Strip diffuser

• US 20080251954A1
• Filed: 06/11/2007
• Published: 10/16/2008
• Est. Priority Date: 08/13/2002
• Status: Active Grant

• Current Assignee: ITT Manufacturing Enterprises, Inc. (ITT, Inc.)
• Original Assignee: ITT Manufacturing Enterprises, Inc. (ITT, Inc.)
• Inventors: Reilly, James A., Laubenstein, Brad D., Schoenenberger, Mark A., Casper, Thomas J., Tischler, Neil S., Krall, Joseph G.
• Granted Patent: US 8,002,249 B2
• Time in Patent Office: Days
• US Class Current: 261/122.1
• CPC Class Codes: B01F 2101/305 Treatment of water, waste water or sewage
• CPC Class Codes: B01F 23/2311 Mounting the bubbling devices or the diffusers
• CPC Class Codes: B01F 23/23113 characterised by the disposition of the bubbling elements in particular configurations, patterns or arrays
• CPC Class Codes: B01F 23/231143 Mounting the bubbling elements or diffusors, e.g. on conduits, using connecting elements; Connections therefor
• CPC Class Codes: B01F 23/231151 the bubbling devices being fixed or anchored in the bottom
• CPC Class Codes: B01F 23/23124 consisting of flexible porous or perforated material, e.g. fabric
• CPC Class Codes: B01F 23/231242 in the form of slits or cut-out openings
• CPC Class Codes: B01F 23/231245 Fabric in the form of woven, knitted, braided, non-woven or flocculated fibers or filaments
• CPC Class Codes: B01F 23/23125 characterised by the way in which they are assembled or mounted; Fabricating the parts of the diffusers
• CPC Class Codes: B01F 23/231264 being in the form of plates, flat beams, flat membranes or films
• CPC Class Codes: C02F 3/201 Perforated, resilient plastic diffusers, e.g. membranes, sheets, foils, tubes, hoses
• CPC Class Codes: Y02W 10/10 Biological treatment of water, waste water, or sewage
• CPC Class Codes: Y10S 261/70 Sewage aerators; diffusers

Abstract

Membrane strip diffusers are disclosed, useful for example in aerating wastewater in activated sludge plants. These diffusers have membranes, diffuser bodies comprising gas conduits and, in addition to the conduits, integral membrane supports elongated in the same general direction. Such conduits are for example co-extruded with the diffuser bodies. The supports are apertured to discharge gas into chambers formed beneath the membranes when they inflate, and the membranes have pores to discharge the gas. Ways to edge- and end-seal the membranes to the diffuser bodies and ways to support the diffusers are also disclosed.

Claims

1. A strip diffuser comprising

a pipe having

a longitudinally extending central axis,

a longitudinally extending gas flow enclosing peripheral wall and

Included in that wall;

at least one elongated, thickened region integral with the pipe and

extending in the same direction as the central axis,

a membrane support member

elongated in the direction of the central axis and having

a connecting portion that is

integral with the pipe and

comprises at least one of said thickened regions, and

at least one lateral portion that

Is integral with the connecting portion and extends

 

laterally from the connecting portion and,

 

longitudinally with the connecting portion in the same direction as the pipe axis and

a membrane diffusion element

elongated in the direction of the central axis and

having ends and longitudinally extending marginal portions which are connected in sealing engagement with the support.

2. A strip diffuser according to claim 1 wherein the connection portion of the membrane support comprises a single elongated, thickened region.

3. A strip diffuser according to claim 1 wherein the connecting portion of the membrane support comprises plural elongated, thickened regions.

4. A strip diffuser according to claim 1 wherein the membrane support comprises plural lateral portions.

5. A strip diffuser according to claim 1 wherein the membrane support connecting portion is positioned at the apex of the pipe.

6. A strip diffuser according to claim 5 wherein the membrane support has plural lateral portions positioned on opposite sides of the pipe apex.

7. A strip diffuser according to claim 1 wherein at least part of at least one lateral portion has beneath it space that is in communication with the environment surrounding the diffuser.

8. A strip diffuser according to claim 1 wherein at least part of at least one lateral portion has beneath it space that is free of bracing connecting that part with the pipe.

9. A strip diffuser according to claim 1 wherein the pipe is integral with the membrane support over approximately the entire length of the support.

10. A strip diffuser according to claim 1 wherein the connecting portion of the support is thicker than portions of the peripheral wall which adjoin it, outside the connecting portion.

11. A strip diffuser according to claim 1 wherein the peripheral wall of the pipe has an inner surface, and the connecting portion is, when viewed in transverse cross-section along a portion of the length of the inner surface which the connecting portion adjoins, thicker than the remainder of the peripheral wall along most of the length, or combined length, as the case may be, of a portion or portions of the length of the inner surface which the remainder adjoins.

12. A strip diffuser according to claim 11 wherein the connecting portion is thicker than the remainder of the peripheral wall along at least about 90% of the length, or combined length of a portion or portions of the length of the inner surface which the remainder adjoins.

13. A strip diffuser according to claim 1 in which the pipe is circular or non-circular in transverse cross-section, the connecting portion is positioned at an upper portion of the pipe peripheral wall, and the wall has at least one side portion which is thinner than the connecting portion.

14. A strip diffuser according to claim 1 wherein the connecting portion comprises a single thickened region which, substantially throughout the length of the pipe, is thicker than most of the remainder of the peripheral wall along its periphery.

15. A strip diffuser according to claim 1 wherein the connecting portion comprises two thickened regions spaced apart from one another as viewed in transverse cross section, and those regions, substantially throughout the length of the pipe, are thicker than most of the remainder of the peripheral wall along its periphery.

16. A strip diffuser according to claim 1 wherein, along at least one lateral portion, extending laterally from a nexus at which that lateral portion is joined with said connecting portion to an outer edge of that lateral portion, that lateral portion is free of underlying bracing connecting it with the pipe.

17. A strip diffuser according to claim 1 in which there are two lateral portions that, respectively, extend to the left and right of the connecting portion as viewed in transverse cross section and are free of underlying pipe-to-lateral portion connecting bracing from the location at which each lateral portion is joined with the connecting portion to an outer edge of that lateral portion.

18. A strip diffuser according to claim 1 in which there are two lateral portions that, respectively, extend to the left and right of the connecting portion as viewed in transverse cross section and in which spaces underlying at least part of both lateral portions are in open communication with the environment surrounding the diffuser.

19. A strip diffuser according to claim 1 in which the pipe is of generally circular cross section having an apex, and the upper portion includes the pipe apex.

20. A strip diffuser according to claim 1 in which the at least one thickened region and at least one lateral portion have upper surfaces, and at least one lateral portion upper surface extends generally horizontally from the at least one thickened region upper surface.

21. A strip diffuser according to claim 1 in which the membrane support has a generally horizontal upper surface with at least one longitudinally extending edge that, as viewed in transverse cross section, comprises a curved edge surface that curves from the upper surface of the support outwardly and downwardly and then downwardly and inwardly to beneath at least one lateral portion, and the membrane diffusion element ends are connected in sealing engagement with the support across the support upper surface by clamping bars which extend across those ends and about said curved surface by arcuate clamps.

22. A strip diffuser according to claim 21 in which the clamping bars and arcuate clamps have inter-engaging, adjacent ends.

23. A strip diffuser according to claim 22 in which the adjacent ends have inter-engaging meshed elements.

24. A strip diffuser according to claim 1 in which the support has at least one longitudinally extending edge and at least one lateral portion comprises a longitudinally extending membrane securing groove.

25. A strip diffuser according to claim 24 in which the groove is inward of the edge.

26. A strip diffuser according to claim 24 in which the support has an upper surface and the groove has a mouth which is located below that surface.

27. A strip diffuser according to claim 24 in which the groove has a mouth which is located in the under-side of the at least one lateral portion.

28. A strip diffuser according to claim 27 in which at least one marginal portion of the membrane extends into the groove and is engaged there by a securing member.

29. A strip diffuser according to claim 28 which includes a blocking member, secured to the support at the mouth of the groove, that obstructs the mouth of the groove.

30. A strip diffuser according to claim 24 in which the groove is formed at least in part by a limb extending integrally from and longitudinally with the at least one lateral portion.

31. A strip diffuser according to claim 30 in which the limb extends generally downward from the at least one lateral portion.

32. A strip diffuser according to claim 30 in which at least one marginal portion of the membrane extends into the groove and is engaged there by a securing member, and a blocking member, secured to the limb at the mouth of the groove, obstructs escape of the securing member.

33. A strip diffuser according to claim 24 in which a J-shaped member forms at least a portion of the groove.

34. A strip diffuser according to claim 1 which comprises, in or on a wall of the pipe, angularly spaced along the pipe peripheral wall from at least one membrane support lateral portion, at least one projection extending longitudinally with at least a portion of the length of, and projecting outwardly from, the pipe wall.

35. A strip diffuser according to claim 34 wherein the at least one projection assists in supporting and/or securing the diffuser in relation to structure in or associated with a liquid impound.

36. A strip diffuser according to claim 34 wherein the at least one projection includes portions relatively closer and further from the pipe outer wall and at least one further portion is thicker than or disposed at least one angle to a closer portion.

37. A strip diffuser according to claim 34 wherein the at least one projection is hook-, T- or L-shaped in cross-section.

38. A strip diffuser according to claim 36 wherein the diffuser is held in vertically and laterally fixed position in a liquid impound by a connection between at least one such projection and structure of complementary shape in or associated with a wastewater aeration vessel.

39. A strip diffuser according to claim 1 wherein the diffuser is held in vertically and laterally fixed position in a liquid impound by attaching members that engage the diffuser pipes below the membrane supports and/or engage connectors that connect adjacent series-connected diffusers and connect the diffusers to structure in or associated with a wastewater aeration vessel.

40. A wastewater treatment plant comprising a water impound having positioned and held in place therein strip diffusers comprising:

A. synthetic resinous pipe having

1. a longitudinally extending central axis,

2. a longitudinally extending gas flow enclosing peripheral wall and

3. Included in that wall, at least one elongated, thickened region

a. integral with the pipe wall and

b. extending in the same direction as the central axis,

B. a membrane support member that

1. is elongated in the direction of the central axis and

2. has a connecting portion that

a. is positioned at an upper portion of the pipe,

b. is integral with the pipe,

c. comprises at least one of said thickened regions,

d. has an upper surface which includes an upper surface of the pipe thickened region and

e. comprises a plurality of lateral portions that

I. are integral with the connecting portion and

ii. extend

 

(a) laterally from the connecting portion on opposite sides of the pipe apex and

 

(b) longitudinally with the connecting portion in the same direction as the pipe axis,

C. the pipe being integral with the membrane support over approximately the entire length of the support,

D. the peripheral wall of the pipe having an inner surface, and the connecting portion being, when viewed in transverse cross-section along a portion of the length of the inner surface which the connecting portion adjoins, thicker than the remainder of the peripheral wall along most of the length, or combined length, as the case may be, of a portion or portions of the length of the inner surface which the remainder adjoins,

E. at least parts of the lateral portions having beneath them underlying open spaces that are free of braces connecting those parts with the pipe,

F. the support lateral portions each having upper surfaces with longitudinally extending edges and longitudinally extending membrane securing grooves inward of the edges and having mouths located in the under-sides of the lateral portions below their upper surfaces, and

G. a membrane diffusion element that

1, is elongated in the direction of the central axis,

2. has ends and longitudinally extending marginal portions and

3. is connected in sealing engagement with the support by the marginal portions of the membrane extending into the grooves and being engaged therein by a securing member.

41. A strip diffuser sub-assembly comprising

A. pipe witha longitudinally extending central axis and

a longitudinally extending gas flow enclosing pipe wall,

B. in addition to the pipe wall, a membrane support member thatis integral with the pipe wall,

as viewed in transverse cross-section, is partially defined, in a central region of the support member, by an upper portion of the pipe wall that extends above and across the pipe axis,comprises plural lateral portions that

a. are positioned at, and extend laterally from opposite sides of, the upper portion of the pipe wall, and

b. extend longitudinally with the pipe wall.

42. A wastewater treatment plant comprising sub-assemblies of claim 41

43. A subassembly according to claim 41 that is apertured for passage of gas through the support from within the pipe.

44. A subassembly according to claim 41 comprising a limb member integral with the at least one lateral portion, extending with the lateral portion in the same direction as the pipe axis, dependent from the at least one lateral portion and forming a groove between itself and an adjacent surface of a lateral portion for insertion of a marginal portion of a membrane and of a longitudinally extending securing member.

45. A strip diffuser comprising a subassembly according to claim 41, a support that is apertured for passage of gas through the support from within the pipe, a membrane diffusion element, a groove in the support having a marginal portion of the membrane secured therein by a longitudinally extending securing member and members for sealing the ends of the membrane to the support.