US 10,781,499 B2Granted

Bottom stirring tuyere and method for a basic oxygen furnace

AssigneeAir Products and Chemicals, Inc.

InventorsGregory J. Buragino, Shailesh Pradeep Gangoli, Anshu Gupta, Anup Vasant Sane, Avishek Guha, Xiaoyi He, Michael David Buzinski, Kyle J. Niemkiewicz, Russell James Hewertson

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Abstract

A method of operating a BOF bottom stir tuyere having an inner nozzle surrounded by an annular nozzle, including during a hot metal pour phase and a blow phase, flowing an inert gas through both nozzles; during a tap phase, initiating a flow of a first reactant through the inner nozzle and a flow of a second reactant through the annular nozzle, and ceasing the flow of inert gas through the nozzles, wherein the first and second reactants includes fuel and oxidant, respectively, or vice-versa, such that a flame forms as the fuel and oxidant exit the tuyere; during a slag splash phase, continuing the flows of fuel and oxidant to maintain the flame; and after ending the slag splash phase and commencement of another hot metal pour phase, initiating a flow of inert gas through both nozzles and ceasing the flows of the first and second reactants.

Claims10

Dependent claims

A method of operating a bottom stir tuyere in a basic oxygen furnace for steel making, wherein the bottom stir tuyere has a concentric nozzle arrangement with an inner nozzle surrounded by an annular nozzle, the method comprising:

(a) during a molten metal pour phase, flowing an inert gas through both nozzles of the bottom stir tuyere;
(b) during a blow phase, continuing to flow the inert gas through both nozzles of the bottom stir tuyere;
(c) during a tap phase, initiating a flow of a first reactant and ceasing the flow of inert gas through the inner nozzle of the tuyere, and initiating a flow of a second reactant and ceasing the flow of inert gas through the annular nozzle of the tuyere, wherein the first reactant includes one of fuel and oxidant and the second reactant includes the other of fuel and oxidant, such that a flame forms as the fuel and oxidant exit the tuyere;
(d) during a slag splash phase, continuing the flows of fuel and oxidant to maintain the flame;
and
(e) after ending the slag splash phase and commencement of another molten metal pour phase, initiating a flow of inert gas through both nozzles of the bottom stir tuyere and ceasing the flows of the first and second reactants.

3 more elements

Dependencies are inferred from the claim text.