JPH07118714A - Method for repairing furnace wall of blast furnace - Google Patents

Abstract

PURPOSE:To provide a repairing method for the furnace wall of a blast furnace which prevents the development of crack and deformation of an iron shell and can easily be executed at an extremely low cost, by stably supporting the repaired refractory over a long period. CONSTITUTION:After fitting, from the inside of furnace, an auxiliary cooling panel 5 performed with monolithic refractory 9 till the intermediate thickness of a water cooling system pipe 8 spraying material 11 is sprayed from the inside of the furnace while using studs 6 arranged to the auxiliary cooling panel 5 as a supporting material. The auxiliary cooling panel 5 is fitted so as to face the intermediate position of the existing cooling panels 4, and after completing the spraying, a force-feeding material 10 is forcedly fed for filling up a gap at the back surface side. Further, the air is vented from an air vent hole 12 in order to improve the filling property of the force-feeding material 10 and prevent the explosive crack at the initial stage. The durability can be improved by this repairing technique for the furnace wall of the blast furnace.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing a blast furnace wall when a refractory material is removed from the furnace wall.

[0002]

2. Description of the Related Art In a furnace wall of a blast furnace, a refractory material is constructed inside a furnace shell, and the refractory material is supported and cooled by a cooling plate, a supporting metal or the like in order to remove the wear and loss thereof. Currently, the stave method and cooling plate method are used in each blast furnace as a highly reliable technology for the furnace wall construction method. By the way, when a refractory material falls off in a stave blast furnace, there are technologies for locally installing a cooling board, press-fitting the refractory material, and partially replacing the stave cooler itself.

On the other hand, in the case of a cooling platen blast furnace, support for refractory materials,
Although the cooling system is different from that of stave, wear of the refractory progresses due to mechanical, physical, chemical, and thermal attack due to long-term blast furnace operation. When the wear of this refractory material progresses, the heat load on the furnace body iron shell increases, which increases damage to the cooling plate, deforms the iron shell, and causes cracks to cause CO
There was a situation in which gas leaked to the outside and the safety was impaired, making it impossible to continue smooth blast furnace operation. In order to protect the iron skin from the refractory falling off and increasing heat load, the following various measures have been proposed and applied in actual machines.

1) Press-fitting of irregularly shaped refractory material In order to extend the life of the press-fitting material, examination of the press-fitting material (JP-A-57-
118073), improvement of press-fitting method, improvement of diffusivity of press-fitting material in furnace, improvement of supporting metal for supporting press-fitting material
8-57700). 2) Spraying of irregularly shaped refractory material Lower the level of the interior of the furnace to expose the refractory material dropout area and spray it from the furnace using a dedicated nozzle or a dedicated machine (Japanese Patent Publication No. 64-9558). 3) Installation of refractory structure A plate-shaped refractory structure that was previously configured outside the furnace is hung and installed inside the furnace at the refractory dropout part. Further, a metallic stave or a stave whose surface is lined with a refractory is installed (Japanese Patent Laid-Open No. 60-2607).

[0005]

However, in the above-mentioned conventional blast furnace repair method, since there are few places where the amorphous refractory material is bonded and held in the furnace wall repair section, the amorphous refractory material bonded to the furnace wall repair section is small. The durability was low, and the remaining thickness was lost in about 2 to 3 months. SUMMARY OF THE INVENTION The present invention aims to solve the above problems and to improve the adhesion rate of an irregular shaped refractory to a furnace wall repair section and the durability of an irregular shaped refractory bonded to a furnace wall repair section. A blast furnace wall repair method is provided.

[0006]

The blast furnace wall repair method of the present invention is a blast furnace wall repair method in which the blast furnace charge is scaled down to below the furnace wall repair section to repair the furnace wall by a water cooling method. It is characterized in that after attaching an auxiliary cooling board in which an amorphous refractory is molded in advance up to the intermediate thickness of the pipe to the repair location from the inside of the furnace, the stud is used as a supporting material to spray the spraying material to the outside of the auxiliary cooling board. This is a blast furnace wall repair method.

[0007]

In the present invention, the auxiliary cooling board is faced to the furnace wall repair section,
In addition to supporting the water cooling pipe water supply and drainage pipes inserted through the iron shell opening between the existing cooling boards as a supporting member, the furnace wall repair section and the auxiliary cooling board from the inside of the furnace to the irregular shape refractory during reduced-scale blast Since the irregular refractory is pressed into the gap on the back side of the auxiliary cooling board from the iron skin side, the irregular refractory is adhered and supported in many places, and the durability of the irregular refractory adhered to the furnace wall repair part is improved. The property is improved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 3 is a partial cross-sectional view showing a furnace wall structure in which a cooling board 4 is embedded, 1 is a furnace body skin, 2 is a fixed refractory,
Reference numeral 4 is a castable layer constructed between the iron shell 1 and the regular refractory 2. The fixed-size refractory 2 is physically and chemically damaged by long-term operation of the blast furnace, most of it is removed as shown in FIG. 4, and the castable layer 14 and the iron shell 1 are exposed in an extreme case. It often happens. In addition, 3 in FIG. 4 shows the falling refractory material.

FIG. 1 is a partial sectional view showing an embodiment according to the present invention, and FIG. 2 is a plan view thereof. Reference numeral 5 in the figure denotes an auxiliary cooling board, which is attached face-to-face to the iron shell to maximize protection of the uncooled portion of the iron shell.
In order to further improve the durability of the water-cooled pipe 8, the water-cooled pipe 8 is molded to an intermediate thickness with an irregular refractory 9 before being attached. In addition, the stud 6 is attached to the water cooling pipe 8,
The spray surface side is exposed in order to improve the adhesive strength of the spray material. The auxiliary cooling board 5 supports the water cooling pipe 8 for water supply and drainage from the existing cooling board 4 and the iron skin opening 7 at the intermediate position between the existing cooling boards 4, and is fixed by welding. After that, the spray material 11 is sprayed to a thickness of 100 to 500 mm from the inside of the furnace, and then the press-fit material 10 is press-fitted into the gap 15 on the back surface of the auxiliary cooling board 5 from the press-fitting hole 13.
The air vent hole 12 is buried in order to improve the filling property of the press-fit material and prevent initial explosion. When the auxiliary cooling board 5 is damaged,
It is also possible to partially replace and repair again.

[0010]

According to the present invention, the supporting force of the studs cooled by the auxiliary cooling plate and the bridge effect with the existing cooling plate delay the falling of the spray material, and further improve the durability of the precast in the auxiliary cooling plate. Furnace wall repair frequency is 3-4
It can be extended twice. As a result, the heat load on the iron shell is reduced, damage to the cooling plate and deformation of the iron shell are reduced, and leakage of CO gas due to cracks in the iron shell is eliminated, and smooth blast furnace operation can be achieved.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view in which an auxiliary cooling board according to the present invention is attached to a furnace wall repair section and repaired.

FIG. 2 is a plan view of FIG.

FIG. 3 is a partial sectional view showing a furnace wall structure in which a horizontal cooling board is buried.

FIG. 4 is a partial cross-sectional view showing a wear-resistant refractory furnace wall.

[Explanation of symbols]

 1 Furnace iron shell 2 Regular refractory material 3 Falling refractory material 4 Cooling board 5 Auxiliary cooling board 6 Stud 7 Iron skin opening 8 Water cooling pipe 9 Irregular refractory material 10 Press fitting material 11 Spray material 12 Air vent hole 13 Press fitting hole 14 Castable layer 15 Gap

Claims (3)

[Claims] 1. In a blast furnace wall repair method in which the blast furnace charge is scaled down to below the furnace wall repair section to repair the furnace wall, an amorphous refractory is preformed to an intermediate thickness of a water-cooled pipe. A method for repairing a blast furnace wall, which comprises mounting an auxiliary cooling board from the inside of a furnace to a repair location, and then spraying a spray material to the outside of the auxiliary cooling board using a stud as a support material. 2. The blast furnace wall repair method according to claim 1, wherein the attachment position of the auxiliary cooling plate is an intermediate position of the existing cooling plate. 3. After the auxiliary cooling board is installed and the spray repair is completed, the press-fitting material is press-fitted to fill the gap on the back side, and the air is vented from the air vent hole to improve the filling property of the press-fitting material and to prevent the initial explosion. A blast furnace wall repair method characterized by the above.