Patent US2194014A successfully refreshed from Google Patents.
Patent US2695323A successfully refreshed from Google Patents.
US2695323A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of para xylene
Assignee: California Research LLC
•
Filing: 1951-01-16
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Granted: 1954-11-23
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Expires: 1971-01-16
Abstract
No abstract record available.
Inventors
- 👤 Arnold Jerome Howard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:45
CPC Classifications
B; B01; B01D; B01D9/00; B01D9/0004; B01D9/0013; B01D9/0036; B01D9/004; B01D9/0059; C; C07; C07C; C07C7/00; C07C7/14; Y; Y10; Y10S; Y10S203/00; Y10S203/19
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
105 words
IN A PROCESS OF RECOVERING PARA XYLENE FROM MIXTURES OF ORTHO, META AND PARA XYLENES BY CHILLING A XYLENE FRACTION TO A TEMPERATURE OF FROM ABOUT -75* F. TO -120* F., THE STEPS OF FEEDING SAID XYLENE FRACTION TO A CRYSTAL FORMING ZONE COMPRISING A RELATIVELY LARGE BODY OF LIQUID XYLENES CONTAINING PARA XYLENE CRYSTALS SUSPENDED THEREIN, CONTINUOUSLY CIRCULATING A PORTION OF THE XYLENE LIQUID FROM SAID CRYSTAL FORMING ZONE THROUGH A CHILLER AND THERE COOLING IT BY INDIRECT HEAT EXCHANGE TO A TEMPERATURE BELOW THAT OF THE CRYSTAL-FORMING ZONE, RETURNING CHILLED XYLENES TO SAID CRYSTALLIZING ZONE WHEREBY CRYSTAL FORMING TEMPERATURES ARE MAINTAINED, AND RE-
Claim 2
Dependent Claim
105 words
IN A PROCESS OF RECOVERING PARA XYLENE FROM MIXTURES OF ORTHO, META AND PARA XYLENES BY CHILLING A XYLENE FRACTION TO A TEMPERATURE OF FROM ABOUT -75* F. TO -120* F., THE STEPS OF FEEDING SAID XYLENE FRACTION TO A CRYSTAL FORMING ZONE COMPRISING A RELATIVELY LARGE BODY OF LIQUID XYLENES CONTAINING PARA XYLENE CRYSTALS SUSPENDED THEREIN, CONTINUOUSLY CIRCULATING A PORTION OF THE XYLENE LIQUID FROM SAID CRYSTAL FORMING ZONE THROUGH A CHILLER AND THERE COOLING IT BY INDIRECT HEAT EXCHANGE TO A TEMPERATURE BELOW THAT OF THE CRYSTAL-FORMING ZONE, RETURNING CHILLED XYLENES TO SAID CRYSTALLIZING ZONE WHEREBY CRYSTAL FORMING TEMPERATURES ARE MAINTAINED, AND RE-
References Cited (Backward Citations)
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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) | 1957-11-22 | 1958-05-24 | 1958-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-11-22 | 1962-05-24 | 1962-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-11-22 | 1966-05-24 | 1966-11-23 | $7700.00 | Window Closed / Lapsed |