US 7,255,333 B2Granted

Strip diffuser

AssigneeITT Manufacturing Enterprises, Inc.

InventorsThomas J. Casper, Mark A. Schoenenberger, Brad D. Laubenstein, James A. Reilly, Joseph G. Krall

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Abstract

Membrane strip diffusers are disclosed, useful for example in aerating wastewater in activated sludge plants. These diffusers have membranes, diffuser bodies and gas conduits elongated in the same general direction. Such conduits may be attached to or formed integrally with the diffuser bodies. Gas chambers form beneath the membranes when they inflate, and these are separate from but communicate with the gas conduits, e.g., through passageways distributed along the lengths of the membrane supports. Preferably, the passageway flow cross-sections are small, thus tending toward uniform distribution of gas along the membrane's length. Ways to edge- and end-seal the membranes to the diffuser bodies are also disclosed.

Claims95

Dependent claims

A strip diffuser comprising:

A. a flexible membrane having
(1) a length to width ratio of at least about 4, more preferably at least about 6, still more preferably at least about 8, and most preferably at least about 10,
(2) gas influent and gas discharge surfaces, and
(3) gas discharge pores extending from said gas influent surface through said membrane and through said gas effluent surface across at least a portion of said gas discharge surface,
B. a diffuser body including a longitudinally-extending membrane support member with a length to width ratio of at least about 4, more preferably at least about 6, still more preferably at least about 8, and most preferably at least about 10,
C. a longitudinally-extending gas supply channel that, when viewed in transverse cross-section, comprises circumferentially closed gas flow confining wall means
(1) at least a portion of which wall means extends beneath and provides structural bracing for the support member along at least a major portion of the length of the support member, and
(2) which wall means comprises one or more walls in addition to the support member,
D. the respective lengths of the membrane, support member and channel extending in the same general direction, and
E. the support member and the membrane, at least when the diffuser is operating, defining a longitudinally-extending gas chamber between them.

7 more elements

A strip diffuser comprising:

A. a flexible membrane of sheet material having
(1) gas influent and gas discharge surfaces,
(2) sides and ends with longitudinal edges along its sides,
(3) a length to width ratio of at least about 4, more preferably at least about 6, still more preferably at least about 8, and most preferably at least about 10, and
(4) gas discharge pores in at least a portion of its gas discharge surface,
B. a diffuser body of extruded material including a longitudinally-extending membrane support member with a length to width ratio of at least about 4, more preferably at least about 6, still more preferably at least about 8, and most preferably at least about 10,
C. a longitudinally-extending, circumferentially closed gas supply channel
(1) at least a portion of which extends beneath and provides structural bracing for the support member along at least a major portion of the length of the support member, and
(2) which comprises, as viewed in transverse cross-section, wall means in addition to the support member,
D. the respective lengths of the membrane, support member and channel extending in the same general direction,
E. the support member and the membrane, at least when the diffuser is operating, defining a gas chamber between them,
F. a plurality of gas-injection passages, spaced longitudinally along the gas supply channel and extending from the interior of the gas supply channel through the membrane support member, said gas-injection passages being of sufficiently small flow cross-section to generate, during operation of said diffuser, sufficient pressure drop across said passages to contribute measurably to enhanced uniformity of distribution of gas flow among the respective passages, thus constituting flow regulating orifices, and
G. said membrane gas discharge surface, when the membrane is operating, being held by the diffuser body substantially within an envelope that, when viewed in a transverse cross-section of the body and membrane, has
(1) a base line that connects two points at which the gas chamber is widest horizontally,
(2) vertical side lines perpendicular to the base line at each of said points, and
(3) a top line, running parallel to, above and at a distance from the base line of about ¼, more preferably about 3/16 and still more preferably about ⅛, of the distance between the side lines.

13 more elements

A gas diffusion system for distributing gas in the form of bubbles into a liquid comprising:

A. a tank having a bottom and upwardly extending sides for holding the liquid,
B. a pipe grid, located substantially below the intended level of the surface of the liquid in the tank, said grid including
(1) one or more manifolds and
(2) one or more branch conduits that
a. are in communication with the manifold(s) to receive flowing gas therefrom,
b. that have circumferentially closed wall means to receive, confine and convey said flowing gas, and
C. plural diffusers respectively comprising
(1) extruded diffuser bodies
a. respectively including longitudinally-extending membrane support members having a length to width ratio of at least about 4, more preferably at least about 6, still more preferably at least about 8, and most preferably at least about 10,
b. having the long dimensions of the respective support members oriented in the same general direction as the lengths of the branch conduits, and
c. having longitudinally-extending gas-confining wall means in addition to the membrane support members
(2) flexible membranes secured to the diffuser bodies and respectively having
a. gas influent and gas discharge surfaces,
b. sides and ends with longitudinal edges along its sides,
C. a length to width ratio of at least about 4, more preferably at least about 6, still more preferably at least about 8, and most preferably at least about 10, and
d. gas discharge pores in at least a portion of its gas discharge surface,
(3) the support members and membranes forming, at least when the diffusers are in operation, longitudinally-extending gas chambers that
a. represent gas spaces in addition to the spaces in the interiors of the branch conduits and
b. provide gas to the gas discharge pores, and
D. plural gas-injection passages (1) at longitudinally spaced positions along the branch conduits,
(2) through the wall means of the branch conduits
(3) providing communication between the interiors of the branch conduits and the gas chambers, and
(4) wherein a plurality of gas chambers are each served by a plurality of said passages spaced along the lengths of those chambers.

20 more elements

A gas diffusion system for distributing gas in the form of bubbles into a liquid comprising:

A. a tank having a bottom and upwardly extending sides for holding the liquid,
B. a pipe grid, located substantially below the intended level of the surface of the liquid in the tank, said grid including
1. one or more manifolds, and
2. one or more branch conduits that
a. are in communication with the manifold(s) to receive flowing gas therefrom,
b. have peripherally closed wall means to receive, confine and convey said flowing gas, and
c. Are held in fixed position in the tank,
C. plural diffusers respectively comprising
1. extruded diffuser bodies supported in a fixed, stationary position relative to the tank bottom,
a. respectively including longitudinally-extending membrane support members that have generally horizontal upper surfaces, parallel sides and length to width ratio of at least about 6,
b. having the long dimensions of the respective support members oriented in the same general direction as the lengths of the branch conduits,
c. having longitudinally-extending gas-confining wall means in addition to the membrane support members, and
d. being generally rectangular in appearance when viewed from above,
2. flexible membranes secured to the diffuser bodies and respectively having
a. gas influent and gas discharge surfaces,
b. sides and ends, with parallel longitudinal edges along their sides,
c. a length to width ratio of at least about 6, and
d. gas discharge pores in at least portions of their gas discharge surfaces,
3. the support members and membranes forming, at least when the diffusers are in operation, longitudinally-extending gas chambers that
a. represent gas spaces in addition to the spaces in the interiors of the branch conduits, and
b. provide gas to the gas discharge pores, and
D. plural gas-injection passages
1. at longitudinally spaced positions along the branch conduits,
2. through the wall means of the branch conduits,
3. providing communication between the interiors of the branch conduits and the gas chambers, and
4. wherein a plurality of gas chambers are each served by a plurality of said passages spaced along the lengths of those chambers.

23 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/639,774Filed 13 Aug 2003 · us provisional application
Priority: 13 Aug 2002
Published: US 2004/0124550 A11 Jul 2004
Granted: 14 Aug 2007
Term ends: Not estimatedThe source records don’t support an estimate.

Classification16 codes

B01F 23/23124
Diffusers: consisting of flexible porous or perforated material, e.g. fabric
B01F 23/2311
Arrangement or manipulation of the gas bubbling devices: mounting the bubbling devices or the diffusers
C02F 3/201
Using diffusers: perforated, resilient plastic diffusers, e.g. membranes, sheets, foils, tubes, hoses
B01F 23/231143
Characterised by the way in which the different elements of the bubbling installation are mounted: mounting the bubbling elements or diffusors,…