Abstract: A method of providing an inerting atmosphere to the surface of molten aluminum in a vortex charge well of a reverberatory melting furnace is provided. The purpose is to improve aluminum recovery (reduce aluminum oxidation melt loss) by displacing the ambient atmosphere above the molten vortex with an inert gas. The method includes introducing a flow of an inerting gas into an inerting region immediately above the surface of the vortex charge well. The inerting gas may be selected from the group consisting of nitrogen, argon, or a mixture thereof. The inerting gas may be introduced into the charge inlet chute, through a diffuser, or a ring manifold. The vortex charge well may include a lid.

Abstract: A gas inerting system and method is provided. This system includes a rotary melting furnace with a furnace barrel, a burner, and a charge of metal to be melted; and an injection manifold with a plurality of injection orifices. The burner is configured to produce a flame directed into the furnace barrel, and the plurality of injection orifices are configured to disperse inert gas streams into the furnace barrel, into an inerting region between the burner flame and the charge of aluminum. The metal to be melted may be aluminum. The method of inerting includes rotating the rotary furnace and introducing heat into the furnace barrel by generating the flame, thereby beginning a melt cycle, then introducing the inert gas streams into an inlet to the injection manifold, thereby directing the inert gas streams through the injection orifices and into the inerting region, after a predetermined condition has been met.

Abstract: A method of providing an inerting atmosphere to the surface of molten aluminum in a vortex charge well of a reverberatory melting furnace is provided. The purpose is to improve aluminum recovery (reduce aluminum oxidation melt loss) by displacing the ambient atmosphere above the molten vortex with an inert gas. The method includes introducing a flow of an inerting gas into an inerting region immediately above the surface of the vortex charge well. The inerting gas may be selected from the group consisting of nitrogen, argon, or a mixture thereof. The inerting gas may be introduced into the charge inlet chute, through a diffuser, or a ring manifold. The vortex charge well may include a lid.

Abstract: Systems and corresponding methods are described herein that provide an effective inert blanket over a metal surface (hot solid (charge) metal or molten metal) in a container such as an induction furnace. The system includes a container of metal and a system configured to delivery biphasic inert cryogen toward the metal. The delivery system may include a lance disposed at the top of the container. The lance has a hood that directs both a flow of liquid cryogen and a flow of vaporous gas toward the metal surface. The liquid cryogen contacts the metal surface, generating a volume of expanding gas over the metal surface, The vaporous cryogen creates a reinforcing vapor that slows the expansion rate of the expanding gas, localizing the expanding gas over the metal surface.

Abstract: A heating system includes a furnace configured to receive a product to be thermally treated within the furnace, where the furnace includes at least one burner to generate combustion gases from a source of oxygen and a carbon-based fuel source provided to the burner, and the combustion gases provide heat to the product disposed within the furnace. A gas pipeline delivers a heated inert gas into the furnace at a location proximate the product so as to at least partially surround and protect a surface of the product and minimize or prevent the product from chemically reacting with other gases within the furnace.

Abstract: Systems and corresponding methods are described herein that provide an effective inert blanket over a metal surface (hot solid (charge) metal or molten metal) in a container such as an induction furnace. The system includes a container of metal and a system configured to delivery biphasic inert cryogen toward the metal. The delivery system may include a lance disposed at the top of the container. The lance has a hood that directs both a flow of liquid cryogen and a flow of vaporous gas toward the metal surface. The liquid cryogen contacts the metal surface, generating a volume of expanding gas over the metal surface. The vaporous cryogen creates a reinforcing vapor that slows the expansion rate of the expanding gas, localizing the expanding gas over the metal surface.

Abstract: A heating system includes a furnace configured to receive a product to be thermally treated within the furnace, where the furnace includes at least one burner to generate combustion gases from a source of oxygen and a carbon-based fuel source provided to the burner, and the combustion gases provide heat to the product disposed within the furnace. A gas pipeline delivers a heated inert gas into the furnace at a location proximate the product so as to at least partially surround and protect a surface of the product and minimize or prevent the product from chemically reacting with other gases within the furnace.

Abstract: A fume extraction system includes a combustion zone coupled with an exhaust outlet of a furnace to receive an exhaust gas stream emerging from the furnace outlet during system operation, where the exhaust gas stream includes explosive gases that undergo combustion reactions within the combustion zone. A duct section is aligned downstream from the combustion zone to deliver the exhaust gas stream toward a venting outlet. A suction unit establishes a negative pressure within the system so as to draw the exhaust gas stream from the furnace outlet and through the fume extraction system during system operation. An exhaust damper is further provided within the system between the combustion zone inlet and the suction unit. A control system selectively controls the negative pressure applied to the furnace, combustion zone and duct section based upon a measured concentration of at least one gas constituent within the exhaust gas stream.

Abstract: A fume extraction system includes a combustion zone coupled with an exhaust outlet of a furnace to receive an exhaust gas stream emerging from the furnace outlet during system operation, where the exhaust gas stream includes explosive gases that undergo combustion reactions within the combustion zone. A duct section is aligned downstream from the combustion zone to deliver the exhaust gas stream toward a venting outlet. A suction unit establishes a negative pressure within the system so as to draw the exhaust gas stream from the furnace outlet and through the fume extraction system during system operation. An exhaust damper is further provided within the system between the combustion zone inlet and the suction unit. A control system selectively controls the negative pressure applied to the furnace, combustion zone and duct section based upon a measured concentration of at least one gas constituent within the exhaust gas stream.

Abstract: Methods and apparatus for efficient utilization of a cryogen in inerting of solid and molten metals are presented. One method and apparatus of the invention includes providing a source of liquid cryogen; transporting the liquid cryogen through a conduit connected to the source of liquid cryogen to a gas/liquid separator, wherein a portion of the liquid cryogen transforms into gaseous cryogen en route; transporting a portion of the liquid cryogen through a first conduit connecting the gas/liquid separator to a cryogen supply nozzle; transporting the gaseous cryogen through a second conduit connecting the gas/liquid separator to a cryogen supply nozzle; and flowing at least a portion of liquid cryogen and at least a portion of the gaseous cryogen through the cryogen nozzle separately and near a surface of solid or molten metal. Thus liquid that transforms into gaseous cryogen en route from storage is not vented and not wasted, but used in inerting of solid or molten metals.

Abstract: Methods and apparatus for efficient utilization of a cryogen in inerting of solid and molten metals are presented. One method and apparatus of the invention includes providing a source of liquid cryogen; transporting the liquid cryogen through a conduit connected to the source of liquid cryogen to a gas/liquid separator, wherein a portion of the liquid cryogen transforms into gaseous cryogen en route; transporting a portion of the liquid cryogen through a first conduit connecting the gas/liquid separator to a cryogen supply nozzle; transporting the gaseous cryogen through a second conduit connecting the gas/liquid separator to a cryogen supply nozzle; and flowing at least a portion of liquid cryogen and at least a portion of the gaseous cryogen through the cryogen nozzle separately and near a surface of solid or molten metal. Thus liquid that transforms into gaseous cryogen en route from storage is not vented and not wasted, but used in inerting of solid or molten metals.

Abstract: A gas-fired combination steam and dry oven has an oven cavity that is heated by heat exchange from one or more fire tubes and a boiler that is located outside the oven cavity and is heated by heat exchange from one or more other fire tubes. Both the oven and boiler fire tube heat exchangers employ natural draft gas burners. The combination oven can be operated as a forced-air convection oven, a forced-flow convection oven circulating superheated steam, or a steamer circulating saturated steam. Sensors in the oven supply information to a microprocessor that controls the gas burners to maintain an oven temperature within 5.degree. F. or less. Sensors of the level of water in the boiler assure that the water level stays within predetermined limits. Tray stops keep foods and the trays containing them away from the walls of the oven to permit free circulation of air, saturated steam, or superheated steam.