| 摘要 |
PURPOSE:To effectively prevent the closing of a nozzle hole through static pouring other than a bubbling method by flowing molten steel into a nozzle body, the top part thereof is provided with a spacing part encircling the nozzle hole, and forming turbulence by providing a small-diameter part in the nozzle hole. CONSTITUTION:The large-diameter part 1 in the top part of the nozzle body is made into double tube constructon, of which the outside tube part 3 is formed with a hollow hole part 4 of a two-step shape, and the inside tube part 2 is joined to the lower step hollow hole 4a. This puts the remaining space 5 of the upper-step hollow hole part 4b of a large diameter into the state of enclosing the upper half part of the inside tube part 2. The smallest hole diameter part 6 is formed in the upper part of the nozzle hole in the part 2. This nozzle shape contributes to the formation of turbulence in molten steel flow owing to the abrupt change in the nozzle hole diameter by the smallest hole diameter part 6 in the upper part of the nozzle where the solidification of the molten steel flow is liable to occur. In addition, the part 6 is kept heated at all times by the heat of the molten steel flowed into the remaining space 6; hence, the solidification and deposition of the molten steel are prevented. |
