Patent ID: 9074601
Filing Date: 2015-07-07
Classification: F04D,F27D

Abstract:
1. A pump for pumping molten metal comprising: a refractory base that can be submerged in a bath of molten metal; a refractory shaft sleeve having upper and lower end portions and being fastened to said base at the lower end portion, wherein said shaft sleeve is enclosed at the upper end portion, said shaft sleeve including openings at a lower end portion; wherein said base includes an impeller chamber that is in fluid communication with said shaft sleeve and includes an outlet from the impeller chamber; a motor; a refractory shaft extending in said shaft sleeve and connected to said motor; a refractory impeller connected to said shaft and rotatable in said impeller chamber of said base; a gas source that flows gas comprising inert gas into said shaft sleeve under pressure; a regulator that regulates at least one of flow rate and pressure of said gas while outletting said gas through said openings of said shaft sleeve; and a plurality of said openings disposed in a region of said shaft sleeve that extends partially or completely around a circumference of said shaft sleeve for a vertical distance of said shaft sleeve, whereby the molten metal is drawn via the rotating impeller into said shaft sleeve through said openings in a first lower portion of said region and the gas is outlet from said shaft sleeve into the molten metal through said openings in a second upper portion of said region.