Patent ID: 7989739

Claim:
An electric heater assembly for heating molten metal, the assembly comprised of: (a) a cylindrical shaped, tubular sleeve suitable for immersing in molten metal, the sleeve comprised of an inner layer of titanium or titanium alloy, an outer coating of refractory resistant to attack by molten metal and a bond coating between the outer refractory coating, said sleeve also having an inside surface; (b) a body selected from the group consisting of an alloy containing 2-15 wt % Al, the remainder Cu; an alloy containing 1-16 wt. % Cr, the remainder Cu; and an alloy containing 0.25-5 wt. % Y, the remainder Cu; contained in said sleeve, said body in contact with said inside surface to improve heat transfer through said sleeve; (c) a coating of aluminum applied to said body and melted to alloy said coating with said copper to suppress oxidation of copper in the body, said body having the ability to creep deform at operating temperatures to eliminate air pockets between said inside surface and said body, said body having at least one electric heating element receptacle; and (d) an electric heating element located in said receptacle in heat transfer relationship therewith for adding heat through said body to said molten metal.