Metallurgical lance and apparatus

摘要

A metallurgical lance for introducing gas from above into a volume of metal in a vessel includes a head having at least one ejector formed therein. The ejector includes a Laval nozzle surrounded by a shrouding gas passage. Both the Laval nozzle and the shrouding gas passage communicate at their proximal ends with a common gas supply chamber. The shrouding gas passage communicates with the chamber via a first annular orifice member which determines the percentage split of the gas flow through the chamber between the Laval nozzle and the shrouding gas passage.