A powder spraying top gun for rh vacuum refining

Abstract

The invention discloses a powder spraying top lance for RH vacuum refining. The powder spraying top lance comprises a laval tube, a core tube, a top lance center tube, a top lance power conveying tube, a top lance inner tube, a top lance outer tube and a top lance waterproof tube, wherein an annular shrinkage tube section and an annular expansion tube section are formed between the laval tube and the core tube. The annular shrinkage tube section and the annular expansion tube section are capable of accelerating airflow to supersonic speed, thereby improving the working lance height, reducing splash steel liquid adhered to the lance and prolonging the service life of a nozzle of the top lance; meanwhile, a throat between the laval tube and the core tube is an annular throat, so that the oxygen blowing flow can be increased, and the heating efficiency of oxygen-blowing decarbonization and oxygen-blowing aluminum addition can be improved; oxygen, gas and desulphurization powder are conveyed to an RH vacuum chamber through different channels; the desulphurization powder can reach the surface of the steel liquid under the surrounding of ambient protective gas; the powder taken away in a vacuum pumping manner is reduced, and the yield of the desulphurization powder is improved; moreover, compared with the existing top lance, the powder spraying top lance for RH vacuum refining is free of precision casting, so that the manufacturing difficulty is obviously reduced.

Description

technical field [0001] The invention relates to a vacuum degassing device used for refining outside a furnace in the metallurgical industry, in particular to a powder spraying top gun for RH vacuum refining. Background technique [0002] Molten steel vacuum circulation degassing (RH) technology is a secondary refining process of molten steel, which is a necessary means of out-of-furnace refining for the production of high-quality steel. RH vacuum refining equipment was originally used for degassing molten steel. Its metallurgical principle is to rely on pressure difference to lift molten steel into a vacuum chamber, and to circulate molten steel by blowing argon, and use the vacuum environment to achieve the purpose of degassing (N2, H2, O2). , which has the advantages of fast reaction speed, high vacuum degree and good metallurgical effect. In recent years, the KTB (Kawasaki Top Blowing) overhead oxygen lance developed by Kawasaki has enabled RH vacuum refining to have mor...

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Problems solved by technology

[0004] In view of this, the purpose of the present invention is to provide a powder-spraying top gun for RH vacuum refining, to overcome the shortcomings of existing top guns such as high manufacturing difficulty, easy blocking of the gun, and low service life.

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