JP6886358B2 - Lining method at the bottom of the electric furnace - Google Patents

Description

The present invention relates to a method of lining an electric furnace bottom, particularly an electric furnace bottom provided with a tuyere receiving block.

In an electric furnace that melts iron scrap, etc., the lining is lined with refractory materials such as bricks. Further, a refractory tuyere receiving block may be lined on the bottom of the electric furnace to mount a tuyere brick for blowing gas (for example, Patent Document 1 and Patent Document 2).

The lined refractory is replaced with a new one when it wears out, but the iron skin is used over and over again. For this reason, the refractory may be lined in a state where the iron skin is deformed such as unevenness, but in particular, the deformation of the refractory iron skin affects the shape of the fire bottom after the refractory is lined. That is, in the conventional electric furnace bottom lining method, if the bottom iron skin is deformed, the deformation affects the shape of the bottom, and as a result, the required molten metal level cannot be secured and the operation is hindered. There was a problem of coming. Specifically, if the surface level of the molten metal becomes too high, there is a problem that overflow occurs due to a splash during smelting. If the molten metal level becomes too low, the electric furnace has a tilt angle limit unlike the converter, and molten steel may remain on the bottom of the furnace. Since electric furnaces melt and smelt different types of steel, if molten steel remains on the bottom of the furnace, there is a problem that contamination occurs, which affects the quality of steel and lowers the product yield.

Jikkenhei 7-266692 Jikkenhei 5-42992

An object to be solved by the present invention is to provide a method for lining an electric furnace bottom portion that can secure a required predetermined molten metal level (predetermined furnace volume) even if the furnace bottom iron skin is deformed. is there.

According to the present invention, the following lining methods (1) to (3) are provided.
(1) In the method of lining the bottom of an electric furnace provided with a tuyere receiving block, a height adjusting member is arranged between the tuyere receiving block and the iron skin of the furnace bottom, and the height adjusting member is used to form a tuyere receiving block. A method of lining the bottom of an electric furnace, which comprises pouring a castable between the iron skin of the bottom of the furnace and the tuyere receiving block after adjusting the height.
(2) The height adjusting member is a bolt and a nut that is screwed into the bolt. Either the head of the bolt or the nut is in contact with the bottom iron skin, and the bottom of the tuyere receiving block is the head of the bolt and the bottom of the tuyere receiving block. The method for lining the bottom of an electric furnace according to (1), wherein the height of the tuyere receiving block is adjusted by receiving the nut on one of the nuts and rotating the bolt or the nut.
(3) The height adjusting member is a turnbuckle, one end of the turnbuckle is in contact with the iron skin of the furnace bottom, the other end of the turnbuckle is in contact with the bottom surface of the tuyere receiving block, and the wings are rotated by rotating the turnbuckle. The method for lining the bottom of an electric furnace according to (1), wherein the height of the mouthpiece block is adjusted.

According to the lining method of the present invention, the height of the tuyere receiving block is adjusted to an arbitrary height by the height adjusting member, and then the castable is poured between the tuyere receiving block and the iron skin on the bottom of the furnace. Even if the bottom iron skin is significantly deformed, the tuyere receiving block should be installed at the designed position without being affected by the deformation of the bottom iron skin to form the bottom iron skin as designed. Can be done. As a result, the required predetermined hot water level (predetermined internal volume of the furnace) can be secured, and stable operation can be performed.

It is a top view which shows an example of the electric furnace bottom part which applied the lining method of this invention. It is a vertical cross-sectional view of the electric furnace bottom part of FIG. It is an enlarged view of the main part (the tuyere receiving block part) of FIG. It is a perspective view which shows another example (turnbuckle) of a height adjusting member.

As shown in the plan view of FIG. 1, the electric furnace bottom portion 2 is lined with a furnace bottom brick 11 and three tuyere receiving blocks 3. Further, as shown in the vertical cross-sectional views of FIGS. 2 and 3, the tuyere receiving block 3 is divided into an upper tuyere receiving block 31 and a lower tuyere receiving block 32, and the tuyere receiving block 3 has a tuyere brick. 4 is inserted and attached.

As clearly shown in FIG. 3, the head of the bolt 7 in which the nut 8 is screwed to the tip as a height adjusting member is welded and fixed to the surface of the furnace bottom iron skin 6 and is in contact with the surface. Although two bolts 7 appear in FIG. 3, the lower tuyere receiving block 32 is actually held by four bolts 7 and a nut 8 screwed thereto. That is, in the present embodiment, the head of each bolt 7 is in contact with the surface of the furnace bottom iron skin 6, and the upper surface of the nut 8 screwed into each bolt 4 is in contact with the bottom surface of the lower tuyere receiving block 32. In addition, upside down from the present embodiment, the head of each bolt 7 abuts on the bottom surface of the lower tuyere receiving block 32, and the lower surface of the nut 8 screwed into each bolt 4 is on the surface of the furnace bottom iron skin 6. It can also be made to abut.

A castable 5 is constructed between the tuyere receiving block 3 (lower tuyere receiving block 32) and the furnace bottom iron skin 6. Around the tuyere receiving block 3, stamping material 9, perm brick 10, and fire bottom brick 11 are constructed in order from the bottom as a refractory material for the bottom of the fire.

Next, a lining method for constructing the above-mentioned electric furnace bottom portion will be described.

As shown in FIG. 3, the heads of the four bolts 7 are welded and fixed to the positions where the lower tuyere receiving block 32 is installed on the bottom iron skin 6. A nut 8 is screwed into the tip of the bolt 7. The four nuts 8 receive the bottom surface of the lower tuyere receiving block 32. Then, the height of the lower tuyere receiving block 32 is adjusted by rotating each nut 8 so that the distance from the design position 12 (see FIG. 2) of the molten metal surface in the furnace becomes the design dimension. After adjusting the height of each lower tuyere receiving block 32, the castable 5 is poured between the lower tuyere receiving block 32 and the furnace bottom iron skin 6. After that, the upper tuyere receiving block 31 is installed on the lower tuyere receiving block 32 to complete the tuyere receiving block 3, and the tuyere brick 4 is attached to the tuyere receiving block 3 and the tuyere receiving block 3 is attached. As a fireproof material for the bottom of the fire, stamp material 9, perma brick 10, and bottom brick 11 are installed around the furnace. At this time, the furnace bottom refractory is constructed with the upper surface of the lower tuyere receiving block 32 as a reference surface. As described above, according to the lining method of the present embodiment, the upper surface of the lower tuyere receiving block 32 whose height has been adjusted as designed can be used as a reference surface, so that the upper tuyere receiving block 31 and the fire bottom refractory Can be easily placed at the designed position without being affected by the deformation of the furnace bottom iron skin 6.

In the above embodiment, after the castable 5 is poured between the lower tuyere receiving block 32 and the furnace bottom iron skin 6, a furnace bottom refractory such as a stamp material 9 or a perm brick 10 is applied, but the stamp material 9 is used. It is also possible to pour the castable 5 between the lower tuyere receiving block 32 and the furnace bottom iron skin 6 after constructing a refractory material such as or perma brick 10. Further, in the above embodiment, the tuyere receiving block 3 is divided into the upper tuyere receiving block 31 and the lower tuyere receiving block 32, but the tuyere receiving block 3 can be lined as an integral body without being divided. .. In this case, the fireproof material such as the stamp material 9 and the perm brick 10 is constructed with the upper surface of the tuyere receiving block 3 as a reference surface as a reference surface. Further, in the above embodiment, bolts and nuts are used as height adjusting members, but known turnbuckles as shown in FIG. 4 can also be used. In this case, the height of the tuyere receiving block is adjusted by contacting one end of the turnbuckle with the surface of the iron skin of the furnace bottom, contacting the other end of the turnbuckle with the bottom surface of the tuyere receiving block, and rotating the turnbuckle. To do.

As described above, according to the lining method of the present invention, the tuyere receiving block can be easily and accurately positioned with respect to the molten metal surface by using the height adjusting member. Then, since it is possible to construct the bottom refractory such as stamp material and perm brick based on the tuyere receiving block whose height is adjusted as designed, the construction work of these bottom refractories is simple and accurate. The shape of the hearth can be made as designed. Further, by pouring a castable between the furnace bottom iron skin and the tuyere receiving block, it is possible to prevent the tuyere receiving block from being displaced during use.

1 Electric furnace 2 Electric furnace bottom 3 Tuft receiving block 31 Upper tuyere receiving block 32 Lower tuyere receiving block 4 Tubing brick 5 Castable 6 Furnace bottom iron skin 7 Bolt (height adjustment member)
8 nut (height adjustment member)
9 Stamp material 10 Perm brick 11 Furnace bottom brick 12 Design position of hot water surface

Claims (3)

In the method of lining the bottom of an electric furnace provided with a tuyere receiving block, a height adjusting member is arranged between the tuyere receiving block and the iron skin of the furnace bottom, and the height of the tuyere receiving block is adjusted by this height adjusting member. A method of lining the bottom of an electric furnace, which comprises pouring a castable between the iron skin of the bottom of the furnace and the tuyere receiving block after adjustment. The height adjusting member is a bolt and a nut that is screwed into it. Either the head of the bolt or the nut is in contact with the bottom iron skin, and the bottom of the tuyere receiving block is either the head of the bolt or the nut. The method for lining the bottom of an electric furnace according to claim 1, wherein the height of the tuyere receiving block is adjusted by receiving the other side and rotating a bolt or a nut. The height adjusting member is a turnbuckle, one end of the turnbuckle is in contact with the iron skin of the bottom of the furnace, the other end of the turnbuckle is in contact with the bottom surface of the tuyere receiving block, and the turnbuckle is rotated to make the tuyere receiving block. The method for lining the bottom of an electric furnace according to claim 1, wherein the height of the buckle is adjusted.

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