US3784370A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of manufacturing pig iron
Assignee: STEPHENSON PAPESCH PROCESSES I
•
Filing: 1971-09-27
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Granted: 1974-01-08
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Expires: 1991-09-27
Abstract
Abstract A method of operating a blast furnace in which the blast furnace gas is stripped of nitrogen by the use of a molecular sieve and recycled.
Inventors
- 👤 E Stephenson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:05
CPC Classifications
C; C21; C21B; C21B5/00; C21B5/06; C21B2100/00; C21B2100/40; C21B2100/44; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
29 words
The method defined in claim 1, including heating the stripped portion of the blast furnace gas to about 2,000* F. prior to injecting it back into the blast furnace.
Claim 2
Dependent Claim
40 words
The method defined in claim 1, including compressing the stripping portion of the blast furnace gas and heating it to about 2,000* F. and injecting the same back into the blast furnace at the same point as the hot air.
Claim 3
Dependent Claim
78 words
The method defined in claim 1, wherein the blast furnace gas contains dust particles, including cleaning the portion of the blast furnace gas to be stripped prior to stripping in order to remove the dust particles therefrom, compressing the stripped portion of the blast furnace gas to about the pressure of the hot air and heating it to about 2,000* F. and injecting the same back into the blast furnace at the same point as the hot air.
References Cited (Backward Citations)
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US3140931A
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Cited
US3458307A
Cited
US3564816A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-07 | 1977-07-09 | 1978-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-07 | 1981-07-09 | 1982-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-07 | 1985-07-09 | 1986-01-08 | $7700.00 | Window Closed / Lapsed |