Patent US4071447A successfully refreshed from Google Patents.
US4071447A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dewatering of wastewater treatment wastes
Assignee: TETRA RESOURCES Inc A CORP OF
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Filing: 1976-09-01
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Granted: 1978-01-31
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Expires: 1996-09-01
Abstract
Abstract Wastewater treatment wastes, such as skimmings or sludges, are processed so as to reduce the water content by approximately two thirds and increase the impurities content thereof. The wastes are passed over a dense supply of very fine bubbles. These fine bubbles assist in floating impurities within the wastes to result in the formation of an upper stratum of gas, residual water and a concentrated impurities content and of a lower stratum that is primarily water, after which the upper and lower strata are separated.
Inventors
- 👤 Ernest R. Ramirez
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:52
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/24; C02F1/46; C02F1/461; C02F1/465
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
236 words
A process for dewatering wastewater treatment wastes such as skimmings or sludges, comprising: supplying wastewater treatment wastes of water and buoyant or precipitated impurities that had been previously coagulated during a primary treatment of the wastewater; entering said wastewater treatment wastes into a lower portion of a vertical column, said entering step being downwardly through a vertical zone; spreading said wastes at the lowermost portion of said vertical zone; passing a dense supply of small gas bubbles from a source lower than said lowermost portion of the vertical zone upwardly through said spread wastes; upwardly feeding a polymer flocculant at a location lower than said lowermost portion of the vertical zone and above the source of bubbles; permitting said spread wastes to contact said gas bubbles and floc to thereby form buoyant composites with the previously coagulated impurities within said wastes, confining said composites within said column, said confining step enhancing vertical movement of water and composites while limiting their horizontal movement; dewatering said wastes by permitting said dense supply of small gas bubbles to continue to rise within the vertical column and thereby downwardly displace all but a residual amount of water from said wastes to form an upper stratum of buoyant composites in wastes that have an impurities content significantly greater than that of said supplied wastes and a lower stratum of substantially clarified water; and separating said upper stratum and said lower stratum.
Claim 2
Dependent Claim
236 words
A process for dewatering wastewater treatment wastes such as skimmings or sludges, comprising: supplying wastewater treatment wastes of water and buoyant or precipitated impurities that had been previously coagulated during a primary treatment of the wastewater; entering said wastewater treatment wastes into a lower portion of a vertical column, said entering step being downwardly through a vertical zone; spreading said wastes at the lowermost portion of said vertical zone; passing a dense supply of small gas bubbles from a source lower than said lowermost portion of the vertical zone upwardly through said spread wastes; upwardly feeding a polymer flocculant at a location lower than said lowermost portion of the vertical zone and above the source of bubbles; permitting said spread wastes to contact said gas bubbles and floc to thereby form buoyant composites with the previously coagulated impurities within said wastes, confining said composites within said column, said confining step enhancing vertical movement of water and composites while limiting their horizontal movement; dewatering said wastes by permitting said dense supply of small gas bubbles to continue to rise within the vertical column and thereby downwardly displace all but a residual amount of water from said wastes to form an upper stratum of buoyant composites in wastes that have an impurities content significantly greater than that of said supplied wastes and a lower stratum of substantially clarified water; and separating said upper stratum and said lower stratum.
Claim 3
Dependent Claim
28 words
The process of claim 1, wherein said upper stratum has an impurities content of from about 2 to about 7 times greater than said supplied wastewater treatment wastes.
Claim 4
Dependent Claim
27 words
The process of claim 1, further comprising the step of heating said supplied wastes to about 100 to 200° F. prior to passing same over said bubbles.
Claim 5
Dependent Claim
26 words
The process of claim 1, wherein said flocculant is added in quantities within the range of about 10 to about 50 milligrams per liter of wastes.
Claim 6
Dependent Claim
68 words
The process of claim 1, further comprising the step of feeding a surfactant into said wastes above the supply of bubbles and prior to passing same over said bubbles, said surfactant being added at a concentration of about 0.01 to 0.001 weight percent of the wastes, thereby increasing the density of said bubble supply and increasing the efficiency of said downward displacement of water from the upper stratum.
Claim 7
Dependent Claim
18 words
The process of claim 1, wherein said entering step passes said wastes along the length of the column.
Claim 8
Dependent Claim
29 words
The process of claim 1, wherein said entering step includes passing said wastes in a downward stream and said spreading step deflects the stream in an open cone-like manner.
Claim 9
Dependent Claim
55 words
The process of claim 1, wherein said separating step includes effluxing said lower stratum from a location that is initially below said dense supply of bubbles to form an effluent stream having a maximum height which is at least as high as said upper stratum, and removing said upper stratum from the upper surface thereof.
Claim 10
Dependent Claim
35 words
The process of claim 8, wherein said lower stratum effluxing step further includes effluxing the lower stratum along substantially the entire length of the column in a substantially horizontal exit zone external to said column.
Claim 11
Dependent Claim
49 words
The process of claim 1, wherein said dense supply of gas bubbles are provided at a rate of about 0.2 to about 2 cubic feet of bubbles per hour per square foot of a horizontal cross-section through said column at a location approximate to that of said bubble supply.
Claim 12
Dependent Claim
65 words
The process of claim 1, further comprising the step of producing said dense supply of small gas bubbles from the water content of said wastes, said bubbles being produced by electrolysis, said electrolysis including applying direct current to a plurality of electrodes alternate ones of which serve as cathodes with the remaining alternate electrodes serving as anodes, and periodically reversing the polarity of said electrodes.
Claim 13
Dependent Claim
61 words
The process of claim 1, further comprising supplying said gas bubbles by recycling a portion of said lower stratum, including maintaining the surface tension of the recycled portion between about 25 to 60 dynes per square centimeter, then mechanically dispersing a gas therein, and directing the recycled portion of lower stratum with dispersed gas to provide said dense supply of bubbles.
Claim 14
Dependent Claim
44 words
The process of claim 1, further comprising supplying said gas bubbles by recycling a portion of said lower stratum, including dissolving a pressurized gas into said recycled portion and directing the recycled portion having gas dissolved therein to provide said dense supply of bubbles.
Claim 15
Independent Claim
160 words
An apparatus for dewatering primary wastewater treatment wastes such as skimmings or sludges, comprising: a vertical chimney; a vertical inlet means opening into said chimney for introducing primary wastewater treatment wastes into the lower portion of the chimney; bubble supply means within said chimney and below said vertical inlet means; an injector located below said vertical inlet means and above said bubble supply means; a deflecting means communicating with said vertical inlet means for spreading said wastes into extensive contacting relationship with bubbles from said bubble supply means and with polymer flocculant supplied through said injector; an efflux means that is in communication with a vertical side of said chimney at a location below said bubble supply means, the horizontal distance between said vertical inlet means and said efflux means being less than the height of the vertical chimney; and said efflux means has a maximum height at least as high as the height of the wastes in the chimney.
Claim 16
Independent Claim
160 words
An apparatus for dewatering primary wastewater treatment wastes such as skimmings or sludges, comprising: a vertical chimney; a vertical inlet means opening into said chimney for introducing primary wastewater treatment wastes into the lower portion of the chimney; bubble supply means within said chimney and below said vertical inlet means; an injector located below said vertical inlet means and above said bubble supply means; a deflecting means communicating with said vertical inlet means for spreading said wastes into extensive contacting relationship with bubbles from said bubble supply means and with polymer flocculant supplied through said injector; an efflux means that is in communication with a vertical side of said chimney at a location below said bubble supply means, the horizontal distance between said vertical inlet means and said efflux means being less than the height of the vertical chimney; and said efflux means has a maximum height at least as high as the height of the wastes in the chimney.
Claim 17
Dependent Claim
43 words
The apparatus of claim 14, wherein said efflux means is external to said chimney and includes a horizontally elongate chamber and a vertical efflux conduit communicating with said chamber and terminating at a height approximately the same as the height of said chimney.
Claim 18
Dependent Claim
48 words
The apparatus of claim 14, wherein said vertical inlet means includes a downwardly opening pipe and a generally cone-shaped baffle immediately therebelow, and said injector includes an upwardly opening pipe and a generally cone-shaped baffle immediately therebelow, said baffles being in complementary, abutting relationship at their broadest ends.
Claim 19
Dependent Claim
17 words
The apparatus of claim 14, further including a heating means located upstream of said bubble supply means.
Claim 20
Dependent Claim
30 words
The apparatus of claim 14, wherein said bubble supply means is a grid of electrodes, alternate ones of which serve as cathodes and alternate others of which serve as anodes.
Claim 21
Dependent Claim
17 words
The apparatus of claim 14, wherein said bubble supply means is a gas dispersion or dissolving means.
Claim 22
Dependent Claim
39 words
The apparatus of claim 19, wherein said bubble supply means includes a recycle pipe in communication with said efflux means, a gas injector along said recycle pipe, and a distributor opening into the chimney below the wastes introducing 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) | 1981-01-30 | 1981-08-01 | 1982-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-30 | 1985-08-01 | 1986-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-30 | 1989-08-01 | 1990-01-31 | $7700.00 | Window Closed / Lapsed |