US3705057A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for treating heat exchangers and similar apparatus in thermal power plants
Assignee: Kraftwerk Union AG
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Filing: 1971-06-09
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Granted: 1972-12-05
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Expires: 1991-06-09
Abstract
Abstract A METHOD OF TREATING HEAT EXCHANGERS AND LIKE APPARATUS USED IN THERMAL POWER PLANTS FOR APPLYING A PROTECTIVE MAGNETITE LAYER TO THE SURFACE OF IRON OR STEEL TUBES OR OTHER WALL PORTIONS OF THE HEAT EXCHANGER HAS THE STEPS OF SUBJECTING THE SURFACE TO A FLOW OF STEAM AT A TEMPERATURE ABOVE 220* C. IN THE ABSENCE OF AIR AND SIMULTANEOUSLY, DURING THE TIME THE PROTECTIVE LAYER IS APPLIED SUBJECTING THE TUBE TO A PRESSURE DIFFERENTIAL CORRESPONDING APPROXIMATELY TO THE PRESSURE DIFFERENTIAL TO WHICH THE TUBE IS SUBJECTED IN ACTUAL USE.
Inventors
- 👤 Fritz Kelp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:51
CPC Classifications
F; F28; F28F; F28F19/00; F28F19/02
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) | 1975-12-05 | 1976-06-05 | 1976-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-05 | 1980-06-05 | 1980-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-05 | 1984-06-05 | 1984-12-05 | $7700.00 | Window Closed / Lapsed |