US3823931A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tapping of a blast furnace
Assignee: Sydney Steel Corp
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Filing: 1972-11-20
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Granted: 1974-07-16
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Expires: 1992-11-20
Abstract
Abstract The use of a tuyere comprising an inner tube and an outer tube spaced from the inner tube and preferably coaxial therewith, a gas being passed through the inner tube and a hydrocarbon fuel such as propane, being passed through the outer tube, in tapping a metal refining furnace, particularly a blast furnace. The tuyere is cemented in a tapping notch and at the selected tapping time the hydrocarbon fuel flow is reduced and preferably stopped, oxygen being passed through the inner tube whereby the tuyere disintegrates providing direct communication between the hearth of the furnace and the exterior of the furnace.
Inventors
- 👤 W Wells
- 👤 D Haysom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:47
CPC Classifications
C; C21; C21B; C21B7/00; C21B7/12
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
176 words
In the operation of a metal refining furnace in which molten metal is periodically tapped from said furnace, a method of tapping said furnace which comprises installing a tuyere in a tapping notch in said furnace so as to provide communication with the hearth of said furnace, said tuyere comprising an inner tube and an outer tube surrounding said inner tube and providing a space therebetween, passing a gas stream into said furnace through said inner tube, and passing a hydrocarbon fuel stream into said furnace through said space between said inner and outer tubes, such that said hydrocarbon stream surrounds said gas stream and protects the end of the tuyere from disintegration during said operation of said furnace, said gas stream at least at the selected time of tapping said molten metal being oxygen, and at the selected time of tapping said molten metal from said furnace, reducing the flow of hydrocarbon fuel to an extent sufficient to cause disintegration of said tuyere and establish liquid communication with said furnace hearth through said tapping notch.
Claim 2
Dependent Claim
176 words
In the operation of a metal refining furnace in which molten metal is periodically tapped from said furnace, a method of tapping said furnace which comprises installing a tuyere in a tapping notch in said furnace so as to provide communication with the hearth of said furnace, said tuyere comprising an inner tube and an outer tube surrounding said inner tube and providing a space therebetween, passing a gas stream into said furnace through said inner tube, and passing a hydrocarbon fuel stream into said furnace through said space between said inner and outer tubes, such that said hydrocarbon stream surrounds said gas stream and protects the end of the tuyere from disintegration during said operation of said furnace, said gas stream at least at the selected time of tapping said molten metal being oxygen, and at the selected time of tapping said molten metal from said furnace, reducing the flow of hydrocarbon fuel to an extent sufficient to cause disintegration of said tuyere and establish liquid communication with said furnace hearth through said tapping notch.
Claim 3
Dependent Claim
18 words
The operation as claimed in claim 1 in which said gas passed through said inner tube is oxygen.
Claim 4
Dependent Claim
16 words
The operation as claimed in claim 1 in which the inner and outer tubes are coaxial.
Claim 5
Dependent Claim
20 words
The operation as claimed in claim 1 in which the hydrocarbon fuel stream is stopped at said selected tapping time.
Claim 6
Dependent Claim
14 words
The operation as claimed in claim 1 in which the hydrocarbon fuel is propane.
Claim 7
Dependent Claim
15 words
The operation as claimed in claim 1 in which the furnace is a blast furnace.
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) | 1977-07-15 | 1978-01-14 | 1978-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-15 | 1982-01-14 | 1982-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-15 | 1986-01-14 | 1986-07-16 | $7700.00 | Window Closed / Lapsed |