JPS6116402B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for repairing a worn portion of a blast furnace wall.

The refractory lining of a blast furnace is prone to cracking, peeling, and wear and tear due to not only wear due to falling charges, but also heat load fluctuations within the furnace and erosive gas attack. As a result, the profile becomes extremely non-uniform, a mixed layer of coke and sintered ore is generated, and the flow path of the reducing gas in the furnace also becomes non-uniform, which poses a major operational problem.
Furthermore, hot spots are generated in the steel shell, causing deformation and cracking, which is a major problem that shortens the life of the furnace body.

Conventionally, in the stave blast furnace, in the brick masonry section at the top of the shaft, monolithic refractories were sprayed from within the furnace in front of the remaining brick refractories, and baked refractory plates, stave coolers, etc. were installed in front of the remaining brick refractories. There is a method of press-fitting and filling the void between the uneven surface of the remaining brick refractory and the fired refractory plate or the back of the stave cooler with an unshaped refractory material from outside the furnace through an injection port. In addition, in cooling plate blast furnaces, the above-mentioned measures and methods have been taken for the entire shaft section and further for the furnace belly.

However, spraying monolithic refractories from inside the furnace
Improvements are desired because the durability is short and the spraying frequency is increased, and there is a natural limit to the spraying thickness. The method of attaching a fired refractory plate or stave cooler to the front of the remaining brick refractories is to press fit the refractories and deposits on the uneven top surface of the remaining bricks, and then press-fit the fired refractory plate or stave cooler to the front of the remaining brick refractories. The gap between the back and the back is filled with impurities,
Since it is a press-fitted and packed bed that contains foreign matter, it is difficult to obtain a dense, low-porosity product, which has shortcomings in durability, and back wind tends to pass through the press-fitted part during operation.

The present invention solves the above-mentioned drawbacks, and after removing the remaining bricks and refractory materials from the damaged part of the furnace wall and exposing the steel shell, it is possible to install a protective type of steel shell, such as a thin stave-type cooling plate, for example. After installing the cooling plate and spraying monolithic refractory material from inside the furnace to the joints and ends of the group of steel shell-protected cooling plates to prevent leakage of the press-fit material,
This is a furnace repair method that improves durability by press-fitting and filling monolithic refractory material from outside the furnace, maintaining the furnace profile over a long period of time, and providing insulation protection for the steel shell.

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

Figure 1 shows how the shell protection type cooling plate 4 is installed on the exposed steel shell part 3 after removing the remaining bricks and refractory material from the damaged part of the blast furnace wall. Figure 4 shows an example of the installation situation in the cooling plate blast furnace 2. 5 is a stave, 6 is a cooling plate, and 7 is a spray nozzle.

FIG. 2 shows an example of the shape, structure, and state of attachment to the steel shell of the shell-protected cooling plate 4. This figure shows a state in which, after the remaining bricks 8 of the brickwork of the furnace wall have been removed to expose the iron skin, the iron skin protection type cooling plate 4 is attached and fixed to the exposed iron skin part 3. The steel shell protection type cooling plate 4 has a cast-in water cooling pipe 10 cast into a metal block 9, and is provided with a precast monolithic refractory material 11, ribs 12, and studs 13 for supporting the same on the front surface. The dimensions may be smaller than the size of the furnace top opening, and the thickness may be selected depending on the expected lifespan. (Approximately 150 mm in 3 to 4 years as a guide) When installing the shell-protected cooling plate 4 to the damaged part of the furnace wall, the remaining bricks 8 or the deposits inside the furnace remain, and the press-fitting and filling described below must be done carefully. Since they are a hindrance to the process, it is necessary to remove them to make the surface smooth. FIG. 3 shows an apparatus for removing the remaining bricks 8 and the deposits 18 inside the furnace. In this device, a rod 17 having a bit at the tip and a support tube 15 for the rod are suspended from a furnace top opening 14 into the furnace by a suspension member 21, and a rod 17 having a bit at the tip and a support tube 15 for the rod are suspended from the furnace top opening 14 into the furnace, and the rod 17 is suspended from the furnace top opening 14 into the furnace. Operate the turning operation wire 22 to turn. The remaining bricks 8 and deposits 18 on the front surface of the part where the steel skin protection type cooling plate 4 is to be installed are moved by impact movement and rotational movement of the bits 16 via rods 17 by a drive device 20 installed outside the furnace. It is possible to remove these and obtain a smooth exposed part of the iron skin. Thereafter, the shell protection type cooling plate is suspended from the furnace top opening 14, lowered to a predetermined level, and then pulled toward the steel shell and attached and fixed to the steel shell.

Next, as shown in Figure 4, in order to prevent the rear wind from blowing on the back side of the steel shell-protected cooling plates, a monolithic refractory material is press-fitted and filled.In order to prevent leakage of the press-fitted material, the joints of the steel-shell-protected cooling plate group are The sealing method is shown by spraying the parts and ends. With the four groups of iron skin protection type cooling plates installed and fixed at the installation site, the end seal plate 26 at the end and the joint overlapping plate 2 at the joint are installed as shown in the figure.
After spraying the unshaped refractory material from inside the furnace using the spray nozzle 7 to prevent leakage of the press-in material, the unshaped refractory material is press-fitted through the injection port 25 attached to the steel shell 24. Press fit the material 28.

In this way, by installing the shell-protected cooling plate over the entire area of the furnace wall repaired area using the method described above, the shell will be reliably protected from heat for a long period of time, preventing hot spots, deformation, and Cracks are prevented, the blast furnace body is maintained in a healthy condition, and stable operations can continue.

As described above, according to the present invention, residual bricks and deposits are removed from the repaired part of the furnace wall of a blast furnace, a steel shell protection type cooling plate is attached to the exposed part of the steel shell in the furnace, and the steel shell is replaced with the steel shell protection type cooling plate. By press-fitting the amorphous refractory material into the gap between the back surface and the back surface, not only can the heat insulation protection of the steel shell be ensured for a long period of time, but also the furnace profile can be restored and a mixed layer of coke and sintered ore can be created. It is also possible to prevent the occurrence of , so more stable operations can be performed.

In addition, if the steel skin protection type cooling plate starts to wear out, it will be repaired by spraying using a hot spraying repair device, and at this time, the ribs will serve as a support for the spraying material, improving the adhesion rate and durability of the spraying material. do. If the shell-protected cooling plate becomes worn out again, it can be removed from the outside of the furnace and a new shell-protected cooling plate can be reinstalled, so this part of the steel shell can be used semi-permanently. It is possible.

As described above, the present invention can exhibit various excellent results, and can not only maintain the soundness of the iron shell but also maintain stable operation over a long period of time.

[Brief explanation of the drawing]

Figures 1A and 1B show how a shell-protecting cooling plate is attached to a damaged part of the blast furnace wall, where A shows an example of a stave blast furnace and B shows an example of a cooling plate blast furnace. Figures 2A and 2B are a plan view and a cross-sectional view showing the shape, structure, and mounting situation of the iron skin protection type cooling plate. Figure 3 shows the equipment for removing bricks remaining in the iron shell and deposits. FIG. 4 is a cross-sectional view showing the rear press-fitting of the iron skin protection type cooling plate and the means for preventing leakage of the press-fitting material. 1...Stave blast furnace, 2...Cooling plate blast furnace, 3...
...Exposed steel skin part, 4...Skin protection type cooling plate, 5...
Stave, 6... Cooling plate, 7... Spray nozzle, 8
...Remaining bricks, 9...Hardware blocks, 10...
Cast water cooling piping, 11... Precast monolithic refractory material, 12... Rib, 13... Stud, 14...
Furnace top opening, 15... Rod support tube, 16...
bit, 17... rod, 18... attachment, 19
... Reduction level, 20 ... Drive device, 21 ... Suspension member, 22 ... Swivel operation wire, 23 ... Support beam, 24 ... Iron shell, 25 ... Pressure port, 26 ... End seal plate , 27... Joint overlapping plate, 28... Press-fitting material.

Claims (1)

[Claims] 1 When repairing the furnace wall by reducing the size of the charge below the blast furnace wall repair section, remove the remaining refractory on the back side of the shell of the repaired section to expose the back surface of the shell, and A cooling plate for protecting the steel shell is installed and fixed in the section, and the joints and ends of the group of cooling plates for protecting the steel shell are spray-formed with monolithic refractories from the inside of the furnace, and pressure is applied from the surface of the steel shell outside the furnace. A blast furnace wall repair method characterized by press-filling a monolithic refractory into the gap between a shell-protected cooling plate and the back surface of the steel shell through an inlet.