Method of switching bottom-blown gases and apparatus therefor
AssigneeNippon Steel Corporation
InventorsShozo Murakami, Hukuyosi Isomura, Yoshihiro Koga
Life of this patent
Estimating the term…
Abstract
A method of switching bottom blown gases and an apparatus suitable for carrying such method into practice in blowing successively in turn a plurality of gases through piping into molten steel in a steel-making furnace through tuyeres or porous plugs for gas blowing located in a lower portion of the steel-making furnace. The method includes the step of directly releasing into atmosphere at least a portion of the gas flowing in and through the piping in response to a rise in the pressure of the gas when switching the blown gases.
Claims8
A method of switching bottom blown gases successively from a first gas to a second gas without interruption immediately after the blowing of said first gas into a molten metal in a steel making furnace, which blowing is effected from tuyeres or porous plugs through piping means connecting the tuyeres or porous plugs to gas sources, said tuyeres or porous plugs being disposed at a part of the steel making furnace below the surface of the molten metal, comprising the steps of:
- increasing the pressure of gas in the piping means to a higher level than a steadystate gas pressure flow condition which occurs when switching from the first gas to the second gas is completed;
- releasing into the atmosphere at least a portion of the gas in the piping means from a predetermined position in the piping means between the gas sources and said furnace when the pressure of the gas is increased to exceed said predetermined level higher than the gas pressure in the steadystate flow condition whereby gas in said piping means is diverted from said furnace into the atmosphere;
- and
- inhibiting the release of the gas into the atmosphere after a lapse of a predetermined period of time from the initiation of the release of the gas, or when the pressure of the gas flowing through the piping drops below a predetermined level.
An apparatus for switching bottom blown gases successively without interruption from a first gas to a second gas immediately after the blowing of said first gas into a molten metal in a steel making furnace, which blowing is effected from tuyeres or porous plugs disposed at a part of the steel making furnace below the surface of the molten metal, said blown gases being fed from a plurality of gas supply sources comprising:
- first piping means connected to each of said plurality of gas supply sources;
- means mounted in said first piping means for controlling the pressure and the flow rate of the gases flowing therethrough;
- second piping means for operatively connecting said first piping means to the plurality of tuyeres or porous plugs;
- and
- means located in a position in said second piping means between said gas sources and said furnace releasing into the atmosphere the gas flowing therethrough before said gas reaches said furnace when the pressure of the gas reaches a predetermined level.
Dependencies are inferred from the claim text.