Method and apparatus for inert gas blanketing of an open top-vessel

摘要

The surface of material, e.g. molten metal, contained in an open top vessel (14), e.g. induction furnace, is blanketed by establishing a swirling flow of an inert gas having a density greater than air in a cylindrical passage (36) extending from the top of the vessel. Inert gas exits the swirl flow passage (36) through an opening (40) having diameter (Dex) that is smaller than the base diameter (Db) of the passage (36) adjacent the open top vessel.