| 摘要 |
PROBLEM TO BE SOLVED: To provide a top-blowing lance for refining with which the generating amount of dust can be reduced in the state of maintaining a high decarburizing-oxygen efficiency. SOLUTION: In the top-blowing lance for refining, in which a gas jetting nozzle 6 for jetting oxidizing gas is installed at the lower end part, the jetting nozzle 6 has a throat 7 at its inlet part, and a divergent part 8 at the downstream side of the throat. Wherein, the throat diameter Dt and the outlet diameter De of the divergent part, with respect to the atmospheric pressure Pe at the nozzle outlet part and a nozzle suitable expanding pressure Po, satisfy the following relation, that is, expression; (De/Dt)<SP>2</SP>=0.259×(Pe/Po)<SP>-5/7</SP>×[1-(Pe/Pc)<SP>2/7</SP>]<SP>-1/2</SP>. Then, the divergent part diameter being the connecting portion with the throat is larger than the throat diameter, and the center line q of the throat to the center line p of the divergent part is made eccentric to the center shaft side of the top-blowing lance, and further, at least one of gas jetting hole for controlling during the refining is provided on the wall surface of the divergent part. COPYRIGHT: (C)2011,JPO&INPIT |
