US4007035A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of using an expendable tap hole tuyere in open hearth decarburization
Assignee: United States Steel Corp
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Filing: 1975-01-27
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Granted: 1977-02-08
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Expires: 1995-01-27
Abstract
Abstract A process of making steel in an open hearth furnace utilizing an expendable tuyere inserted within the furnace tap-hole for injecting oxygen into the furnace charge to assist in oxidizing impurities from said charge.
Inventors
- 👤 Robert W. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:25
CPC Classifications
C; C21; C21C; C21C5/00; C21C5/04
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
99 words
A process for refining molten iron in a refractory-lined open hearth furnace, comprising: a. inserting a tuyere in a passage extending through the furnace and the refractory lining thereof and communicating with the interior of the furnace in a position whereby molten iron contained in the furnace may be discharged through said passage; b. providing molten iron in the furnace and, while said iron is contained in the furnace, injecting a refining fluid through the tuyere and into the iron for a period of time sufficient to substantially refine the iron, and tapping the refined iron through the tuyere.
Claim 2
Dependent Claim
99 words
A process for refining molten iron in a refractory-lined open hearth furnace, comprising: a. inserting a tuyere in a passage extending through the furnace and the refractory lining thereof and communicating with the interior of the furnace in a position whereby molten iron contained in the furnace may be discharged through said passage; b. providing molten iron in the furnace and, while said iron is contained in the furnace, injecting a refining fluid through the tuyere and into the iron for a period of time sufficient to substantially refine the iron, and tapping the refined iron through the tuyere.
Claim 3
Dependent Claim
13 words
A process in accordance with claim 1, wherein the refining fluid is oxygen.
Claim 4
Dependent Claim
45 words
A process in accordance with claim 2, wherein the refining fluid comprises a stream of oxygen and a protective jacket fluid selected from the group consisting of hydrocarbon, inert gas, steam, carbon dioxide, and non-explosive mixtures thereof is simultaneously injected enveloping said stream of oxygen.
Claim 5
Dependent Claim
21 words
A process in accordance with claim 3, wherein the protective jacket fluid comprises at least an effective amount of a hydrocarbon.
Claim 6
Dependent Claim
14 words
A process in accordance with claim 2, wherein the passage is the furnace tap-hole.
Claim 7
Dependent Claim
49 words
A process in accordance with claim 5, wherein the refining fluid comprises a stream of oxygen and a protective jacket fluid comprising a hydrocarbon in an amount from an effective amount up to about 20 weight percent of the injected oxygen is simultaneously injected enveloping said stream of oxygen.
Claim 8
Dependent Claim
21 words
A process in accordance with claim 4, wherein the hydrocarbon is in a gaseous state upon introduction thereof into the tuyere.
Claim 9
Dependent Claim
42 words
A process in accordance with claim 7, wherein an inert gas is substituted for oxygen and protective jacket fluid after completion of refinement of the iron and prior to tapping of the iron and without interruption of fluid injection into the melt.
Claim 10
Dependent Claim
41 words
A process in accordance with claim 2, wherein: a. solid iron-base metal is added to the furnace, and b. the solid metal is preheated by injection of at least one heated gas stream into the furnace above the metal melt level.
Claim 11
Dependent Claim
28 words
A process in accordance with claim 3, wherein solid iron-base metal is added to the vessel and preheated by injection of oxygen and hydrocarbon fuel through the tuyere.
Claim 12
Dependent Claim
34 words
A process in accordance with claim 10, wherein preheating and melting of the solid metal is facilitated by injection of at least one heated gas stream into the furnace above the metal melt level.
Claim 13
Dependent Claim
18 words
A process in accordance with claim 2, wherein a solid particulate material is suspended in the injected oxygen.
Claim 14
Dependent Claim
13 words
A process in accordance with claim 12, wherein the particulate material is lime.
References Cited (Backward Citations)
US3823931A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-08 | 1980-08-09 | 1981-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-08 | 1984-08-09 | 1985-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-08 | 1988-08-09 | 1989-02-08 | $7700.00 | Window Closed / Lapsed |