JPH09273870A - Water-cooled furnace cover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the adhesion of splash to a sleeve by providing the sleeve for penetrating an electrode in which the releasability of adhering plash is improved by forming it of carbon, carbon magnesia or the other material at the cooling water circulation type furnace cover in an arc furnace or refining furnace. SOLUTION: A sleeve 5 for penetrating an electrode 6 is provided at substantially the center of a cooling water circulation type furnace cover 2 of an arc furnace or a refining furnace. That is, the sleeve 6 for penetrating the electrode 6 is molded in a ring state b the material such as carbon or carbon magnesia, formed on the outer periphery in a tapered state, directed down at the reduced diameter side, inserted from above into the through hole of the cover 2, and brought on the outer periphery of the sleeve 5 into close contact within the hole of the cover 2. Thus, the adherence of the sleeve 5 to the splash can be prevented, and the spark due to the leakage of a large current can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a water-cooled furnace lid in a furnace body in which electrodes are suspended in an arc furnace, a ladle refining furnace or the like.

[0002]

2. Description of the Related Art The furnace lids of recent arc furnaces (AC furnaces, DC furnaces), ladle refining furnaces, etc. have a conventional ceiling refractory structure and are constructed to circulate cooling water inside. It has been greatly changed to the water cooling type. By the way, also in the conventional water-cooled furnace lid of the above-mentioned whole surface water-cooled type, the water-cooled furnace lid is generally provided with a sleeve made of refractory having insulation and spalling resistance mainly composed of alumina in a portion where the electrode penetrates. The lid and the electrode are electrically insulated, and the gas in the furnace is prevented from blowing out through the gap.

However, in the conventional water-cooled furnace lid, when the conductive splash scattered from the molten steel adheres to the sleeve, the insulating property is destroyed, and when the splash grows to the lower surface of the water-cooled furnace lid, the splash and the water-cooled furnace cover. Since a spark is generated between the lid and the lid, a large current flows, there is a great risk that a water-cooled furnace lid has a hole in its surface and causes water leakage.

[0004]

SUMMARY OF THE INVENTION Therefore, the present invention is intended to prevent the above-mentioned drawbacks by preventing the splash from adhering to the sleeve and preventing the spark from being generated due to the leakage of a large current.

[0005]

To this end, the water-cooled furnace lid of the present invention comprises a sleeve for electrode penetration which is formed of carbon, carbon / magnesia, or other material and has a good releasability against adhered splash. It is characterized by being provided in a cooling water circulation type furnace lid in a refining furnace or the like. Further, the water-cooled furnace lid of the present invention is characterized in that the sleeve for electrode penetration provided in the furnace lid and the furnace lid are connected by a conductive member.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. The arc furnace is shown in FIG. 1 in a vertical sectional view.
Is a furnace main body, and 2 is a furnace lid that covers the furnace main body 1. The furnace lid 2 is formed in a hollow shape by an iron shell 3 and has an inner portion 4
Is configured to allow cooling water to circulate. Reference numeral 5 denotes a sleeve for electrode penetration, which is provided at a substantially central portion of the furnace lid 2, 6
Is a rod-shaped electrode supported by the electrode arm 7 and suspended in the furnace body 1. Sleeve 5 is carbon or carbon
By forming it into a ring shape with a material such as magnesia (called mag carbon) and forming its outer peripheral surface into a taper shape, and inserting it into the through hole of the furnace lid 2 from above from the small diameter side downward. The outer peripheral surface is brought into close contact with the inside of the through hole of the furnace lid 2. Then, the lower surface 5a, the inner peripheral surface 5b, the lower outer peripheral surface 5c, and the like of the sleeve 5 are finished smoothly. Therefore, even if splashes scattered in the furnace adhere to these sleeve surfaces, they easily separate due to their own weight due to the good peeling property due to the constituent materials, fall into the furnace, and deposit thickly as in the past. I try not to.

Further, a conductive rod-shaped terminal 8 is fixed to the sleeve 5, one end of a conductive cable 10 is fixed to the terminal 8 with a bolt 9, and the other end of the conductive cable 10 is attached to the furnace lid 2. A terminal 11 welded to a part of the inner wall of the furnace is fixed with a bolt 12 to connect the sleeve 5 and the furnace lid 2 to the conductive cable 10.
It is electrically connected via. Therefore, the spark does not fly between the sleeve 5 and the furnace lid 2, or between the splash attached to the sleeve 5 and the furnace lid 2, and the furnace lid 2 may be destroyed by the spark of a large current. Disappears.

Although carbon or magcarbon has good conductivity, it is suitable as a material for forming the sleeve 5 in that the molten steel splatter is easily peeled off.

Also, when ceramics is used as the material for forming the sleeve 5, glaze may be applied to smooth the surface to improve the peelability of the splash. Even when the material of the defective conductor is used for the sleeve 5, as shown in FIG. 3, the conductive reinforcing bar 15 is embedded in the sleeve 5 and the terminal 8 which is electrically connected to the reinforcing bar 15 is provided. By connecting the other end of the conductive cable 10 whose one end is connected to 8 to the furnace lid body 2, it is possible to reliably prevent sparks between the splash attached to the sleeve 5 and the furnace lid body 2. Further, as the conductive member, in addition to the conductive cable, a rod material such as steel, copper, aluminum, a wire material, a plate material, or the like is suitable.

[0010]

As described above, in the water-cooled furnace lid of the present invention, the splash of the sleeve can be prevented from adhering, and the electric current can surely flow from the sleeve to the furnace lid through the conductive member, so that the spark is generated. It is possible to prevent the damage due to the electric discharge.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an arc furnace according to the present invention.

FIG. 2 is a vertical cross-sectional view of the water cooling furnace lid of FIG.

FIG. 3 is a vertical cross-sectional view showing another embodiment of the water cooling furnace lid.

[Explanation of symbols]

 1 Furnace Main Body 2 Furnace Lid 5 Sleeve 6 Electrode 10 Conductive Cable

Claims (2)

[Claims] 1. A sleeve for electrode penetration, which is made of carbon, carbon / magnesia, or other material and has good peeling property against adhered splash, is provided on a cooling water circulation type furnace lid in an arc furnace, a refining furnace, or the like. A water-cooled furnace lid characterized in that. 2. A water-cooled furnace lid characterized in that a sleeve for electrode penetration provided in a cooling water circulation type furnace lid and the furnace lid are connected by a conductive member.