Patent US3748224A successfully refreshed from Google Patents.
US3748224A
Expired / Lapsed
US
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Control system for the pre dryer section of a paper machine
Assignee: Westinghouse Electric Corp
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Filing: 1970-11-24
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Granted: 1973-07-24
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Expires: 1990-11-24
Abstract
Abstract SYSTEM FOR CONTROLLING THE PRESSURE OF STEAM INTRODUCED INTO A PAPER DRYING DRUM IN SUCH A WAY THAT THE TEMPERATURE OF THE PAPER WEB LEAVING THE DRUM WILL NE CONSTANT. THIS IS ACCOMPLISHED BY DERIVING A PREDICTIVE FEED-FORWARD SIGNAL FROM CONSIDERATION OF A HEAT BALANCE AROUND THE DRUM AND BY VARYING THE PREDICTIVE SIGNAL WITH A FEEDBACK SIGNAL PROPORTIONAL TO ACTUAL EXIT TEMPERATURE. THE MODIFIED FEED-FORWARD SIGNAL IS THEN USED AS AN ERROR SIGNAL FOR CONTROLLING THE STEAM PRESSURE WITHIN THE DRUM, AND, HENCE, ITS TEMPERATURE. D R A W I N G
Inventors
- 👤 W Tillie
- 👤 J Carleton
- 👤 R Putman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:59
CPC Classifications
D; D21; D21G; D21G9/00; D21G9/0009; D21G9/0036; Y; Y10; Y10S; Y10S162/00; Y10S162/09; Y10S162/10; Y10S162/11
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) | 1976-07-23 | 1977-01-22 | 1977-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-23 | 1981-01-22 | 1981-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-23 | 1985-01-22 | 1985-07-24 | $7700.00 | Window Closed / Lapsed |