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US5217609A Expired / Lapsed US ⏱️ 0.0 years remaining

Combination sludge collector, aerator, and return pump

Assignee: Individual
•
Filing: 1992-02-18
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Granted: 1993-06-08
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Expires: 2012-02-18
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Abstract

Abstract The clarifier in any activated sludge sewage treatment plant must provide (a) a quiescent environment to allow gravity settling of the bio-mass (sludge) grown within the aeration tank, (b) the decanting of clear supernatant thus produced, and (c) the timely removal of all accumulated clarifier sludge. This invention improves prior clarifier performance by (a) providing vacuum assistance to gravity settling, (b) trapping all sedimentation within an aerated sludge containment zone, (c) providing clarifier sludge aeration to prevent denitrification, (d) utilization of spent aeration air for energy-free return sludge pumping, (e) the elimination of density currents and induced currents created by return sludge pumping, and (f) providing uniform hydraulic sludge collection eliminating the need for mechanical collection. The lower portion of the clarifier walls must be inward sloped to provide a hopper bottom. This invention then provides prefabricated hood(s), strategically placed over the hopper walls to form a sludge containment zone. The hood supports shall maintain continuous and adjustable spacing between the hood's lower edges and the hopper walls, forming access slots for sedimentation to enter the containment zone. The hopper sides shall continue their inward slope down and under the hood. The upper sides of the hood shall likewise be properly sloped to compliment the hopper slope. This invention invention shall provide aeration diffusers for uniform and consistent aeration without diffuser leveling and located below the hood, near the floor. Their size and placement are critical to (a) create a uniform vertically disposed rolling current to collect sedimentation below the protective hood and (b) insure entrapment of all entrained air and sedimentation. The aerators shall also provide free oxygen to negate potential clarifier sludge denitrification.

Inventors

  • 👤 Robert K. Holdeman

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 13:37
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/02; C02F3/12; B; B01; B01D; B01D21/00; B01D21/24; B01D21/245; B01D21/2466; C02F3/22; C02F3/223; Y; Y02; Y02W; Y02W10/00; Y02W10/10

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 467 words
An apparatus for collecting, aerating and pumping settled sludge from the bottom of an activated sludge clarifier comprising a hopper bottomed clarifier having an upper and bottom portion, said hopper having at least inwardly and downwardly sloping opposing sidewalls and either sloping or vertically closed opposing end walls, said walls meeting and thus defining a relatively small plan view floor area of either rectangular or square shape, said apparatus further comprising a collector hood located in the bottom portion of said clarifier and having opposing sidewalls which extend outwardly and downwardly from a common edge to their respective terminal edge generally in the form of an isosceles triangular cross section, said collector hood opposing walls defining an open bottom plane between its lower terminal edges, each of said collector hood opposing walls is located adjacent to, and extends the length of one of said hopper sloping sidewalls, each of said terminal edges being located in said hopper of the hopper bottomed clarifier such that a vertical line through each terminal edge will intersect its associated hopper sloping sidewall below said terminal edge and a horizontal line through each terminal edge will intersect its associated sidewall outside of said terminal edge, each of said terminal edges being spaced from said associated hopper sloped wall to define an access slot between each terminal edge and the associated hopper sloped wall, said hopper sloped walls commence above and outside said access slot and terminate below and inside said slot insuring that all sedimentation passing through said access slot will move inwardly and beneath the collector hood, said apparatus further including diffused aeration means located inside said hopper bottom and below said collector hood and positioned to provide consistent and uniform diffused aeration along the entire length of said collector hood, said apparatus further comprising at least one pipe means connected generally to the apex of said collector hood at said common edge and extending upwardly therefrom and out of the clarifier, said pipe means functioning as a sludge return airlift to move sludge from said hopper bottom out of said clarifier, whereby sludge that descends through one of said slots will move inwardly and downwardly to below the collector hood and then be caused to circulate upwardly due to the diffused aeration means and come into contact with the underside of the collector hood, some of said upwardly circulating sludge passing out through said pipe means and some being deflected downwardly and outwardly toward one of said slots, thereby creating a rolling current below said collector hood, said apparatus further comprising support means connecting said clarifier to said collector hood for supporting said collector hood in said clarifier, said support means comprises means for adjusting the collection hood relative to the clarifier to thereby adjust the size of said slot.
Claim 2
Independent Claim 467 words
An apparatus for collecting, aerating and pumping settled sludge from the bottom of an activated sludge clarifier comprising a hopper bottomed clarifier having an upper and bottom portion, said hopper having at least inwardly and downwardly sloping opposing sidewalls and either sloping or vertically closed opposing end walls, said walls meeting and thus defining a relatively small plan view floor area of either rectangular or square shape, said apparatus further comprising a collector hood located in the bottom portion of said clarifier and having opposing sidewalls which extend outwardly and downwardly from a common edge to their respective terminal edge generally in the form of an isosceles triangular cross section, said collector hood opposing walls defining an open bottom plane between its lower terminal edges, each of said collector hood opposing walls is located adjacent to, and extends the length of one of said hopper sloping sidewalls, each of said terminal edges being located in said hopper of the hopper bottomed clarifier such that a vertical line through each terminal edge will intersect its associated hopper sloping sidewall below said terminal edge and a horizontal line through each terminal edge will intersect its associated sidewall outside of said terminal edge, each of said terminal edges being spaced from said associated hopper sloped wall to define an access slot between each terminal edge and the associated hopper sloped wall, said hopper sloped walls commence above and outside said access slot and terminate below and inside said slot insuring that all sedimentation passing through said access slot will move inwardly and beneath the collector hood, said apparatus further including diffused aeration means located inside said hopper bottom and below said collector hood and positioned to provide consistent and uniform diffused aeration along the entire length of said collector hood, said apparatus further comprising at least one pipe means connected generally to the apex of said collector hood at said common edge and extending upwardly therefrom and out of the clarifier, said pipe means functioning as a sludge return airlift to move sludge from said hopper bottom out of said clarifier, whereby sludge that descends through one of said slots will move inwardly and downwardly to below the collector hood and then be caused to circulate upwardly due to the diffused aeration means and come into contact with the underside of the collector hood, some of said upwardly circulating sludge passing out through said pipe means and some being deflected downwardly and outwardly toward one of said slots, thereby creating a rolling current below said collector hood, said apparatus further comprising support means connecting said clarifier to said collector hood for supporting said collector hood in said clarifier, said support means comprises means for adjusting the collection hood relative to the clarifier to thereby adjust the size of said slot.
Claim 3
Dependent Claim 22 words
The apparatus of claim 1, wherein said at least one pipe means has at least one notch at the lower terminus thereof.
Claim 4
Dependent Claim 13 words
The apparatus of claim 1, wherein said diffusers are fine bubble membrane diffusers.

References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-06-07 1996-12-07 1997-06-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-06-07 2000-12-07 2001-06-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-06-07 2004-12-07 2005-06-08 $7700.00 Window Closed / Lapsed

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