TOP-BLOWN LANCE FOR BLOWING GAS INTO CONVERTER AND ALSO MELTING SKULL STUCK TO NOSE

摘要

PROBLEM TO BE SOLVED: To resolve such problem as to be difficult to stably melt and remove the metal stuck to furnace opening hole part over long time without accompanying the stopping of operation and the erosion of refractory in a converter in the conventional lance. ;SOLUTION: In the top-blown lance 1 having a Laval-shaped nozzle spouting holes 2a, 2b arranged in the circular direction toward the downward outside at the tip part and jetting gaseous oxygen toward molten metal surface through the nozzle spouting holes 2a, 2b, the outlet opening hole surfaces 4a, 4b of the nozzle spouting holes 2a, 2b are formed as inclined state in the range of 90° to ≤120° to the center axes (m), (n) so that the length (1₁) at the center side of the lance becomes larger than the length (1₂) at the outside of the lance in the nozzle spouting holes 2a, 2b. By this constitution, the jetting gaseous oxygen is directed to the downward center side of the top-blown lance 1 and the secondary conbustion ratio is suitably improved, and the promotion of the melting of skull stuck to the nose and also, the restraint of the erosion of refractory in the converter are obtd.;COPYRIGHT: (C)1998,JPO