentate head with a hydraulically actuated DPA valve when a feed pressure exceeds a retentate pressure; and

varying at least one parameter of the pulsed flow to optimize a desired characteristic of permeate filtered by the filtration element and the pump;

wherein the DPA valve comprises;

a single piston slideably disposed in a single chamber, the chamber comprising a feed inlet port, a retentate inlet port, and a retentate discharge port; and

the piston comprising a feed side and a retentate side;

wherein an area of the feed side is larger than an area of the retentate side for keeping the retentate inlet port sealed during a compression stroke of the pump.

34. The method of claim 33 wherein the step of providing a pump comprises providing a diaphragm pump.

35. The method of claim 33 wherein the step of providing a dual head pump further comprises connecting the two pump heads.

36. The method of claim 33 wherein the step of providing a dual head pump further comprises providing a pressure recovery.

37. The method of claim 36 wherein the step of providing a pressure recovery further comprises reducing energy required to filter the substance.

38. The method of claim 33 wherein the step of providing a filtration element comprises providing a reverse osmosis element.

39. The method of claim 38 wherein the step of providing a reverse osmosis element comprises providing a spiral wrapped element.

40. The method of claim 39 wherein the step of providing a spiral wrapped element comprises providing at least one membrane and at least one thin feed spacer in the element.

41. The method of claim 40 wherein the step of providing at least one membrane and at least one thin feed spacer in the element comprises reducing the amount of total dissolved solids at a surface of the membrane.

42. The method of claim 33 wherein the step of varying at least one parameter of the pulsed flow comprises varying a pulse frequency and a pulse amplitude.

43. The method of claim 33 wherein the step of varying at least one parameter of the pulsed flow further comprises measuring a desired characteristic of permeate.

44. The method of claim 43 wherein the step of measuring the desired characteristic of the permeate comprises measuring a permeate flow rate.

45. The method of claim 43 wherein the step of measuring the desired characteristic of the permeate comprises measuring total dissolved solids in the permeate.

46. The method of claim 43 wherein the step of varying at least one parameter of the pulsed flow further comprises measuring an amperage load on the pump.

47. The method of claim 46 wherein the step of measuring the amperage load on the pump further comprises minimizing the amperage load on the pump.

48. The method of claim 46 further comprising providing a feedback loop to automatically vary the parameter of the pulsed flow, thereby optimizing the desired characteristic of the permeate and pump.

57. The method of claim 33 wherein the two pump heads are connected by a single shaft.

49. A pressure recovery filtration system comprising:

a dual head pump comprising a single primary feed head, a single secondary retentate head separate from said primary feed head and a single connection between the two heads;

a filtration element; and

a hydraulically actuated differential pressure activated (DPA) valve;

wherein a front side of said primary feed head comprises a different swept volume than a front side of said secondary retentate head; and

wherein said DPA valve comprises;

a single piston slideably disposed in a single chamber, said chamber comprising a feed inlet port, a retentate inlet port, and a retentate discharge port; and

said piston comprising a feed side and a retentate side;

wherein an area of said feed side is larger than an area of said retentate side for keeping said retentate inlet port sealed during a compression stroke of said pump.

50. The pressure recovery filtration system of claim 49 wherein at least one of said heads comprises a diaphragm.

51. The pressure recovery filtration system of claim 49 wherein said connection is mechanical.

52. The pressure recovery filtration system of claim 51 wherein said single connection is a shaft.

53. The pressure recovery filtration system of claim 49 wherein a force on said secondary retentate head offsets a force on said primary feed head.

54. The pressure recovery filtration system of claim 53 wherein said valve seals a discharge port of said retentate head when a feed pressure exceeds a retentate pressure.

55. The pressure recovery filtration system of claim 54 wherein said valve comprises an inlet port connected to said retentate head and an inlet port connected to said feed head.

56. The pressure recovery filtration system of claim 55 wherein said valve actuates according to a relative pressure difference between said inlet ports.