| 摘要 |
PROBLEM TO BE SOLVED: To prevent clogging of a nozzle when a tundish and the nozzle are preheated. SOLUTION: This nozzle stopper 10 is formed with a refractory and the like into a tubular shape, and is temporarily tacked to an upper face position of a nozzle 2 at the inner bottom of a tundish 1 with a mortar M and the like. Four opening parts 12 are formed at an outer peripheral portion of the stopper 10 in a peripheral direction, and arranged at such a height that the molten steel does not enter. An upper end opening of the stopper 10 is closed by an umbrella shaped part 13. Before the molten steel is poured, the tundish 1 is preheated with a combustion gas of a burner, and also the nozzle 2 is preheated with a combustion gas coming from the opening parts 12 of the stopper 10. The molten steel solidification can be prevented in the nozzle 2, because the nozzle 2 has been fully preheated, when the molten steel is poured.
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