Nkk Corporation

Nippon Kokan Kabushiki Kaisha

Jp Steel Plantech Co.

Toshin Seiko Kabushiki Kaisha

Tokyo Steel M.f.g. Co., Ltd.

Toshimichi Maki

Norio Ao

Ryuji Yamaguchi

Mitsuya Iguchi

Hisashi Watanabe

Takato Matsuo

Takasaburo Date

Hideaki Mizukami

Sumifusa Iwamaru

Takashi Nakayama

Yasuhiro Sato

Hirotsugu Kubo

Hiroyuki Yamashita

Yoshimi Kawazu

Teruo Tatefuku

Hidefumi Nakashima

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. The preheating shaft of the melting furnace and the tapping portion have a distance between the mutual part, so that scraps do not flow out on a the tapping hole side.

Apparatus for arc-melting cold iron source and method thereof

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. The preheating shaft of the melting furnace and the tapping portion have a distance between the mutual part, so that scraps do not flow out on a the tapping hole side.

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.

Direct current arc furnace

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.

Method for increasing the efficiency of a direct current electric arc

Direct current electric arc furnace

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 combustible substances entrapped in said steel scrap and which is contained in said combustion exhaust gas.

Method for preheating steel scrap by exhaust gas from steelmaking

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, the gap between the periphery of said canopy and said pit being liquid-sealed. The apparatus is characterized in that: said canopy is gas-tightly fixed to said hood; and, the gap between said canopy and said preheating vessel housed in said pit is sealed by an expansion bellows fixed at an end thereof to said canopy.

Apparatus for preheating a steel scrap

Growing community of inventors

Tokyo, Japan

Toshimichi Maki