JPH03210788A - Furnace wall electrode of d.c. electric furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a furnace wall electrode for a DC electric furnace used for melting metal materials, refining molten metal, and the like.

[Conventional technology]

As an electric furnace for refining, a DC electric furnace is known, which refines molten metal by passing an electric current between an electrode placed above the molten metal charged into the furnace and an electrode attached to the bottom and side walls of the furnace. It is being

The bottom electrode in this type of DC electric furnace is exposed to a harsh working atmosphere inside the furnace.

Therefore, various proposals have been made to improve the durability of hearth bottom electrodes that can withstand this atmosphere. For example, Tokko Sho 6
In the furnace wall electrode described in Publication No. 3-43675, a cooling sleeve for a refrigerant passage is attached around the electrode portion (hereinafter referred to as the rear end portion) protruding from the furnace wall, and a refrigerant such as water is supplied to the refrigerant passage. Forced cooling of the electrode by circulation is disclosed.

[Problem to be solved by the invention]

However, even if the rear end is cooled with a refrigerant, the amount of heat transfer is low due to the low thermal conductivity inside the electrode and the distance from the tip. For this reason, the above-mentioned method often has insufficient cooling capacity and is not effective in terms of electrode durability.

Therefore, the present invention provides a furnace wall electrode with excellent durability by mounting a cooling box inside the rod-shaped electrode and effectively cooling the electrode part closer to the tip than the rear end with the cooling box. purpose.

[Means to solve the problem]

In order to achieve the purpose, the furnace wall electrode of the present invention includes a rod-shaped electrode whose tip portion penetrates the furnace wall of a DC electric furnace and faces into the furnace, and a cooling surface installed inside the rod-shaped electrode. It is characterized by:

Further, the present invention is characterized in that a rod-shaped electrode whose tip penetrates the furnace wall and faces into the furnace is provided with a cooling surface mounted inside the rod-shaped electrode and a mechanism for moving the cooling surface.

[Effect]

In the present invention, a coolant such as water is passed through a cooling surface installed inside the rod-shaped electrode, and the coolant carries away heat from the rod-shaped electrode via the cooling surface. This cooling surface can be installed inside the rod-shaped electrode to the inside of the furnace wall, and the rod-shaped electrode is effectively cooled.

In addition, if the heat load on the rod electrode increases due to wear and tear of the refractories around the rod electrode, and the melted part of the rod electrode comes too close to the cooling surface, move the position of the cooling surface to the inside of the furnace. This allows for safe cooling and cooling over a long period of time.

〔Example〕

Although FIG. 1 shows the case where electrodes are attached to the bottom of a DC electric furnace, it goes without saying that the invention is similarly applicable to the side walls.

The bottom of the DC electric furnace is lined with refractory 1.
The outside is supported by iron skin 2. These 2 iron skins, 1 refractory material
A steel rod-shaped electrode 3 is attached to the bottom of the furnace by penetrating the furnace wall.

A cooling surface 4 made of copper is installed inside the rod-shaped electrode 3, and a coolant 5 such as water is supplied to and discharged from the internal cavity of the cooling surface 4, and the heat from the rod-shaped electrode 3 is absorbed by the coolant 5. being carried away.

FIG. 2 shows an example in which a driving device 6 such as a hydraulic cylinder for moving the cooling surface 4 inside the rod-shaped electrode 3 is arranged. The position of the cooling surface 4 can be moved depending on the state of wear and tear on the refractory 1.

Fig. 3 shows an example in which the cooling surface 4 is moved downward.As the cooling surface 4 is moved, the space created between it and the rod-shaped electrode 3 is filled with material in order to maintain the heat transfer effect. A spacer 8, which is the same as the rod-shaped electrode 3, is embedded therein.

This movement of the cooling surface 4 can be carried out as appropriate depending on the progress of wear and tear of the refractory 1 and the progress of melting of the rod-shaped electrode 3, so that optimum cooling can be always performed and the durability of the rod-shaped electrode 3 can be improved.

Example 3 A rod-shaped electrode 3 with a length of 50 mm and a diameter of 1100 m has a thickness of 750 mm.
Attach the cooling surface 4 of 250mmφXX100h length to the hole drilled in the rod-shaped electrode 3.
A length of a+m was inserted. 0.5 of 20℃ water as refrigerant 5
When passed through the cooling surface 4 at a flow rate of m'/min, the length of the rod-shaped electrode 3 that was eroded did not exceed 15 hm, and the cooling effect was remarkable compared to 600 mm without a cooling surface. . As a result, the life of the rod-shaped electrode 3 is significantly extended compared to the conventional operating time.

〔Effect of the invention〕

As explained above, in the furnace wall electrode of the present invention, the rod-shaped electrode is cooled.

This cooling surface can be cooled inside the rod-shaped electrode near the tip, thereby effectively cooling the rod-shaped electrode and greatly extending the life of the electrode. In addition, by moving the cooling surface, safe and effective cooling can be performed in accordance with the melting condition of the refractories and rod-shaped electrodes, and furthermore, the life of the electrodes is synergistically extended. This extended life span of the electrodes greatly reduces the frequency of replacing the rod-shaped electrodes and improves operability.

[Brief explanation of drawings]

1 to 3 are longitudinal sectional views of an example in which the furnace wall electrode of the present invention is applied to the bottom of a DC electric furnace. Note that the structure for feeding power to the rod-shaped electrodes is omitted. 1: Refractory 2: Iron shell 3: Rod-shaped electrode 4: Cooling surface 5: Refrigerant 6: Drive device

Claims (1)

[Claims] 1. A furnace wall electrode for a DC electric furnace, comprising a rod-shaped electrode whose tip part passes through the furnace wall and faces into the furnace, and a cooling box installed inside the rod-shaped electrode. . 2. A furnace wall electrode for a DC electric furnace, comprising a mechanism for moving the cooling box according to claim 1 to an arbitrary position inside the rod-shaped electrode.