JPS602609A - Construction of wall of blast furnace - Google Patents

Abstract

PURPOSE:To decrease the damage of a shell and cooling box and to extend the life of a blast furnace wall in lining said wall by forming the cooling box in the opening of the shell into a round shape and adhering tightly a lining material of castable refractories via an expansion absorbent material to the shell and the cooling box. CONSTITUTION:The opening of a blast furnace shell 1 is made into a circular shape to disperse the concentrated stress between said opening and the shell 1. A circular cooling box 4 is forced into the opening. An expansion absorbent material 5 is adhered tightly onto the surface of the shell 1 and the box 4 on the furnace inside. A lining material 6 of castable refractories is applied thereon by casting or installation of the precast material or combination of both. The life of the furnace wall is extended by such dispersion of the concentrated stress of the shell as well as by the air permeability, coefft. of linear expansion and dominant wear resistance of the lining materials consisting of the castable refractories.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a furnace body used in a high-temperature metallurgical furnace such as a blast furnace, and more particularly to a furnace wall structure.

Generally, a blast furnace for steelmaking is lined with a large amount of refractory over its entire height. The material and structure of these refractories are selected depending on the location of the furnace, taking into consideration chemical and physical erosion factors, the combination of furnace cooling methods, etc. The morning glory, the furnace belly, and the furnace chest are lined with refractory bricks with a thickness of 500 to 900 square meters, and the middle and lower parts of the furnace chest are cooled by furnace body cooling equipment.

Next, FIG. 1 shows a conventional furnace wall structure, and FIG. 2 shows a view taken in the direction of arrow A in FIG. 1.

Conventionally, blast furnace furnace body refractory bricks contain <Si> as shown in Fig. 1.
Refractory bricks 2 of C quality, high alumina quality, etc. are used inside the steel shell 1, and the quality of the bricks alone has been improved, but as a lining structure, joints 3 made of the same quality refractory mortar are used. There is a joint between the refractory bricks 2, and this joint 3 has very weak strength and corrosion resistance compared to the refractory bricks 2, so the refractory bricks often fall off and are damaged, especially in blast furnaces that have been used for 5 to 6 years. This was a contributing factor. In the case of a refractory brick structure, the cooling device has a structure in which, for example, a cooling surface 4 is inserted into the refractory brick 2, and an expansion absorbing material 5 is interposed between the refractory brick 2 and the cooling surface 4. Further, an expansion absorbing material 5 is inserted between the iron shell 1 and the refractory bricks 2 to absorb expansion.

Since the conventional cooling surface 4 is inserted into the refractory brick, it has to be shaped to match the shape of the refractory brick 2, that is, a plate shape (square shape) as shown in FIG. Since the shape of the opening is also rectangular, stress concentration tends to occur on the surface of the steel skin crack, and especially in areas where the lining is severely damaged, steel skin cracks are likely to occur starting from the cooling surface opening.

In addition, in the case of a plate-type cooling box, its rigidity is low and it is easily bent and damaged by the load of the charge during operation, and it is not easy to replace it.

The present invention replaces the furnace wall structure of the conventional furnace body with a monolithic refractory lining material that has superior wear resistance, corrosion resistance, and spalling resistance compared to conventionally used refractory bricks. The purpose of improving the cooling surface is to improve the durability of the lining, reduce the manufacturing cost of the cooling surface, reduce cracks in the steel shell, and make repairs easier and more efficient.

The present invention provides a furnace wall structure comprising a monolithic refractory lining material and a cooling surface having a round shell opening inserted into the monolithic refractory lining material through an expansion absorbing material. be.

FIG. 3 shows a furnace wall structure that is an example of an embodiment of the present invention.
FIG. 4 is a view of the person.

As shown in Fig. 6, the present invention eliminates the joints, which are the weak points of the brickwork structure, and improves the durability of the relining, as shown in Table 1 below. An expansion absorbing material consisting of a high-quality monolithic refractory lining material 6 and a highly thermally conductive compressible sheet inside the iron shell 1 to facilitate thermal displacement absorption with the monolithic refractory material 6. 5. The filling of the monolithic refractory lining material 6 can be carried out by pouring, installing a precast product, or a combination thereof.

Table 1 Quality of monolithic refractory lining material Furthermore, the cooling system is as shown in Figure 4. By using monolithic refractory lining material instead of the conventional plate type (square type), restrictions on the shape of the cooling surface are eliminated. In order to absorb thermal displacement or to facilitate replacement of the cooling surface 4, an expansion absorbing material 5 having the above-described structure can be wrapped around the round cooling surface 4 and inserted into the monolithic refractory lining material. It has become possible.

By adopting such a configuration, the lining cost was significantly reduced as shown in Table 2 regarding the lining material.

Table 2 Irregular lining cost Further improvement in # requirements and since it is not made of refractory bricks, it does not require skilled workers, and the mechanization of construction is easy, creating a good working environment and shortening the construction period. Furthermore, since the cold leg system is round, the rigidity of the cooling surface itself is high, reducing bending damage and reducing the manufacturing cost of the cooling surface. In addition, in order to install a cooling surface in the monolithic refractory lining material,
Compared to the plate type, the number of installations can be increased and distributed installation is possible, the supporting effect and cooling effect of the lining material is improved, and the round openings in the steel shell reduce stress concentration, reducing cracks in the steel skin. Not only does it have great effects, such as reducing the amount of damage, but it is also easy to repair.

Note that the furnace wall structure of the present invention is not limited to blast furnace walls, and is not useful even when applied to other metallurgical furnaces.As the monolithic refractory lining material, a material suitable for each application should be selected. I can do it. Furthermore, the material of the cooling surface is not limited to iron, but may also be made of copper or other materials.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view showing the conventional furnace wall structure, and Figure 2 is a vertical cross-sectional view showing the conventional furnace wall structure.
3 is a longitudinal sectional view showing the furnace wall structure of the present invention, and FIG. 4 is a view taken along arrow A in FIG. 3. 1... Iron shell 2... Refractory brick 4... Cooling surface 5
... Expansion absorbing material 6 ... Monolithic fireproof lining material agent Patent attorney Sanro Kimura

Claims (1)

[Claims] In the space hearth body structure, a monolithic refractory lining material and a cooling surface having a round shell opening are inserted into the monolithic refractory lining material via an expansion absorbing material. Characteristic furnace wall structure