Method for the removal of scum

摘要

A method of removing slag or like scum from the surface of molten metal by suction. A tubular gaseous stream directed toward the surface of scum is formed, with its interior space communicating with a suction source such as an ejector or vacuum pump. The gaseous stream hampers the inflow of external air into the suction zone surrounded by the stream. On reaching the scum surface, the gaseous stream flows inward along the scum surface and is thereafter drawn toward the suction source, so that the stream acts to blow the scum radially inwardly of the stream and thereafter raises the scum from the surface of molten metal, thus permitting efficient removal of the scum with a relatively low suction. A scum removing apparatus for practicing this method includes a suction source, a suction head communicating with the suction source, and annular nozzle means provided around the suction head for forming a tubular gaseous stream flowing toward the surface of scum.