Abstract: An oxygen injector for a post combustion system used in an electric arc furnace includes a housing formed of a concave configured front wall and a spaced rear wall. The housing has a width greater than the spacing defined between the front wall and spaced rear wall. An oval configured conduit wall is located medially in the housing and extends from the rear to front wall to form an oval configured oxygen chamber and a water chamber with the oxygen chamber bound internally by the conduit wall. Orifices are formed in the front wall within the oxygen chamber.

Abstract: An electric arc furnace includes a substantially cylindrically configured melting vessel having an upper shell defining a top opening. A water-cooled roof assembly is supported by the upper shell and positioned over the top opening and can be removed from the top opening for permitting the charging of scrap into the melting vessel. The water-cooled roof assembly includes an annular configured, water-cooled outer roof panel defining a central opening. An annular configured, water-cooled inner roof panel is positioned within the central opening of the outer roof panel and is removably mounted on the outer roof panel. The inner roof panel includes a central opening that removably mounts a central refractory. At least one electrode is mounted in the central refractory and extends into the melting vessel.

Abstract: An electric arc furnace comprises a closed melting vessel and includes means for charging metal to be molten into the melting vessel. At least one electrode extends into the melting vessel and generates an electric arc and forms a molten metal bath. At least one oxygen lance can be extended into the melting vessel for injecting oxygen into the molten metal bath and create a reaction where the carbon monoxide is generated. Gas is exhausted from the melting vessel and the carbon monoxide gas concentration of the exhaust gas is measured. A post combustion chamber receives the exhaust gas and provides post combustion of the exhaust gas. Post combustion oxygen is injected into the melting vessel in an amount sufficient to provide post combustion based on the amount of oxygen necessary for post combustion of the exhaust gas and the post combustion chamber.

Abstract: An electric arc furnace comprises a closed melting vessel and includes a roof through which metal to be molten is charged into the melting vessel. At least one electrode extends into the melting vessel and generates an electric arc and forms a molten metal bath. At least one oxygen lance can be extended into the melting vessel for injecting oxygen into the molten metal bath and create a reaction where the carbon monoxide is generated. Gas is exhausted from the melting vessel and the carbon monoxide gas concentration of the exhaust gas is measured. A post combustion chamber receives the exhaust gas and provides post combustion of the exhaust gas. Post combustion oxygen is injected into the melting vessel in an amount sufficient to provide post combustion based on the amount of oxygen necessary for post combustion of the exhaust gas and the post combustion chamber.

Abstract: An electric arc furnace includes a closed melting vessel and includes an opening that can be closed where metal to be molten is charged into the melting vessel. At least one electrode extends into the melting vessel and generates an electric arc and forms a molten metal bath. At least one oxygen lance can be extended into the melting vessel for injecting oxygen into the molten metal bath and create a reaction where the carbon monoxide is generated. Gas is exhausted from the melting vessel and the carbon monoxide gas concentration of the exhaust gas is measured. A post combustion chamber receives the exhaust gas and provides post combustion of the exhaust gas. Post combustion oxygen is injected into the melting vessel in an amount sufficient to provide post combustion based on the amount of oxygen necessary for post combustion of the exhaust gas and the post combustion chamber.

Abstract: An electric arc furnace includes a melting vessel having a top opening and an inside wall surface. A removable roof is positioned over the top opening and can be removed for permitting the charging of scrap into the melting vessel. An electrode extends through the roof into the melting vessel. A slag door portion defines a slag discharge opening discharged from the melting furnace. An arcuate configured water-cooled panel includes opposing upper and lower ends and opposing side ends. This water-cooled panel is mounted in the melting vessel above the slag door portion so that the lower end is angled inwardly away from an adjacent inside surface of the melting vessel. The side ends curve toward the adjacent inside surface of the melting vessel to minimize any arcing between the opposing side ends and the electrodes, and to avoid damage from scrap charging. The water-cooled panel forms a scrap free area adjacent to slag door portion.

Abstract: A water cooled roof for an electric arc furnace made up of a multiplicity of water cooled panels surrounded by a water distribution and collection ring, each portion of the roof being insulated from each other portion, including the roof panel, support arms and the roof rack. The invention provides a means for interrupting the flow of an inductive current around each electrode by creating a gap in the metal surrounding each electrode, thus insulating the furnace roof or cover from each phase of the three phase current.

Abstract: A burner apparatus for introducing auxilliary heat into a furnace, particularly for metallurgical heating and melting.The apparatus includes a gland which fits into a wall of a furnace, a drum-like device which fits into a mating opening in the gland, a burner sleeve in the drum for receiving a burner such as an oxy-fuel burner and directing the burner flame into the interior of the furnace. The drum and the integral burner are rotatable about an axis. Rotation of the drum moves the burner into the operative position or into the standby position clear of the furnace. Provision is made for oscillating the drum and burner during the heating operation.