JPS6036444B2 - Blast furnace wall repair method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for repairing a damaged section of a blast furnace wall by installing a replaceable staple cooler.

At the end of a blast furnace's life, the furnace profile collapses in areas where bricks have fallen off, disrupting the uniform descent of raw materials and making it impossible to maintain optimal operation, or causing the steel shell to become red hot, creating a dangerous situation. As a result, it is often necessary to operate with a lower pig iron tap amount than specified.

For this reason, conventional methods have been used to improve the profile by spraying monolithic refractories onto the inside of the blast furnace, attaching pre-fired refractory plates to the furnace meat side, or press-fitting monolithic refractories from the outside of the blast furnace. Efforts have been made to maintain and protect the pig skin. However, with these measures, it was not possible to maintain the purpose for a long period of time due to the limited durability of the refractories, and the plant continued to operate with repeated repair work. This invention was made in view of the above circumstances, and its purpose is to provide a replaceable stave cooler that can maintain the furnace profile and protect the shell over a long period of time in a blast furnace at the end of its life. There is a method for repairing a reactor crash by installing. The gist of this is that a replaceable stave cooler, which has excellent wear resistance under high temperature conditions, is installed at the part where bricks fall off inside the furnace during wind breaks, and is attached to the steel shell using a chain and a guide pipe that is inserted from outside the furnace. By fixing the stave and then press-fitting a monolithic refractory between the back of the stave and the brick surface, consideration was given to preventing the furnace gas from escaping through the back of the stave, and maintaining the furnace profile over a long period of time. and a method for repairing a furnace crash, which is characterized by ensuring protection of the iron shell. The present invention will be explained below based on an illustrated embodiment.

In FIG. 1, numeral 1 shows a brick head structure from the early stage of the furnace age, and the profile on the inner surface of the furnace is generally worn out and fallen off as shown in the figure at the end of the furnace age. 2 shows a stave cooler from the early furnace age, and 3 is a blast furnace shell.

FIG. 1 shows a case where a replaceable stave cooler 4 is installed from inside the furnace in this state. A fixing chain 5 is attached in advance to the 4, and a pipe 7 for passing cooling water of the stave cooler and a brick 8 for suppressing the amount of heat taken from inside the furnace are cast. Select the number of cooling pipes and the shape of the pipe bends to minimize the number of holes through which the cooling pipes penetrate the steel shell. In addition, when taking it into the furnace, we make sure that it is as light and lightweight as possible.
4. It is necessary to make the installation work inside the furnace easier by creating a mold. In this example, by reducing the wall thickness of the stave cooler, consideration has been given to reducing the degree of interference with adjacent stave coolers during installation and facilitating installation. In addition, when the cooling pipe protrudes, it may be difficult to take the stave cooler into the furnace.
In such a case, as shown in Fig. 2, a method is used in which a flexible hose 10 is used, a protective tube 11 is inserted from the outside of the furnace, and a monolithic refractory is press-fitted between the protective tube 11 and the flexible hose 10. You can also do that. When installing the stave cooler, the existing steel shell and bricks are bored from outside the furnace so that the piping 7 and guide pipe 6 can penetrate.

Pull the chain 5 out of the furnace through the guide pipe through hole,
Set the guide pipe 6 to a predetermined length and attach it to the steel shell, tighten the chain 5, and install the replaceable staple cooler 4.
to be fixed. Thereafter, the gap between the piping 7 and the mounting hole provided in the steel shell 3 is sealed by welding. After this, a monolithic refractory 9 is press-filled between the back of the replaceable stave cooler 4 and the front of the existing brick from the outside of the furnace through the refractory filling hole 12, and high-temperature gas during operation flows through the back of the stave cooler. to prevent damage to piping and guide pipes. Perform this work on the stave coolers at the same height so that they are installed all around the circumference. If the area of wear and tear on the bricks inside the furnace cannot be covered by one stage of stave coolers, two or three stages of stave coolers will be installed. By installing the stave cooler all around the circumference in this way, the collapsed brick profile at the end of the furnace age is replaced with the stave cooler front profile, and the uniform fall of the raw material in the furnace, which is a basic condition for stable operation, can be achieved. becomes possible.

In addition, the high-temperature furnace contents are blocked by the stave cooler, and the heat-insulating effect of the refractory on the back side of the stave cooler eliminates the red-hot phenomenon of the iron skin. The excellent wear resistance of stave coolers under high-temperature conditions has been demonstrated in many blast furnaces, and this method can also be expected to have far superior durability compared to conventional methods. As explained above, by attaching a stave cooler with excellent wear resistance under high temperature conditions to the fallen part of the bricks in the blast furnace, the furnace profile can be maintained in a healthy manner so that the raw materials can descend uniformly. This, combined with the protective effect of the iron shell, makes it possible to stabilize the operation for a long period of time at the end of the furnace life.

This has an extremely excellent effect.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal sectional view of a blast furnace wall, and FIG. 2 shows an example in which a flexible hose is used as a part of the cooling piping. 1... Brick loss composition from the early stage of furnace life, 2...
・・Stave cooler from the early days of the furnace, 3...
Blast furnace shell, 4... Replaceable staple cooler, 5
...Fixing chain, 6... Guide pipe, 7... Cooling pipe, 8... Zenigome brick, 9.
..... Monolithic press-fit refractories, 10 ..... flexible hoses, 11 ..... protection tubes, 12 .....
Monolithic refractory filling hole. Figure 1 Figure 2

Claims (1)

[Claims] 1. In a blast furnace at the end of its life, when bricks in the furnace fell off and damaged parts were repaired, the contents inside the furnace were reduced to below the repaired part of the furnace wall and after the air was rested, a replaceable stave was removed from the top opening of the furnace. A blast furnace characterized in that the cooler is hung down and attached to a repaired part of the furnace wall, and monolithic refractories are press-filled from outside the furnace through a refractory filling hole between the back of the replaceable stave cooler and the front of the bricks in the furnace. Furnace wall repair method.