US3792773A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for treating waste liquid
Assignee: Hydro Clear Corp
•
Filing: 1971-09-30
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Granted: 1974-02-19
•
Expires: 1991-09-30
Abstract
Abstract An apparatus and method for treating waste effluent from a sewage treatment plant using a filter unit having a backwash arrangement, wherein the backwash liquid, after backwashing, is subjected to flocculation, coagulation and settlement to produce a supernatant and, then, introducing the supernatant directly into the inlet of the filter without returning the backwash liquid to the sewage treatment plant. The solids in the backwash liquid are concentrated and removed without being reintroduced into the sewage treatment plant.
Inventors
- 👤 D Ross
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 02:38
CPC Classifications
B; B01; B01D; B01D37/00; B01D37/03; B01D21/00; B01D21/0012; B01D21/02; B01D21/08; B01D21/30; B01D21/34; C; C02; C02F; C02F1/00; C02F1/001; C02F1/004; C02F1/52; C02F1/5236; C02F1/5245; C02F2303/00; C02F2303/16
Claims Analysis
Total Claims: 43
Claim 1
Independent Claim
38 words
The improvement as defined in claim 1 wherein said concentrating means includes means for coagulating solids in said used backwashing liquid and means for settling said coagulated solids from said used backwashing liquid to produce said clarified liquid.
Claim 2
Dependent Claim
40 words
The improvement as defined in claim 2 wherein said coagulating means comprises a first tank adjacent said filter elements, means for directing said used backwashing liquid into said first tank, and means for introducing a coagulant into said first tank.
Claim 3
Dependent Claim
22 words
The improvement as defined in claim 3 including means in said first tank for mixing said coagulant and said used backwashing liquid.
Claim 4
Dependent Claim
19 words
The improvement as defined in claim 4 wherein said mixing means is an air diffuser in said first tank.
Claim 5
Dependent Claim
15 words
The improvement as defined in claim 4 including means for selectively actuating said mixing means.
Claim 6
Dependent Claim
58 words
The improvement as defined in claim 3 wherein said coagulant introducing means includes a first supply of a first coagulant, means connected to said first supply for directing said first coagulant to said first tank, a second supply of a second coagulant, and means connected to said second supply for directing said second coagulant to said first tank.
Claim 7
Dependent Claim
48 words
The improvement as defined in claim 3 wherein said first tank includes an outlet means for directing coagulant and used backwashing liquid from said first tank and including a second tank means for receiving said coagulant and used backwashing liquid, said second tank means being a settlement tank.
Claim 8
Dependent Claim
20 words
The improvement as defined in claim 8 wherein said settlement tank includes means for introducing oxygen into said settlement tank.
Claim 9
Dependent Claim
20 words
The improvement as defined in claim 9 wherein said oxygen introduction means includes an air diffuser in said settlement tank.
Claim 10
Dependent Claim
14 words
The improvement as defined in claim 10 including means for selectively operating said diffuser.
Claim 11
Dependent Claim
33 words
The improvement as defined in claim 1 wherein said filter element is a layer of particulate matter having an upper surface forming said inlet portion and a lower portion forming said outlet portion.
Claim 12
Dependent Claim
185 words
In a waste liquid treatment system including a first tank means having a lower portion; a filter element in said first tank means and adjacent said lower portion, said filter element comprising a layer of particulate material having an upper surface and an outlet passage generally below said layer; an outlet conduit means connected to said passage; second tank means communicated with said outlet conduit means for receiving filtered effluent from said passage; an effluent inlet above said surface; a backwash conduit means in said first tank means; third tank means communicated with said backwash conduit means for receiving backwash liquid from said backwash conduit means; and, backwashing means for selectively forcing filtered effluent from said second tank means, through said outlet conduit means, through said outlet passage, through said filter element, through said backwash conduit means, and into said third tank means, the improvement comprising: means for removing solids from said backwash liquid to produce a clear liquid formed essentially of said backwash liquid and having less suspended solids and means for directing said clear liquid to said first tank means above said surface.
Claim 13
Dependent Claim
21 words
The improvement as defined in claim 13 including a means for creating currents above said surface for lifting solid accumulated thereon.
Claim 14
Dependent Claim
19 words
The improvement as defined in claim 14 wherein said current creating means includes an air diffuser above said surface.
Claim 15
Dependent Claim
16 words
The improvement as defined in claim 14 including means for selectively actuating said current creating means.
Claim 16
Dependent Claim
22 words
The improvement as defined in claim 16 wherein said actuating means includes means for sensing a level of effluent above said surface.
Claim 17
Dependent Claim
31 words
The improvement as defined in claim 13 including means for forcing fluid upwardly from said passage through said filter and means for actuating said fluid forcing means for relatively short periods.
Claim 18
Dependent Claim
25 words
The improvement as defined in claim 18 wherein said actuating means includes means for sensing the rate of rise of effluent level above said surface.
Claim 19
Dependent Claim
27 words
The improvement as defined in claim 13 including indicator means for indicating a rate of rise of effluent above said surface exceeding a preselected rate of rise.
Claim 20
Dependent Claim
32 words
The improvement as defined in claim 20 including a fourth tank means for receiving said removed solids and means responsive to said indicator means for removing solids from said fourth tank means.
Claim 21
Dependent Claim
29 words
The improvement as defined in claim 13 wherein said solids removing means includes means for coagulating solids from said backwash liquid and means for settling out said coagulated solids.
Claim 22
Dependent Claim
43 words
The improvement as defined in claim 22 wherein said coagulating means includes a fourth tank means, means for directing said backwash liquid from said third tank means to said fourth tank means and means for introducing a coagulant into said fourth tank means.
Claim 23
Dependent Claim
22 words
The improvement as defined in claim 23 including means in said fourth tank means for mixing said coagulant and said backwash liquid.
Claim 24
Dependent Claim
15 words
The improvement as defined in claim 24 wherein said mixing means is an air diffuser.
Claim 25
Dependent Claim
15 words
The improvement as defined in claim 25 including means for selectively actuating said mixing means.
Claim 26
Dependent Claim
15 words
The improvement as defined in claim 22 wherein said settling means includes a settlement tank.
Claim 27
Dependent Claim
17 words
The improvement as defined in claim 27 including means in said settlement tank for pumping solids therefrom.
Claim 28
Dependent Claim
16 words
The improvement as defined in claim 27 including means for introducing oxygen into said settlement tank.
Claim 29
Dependent Claim
20 words
The improvement as defined in claim 29 wherein said oxygen introducing means includes an air diffuser in said settlement tank.
Claim 30
Dependent Claim
45 words
The improvement as defined in claim 22 wherein said settling means is a settlement tank adjacent said third tank means and said means for directing clear liquid to said first tank means is a conduit extending from said settlement tank to said first tank means.
Claim 31
Dependent Claim
21 words
The improvement as defined in claim 31 wherein said first, second, and third tank means are secured together as a unit.
Claim 32
Dependent Claim
16 words
The improvement as defined in claim 32 wherein said settlement tank is secured to said unit.
Claim 33
Dependent Claim
37 words
The improvement as defined in claim 22 wherein said coagulating means includes a coagulant tank and means for introducing a coagulant into said coagulant tank, and including means for forcing said backwash liquid into said coagulant tank.
Claim 34
Dependent Claim
36 words
The improvement as defined in claim 34 including means for sensing backwash liquid level in said third tank means and means responsive to said sensing means for actuating said coagulant introduction means and said forcing means.
Claim 35
Dependent Claim
44 words
The improvement as defined in claim 35 wherein said settling means includes a settlement tank and including means for introducing oxygen into said settlement tank and means responsive to said sensing means for deactivating said oxygen introducing means while said forcing means is actuated.
Claim 36
Independent Claim
125 words
A method of treating waste effluent comprising the steps of: a. filtering said effluent through a filter element having an inlet portion to remove solids therefrom; b. backwashing said filter element to remove solids separated from said effluent by said filter element to create a backwash liquid having previously filtered solids therein; c. coagulating only said solids in said backwash liquid; d. separating out at least a portion of said coagulated solids to form a clear liquid formed essentially from said backwash liquid of reduced suspended solid content; e. passing said clear liquid to the inlet portion of said filter element without prior coagulation of said backwash liquid and said effluent jointly; and, f. filtering said clear backwash liquid and effluent by said filter element.
Claim 37
Dependent Claim
16 words
The method as defined in claim 37 including the additional step of extracting said settled solids.
Claim 38
Dependent Claim
28 words
the method as defined in claim 37 including the additional step of creating currents adjacent said filter elements to remove solids from said element during said filtering step.
Claim 39
Independent Claim
114 words
A method of treating waste effluent coming from a treatment plant comprising the steps of: a. filtering said effluent through a filter bed to remove solids therefrom; b. backwashing said filter bed to remove solids separated from said effluent by said filter bed to create a backwashing liquid having previously filtered solids therein; c. concentrating said solids in said backwashing liquid separately from said effluent to produce a supernatant made up essentially of said backwashing liquid having a lower solids content than said backwashing liquid; d. passing said supernatant directly to a position between said treatment plant and said filter bed; and, e. refiltering said supernatant by passing it through the same filter bed.
Claim 40
Dependent Claim
19 words
The method as defined in claim 40 including the step of retaining said backwashing liquid during said concentrating step.
Claim 41
Dependent Claim
28 words
The method as defined in claim 40 wherein said concentrating step includes the steps of coagulating said solids in said backwashing liquid and settling out said coagulated solids.
Claim 42
Dependent Claim
108 words
A filtering device for removing solids from a waste liquid effluent coming from a treatment plant, said device comprising: means for intercepting and removing solids from said effluent; means for washing these intercepted solids into a holding tank as an admixture of such solids and backwashing liquid; means for coagulating said solids in said admixture separately from said waste liquid effluent coming from said treatment plant; means for passing said admixture and coagulated solids to a settling tank wherein said solids settle to profuce an upper supernatant of reduced solids content; an overflow means in said settling tank for directing said supernatanT to said intercepting and removal means.
Claim 43
Dependent Claim
29 words
A filtering device as defined in claim 43 wherein said overflow means includes a conduit extending from said settling tank to a position adjacent said intercepting and removal means.
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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) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |