Abstract: An inert gas bubble-actuated molten metal pump, for the movement of molten metal in a molten-metal bath, which obviates the necessity of a heatproof and flameproof cover to counteract splashing and spattering at the surface of the molten metal bath above the pump, comprising an inert gas diffusion means at an upper end thereof, the diffusion means having an upper surface containing a multiplicity of small upwardly-opening apertures for the breaking up of large bubbles and the diffusion of small bubbles of inert gas upwardly therethrough. The pump includes a refractory block which comprises a conveying conduit which is preferably elongated in width and a spreader cavity in communication with both a passageway in the block for providing a source of inert gas and a lower end of the conveying conduit.

Abstract: The charge well of a metal melting furnace is provided with an internal cavity having a circular cross section when viewed from the top, preferably a cavity of cylindrical or conical configuration, and with a peripheral exit port located tangentially with respect to said cavity at a lower level thereof for exit of molten metal into the main chamber of the furnace. An inert gas bubble-actuated molten metal pump brings molten metal from a hotter section of the furnace, advantageously directly from the main chamber, and has its exit port located tangentially to the periphery of the cavity at an upper level thereof, thereby creating vortical flow of molten metal within the charge well for the more rapid and efficient melting of metal chips and scraps into the molten metal therein and for circulation of hotter molten metal throughout the furnace.

Abstract: An inert gas bubble-actuated molten metal pump is located between one section of a metal-melting furnace and a second section to pump molten metal from the one section, wherein the molten metal is at a higher temperature, into the second section, wherein the molten metal is at a lower temperature, and its effluent is directed into contact with metal chips being charged into the second section, thereby assisting in the more rapid melting of the chips into the molten metal mass in the second section. The inert gas employed to actuate the molten metal pump is captured beneath a heat-resistant and flame-resistant cover located above the exit port of the pump and over a substantial portion of the molten metal mass in the second section, thereby providing a non-oxidizing atmosphere at the surface of the molten metal mass or pool beneath said cover.

Abstract: An inert gas bubble-actuated molten metal pump is located in a metal-melting furnace to effect circulation of molten metal throughout the furnace. The inert gas employed to actuate the molten metal pump is captured beneath a heat-resistant and flame-resistant cover located above the exit port of the pump and over a substantial portion of the molten metal, thereby to prevent splashing, spattering, and disruption of a thin protective layer or skin of oxidized metal at the surface of the molten metal as well as to provide a non-oxidizing atmosphere at the surface of the molten metal beneath said cover. In this manner and by this combination, the inert gas is employed most efficiently and economically.

Abstract: A method, for the conveyance of molten metal from one place to another, in a high-temperature molten metal pool in a metal-melting furnace or out of said molten metal pool, employing an at least partially-inclined elongated conveying conduit and gas feed means for feeding inert gas into the lower end of the conveying conduit and thereby inducing a flow of molten metal in and through said conveying conduit, is disclosed, along with suitable apparatus for carrying out the said method wherein the parts or elements coming into contact with the high-temperature molten metal pool are of a suitable refractory material. According to the present invention, the inert gas is fed into the conveying conduit at a supersonic velocity, thereby simultaneously effecting a degassing of the molten metal while it is being conveyed.

Abstract: A method, for the conveyance of molten metal from one place to another, in a high-temperature molten metal pool in a metal-melting furnace or out of said molten metal pool, employing an at least partially-inclined elongated conveying conduit and gas feed means for feeding inert gas into the lower end of the conveying conduit and thereby inducing a flow of molten metal in and through said conveying conduit, is disclosed, along with suitable apparatus for carrying out the said method wherein the parts or elements coming into contact with the high-temperature molten metal pool are of a suitable refractory material. According to the present invention, the inert gas is fed into the conveying conduit at a supersonic velocity, thereby simultaneously effecting a degassing of the molten metal while it is being conveyed.

Abstract: A method, for the conveyance of molten metal from one place to another, in a high-temperature molten metal pool in a metal-melting furnace or out of said molten metal pool, employing an at least partially-inclined elongated conveying conduit and gas feed means for feeding inert gas into the lower end of the conveying conduit and thereby inducing a flow of molten metal in and through said conveying conduit, is disclosed, along with suitable apparatus for carrying out the said method wherein the parts or elements coming into contact with the high-temperature molten metal pool are of a suitable refractory material. According to the present invention, the molten metal is alloyed simultaneously with its conveyance, the same inert gas being employed for both conveying the molten metal and for entrainment of the alloying metal.

Abstract: A method, for the conveyance of molten metal from one place to another, in a high-temperature molten metal pool in a metal-melting furnace or out of said molten metal pool, employing an at least partially-inclined elongated conveying conduit and gas feed means for feeding inert gas into the lower end of the conveying conduit and thereby inducing a flow of molten metal in and through said conveying conduit, is disclosed, along with suitable apparatus for carrying out the said method wherein the parts or elements coming into contact with the high-temperature molten metal pool are of a suitable refractory material. According to the present invention, the molten metal is alloyed simultaneously with its conveyance, the same inert gas being employed for both conveying the molten metal and for entrainment of the alloying metal.

Abstract: A method, for the conveyance of molten metal from one place to another, in a high-temperature molten metal pool in a metal-melting furnace or out of said molten metal pool, employing an at least partially-inclined elongated conveying conduit and gas feed means for feeding inert gas into the lower end of the conveying conduit and thereby inducing a flow of molten metal in and through said conveying conduit, is disclosed, along with suitable apparatus for carrying out the said method wherein the parts or elements coming into contact with the high-temperature molten metal pool are of a suitable refractory material. According to the present invention, an intermittent or pulsating inert gas feed is employed to produce essentially spherical or cylindrical bubbles within the conveying conduit, thereby resulting in greater efficiency and economy because of the possibility of reducing the quantity of inert gas employed to induce the flow of an identical amount of molten metal.

Abstract: A method, for the conveyance of molten metal from one place to another, in a high-temperature molten metal pool in a metal-melting furnace or out of said molten metal pool, employing an at least partially-inclined elongated conveying conduit and gas feed means for feeding inert gas into the lower end of the conveying conduit and thereby inducing a flow of molten metal in and through said conveying conduit, is disclosed, along with suitable apparatus for carrying out the said method wherein the parts or elements coming into contact with the high-temperature molten metal pool are of a suitable refractory material.