| 摘要 |
<p>Lance comprising an injection pipe (1), an intermediate pipe (2) coaxial with the injection pipe (1) and a protective sheath (4) of refractory material extending over at least a proportion of the length of the injection pipe (1), the injection pipe (1) and the intermediate pipe (2) defining between them a chamber (20), characterised by at least one delivery pipe for coolant fluid (22) extending along and outside the intermediate pipe (2), this delivery pipe (22) being connected at its upper end to a device for feeding coolant fluid (23) and communicating at its lower end (21) with the lower part of the chamber (20) so as to cause a flow of coolant fluid to travel downwards outside the said intermediate pipe (2) and upwards in the cooling chamber (20). <IMAGE></p> |
