JPH0587458A - Replacing method for tuyere brick for blowing gas from furnace bottom into electric furnace - Google Patents

Abstract

PURPOSE:To raise the workability by assembling beforehand a plurality of tuyere bricks in one body in casette fashion and removing from the furnace bottom the used casette of bricks by pushing it up by a lifting device to remove it from the furnace bottom and hanging and lowering a new casette of bricks to receive it in the furnace by the lifting device and set it in the furnace bottom. CONSTITUTION:When the tuyere bricks that are placed in the bottom 2 of an electric furnace, firstly a repair cart 4 is brought near the lower side of the furnace bottom 2. Then a castable refractory material is broken around the casette of bricks formed by winding a steel band round a plurality of tuyere bricks and refractory bricks around them and tightening the steel band. Then an operation panel 41 is operated to let the receiving end of the piston in a lifting machine 40 abut the lower surface of the casette of bricks, and the receiving end is further lifted to push up the casette of bricks 3 and then this raised casette of bricks 3 is lifted by a crane and carried away out of the furnace. After this, a new casette of bricks 3 is hung down by the crane and it is put in the furnace and placed on the receiving end, and then it is lowered with the receiving end and inserted into the hole in the furnace to install it there and fixed. Then a castable refractory material is stamped around the casette of bricks 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for replacing tuyere bricks for gas injection into the bottom of an electric furnace.

[0002]

2. Description of the Related Art Electric furnaces, for example, arc furnaces for steelmaking, are widely used as steel melting furnaces because they have the advantages of high productivity and low equipment cost.

Usually, in this type of electric furnace, a refractory brick is lined inside the furnace shell, one to three electrodes are suspended from above, and an arc is blown to melt scrap. Recently, a plurality of tuyere bricks are arranged on the bottom of the furnace, and non-oxidizing gas or inert gas is supplied to stir molten steel in the furnace.

By the way, when such an electric furnace is continuously operated for a long period of time, for example, for about one month, the erosion and melting loss of the refractory bricks in the furnace increase, so that it is necessary to stop the operation and repair the furnace. However, during such furnace repair, the furnace bottom tuyere brick is also replaced or repaired.

Conventionally, when replacing the bottom tuyeres of the furnace bottom, as shown in FIG. 6, an operator 5 enters the furnace with a breaker 6 and surrounds each of a plurality of tuyere bricks 31 from inside the furnace. After removing the tuyere bricks 31 by breaking the bricks with oxygen cutting and breaker 6, new tuyere bricks 31 are set one by one from the repair truck 4 on the lower side of the furnace bottom, and casters are placed around them. It was

[0006]

As described above, in the conventional method for replacing the tuyere bricks for gas blowing into the bottom of the electric furnace, the porous bricks are replaced one by one by the manual operation of the operator. There is a problem that workability is poor and long-time work in high heat is required.

In view of the above problems, the present invention provides a method for replacing a tuyere brick for blowing gas into an electric furnace hearth, which improves the workability of replacing the tuyere brick at the bottom of the furnace so that the replacement time can be greatly shortened. The challenge is to provide.

[0008]

Therefore, an electric furnace bottom gas inlet tuyere brick replacement method according to the present invention is described as follows. In an electric furnace capable of blowing gas, a plurality of tuyere bricks and surrounding refractory bricks are arranged in a furnace bottom mounted state on a circular iron plate, while the outer periphery is a cassette brick wound with an iron strip, The used cassette brick on the side to be replaced is pushed up from the bottom side of the furnace bottom by an elevator tool, lifted and removed, and instead the replacement cassette brick is hung from the top side and loaded into the furnace to the bottom side of the furnace bottom. It was received by an elevator that extends from the bottom, and the elevator was lowered to set the cassette brick on the bottom of the furnace. "

Here, the lifting and hanging operations of the cassette bricks can be carried out, for example, by hanging a wire from the crane on the ears attached to the peripheral edge of the circular iron plate. Further, a hydraulic cylinder or an air cylinder can be used as the elevator tool.

[0010]

In the present invention, a plurality of tuyere bricks are assembled in advance into a cassette-type united body, while a used cassette brick is pushed up from the bottom of the furnace bottom by an elevator tool and removed from the furnace bottom, and a new replacement cassette is used. Since the bricks are suspended and received by the elevator and set on the bottom of the furnace, multiple tuyere bricks can be replaced at once without relying on the manual work of the operator.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the specific examples shown in the drawings. FIG. 1 is a schematic diagram of a method for replacing a tuyere brick for blowing gas into an electric furnace hearth according to an embodiment of the present invention.
5 to 5 show the furnace bottom structure around the cassette. 2 to 5, in the furnace shell 1 having a predetermined shape, typical refractory bricks 20 are appropriately laminated, and indeterminate refractories 21 are stamped between and on the upper surface to form the furnace bottom 2.

A cassette brick 3 is attached to the furnace bottom 2. In this cassette brick 3, three tuyere bricks 31 and a standard fireproof brick 32 are mounted on a circular iron plate 30.
Are combined and arranged in a state of being attached to the hearth bottom 2, the outer periphery of the standard refractory brick 32 is integrally wound by an iron band 33, and the tuyere brick 31 has about 10 thin tubes in an irregular refractory material. It is embedded and configured. A thermocouple 34 is installed inside the tuyere brick 31, and a gas supply pipe 36 is inserted from below. The tuyere brick 31 is connected to the circular iron plate 30 to prevent the whole cassette from rising. Although the tuyere is three in this example, it may be more or one.

Further, a cassette mounting hole 22 is bored in the furnace bottom 2, the cassette brick 3 is loaded in the cassette mounting hole 22, and an amorphous refractory material 23 is stamped between the both. There is. Further, a cassette supporting step portion 10 is formed on the outer peripheral edge of the cassette mounting hole 22.
At 0, the circular iron plate 30 of the cassette brick 3 is placed.

Further, in FIG. 1, an elevator tool 40 for raising and lowering the cassette brick 3 is mounted on the repair carriage 4,
The elevator tool 40 is constructed by fixing a pedestal to the tip of the piston of the hydraulic cylinder, and the hydraulic cylinder of the elevator tool 40 is configured so that the supply of hydraulic pressure is controlled by the operation of the operation panel 41 and the piston is expanded and contracted. ing.

Next, a method of replacing the furnace bottom tuyere brick will be described with reference to FIG.

When replacing the furnace bottom tuyere bricks, first, the repair truck 4 is run to the lower side of the furnace bottom 2, and the irregular refractory material 22 around the cassette bricks 3 is appropriately broken, and then the worker 5 operates it. The board 41 is operated to bring the tip end pedestal of the piston of the elevator tool 40 into contact with the lower surface of the cassette brick 3, further push it up, and then lift it by a crane and carry it out of the furnace.

When the removal of the used cassette brick 3 is completed in this way, a new cassette brick 3 for replacement is suspended by a crane and loaded into the furnace from the upper side, and the tip support of the piston extending from the lower side of the furnace bottom 2 is received. Place it on the top, remove the hook, operate the operation panel 41 to contract the piston of the elevator tool 40, and lower the cassette brick 3 to lower the furnace bottom 2
Of the circular iron plate 30 at the lower end of the cassette is placed on the cassette supporting step portion 10 of the furnace shell 1 to connect and fix it, and then between the cassette brick 3 and the mounting hole 22. The refractory 23 may be stamped.

In the method for exchanging the furnace bottom tuyere bricks of the present embodiment as described above, the three tuyere bricks 31 and the refractory bricks 32 are assembled in advance in the mounted state to form the cassette-type integrated body 3. The two tuyere bricks 31 can be mechanically removed at the same time and mechanically set.

[0019]

As described above, according to the method of replacing the tuyere brick for blowing gas into the bottom of the electric furnace according to the present invention, most of the replacement work of the tuyere brick at the bottom of the furnace depends on the manual work of the operator. Without
It has the effect that it can be replaced mechanically efficiently and the work time can be reduced to about half.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a method of replacing tuyere bricks for gas injection into the bottom of an electric furnace according to an embodiment of the present invention.

FIG. 2 is a side view of a main part showing a furnace bottom structure around a cassette brick in the electric furnace.

FIG. 3 is a main part plan view showing a furnace bottom structure around the cassette brick.

4 is a cross-sectional view taken along the line AA of FIG.

5 is a sectional view taken along line BB of FIG.

FIG. 6 is a diagram for explaining a conventional exchange method.

[Explanation of symbols]

 2 Furnace bottom 3 Cassette bricks 31 Tuyere bricks 32 Fireproof bricks 33 Iron strips 40 Lifting equipment

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takemoto Hayashi No. 3007 Nakajima, Shikama-ku, Himeji City, Hyogo Prefecture Sanyo Special Steel Co., Ltd. Banchi Sanyo Special Steel Co., Ltd.

Claims (1)

[Claims] 1. An electric furnace in which a plurality of gas-blowing tuyere bricks 31 are arranged on the furnace bottom 2 to allow gas to be blown from the furnace bottom, and a plurality of tuyere bricks 31 and surrounding refractory bricks 32 are provided. Are arranged in a state of being attached to the hearth bottom 2 and a cassette brick 3 whose outer periphery is wound with an iron band 33 is prepared, and the used cassette bricks 3 attached to the hearth bottom 2 are arranged from the lower side of the hearth bottom 2 The lifter tool 40 pushes it up and lifts it up to remove it, while the replacement cassette brick 3 is hung from the upper side and loaded into the furnace to be received by the lifter tool 40 extending from the lower side of the furnace bottom 2, and the lifter tool 40 is lowered. A method for replacing a tuyere brick for blowing gas into an electric furnace hearth, characterized in that the cassette brick 3 is set on the furnace bottom 2.