Abstract: The present invention provides an arc-melting apparatus which attains extremely high efficiency by preheating scraps using exhaust gas from the melting chamber. The arc-melting apparatus needs for no device to carry and supply an iron source to a melting chamber, which makes it possible to preheat the next charge. The arc-melting apparatus has a melting furnace which melts scraps, a preheating shaft connected directly to an upper part of one side of the melting furnace, an arc electrode for melting scraps in the melting furnace, a bucket for supplying scraps to the preheat shaft so as to continuously maintain scraps in the melting furnace and in the preheating shaft, a tapping portion having a tapping hole, being projected outward from the melting furnace and a tilting device for tilting the melting furnace on a side of the tapping portion. The tapping portion is arranged at an orthogonal direction to the direction of the supplied cold iron source.

Abstract: The present invention provides an arc-melting apparatus which attains extremely high efficiency by preheating scraps using exhaust gas from the melting chamber. The arc-melting apparatus needs for no device to carry and supply an iron source to a melting chamber, which makes it possible to preheat the next charge. The arc-melting apparatus has a melting furnace which melts scraps, a preheating shaft connected directly to an upper part of one side of the melting furnace, an arc electrode for melting scraps in the melting furnace, a bucket for supplying scraps to the preheat shaft so as to continuously maintain scraps in the melting furnace and in the preheating shaft, a tapping portion having a tapping hole, being projected outward from the melting furnace and a tilting device for tilting the melting furnace on a side of the tapping portion. The tapping portion is arranged at an orthogonal direction to the direction of the supplied cold iron source.

Abstract: The present invention provides an arc-melting apparatus, which attains extremely high efficiency by preheating scraps using exhaust gas from the melting chamber. The arc-melting apparatus needs for no device to carry and supply an iron source to a melting chamber, which makes it possible to preheat the next charge. The arc-melting apparatus has a melting furnace which melts scraps, a preheating shaft connected directly to an upper part of one side of the melting furnace, an arc electrode for melting scraps in the melting furnace, a bucket for supplying scraps to the preheat shaft so as to continuously maintain scraps in the melting furnace and in the preheating shaft, a tapping portion having a tapping hole, being projected outward from the melting furnace and a tilting device for tilting the melting furnace on a side of the tapping portion. The tapping portion is arranged at an orthogonal direction to the direction of the supplied cold iron source.

Abstract: The present invention provides an arc-melting apparatus, which attains extremely high efficiency by preheating scraps using exhaust gas from the melting chamber. The arc-melting apparatus needs for no device to carry and supply an iron source to a melting chamber, which makes it possible to preheat the next charge. The arc-melting apparatus has a melting furnace which melts scraps, a preheating shaft connected directly to an upper part of one side of the melting furnace, an arc electrode for melting scraps in the melting furnace, a bucket for supplying scraps to the preheat shaft so as to continuously maintain scraps in the melting furnace and in the preheating shaft, a tapping portion having a tapping hole, being projected outward from the melting furnace and a tilting device for tilting the melting furnace on a side of the tapping portion. The tapping portion is arranged at an orthogonal direction to the direction of the supplied cold iron source.

Abstract: A DC arc furnace according to the invention has a bottom electrode, which comprises a plurality of contact pins each having an end to be brought into contact with an object and to supply arc-forming current thereto, a current base electrically connected to the other end of each of the contact pins for distributing current from a power supply to the contact pins, and a cooling device for cooling the current base with the use of cooling water.

Abstract: The invention provides a direct current electric arc furnace which is composed of a feeding system of direct current to the furnace, a movable electrode at the roof of the furnace, and a bottom electrode attached to the bottom of the furnace at the position deviated from the center of the bottom of the furnace, the deviated distance from the center being determined by a magnetic field, generated by a current in the steel bath of the furnace, from under an arc generated by the movable electrode to the bottom electrode, which can cancel a second magnetic field generated by the current of the feeding system.

Abstract: The invention provides a direct current electric arc furnace which is composed of a feeding system of direct current to the furnace, a movable electrode at the roof of the furnace, and a bottom electrode attached to the bottom of the furnace at the position deviated from the center of the bottom of the furnace, the deviated distance from the center being determined by a magnetic field, generated by a current in the steel bath of the furnace, from under an arc generated by the movable electrode to the bottom electrode, which can cancel a second magnetic field generated by the current of the feeding system.

Abstract: A method for preheating steel scrap by an exhaust gas from a steelmaking electric furnace, which comprises: directing, when manufacturing steel from steel scrap in an electric furnace, an exhaust gas produced in said electric furnace to an exhaust gas combustion chamber provided in the middle of a discharge duct of said exhaust gas to cause combustion of carbon monoxide contained in said exhaust gas to form a combustion exhaust gas; and selectively directing part of said combustion exhaust gas into at least one scrap preheating chamber provided in the middle of a branch duct branching off from said discharge duct to preheat steel scrap charged in said scrap preheating chamber to a prescribed temperature; said method being characterized by: feeding back all of said combustion exhaust gas after preheating said steel scrap charged in said scrap preheating chamber to said exhaust gas combustion chamber to cause combustion of an incomplete-combustion gas which is produced by the incomplete combustion of combustibl

Abstract: An apparatus for preheating steel scrap comprises: a preheating vessel, having an open top and a bottom lid capable of being opened and closed, for receiving and preheating steel scrap, said preheating vessel being adapted to receive steel scrap to be preheated from said open top and to discharge the steel scrap preheated in said preheating vessel by opening said bottom lid; a hood downwardly flaring for covering said open top of said preheating vessel, said hood being movable from said open top of said preheating vessel and adapted to introduce high-temperature waste gases discharged from a steel-refining metallurgical furnace into said preheating vessel; a pit for housing said preheating vessel, said pit being provided with a duct for discharging to the outside said waste gases discharged into said pit from the bottom of said preheating vessel after preheating said steel scrap received in said preheating vessel; and, a canopy for sealing the gap between said pit and said preheating vessel housed in said pit