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US3900311A Expired / Lapsed US ⏱️ 0.0 years remaining

Conversion of pig iron into steel

Assignee: Centre de Recherches Metallurgiques CRM ASBL
•
Filing: 1972-11-03
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Granted: 1975-08-19
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Expires: 1992-11-03
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Abstract

Abstract A refining process for converting pig iron into steel wherein at least one tuyere is mounted in the side wall on the converter and the tuyere has an inner conduit and an outer conduit. Substantially pure oxygen is injected through the inner conduit and a protective fluid is injected through the outer conduit. The axis of the tuyere is inclined towards the bottom of the converter so that the injected oxygen creates rotational movement in the molten metal so as to better distribute the oxygen throughout the melt and control the decarbonization of the converter. The tuyere in the side wall is mounted at the level of the zone occupied by the slag.

Inventors

  • 👤 Paul Emile Nilles

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 11:30
CPC Classifications
C; C21; C21C; C21C5/00; C21C5/28; C21C5/30; C21C5/32

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 128 words
A REFINING PROCESS FOR THE CONVERSION OF PIG IRON INTO STEEL IN A CONVERTER WHEREIN THE MOLTEN METAL IS AGITATED BY BLOWN OXYGEN SO AS TO BETTER DISTRIBUTE THE OXYGEN THROUGHOUT THE MELT AND CONTROL THE DECARBURIZATION, THE CONVERTER HAVING A BOTTOM, A SIDE WALL, AND AT LEAST ONE TUYERE IN THE SIDE WALL, THE TUYERE COMPRISING AN INNER CONDUIT AND AN OUTER CONDUIT SURR OR INJECTING SUBSTANTIALLY PURE OXYGEN THROUGH SAID INNER CONDUIT ONTO THE MOLTEN METAL IN THE CONVERTER, AND INJECTING A PROTECTIVE FLUID THROUGH THE OUTER CONDUIT, TE TUYERE OPENING INTO THE CONVERTER THROUGH THE SIDEWALL AT THE LEVEL OF THE ZONE OCCUPIED BY SLAG AN THE AXIS OF THE TUYERE BEING INCLINED TOWARDS THE CONVERTER BOTTOM TO CREATE ROTATIONAL MOVEMENT OF THE MOLTEN METAL.
Claim 2
Dependent Claim 128 words
A REFINING PROCESS FOR THE CONVERSION OF PIG IRON INTO STEEL IN A CONVERTER WHEREIN THE MOLTEN METAL IS AGITATED BY BLOWN OXYGEN SO AS TO BETTER DISTRIBUTE THE OXYGEN THROUGHOUT THE MELT AND CONTROL THE DECARBURIZATION, THE CONVERTER HAVING A BOTTOM, A SIDE WALL, AND AT LEAST ONE TUYERE IN THE SIDE WALL, THE TUYERE COMPRISING AN INNER CONDUIT AND AN OUTER CONDUIT SURR OR INJECTING SUBSTANTIALLY PURE OXYGEN THROUGH SAID INNER CONDUIT ONTO THE MOLTEN METAL IN THE CONVERTER, AND INJECTING A PROTECTIVE FLUID THROUGH THE OUTER CONDUIT, TE TUYERE OPENING INTO THE CONVERTER THROUGH THE SIDEWALL AT THE LEVEL OF THE ZONE OCCUPIED BY SLAG AN THE AXIS OF THE TUYERE BEING INCLINED TOWARDS THE CONVERTER BOTTOM TO CREATE ROTATIONAL MOVEMENT OF THE MOLTEN METAL.
Claim 3
Dependent Claim 27 words
A process as claimed in claim 1, in which the axis of the tuyere is directed along a line contained in a diametrical plane of the converter.
Claim 4
Dependent Claim 35 words
A process as claimed in claim 1, in which only one tuyere is used, the axis of the tuyere being directed towards the converter bottom along a line which does not intersect the converter axis.
Claim 5
Dependent Claim 76 words
A process as claimed in claim 1, in which two tuyeres are used, one opening into the converter above the slag layer and the other opening into the slag layer, the axis of each tuyere being directed along a line which does not inersect the axis of rotation of the converter, the speed and flow rate of the materials injected through the tuyere being such that the molten metal and the slag rotate at different speeds.
Claim 6
Dependent Claim 18 words
The process as claimed in claim 1, in which powdery material is in suspension in the injected oxygen.
Claim 7
Dependent Claim 15 words
The process as claimed in claim 1, in which the protective fluid is a hydrocarbon.

References Cited (Backward Citations)

US1793153A Cited
US2918365A Cited
US2855293A Cited
US3015554A Cited
US3079249A Cited
US3330645A Cited
US3556773A Cited
US3706549A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-08-18 1979-02-17 1979-08-19 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-08-18 1983-02-17 1983-08-19 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-08-18 1987-02-17 1987-08-19 $7700.00 Window Closed / Lapsed

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