BOTTOM-BLOWN GAS BLOWING NOZZLE FOR MOLTEN METAL REFINING FURNACE AND STEEL REFINING METHOD USING THE SAME

摘要

ABSTRACT OF THE DISCLOSUREA Nozzle used to introduce a bottom-blown gasinto a molten metal refining furnace so as to minimize thelower limit value of the rate of blowing gas flow. Thenozzle includes a refractory (1) having a plurality ofsmall holes (2) having an inner diameter of from 0.5 to 3.0mm formed from its working surface to its back, a metalcover (3) enclosing at least a part of the sides of therefractory (1) and a pressure box (4) formed in the bottomof the refractory (1) so as to communicate with the holes(2) and define a gas reservoir space. Due to the smalldiameter of the holes (2), the molten metal is preventedfrom entering the pressure box (4) through the holes (2)when the blowing gas pressure and the rate of blowing gasflow are decreased.