Patent US2720489A successfully refreshed from Google Patents.
US2720489A
Expired / Lapsed
US
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Digester
Assignee: Walker Process Equipment Inc
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Filing: 1950-11-22
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Granted: 1955-10-11
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Expires: 1970-11-22
Abstract
No abstract record available.
Inventors
- 👤 Walker James Donald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:54
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/28; C02F3/2866; C02F3/2873
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
130 words
A DIGESTER FOR SOLIDS GATHERED IN WASTE TREATMENT PLANTS INCLUDING A TANK HAVING AN UPPER ZONE OF SUBSTANTIALLY UNRESTRICTED CIRCULATION AND IN WHICH GAS FORMATION OCCURS, AN OUTFLOW CONDUIT HAVING MEANS FOR MAINTAINING THE LIQUID IN THE TANK AT A GIVEN LEVEL, A PARTITION WITHIN THE TANK FORMING AN ISOLATED CLARIFIER CHAMBER CONSTANTLY COMMUNICATING WITH THE TANK ONLY AT A DEPTH BELOW THE LEVEL OF SUBSTANTIAL GAS FORMATION TO RECEIVE SOLIDS AND LIQUID FROM THE TANK AND TO ALLOW THE SOLIDS TO SETTLE BACK INTO THE TANK AT ANY TIME, AND A SLOW FLOW DRAW-OFF INTAKE IN THE CLARIFIER CHAMBER BELOW THE LIQUID LEVEL BUT SUBSTANTIALLY ABOVE THE LEVEL OF COMMUNICATION BETWEEN THE CHAMBER AND THE TANK FOR WITHDRAWING CLARIFIED LIQUOR FROM THE CHAMBER, SAID INTAKE COMMUNICATING WITH SAID CONDUIT.
Claim 2
Dependent Claim
130 words
A DIGESTER FOR SOLIDS GATHERED IN WASTE TREATMENT PLANTS INCLUDING A TANK HAVING AN UPPER ZONE OF SUBSTANTIALLY UNRESTRICTED CIRCULATION AND IN WHICH GAS FORMATION OCCURS, AN OUTFLOW CONDUIT HAVING MEANS FOR MAINTAINING THE LIQUID IN THE TANK AT A GIVEN LEVEL, A PARTITION WITHIN THE TANK FORMING AN ISOLATED CLARIFIER CHAMBER CONSTANTLY COMMUNICATING WITH THE TANK ONLY AT A DEPTH BELOW THE LEVEL OF SUBSTANTIAL GAS FORMATION TO RECEIVE SOLIDS AND LIQUID FROM THE TANK AND TO ALLOW THE SOLIDS TO SETTLE BACK INTO THE TANK AT ANY TIME, AND A SLOW FLOW DRAW-OFF INTAKE IN THE CLARIFIER CHAMBER BELOW THE LIQUID LEVEL BUT SUBSTANTIALLY ABOVE THE LEVEL OF COMMUNICATION BETWEEN THE CHAMBER AND THE TANK FOR WITHDRAWING CLARIFIED LIQUOR FROM THE CHAMBER, SAID INTAKE COMMUNICATING WITH SAID CONDUIT.
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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) | 1958-10-10 | 1959-04-11 | 1959-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-10-10 | 1963-04-11 | 1963-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-10-10 | 1967-04-11 | 1967-10-11 | $7700.00 | Window Closed / Lapsed |