Patent US3733244A successfully refreshed from Google Patents.
US3733244A
Expired / Lapsed
US
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Plate heat exchanger from polytetrafluoroethylene
Assignee: Hoechst AG
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Filing: 1971-02-16
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Granted: 1973-05-15
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Expires: 1991-02-16
Abstract
Abstract A PLATE HEAT EXCHANGER WHICH CONSISTS OF PLATES AND SEPARATING SHEETS MADE FROM POLYTETRAFLUOROETHYLENE, THE PLATES BEING PROVIDED WITH CHANNELS ON ONE OR BOTH SIDES. THE CHANNELS OF ADJACENT PLATES ARE SEPARATED BY SHEETS MADE FROM POLYTETRAFLUOROETHYLENE.
Inventors
- 👤 L Sanberger
- 👤 G Burgstaller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:14
CPC Classifications
F; F28; F28F; F28F3/00; F28F3/08; F28F3/083; F28F21/00; F28F21/06; F28F21/065
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-14 | 1976-11-13 | 1977-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-14 | 1980-11-13 | 1981-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-14 | 1984-11-13 | 1985-05-15 | $7700.00 | Window Closed / Lapsed |