| 摘要 |
PURPOSE:To promote cooling and solidification of the center part of molten steel as stirring the molten steel, to restrain the center segregation of a cast slab and to obtain the good surface quality by pouring the molten steel as rotating a nozzle having two discharging holes, which pours the molten steel at different height into a cooling mold. CONSTITUTION:Revolution of electric motor 25 is transmitted to a drum plate 16 and the submerged nozzle 14 through a power transmitting shaft 26,... sprocket 20, and the submerged nozzle 14 is rotated at the prescribed number of revolution. As each discharging hole 14e, 14f of the nozzle 14 has difference of height, the swirling flow of the molten steel is widened toward upper and lower direction by this height difference to widen the stirring range. Therefore, heat conduction to the wall face of the cooling mold 13 cooled from liquids phase part 40b by cooling water is promoted and so formation of solids phase is quickened. Further, by centrifugal force effect caused by rotation of the molten steel, the surface layer inclusion of the cast slab 40 is reduced. |
