Patent ID: 6666902
Filing Date: 2003-12-23
Classification: C21C,F27D

Abstract:
A vacuum/decompression refining apparatus to refine molten steel, comprising:a ladle adapted to contain molten steel, said ladle having a bottom and an upper portion defining an inner diameter; a vacuum/decompression chamber having (i) a lower portion sealingly coupled to said upper portion of said ladle; (ii) a top portion; and (iii) a shaft portion extending from said lower portion to said top portion, said shaft portion at a location adjacent to said lower portion of said vacuum/decompression chamber defining an inner diameter that is less than said inner diameter defined by said upper portion of said ladle; and an injection apparatus at said bottom of said ladle for injecting an inert gas into said ladle, such that when internal pressure within said vacuum/decompression chamber is reduced and molten steel contained within said ladle is agitated via injection of an inert gas into said ladle from said injection apparatus, a bulging portion of the molten steel is formed at a surface of the molten steel, wherein the bulging portion defines a diameter that is not larger than said inner diameter of said shaft portion.