Patent US3421610A successfully refreshed from Google Patents.
US3421610A
Expired / Lapsed
US
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Automatic control of reflux rate in a gas separation fractional distillation unit
Assignee: Lummus Technology LLC
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Filing: 1966-02-28
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Granted: 1969-01-14
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Expires: 1986-02-28
Abstract
No abstract record available.
Inventors
- 👤 Louis Marshall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:49
CPC Classifications
B; B01; B01D; B01D3/00; B01D3/42; B01D3/4211; B01D3/4233; C; C10; C10G; C10G7/00; C10G7/12; Y; Y10; Y10S; Y10S203/00; Y10S203/09; Y10S203/19; Y10S208/00; Y10S208/01
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2990437A
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US3020213A
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US3212997A
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US3197138A
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US3227631A
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US3237376A
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US3309287A
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US3224210A
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US3342702A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-01-14 | 1972-07-15 | 1973-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-01-14 | 1976-07-15 | 1977-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-01-14 | 1980-07-15 | 1981-01-14 | $7700.00 | Window Closed / Lapsed |