Patent US2897149A successfully refreshed from Google Patents.
US2897149A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sewage scum removal
Assignee: Individual
•
Filing: 1954-09-29
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Granted: 1959-07-28
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Expires: 1974-09-29
Abstract
No abstract record available.
Inventors
- 👤 Llewellyn B Griffith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:14
CPC Classifications
B; B01; B01D; B01D21/00; B01D21/02; B01D21/04; B01D21/24; B01D21/2433
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
165 words
THE METHOD OF REMOVING SCUM FROM A PRIMARY SETTLING SEWAGE TANK IN A MANNER TO DECREASE THE RATIO OF WATER TO SLUDGE SOLIDS IN THE MATERIAL TRANSFERRED FROM THE TANK TO A DIGESTER; WHICH METHOD CONSISTS IN LOWERING THE LEVEL OF THE LIQUID SURFACE IN THE PRIMARY TANK BY REMOVING FROM THE TANK A QUANTITY OF CLEAR LIQUID, IMMEDIATELY THEREAFTER BREAKING UP THE SCUM FLOATING IN THE TANK AT THE LOWERED LEVEL BY VIOLENT AGITATION TO RELEASE CARBON DIOXIDE GAS FROM THE SCUM MADE BUOYANT THEREBY, SO THE SOLIDS OF THE SCUM WILL FALL TO THE BOTTOM OF THE TANK, SUCH LOWERING OF THE LIQUID LEVEL PERMITTING THE COMPLETION OF THE STEP OF VIOLENT AGITATION WITHOUT THE PASSING OF MATERIAL FROM THE PRIMARY SETTLING TANK, THEN COLLECTING THE SETTLED SLUDGE SOLIDS, AND FINALLY TRANSFERRING THE COLLECTED SLUDGE SOLIDS TO THE DIGESTER IN A PERIOD NOT EXCEEDING TWO HOURS AFTER COLLECTION OF THE SLUDGE TO AVOID STICKING OF THE SOLIDS TO THE WALL OF THE TANK.
Claim 2
Independent Claim
165 words
THE METHOD OF REMOVING SCUM FROM A PRIMARY SETTLING SEWAGE TANK IN A MANNER TO DECREASE THE RATIO OF WATER TO SLUDGE SOLIDS IN THE MATERIAL TRANSFERRED FROM THE TANK TO A DIGESTER; WHICH METHOD CONSISTS IN LOWERING THE LEVEL OF THE LIQUID SURFACE IN THE PRIMARY TANK BY REMOVING FROM THE TANK A QUANTITY OF CLEAR LIQUID, IMMEDIATELY THEREAFTER BREAKING UP THE SCUM FLOATING IN THE TANK AT THE LOWERED LEVEL BY VIOLENT AGITATION TO RELEASE CARBON DIOXIDE GAS FROM THE SCUM MADE BUOYANT THEREBY, SO THE SOLIDS OF THE SCUM WILL FALL TO THE BOTTOM OF THE TANK, SUCH LOWERING OF THE LIQUID LEVEL PERMITTING THE COMPLETION OF THE STEP OF VIOLENT AGITATION WITHOUT THE PASSING OF MATERIAL FROM THE PRIMARY SETTLING TANK, THEN COLLECTING THE SETTLED SLUDGE SOLIDS, AND FINALLY TRANSFERRING THE COLLECTED SLUDGE SOLIDS TO THE DIGESTER IN A PERIOD NOT EXCEEDING TWO HOURS AFTER COLLECTION OF THE SLUDGE TO AVOID STICKING OF THE SOLIDS TO THE WALL OF THE TANK.
Claim 3
Dependent Claim
158 words
A SEWAGE TANK HAVING A SCUM BAFFLE NEAR THE EXIT END OF THE TANK, A SUMP BELOW THE MAJOR PORTION OF THE BOTTOM OF THE TANK, A WEIR FOR DETERMINING THE NORMAL LIQUID LEVEL IN THE TANK, MEANS FOR SCRAPING SOLIDS SETTLING ON THE BOTTOM OF THE TANK, INTO THE SUMP, PIPING FOR TRANSFERRING COLLECTED SLUDGE FROM THE SUMP TO A DIGESTER, MEANS FOR DISCHARGING AIR BETWEEN THE BOTTOM OF THE TANK AND THE SCUM LAYER TO VIOLENTLY AGITITATE THE SCUM LAYER, AND MEANS LOCATED ADJACENT THE WEIR FOR LOWERING SAID NORMAL LIQUID LEVEL IN THE TANK BY A CHOOSEN AMOUNT, SAID LAST NAMED MEANS INCLUDING A LEVEL-LOWERING PIPE HAVING ITS ENTRY END BETWEEN THE EXIT END OF THE TANK AND THE SCUM BAFFLE AND THE HEIGHT OF THE CHOSEN LOWERED LEVEL, WHEREBY WHEN THE LOWERING IS DONE AT A PERIOD OF MINIMUM FLOW INTONTHE TANK THE LIQUID PASSING THROUGH THE LEVEL-LOWERING PIPE WILL BE SUBSTANTIALLY PURE WATER.
Claim 4
Dependent Claim
158 words
A SEWAGE TANK HAVING A SCUM BAFFLE NEAR THE EXIT END OF THE TANK, A SUMP BELOW THE MAJOR PORTION OF THE BOTTOM OF THE TANK, A WEIR FOR DETERMINING THE NORMAL LIQUID LEVEL IN THE TANK, MEANS FOR SCRAPING SOLIDS SETTLING ON THE BOTTOM OF THE TANK, INTO THE SUMP, PIPING FOR TRANSFERRING COLLECTED SLUDGE FROM THE SUMP TO A DIGESTER, MEANS FOR DISCHARGING AIR BETWEEN THE BOTTOM OF THE TANK AND THE SCUM LAYER TO VIOLENTLY AGITITATE THE SCUM LAYER, AND MEANS LOCATED ADJACENT THE WEIR FOR LOWERING SAID NORMAL LIQUID LEVEL IN THE TANK BY A CHOOSEN AMOUNT, SAID LAST NAMED MEANS INCLUDING A LEVEL-LOWERING PIPE HAVING ITS ENTRY END BETWEEN THE EXIT END OF THE TANK AND THE SCUM BAFFLE AND THE HEIGHT OF THE CHOSEN LOWERED LEVEL, WHEREBY WHEN THE LOWERING IS DONE AT A PERIOD OF MINIMUM FLOW INTONTHE TANK THE LIQUID PASSING THROUGH THE LEVEL-LOWERING PIPE WILL BE SUBSTANTIALLY PURE WATER.
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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) | 1962-07-27 | 1963-01-26 | 1963-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-07-27 | 1967-01-26 | 1967-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-07-27 | 1971-01-26 | 1971-07-28 | $7700.00 | Window Closed / Lapsed |