Patent US3780997A successfully refreshed from Google Patents.
US3780997A
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US
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Aerobic sewage treatment
Assignee: BERTRAN AND HARGRAVES Inc
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Filing: 1971-04-19
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Granted: 1973-12-25
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Expires: 1991-04-19
Abstract
Abstract Diffuser means for effecting contact between gas and a mass of liquid sewage comprising a plurality of open ended, inclined air lift pipes immersed one above another in said sewage.
Inventors
- 👤 W Hargraves
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:32
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/02; C02F3/12; C02F3/1236; C02F3/1242; C02F3/20; Y; Y02; Y02W; Y02W10/00; Y02W10/10; Y10; Y10S; Y10S261/00; Y10S261/75
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
137 words
An improved diffuser for effecting contact between a gas stream and a mass of liquid sewage contained within sidewalls of a chamber comprising: a plurality of open ended inclined air-lift pipes immersed one above another in the mass of liquid sewage; and means for introducing a stream of gas bubbles into the lowermost pipe whereby liquid is entrained therein, the upper end of each pipe, except the uppermost pipe, being disposed in a position below the lower end of the next higher pipe such that air bubbles issuing from the upper end of a lower pipe cause the liquid entrained therewith to be forced outwardly into the mass of liquid sewage and so that the gas bubbles subsequently enter the lower end of the next higher pipe and entrain new liquid sewage from said mass of liquid.
Claim 2
Dependent Claim
137 words
An improved diffuser for effecting contact between a gas stream and a mass of liquid sewage contained within sidewalls of a chamber comprising: a plurality of open ended inclined air-lift pipes immersed one above another in the mass of liquid sewage; and means for introducing a stream of gas bubbles into the lowermost pipe whereby liquid is entrained therein, the upper end of each pipe, except the uppermost pipe, being disposed in a position below the lower end of the next higher pipe such that air bubbles issuing from the upper end of a lower pipe cause the liquid entrained therewith to be forced outwardly into the mass of liquid sewage and so that the gas bubbles subsequently enter the lower end of the next higher pipe and entrain new liquid sewage from said mass of liquid.
Claim 3
Dependent Claim
29 words
A diffuser as defined in claim 1, wherein said air-lift pipes are arranged in a spiral arrangement so that mixing movement is imparted to said mass of liquid sewage.
Claim 4
Dependent Claim
28 words
A diffuser as in claim 2 wherein said chamber side walls form corners in said chamber and wherein the ends of said pipes are disposed in said corners.
Claim 5
Dependent Claim
37 words
A diffuser as defined in claim 1, wherein each of said lower ends except said lower end of said lowermost pipe is cut at an angle so as to expose a concave surface to said air bubbles.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |