A top gun for rh vacuum refining

Abstract

The invention discloses a top lance for RH vacuum refining. The top lance comprises a Laval tube, a core tube, a top lance central tube, a top lance inner tube, a top lance outer tube and a top lance water separating tube, wherein a ring-shaped shrunk tube section and a ring-shaped expanded tube section are formed between the Laval tube and the core tube. According to the invention, the ring-shaped shrunk tube section and the ring-shaped expanded tube section enable airflow to reach supersonic speed through acceleration, further, the operating lance position can be raised, the amount of splashing molten steel sticking the lance is reduced, the service life of a nozzle of the top lance is longer; a ring-shaped throat-like component is arranged between the Laval tube and the core tube, so that the oxygen blowing flux can be increased, the oxygen blowing decarburization efficiency and oxygen blowing aluminum adding heating efficiency are improved; oxygen, combustion gas and desulfurizing powder are conveyed to an RH vacuum chamber through respective different channels; the desulfurizing powder can reach the surface of molten steel under the covering of surrounding protective gas, the amount of powder absorbed away through vacuum exhausting is less, so that the yield of the desulfurizing powder is high; besides, compared with the conventional top lance, the top lance provided by the invention is not needed to be manufactured by adopting 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 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 more functions such...

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Problems solved by technology

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

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