| 摘要 |
PURPOSE:To reduce defect in a cast slab and to reduce the equipping cost by arranging flow control plate at upper part of molten metal discharging hole in a nozzle body and forming a rotating flow along the flow control plate in the molten surface. CONSTITUTION:One pair of the flow control plates 13 are projected at upper part of the molten steel discharging hole 15 on outer wall of the submerged nozzle 11. At the time of pouring the molten steel 20 into a mold 14 from a tundish through the submerged nozzle 11, ascending flow, which flows out from the molten steel discharging hole 15 to the arrow mark 17, is rotated along the flow control plate 13 to the arrow mark 21. Therefore, the molten flow is not stayed at the molten surface near the submerged nozzle 11, and the accumulation of inclusions is restrained. As new molten steel 20 is always supplied to the molten surface, lowering of the molten steel temp. near at the nozzle 11 is prevented, and removability of inclusion by the powder 18 is not reduced. Therefore, the defect in the cast slab caused by accumulated inclusions on the molten surface is restrained and also the equipping cost is reduced. |
