REFRACTORY PLUG FOR CLOSING OUTFLOW HOLE AND METHOD FOR OPENING PLUG

摘要

PURPOSE:To open easily a closing plug in contact with the outflow hole in the bottom of a vessel for contg. a molten metal so that the outflow of the metal is made sure by the constitution in which the outside flank of the plug has a taper of a prescribed angle or above upward and outward relative to the vertical center line of the outflow hole. CONSTITUTION:This invention relates to the colsing plug 7 which fits into the molten metal outflow hole formed of tuyeres 2, 8 and an upper nozzle 1. The outside flank of the plug 7 in contact with the outflow hole is formed to the taper having an angle of >=10 deg. upward and outward relative to the vertical center line of the outflow hole. The lifting distance S of a lifting mechanism consisting of a cylinder 9 and a piston 10 is set in an S>2.0H (h; the vertical height of the contact surface) range in the stage of opening the plug 7 from the lower part by using said lifting mechanism. The opening of the closing plug and the outflow hole is thus made easy and the outflow of the metal is made sure.