Improvements in sealing injection apparatus for injecting substances into molten metals.

摘要

Apparatus (110) for injecting substances into molten metal includes a nozzle block (111) for installation in the wall of a vessel, the nozzle block having at least one initially-closed injection passage and an injectant pipe (114) movable in the passage and advanceable to open the passage for injection ot commence. Melt-arresting means (135) are provided in the vicinity of the respective discharge ends of the pipe and passage to limit run back of molten metal in a space between the lance pipe (114) and the passage when the pipe has been advanced to its injection position, the arresting means (135) defining a clearance which affords advancing movement of the pipe but is so small as to prevent significant flow of metal through the clearance. In case melt is not arrested by the arresting means (135), a compressible melt-impervious seal means (127) is provided adjacent an outer end of the pipe.