| 摘要 |
<p>Exothermic hot top comprising a box made of two layers the first, close to the melt being rapidly exothermic, the second, being more slowly exothermic. A rapidly exothermic powder is sprinkled on top of the melt and a slower exothermic powder on top of the first layer. The rate of cooling of the head of the ingot is reduced, so that the piping can be filled over a longer period giving rise to sounder ingots. The refractory part of the hot top falls to powder after cooling.</p> |
