US2822257A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for controlling blast furnaces
Assignee: United States Steel Corp
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Filing: 1955-06-21
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Granted: 1958-02-04
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Expires: 1975-06-21
Abstract
No abstract record available.
Inventors
- 👤 Ralph T Hanna
- 👤 Carl G Hogberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:34
CPC Classifications
C; C21; C21B; C21B5/00; C21B5/006
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
142 words
IN THE OPERATION OF A BLAST FURNACE, WHEREIN A PREHEATED AIR BLAST IS APPLIED TO THE LOWER PORTION OF THE FURNACE AND THE PRESSURE WITHIN THIS PORTION IS A FUNCTION OF FACTORS WHICH INCLUDE VOLUME OF THE BLAST AND TEMPERATURE OF THE BLAST, A METHOD OF MAINTAINING THIS PRESSURE AT ABSOLUTE VALUES CLOSE TO THE CRITICAL THAT CAUSES HANGING COMPRISING PERIODICALLY GRADUALLY INCREASING AT LEAST ONE OF SAID FACTORS FROM A STARTING POINT SUBSTANTIALLY BELOW THAT WHICH PRODUCES A CRITICAL PRESSURE AND THEREBY GRADUALLY INCREASING THE ABSOLUTE PRESSURE, CONTINUOUSLY MEASURING THE RATE OF PRESSURE CHANGE AS THE ABSOLUTE PRESSURE INCREASES, CONTINUING TO INCREASE THIS FACTOR AS LONG AS NO INCREASE OCCURS IN SAID RATE REGARDLESS OF INCREASES IN THE ABSOLUTE PRESSURE UP TO THE LIMIT WHICH ITSELF CAUSES HANGING, AND CUTTING BACK THIS FACTOR WHEN AN INCREASE IS DETECTED IN SAID RATE.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-02-03 | 1961-08-05 | 1962-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-02-03 | 1965-08-05 | 1966-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-02-03 | 1969-08-05 | 1970-02-04 | $7700.00 | Window Closed / Lapsed |