Gas blowing lance and operation method of top bottom blowing converter using the same

摘要

PROBLEM TO BE SOLVED: To improve the secondary combustion ratio and heat conductive efficiency without increasing the damage to a refractory by disposing a working gas supplying nozzle so as to be inclined from a gas jetting direction on the downstream wall surface of an orifice eccentrically disposed at the inlet part of a gas jetting nozzle. SOLUTION: Oxidizing gas 5 is supplied from the orifices 2 arranged at the inlet parts of above one gas jetting nozzle 3 arranged in a gas blowing lance 1 and jetted as gas jet to execute refining of molten iron in a top-bottom combined-blown converter. The gas jetting nozzle 3 is preferably inclined at an angle of about 10-15 deg. to the center axis of the lance 1, and the center of the orifice 2 is eccentrically arranged to the center axis of the gas jetting nozzle 3. Further, the working gas supplying nozzles 4 are disposed at the reverse side to the orifices 2 on the wall surface of the gas jetting nozzles 3 on the downstream side of the orifices 2, and their center axes are inclined at 20-90 deg. from the jetting direction of the orifices 2. Thus, the flow rate of the working gas is controlled and the jetting angle of the oxidizing gas can be held in a suitable range.