NATURAL OPENING METHOD FOR POURING LADLE NOZZLE

摘要

PURPOSE:To improve the natural rate of perforation of a ladle nozzle by inserting a sand cylinder into which the silica sand consisting of the high-purity silica sand for the upper part and ordinary silica sand for the lower part is packed and of which the outside cylinder in the upper part is a tin-plate cylinder and the outside cylinder in the lower part is a paper cylinder into a pouring nozzle hole and receiving a steel from the ladle. CONSTITUTION:The sand cylinder 6 consists of the silica sand 8 contg. >=98% SiO2 at 200-300mm in the upper part and the silica sand 9 contg. <98% SiO2 in the lower part. Said cylinder is coated with the tin-plate cylinder 10 and paper cylinder 11 respectively at about 2/3 of the upper part and about 1/3 of the lower part. Such sand cylinder 6 is inserted into the pouring nozzle hole 5 of the ladle 1 and after the silica sand 7 contg. <98% SiO2 is packed into the upper part, the cylinder is opened with a hole when the cylinder receives the molten steel. The natural rate of perforation of the ladle nozzle is thus considerably increased and the safe and smooth casting operation is executed.