JPH07101157B2 - Furnace bottom refractory grooving device for DC electric furnace - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention cuts slag, metal, etc. remaining on the top of the bottom electrode of a DC electric furnace used for melting metal materials and refining molten metal when replacing the bottom electrode. The present invention relates to a device for grooving a fired refractory.

[0002]

2. Description of the Related Art As an electric furnace used for melting metal materials, refining molten metal, etc., an electrode arranged above the melting or molten metal material charged in the furnace and a furnace attached to the bottom of the furnace. Applying an electric current between the bottom electrode and melting the metal material,
A DC electric furnace for refining molten metal is known. The integrally molded bottom electrode in this type of DC electric furnace has a structure that can be replaced by a cassette method as disclosed in, for example, JP-A-1-128392. However, when replacing the integrally molded bottom electrode, molten metal, slag, and metal, etc., are the molten metal, slag and metal that contain as much oxide as possible are left in the furnace, and stick to the upper part of the bottom electrode. Then, the furnace bottom electrode and the refractory around the furnace bottom electrode are joined. For this reason, an operator enters the furnace to cut the edge between the bottom electrode and the refractory around the bottom electrode, and the worker manually uses an air breaker or the like to manually remove the slag and metal that remain above the bottom electrode. Etc., and further, during operation, the refractory material at the bottom of the furnace, which was fired by the high temperature heat of the molten metal, was collapsed, and the integrally formed bottom electrode was replaced by a cassette method.

[0003]

However, the following problems arise in the work of removing slag, metal, etc. by such workers and the work of breaking down the refractory material on the fired furnace bottom. (1) In order to cool the furnace body for a long time to a temperature at which the worker can put it in the furnace, the furnace must be stopped for a long time, which deteriorates the productivity. (2) Refractory outside the replacement range is damaged when the bottom electrode is replaced due to thermal change due to furnace body cooling, and the refractory unit and power unit are deteriorated due to large thermal loss. (3) Workers are working to remove slag, metal, etc. and to destroy fired refractory at the bottom of the furnace under adverse conditions of high temperature and large amount of dust atmosphere in the furnace. Therefore, the present invention is for solving the above-mentioned problems and is a furnace material out of the exchange range due to a thermal change by quickly performing hot work for removing slag, metal, etc. The purpose of the present invention is to eliminate the adverse effect on the temperature, suppress the thermal loss, and eliminate the work inside the furnace by the operator under a high temperature and a large amount of dust atmosphere inside the furnace.

[0004]

In order to achieve the above object, the structure of the present invention has a grooving bit attached to the tip thereof and a swivel ring for transmitting a rotational force attached to the middle thereof so that the inner and outer surfaces are insulated or cooled. And a guide roller for supporting and fixing the casing, and an elevating and lowering frame for accommodating a driving device for rotating the casing through a swivel ring, an elevating and lowering device for elevating and lowering the elevating frame, and fixing the elevating and lowering device for reaction force. It is characterized in that it is provided with a frame supporting metal member which is transmitted to the furnace body or the working floor.

[0005]

[Operation] By using this device, the casing is rotated by the rotary drive device housed in the elevating frame, and the bit attached to the tip of the casing cuts the slag, the metal, and the fired furnace bottom refractory. The refractory material is grooved, and at the same time, the elevating device fixed to the frame supporting metal is lowered to sequentially grind the refractory material in a groove shape to cut the edge between the furnace bottom electrode of the cassette structure and the refractory material around the furnace bottom electrode. This can be done without the worker having to enter the furnace.

[0006]

EXAMPLE An example of a furnace bottom refractory grooving device for a DC electric furnace according to the present invention will be described with reference to FIGS. Figure 1
[Fig. 3] is an explanatory view schematically showing a furnace bottom refractory grooving device for a DC electric furnace that takes a reaction force of a grooving from a furnace body. The cassette type bottom electrode 1 which is integrally formed is used for a certain period of time and then replaced with a new bottom electrode. At this time, the molten metal is discharged as much as possible, but slag and metal 2 containing a large amount of oxides remain in the furnace and adhere to the furnace bottom electrode portion, and the furnace bottom electrode 1 and the refractory material 3 around the furnace bottom electrode are formed. Will be joined. Further, the refractory 3 on the bottom of the furnace is hard to be burned by the high temperature molten metal during the operation. Since the furnace bottom electrode 1 is taken out above or below the furnace body,
It is necessary to cut the edge between the furnace bottom electrode 1 and the refractory 3 around the furnace bottom electrode. In FIG. 1, the casing is rotated by transmitting a rotational force from a drive device 7 of an electric motor or a hydraulic motor housed in the lifting frame 6 to a swivel ring 10 fixed to the casing 4 by welding or the like via a gear 8 to rotate the casing. Bit 5 attached to the tip of 4 allows 2 slags, bullion, etc.
Is cut and the refractory 3 is grooved. The casing 4 and the lifting frame 6 are set in the electric furnace immediately after the operation is stopped,
For this reason, it receives high-temperature radiant heat from the inside of the furnace, and as shown in FIG. 2, the outside has a structure with an adiabatic refractory 15 lined up, and the inside of the lifting frame 6 is installed outside for air cooling ventilation for protection of the drive unit 7 and the like. Fan (not shown)
More air-cooled piping 17 is used. Further, the casing 4 is provided with a water cooling jacket 16 on the inner surface to positively cool the casing. A swivel joint 21 is used for water supply and drainage of the water cooling pipe. The casing 4 is supported and fixed by the vertical and horizontal guide rollers 9 fixed to the elevating frame 6 through the swivel ring 10, and as shown in FIG. The directional guide rollers 14 can also be arranged at different levels.
Further, instead of the method of supporting and fixing with the guide roller 9, a slewing wheel bearing fixed to the elevating frame 6 may be used (not shown). A lifting device 1 such as a hydraulic cylinder or an electric cylinder fixed to the frame supporting metal 11 of FIG.
2 raises and lowers the lifting frame 6 and supports it on the lifting frame 6.
The fixed casing 4 is moved up and down. This lifting device 12
Lowering down and applying pushing force at the same time, casing 4
The refractory material 3 on the bottom of the furnace is cut by rotating. FIG. 1 shows a structure in which the reaction force generated when grooving the refractory 3 on the furnace bottom is taken from the furnace body 13, but the frame support metal 11 and the furnace body 13 are fixed by bolts or the like ( (Not shown). The bit 5 is a consumable item and is attached to the casing 4 so that it can be replaced. However, as shown in FIG. 3, the lower part of the casing has a high heat load, and in consideration of deformation and strength reduction, the casing 4 is a split type, and the bit 5 Casing body 4 with fixed lower casing 4a and swivel ring 10 fixed
It is also effective to divide it into b. Figure 4 shows casing 4
And another embodiment for protecting the tip bit 5 from high temperature radiant heat. The steam or water flowing through the pipe 18 fixed to the elevating frame 6 enters the spray header 19 fixed to the elevating frame 6 arranged in an annular shape on the outer circumference of the casing 4, and is attached to the spray header. It is sprayed onto the casing 4 from the individual nozzles 20. The sprayed steam or water travels down the outer surface of the casing 4 and drops downward, cooling the tip bit 5 as well, so that the life of the casing 4 and the tip bit 5 can be extended. The amount of steam or water sprayed is adjusted by a valve (not shown) attached to the pipe so that the surrounding refractories are not adversely affected.

[0007]

INDUSTRIAL APPLICABILITY According to the present invention, when exchanging an integrally molded cassette-type bottom electrode of a DC electric furnace, the slag, metal, etc. remaining on the top of the bottom electrode are cut and removed and fired into a bottom refractory material. It has a great effect on efficient work and labor saving in a bad working environment. (1) Since the edge of the furnace bottom electrode and the refractory around the furnace bottom electrode is easily and quickly cut, the furnace bottom electrode can be replaced easily and quickly, and the productivity is improved. (2) Since it is not necessary to cool the furnace body to a temperature that an operator can put in the furnace for a long time, deterioration of refractories outside the replacement range due to thermal change is prevented, and heat loss is small, so that Electric power consumption is improved. (3) It is possible to eliminate the work inside the furnace by an operator under a high temperature and large amount of dust atmosphere inside the furnace, and it is possible to save labor.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing a furnace bottom refractory grooving device for a DC electric furnace of the present invention which takes a reaction force of a grooving from a furnace body,

FIG. 2 is a partial cross-sectional view of a lifting frame and a casing of the present invention,

FIG. 3 is a partial sectional view of a casing of another embodiment according to the present invention,

FIG. 4 is a partial cross-sectional view in which a device for cooling a casing bit according to another embodiment of the present invention is arranged. 1 Integrated bottom electrode 2 Slag, metal, etc. 3 Refractory at the bottom 4 Casing 5 Bit 6 Lifting frame 7 Drive device 9 Guide roller 10 Swivel ring 11 Frame support hardware 12 Lifting device 16 Water cooling jacket 17 Air cooling pipe 19 Spray Header 20 Nozzle 4a Lower casing 4b Main body casing

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinjiro Uchida 46-59 Nakahara, Tobata-ku, Kitakyushu, Fukuoka 46-59 Nippon Steel Corporation Machinery & Plant Division (72) Inventor Tatsuo Kaihara Tobata, Kitakyushu, Fukuoka 46-59, Nakahara, Naka Ward, Nippon Steel Corporation Machinery & Plant Division

Claims (1)

[Claims] 1. A casing having a grooving bit attached at its tip and a slewing ring for transmitting a rotational force attached in the middle thereof, the casing having a heat-insulated or cooled inner and outer surface, and a casing supported.
An elevating frame for accommodating a drive device for rotating the casing through a fixed guide roller and a swivel ring, an elevating device for elevating the elevating frame, and fixing the elevating device, and transmitting the reaction force to the furnace body or work floor. A furnace bottom refractory grooving device for a DC electric furnace, comprising a frame supporting metal.