JPH04214179A - Mount structure of furnace wall electrode for dc current arc furnace - Google Patents

Abstract

PURPOSE:To make it possible to replace a furnace wall electrode only from the outside of a furnace by installing a gap between a side and a mount hole of the furnace wall electrode and a nozzle which allows refractories to be injected into said gap from the outside of the furnace. CONSTITUTION:A furnace wall electrode 2 is mounted to a mount hole 16 which comprises a furnace casing metallic material 6 for an electric furnace main body and a furnace floor 1. During this mount operation, the refractories are injected into a gap 14 generated between a removal area 15 and a steel plate frame body 9 by way of a nozzle 13 from the outside of the furnace, which makes it possible to replace all furnace wall electrodes 2 from the outside of the furnace. Therefore, there is no need to cool the furnace. Furthermore, this construction makes it possible to replace the furnace wall electrodes 2 in a short time and relieve replacement working environment from high temperature sections.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a furnace wall electrode of a DC arc furnace used for melting metal materials, refining molten metal, etc., and particularly relates to a mounting structure for a replacement part thereof.

0002

[Prior Art] As an arc furnace for melting and refining, an electric current is passed between an electrode placed above the molten metal charged in the furnace and an electrode attached to the furnace wall such as the bottom or side wall of the furnace. 2. Description of the Related Art Direct current arc furnaces are known for melting metal materials, refining molten metal, and the like. The furnace wall electrodes in this type of DC arc furnace are exposed to an extremely harsh operating atmosphere due to heat received from the high-temperature molten metal in the furnace, Joule heat generated when a supplied current passes through the furnace, and the like. Therefore, various proposals have been made to withstand this atmosphere and improve the durability of the furnace wall electrode, but in any case, the furnace wall electrode wears out as the furnace continues to operate, and the furnace wall The electrodes have to be replaced.

Regarding this furnace wall electrode replacement structure, the furnace wall electrode part is formed into a cassette system by integrally molding an anode pin set up through the bottom plate and a refractory composition filled around the anode pin. Japanese Patent Laid-Open No. 01-128392 discloses a structure in which repair and replacement of the electrode part, such as stamping, which was conventionally an inferior work inside the furnace, can be easily done by replacing each furnace wall electrode when replacing the electrodes. However, this method has the following problems.

0004

[Problems to be solved by the invention] ■ The area around the anode (SS material) can be stamped in a factory, but the area around the steel plate frame is stamped on-site, so the furnace must be cooled, which takes time. Loss occurs due to thermal loss, cracks in furnace materials other than the repaired part due to cooling, etc. ■Alternatively, in order to reduce these losses and wear and tear, it is required to construct the furnace without cooling it, but with this method, it is necessary to construct the refractories around the steel plate frame from inside the furnace. Therefore, you will have to work in a hot area. ■Stamps are installed on-site under the working environment described above, so the quality of the work is not sufficient, and the stamp material cracks and peels, and the refractories around the furnace wall electrodes wear out quickly. As a result, the frequency of replacement will increase, and the productivity of the electric furnace will decrease.

[0005] The conventional method is disclosed in Japanese Patent Application Laid-Open No. 01-12839.
According to Publication No. 2, when the electrode block is removed downward, the furnace material filling layer collapses, or when a new electrode block is installed, due to manufacturing errors between the electrode block and the furnace material filling layer, etc. Gaps inevitably occur. If the operation is continued with this gap remaining, molten steel will flow into this gap, and the molten steel will continue to flow out from the bottom of the furnace. Therefore, in order to prevent this gap from occurring, it is necessary to construct the furnace material filling layer around the electrode block on-site from inside the furnace after the electrode block is installed.

[0006] The present invention is intended to solve the above problems, and makes it possible to replace the furnace wall electrode only from outside the furnace.
The purpose of the present invention is to provide a mounting structure for the furnace wall electrode of a DC arc furnace, which does not require cooling the furnace, allows the furnace wall electrode to be replaced in a short time, and allows the replacement work environment to be freed from high-temperature parts. shall be.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the mounting structure of the furnace wall electrode of the DC arc furnace of the present invention includes a fireproof A furnace wall of a DC arc furnace in which a furnace wall electrode of a DC arc furnace filled with material and integrally molded with a tapered side surface can be freely attached to a mounting hole of the furnace wall electrode made in the hearth of the DC arc furnace. The electrode attachment structure is characterized in that a gap is provided between the side surface of the furnace wall electrode and the attachment hole of the furnace wall electrode, and a nozzle that can press-fit a refractory from outside the furnace is provided in the gap.

[0008] By providing a gap between the side surface of the furnace wall electrode and the attachment hole of the furnace wall electrode, and providing a nozzle that can press-fit the refractory from outside the furnace into the gap, the furnace wall electrode can be easily removed. After replacement, it is possible to press-fit refractories into the gap from outside the furnace,
All furnace wall electrode replacement work can be performed from outside the furnace.

[0009]

[Example] Figure 1 is a sectional view of the mounting structure of the furnace wall electrode of the present invention.
FIG. 2 shows a detailed view of the mounting structure of the furnace wall electrode of the present invention. As shown in FIG. 1, the furnace wall electrode 2 of the DC arc furnace has a tapered side surface attached to a mounting hole 16 formed in the hearth 1, and this furnace wall electrode 2 is connected to a conductive pin. Or steel plate frame 9 for constructing billet 3 and refractory 4
is attached to the furnace bottom plate 5. This furnace wall electrode 2 is attached via an insulator 8 to a mounting flange 7 protruding from a furnace metal fitting 6 of the electric furnace main body.

FIG. 2 shows the details of the mounting structure of this part.
The furnace wall electrode 2 is fixedly installed from the outside of the furnace with mounting bolts 11. Since the furnace body hardware 6 and the furnace wall electrode 2 require electrical insulation, an inter-flange insulator 8, an inner flange insulator 10, and a mounting bolt insulator 1 are provided at the necessary locations, respectively.
Install 2.

When the furnace wall electrode 2 is attached to the furnace metal fittings 6, there is a gap between the removal surface 15 of the hearth 1 and the steel plate frame 9.
A gap 14 occurs. Refractories are press-fitted into this gap 14 from nozzles 13 provided at several points around the circumference outside the furnace, and this gap 14 is filled. The amount of the gap is 10-50m
About m is desirable. If it is smaller than 10 mm, the press-fitting material will not be filled uniformly, and if it is too large, it will be uneconomical, so the upper limit was set to 50 mm. Moreover, within this range, manufacturing errors of the furnace wall electrode can be absorbed. Furthermore, in order to more reliably fill the gap with the press-fitting material, when repairing the mounting surface 15 when replacing the furnace wall electrode, the gap at the top, that is, the part a in FIG. 2, should be repaired to be as small as possible. All you have to do is

In this manner, the furnace wall electrode 2 is attached from the outside of the furnace to the attachment hole 16 formed by the furnace metal fittings 6 of the electric furnace main body and the hearth 1, and when attached, the furnace wall electrode 2 is connected to the removal surface 15 of the hearth 1. By making it possible to press-fit a refractory from outside the furnace into the gap 14 that occurs between the furnace wall electrode 2 and the steel plate frame 9, all work for replacing the furnace wall electrode 2 can be done from outside the furnace. Note that the steel plate frame 9 is used when manufacturing a replacement furnace wall electrode.
This is a guide for filling refractories, and does not need to be installed when replacing the furnace wall electrode in an electric furnace.

As explained above, the present invention makes it possible to replace the furnace wall electrodes only from outside the furnace, there is no need to cool the furnace, and the furnace wall electrodes can be replaced in a short time. The work environment can be freed from high heat areas. Furthermore, the time required to replace the furnace wall electrodes was reduced to about 1/3 compared to the conventional method, as shown in Table 1.

[0014]

[Table 1]

[0015]

[Effects of the invention] By adopting the present invention, there is no need to cool the furnace when replacing the furnace wall electrode, so cracks in the furnace material other than the repaired area are reduced, and stamping on site is eliminated. As a result, the wear and tear of the refractories around the furnace wall electrodes is reduced, and the life of the furnace wall electrodes is increased, which reduces the frequency of replacement and improves the productivity of the electric furnace.

[Brief explanation of the drawing]

[Fig. 1] Cross-sectional view of the mounting structure of the furnace wall electrode of the present invention

[Fig. 2] Detailed diagram of the mounting structure of the furnace wall electrode of the present invention

[Explanation of symbols]

1 Hearth 2 Furnace wall electrode 3 Conductive pin or billet 4 Refractories 5 Hearth bottom plate 6 Furnace hardware 7 Mounting flange 8 Insulator between flanges 9 Steel plate frame 10　Flange inner surface insulation 11 Mounting bolt 12 Insulator for mounting bolts 13 Nozzle 14 Gap 15 Removal surface 16 Furnace wall electrode mounting hole

Claims (1)

[Claims] Claim 1: A furnace wall electrode of a DC arc furnace, which is filled with a refractory and integrally formed with a tapered side surface, is placed around a conductive pin or billet erected through a furnace bottom plate. In the mounting structure of the furnace wall electrode of a DC arc furnace, which can be freely installed in the furnace wall electrode installation hole drilled in the hearth, a gap is provided between the side surface of the furnace wall electrode and the furnace wall electrode installation hole. A mounting structure for a furnace wall electrode of a DC arc furnace, characterized in that a nozzle capable of press-fitting a refractory from outside the furnace is provided in the gap.