Patent US2738306A successfully refreshed from Google Patents.
US2738306A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dewaxing oils with periodic changes in solvent composition
Assignee: Shell Development Co
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Filing: 1953-06-15
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Granted: 1956-03-13
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Expires: 1973-06-15
Abstract
No abstract record available.
Inventors
- 👤 Jr John G Pratt
- 👤 Jr John N Limbach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:30
CPC Classifications
C; C10; C10G; C10G73/00; C10G73/02; C10G73/06
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
112 words
IN A CONTINUOUS METHOD FOR SEQUENTIAL BLOCKED-OUT CYCLIC SOLVENT DEWAXING OF WAXY DISTILLATE LUBRICATING OIL FRACTIONS AND WAXY RESIDUAL LUBRICATING OIL FRACTIONS WHEREIN A CIRCULATING SOLVENT MIXTURE USED IS A MIXTURE OF A SOLVENT AND AN ANTI-SOLVENT HAVING DIFFERENT AVERAGE VOLATILITIES AND WHEREIN RECOVERY OF THE SOLVENT MIXTURE FROM DEWAXED LUBRICATING OIL-SOLVENT MIXTURE SOLUTION FROM WHICH PRECIPITATED WAX HAS BEEN REMOVED IS EFFECTED IN A PLURAL NUMBER OF SEQUENTIAL VAPORIZATION STEPS, THE IMPROVEMENT WHICH COMPRISES INCREASING THE ANTI-SOLVENT CONCENTRATION OF THE CIRCULATING SOLVENT MIXTURE AT THE BEGINNING OF CHARGING OF WAXY DISTILLATE STOCK BY DIVERTING TO A FIRST STORAGE ZONE SOLVENT MIXTURE FROM A NUMBER OF SAID VAPORIZATION STEPS WHICH YIELD A
Claim 2
Dependent Claim
112 words
IN A CONTINUOUS METHOD FOR SEQUENTIAL BLOCKED-OUT CYCLIC SOLVENT DEWAXING OF WAXY DISTILLATE LUBRICATING OIL FRACTIONS AND WAXY RESIDUAL LUBRICATING OIL FRACTIONS WHEREIN A CIRCULATING SOLVENT MIXTURE USED IS A MIXTURE OF A SOLVENT AND AN ANTI-SOLVENT HAVING DIFFERENT AVERAGE VOLATILITIES AND WHEREIN RECOVERY OF THE SOLVENT MIXTURE FROM DEWAXED LUBRICATING OIL-SOLVENT MIXTURE SOLUTION FROM WHICH PRECIPITATED WAX HAS BEEN REMOVED IS EFFECTED IN A PLURAL NUMBER OF SEQUENTIAL VAPORIZATION STEPS, THE IMPROVEMENT WHICH COMPRISES INCREASING THE ANTI-SOLVENT CONCENTRATION OF THE CIRCULATING SOLVENT MIXTURE AT THE BEGINNING OF CHARGING OF WAXY DISTILLATE STOCK BY DIVERTING TO A FIRST STORAGE ZONE SOLVENT MIXTURE FROM A NUMBER OF SAID VAPORIZATION STEPS WHICH YIELD A
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-03-13 | 1959-09-12 | 1960-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-03-13 | 1963-09-12 | 1964-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-03-13 | 1967-09-12 | 1968-03-13 | $7700.00 | Window Closed / Lapsed |