Abstract: A metallurgical vessel having an energy source and in which molten metal is contained for processing. A tuyere system is provided below the level of molten metal to permit the injection of gases, fluxes, ores, alloying additions and other materials to convert the molten metal to steel.

Abstract: A steel conversion method includes the steps of delivering a first quantity of oxygen and a surrounding sheath of hydrocarbon shielding fluid beneath the level of a quantity of molten ferrous metal or bath contained in a vessel by means of bottom tuyeres and simultaneously delivering a second quantity of oxygen to the bath from above through a top lance. The oxygen delivered through the bottom tuyeres is sufficient to promote mixing and is about 10% to 40% of the oxygen required for oxidation of impurities with the balance delivered through the top lance. An additional quantity of oxygen is delivered through the top lance to the space above the bath for post-combustion of off-gases to increase the thermal energy in the bath. Fluxes such as lime are added from above in lump form in the conventional manner or are entrained in the upper oxygen stream as required.

Abstract: A metallurgical vessel has releasably coupled, semicylindrical upper and lower sections arranged such that the axis of revolution of one section lies in a plane normal relative to the rotational axis of the other. The dimension of each section in the axial direction being the same as the dimension of the other section in the direction normal to the axis. The vessel is mounted for rotation about the axis of the lower section and an elongate charging mouth is formed in the upper section and is arranged with its major axis parallel to the axis of the lower section. A plurality of tuyeres extend through the lower section of the vessel and each tuyere includes a first tuyere pipe for injecting oxygen beneath the level of molten metal within the vessel, a second tuyere pipe disposed in surrounding relation to the oxygen pipe for injecting powdered materials entrained in a nonoxidizing gas and a third pipe surrounding the second pipe for injecting a hydrocarbon shielding fluid.

Abstract: A metallurgical vessel has releasably coupled, semicylindrical upper and lower sections arranged such that the axis of revolution of one section lies in a plane normal relative to the rotational axis of the other. The dimension of each section in the axial direction being the same as the dimension of the other section in the direction normal to the axis. The vessel is mounted for rotation about the axis of the lower section and an elongate charging mouth is formed in the upper section and is arranged with its major axis parallel to the axis of the lower section. A plurality of tuyeres extend through the lower section of the vessel and each tuyere includes a first tuyere pipe for injecting oxygen beneath the level of molten metal within the vessel, a second tuyere pipe disposed in surrounding relation to the oxygen pipe for injecting powdered materials entrained in a nonoxidizing gas and a third pipe surrounding the second pipe for injecting a hydrocarbon shielding fluid.

Abstract: An arc furnace enclosure has front, side and rear walls and a roof. A front opening in the enclosure allows a charging bucket to be moved into the enclosure and there is a roof opening for access to the furnace electrodes. A door assembly is movable into and out of a closed position to cover the front and top openings except for a gap which permits the charging bucket support hooks to extend from the enclosure so that the door assembly may be closed during charging. An air curtain seals the roof gaps and a vent withdraws gases and smoke from the enclosure.

Abstract: A method of treating ferrous metal in a metallurgical vessel having a plurality of two-pipe tuyeres extending generally upwardly through the vessel bottom and in spaced apart relation relative to each other. A flux, such as line, is first blown into the ferrous metal charge through the center tuyere pipe along with the process gas and a second gas is delivered to the outer tuyere pipe. After fluxing, a first process gas consisting principally of oxygen is blown into the charge through the center tuyere pipe along with a sheath of hydrocarbon shielding fluid delivered through the outer tuyere pipe. After a significant portion of carbon oxidation has proceeded to the point where excess oxygen would tend to oxidize chromium or iron, argon is mixed with the oxygen in the center tuyere pipe to the point where it equals or exceeds the proportion of oxygen while the delivery of hydrocarbon shielding fluid is continued through the outer tuyere pipe.

Abstract: A pair of metallurgical vessels are each coupled by a gas collecting hood having a movable skirt to a gas cleaning system which includes an exhaust fan and a quencher and scrubber each having flow varying means. Each vessel is surrounded by an enclosure having an access door toward which the open upper end of the vessel may be tilted for receiving a metal charge. A secondary gas collecting hood is disposed in each enclosure above the access door for creating an indraft when the door is open. A valve system permits the selective connection of the secondary hood of one enclosure to the fan of the other to increase the indraft during furnace charging, sampling and pouring.

Abstract: A pair of metallurgical vessels are each coupled by a gas collecting hood having a movable skirt to a gas cleaning system which includes an exhaust fan and a quencher and scrubber each having flow varying means. Each vessel is surrounded by an enclosure having an access door toward which the open upper end of the vessel may be tilted for receiving a metal charge. A secondary gas collecting hood is disposed in each enclosure above the access door for creating an indraft when the door is open. A valve system permits the selective connection of the secondary hood of one enclosure to the fan of the other to increase the indraft during furnace charging, sampling and pouring.

Abstract: An open-topped vessel for converting molten ferrous metal to steel is pivotal about a horizontal axis and has bottom tuyeres for blowing oxygen or other gases upwardly through molten metal. An enclosure at least partially surrounds the vessel and has a top opening to permit a primary smoke hood to prevent the escape of pollutants when the vessel is in its vertical position. An auxiliary hood is disposed above an access door and is provided in the enclosure laterally of the vessel tilt axis. An elevatable auxiliary smoke hood is disposed in surrounding relation to the smoke hood for sealing the top opening.

Abstract: An electric arc furnace pivotable between a first position wherein a gas delivery tuyere system is above the level of a metal charge for preheating the same and a second position wherein the tuyere system is below the level of metal charge to permit the injection of gases, fluxes, ores, alloying additions and other materials for converting a metal charge. A first furnace hood is engageable with the furnace when in its first position for positioning electrodes in the furnace and a second hood is engageable with the furnace when in its second position for withdrawing gases evolved during the gas blowing period.