| 摘要 |
A method and apparatus for heating molten steel in a steel making operation is disclosed, and which includes a refractory lined vessel having an open top, a removable cover adapted to overlie the top, and at least one plasma arc torch mounted so as to extend through the cover at an angle of about 60 DEG . The arc gas for the torch includes a substantial percentage of nitrogen, which permits a higher power level as compared to conventionally used argon, and the mass flow rate of the arc gas is maintained at a sufficiently high level to produce a continuous blast of gas which impinges at an angle upon any slag formed on the surface of the molten steel with sufficient force to move the slag and expose the underlying molten steel. As a result, the attachment of the arc to the underlying molten steel is facilitated, and the impingement of the gas contributes to the mixing of the steel to avoid heat stratification. |
