Furnace outlet

In an electric furnace for melting glass and other high melting point materials at temperatures exceeding 2500.degree. F. said furnace including a vessel, means for electrically heating and melting the materials with the vessel, and an outlet means extending through a wall of said vessel from the interior of said furnace to the exterior of said furnace for withdrawing molten material from said vessel, the improvement comprising:

• said outlet means including a first outlet orifice having one end in the interior of said vessel and through which molten material passes upon withdrawal from said vessel, said first outlet orifice comprising a corrosion resistant metal having a melting point in excess of 2500.degree. F, but which must be protected from an oxidizing atmosphere at the temperature of the molten material, and means for shielding said first outlet orifice from an oxidizing atmosphere without the need for the use of a neutral or reducing gas surrounding the outlet, said shielding means consisting essentially of a second outlet orifice below said first outlet orifice, said second outlet orifice being made from a material having a higher resistance to oxidation from air than the metal in said first outlet orifice, said second outlet orifice being located in a recess in the bottom of said vessel and fluid cooling means at least partially surrounding said second outlet orifice for maintaining said second outlet orifice at a temperature below its critical or melting temperature.