METHOD AND DEVICE FOR DEGASSING OF MOLTEN STEEL

摘要

PURPOSE:To remove efficiently the gas in a molten steel in a ladle by immersing a cap body made of refractories into the molten steel, pulling up the cap body in a hermetic state to rise the molten steel surface in the cover body then releasing the hermetic state and dropping the molten metal to stir the same and repeating such operation. CONSTITUTION:A cap body 10 which is made of refractories and has a space 11 in the lower part is lowered into the molten steel 1 in a ladle 2 and the top end 16 thereof is immersed into the molten steel. An inert gas 30 such as Ar is forced via a flexible pipe 14 through a gate valve 13 attached to the upper part of the body 10 into the cap body. The molten slag 17a in the cap body is passed through the molten steel as shown by arrows 18 and is discharged to the outside of the body 10. The body 10 is further pushed into the molten steel 1 and thereafter the stop valve 15 is closed and the body 10 is pulled up. A negative pressure space is formed into the body 10 and the molten steel surface rises. The valve 15 is opened at the point of this time to communicate the molten steel with the atm. and to allow the rising molten steel to fall by gravity, thereby stirring the molten steel. Such operation is repeated plural times to degas efficiently the molten steel.