JPS602607A - Repairing method of blast furnace wall - Google Patents

Abstract

PURPOSE:To restore a defectless wall of a blast furnace and to operate stably the furnace for a long period of time in reducing the stock line and blowing down the blast furnace and repairing the wall thereof by disposing and fixing a cooling plate for protecting the exposed shell of the part to repair to said shell and spraying and forcing castable refractories between the boundary part thereof and the shell. CONSTITUTION:Repair of a blast furnace wall is performed by reducing the stock line and blowing down the blast furnace to expose a part 3 to repair. The furnace wall to be repaired is cleaned with a suspending nozzle, etc. to remove the residual material from the shell. A cooling plate 4 of a shell protection type having a precast castable refractory 11 surface and water cooling pipes 10 cast therein is attached to the shell by using an existing cooling plate 6. Castable refractories are sprayed from a nozzle 7 from the inside to the clearance around the plate 4 and said refractories are also forced into the space between the shell and the plate 4 by utilizing the holes of the cooling plate 6. The furnace wall is renewed by the above-mentioned method and the long-period stable operation of the blast furnace is made possible.

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 wear and tear due to not only wear due to falling charges, but also cracks, flaking, and peeling due to heat load fluctuations within the furnace and corrosive gas attack. As a result, the profile is extremely non-uniform, a mixed layer of coke and sintered ore is generated, and the flow path of the reducing gas in the furnace is also 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 staple blast furnace, monolithic refractories were sprayed from within the furnace in front of the remaining brick refractories in the brick section at the top of the shaft, and baked refractory plates, staple coolers, etc. were installed in front of the remaining brick refractories. There is a method of press-fitting and filling an unshaped refractory material into the gap between the uneven surface of the remaining brick refractory and the fired refractory plate or the back of the staple cooler from outside the furnace through a press inlet. In addition, in cooling plate blast furnaces, the above-mentioned measures and methods have been taken for the entire shaft section and furthermore for the furnace abdomen. However, since the spraying of monolithic refractories from within the furnace has short durability, the spraying frequency increases, and there is a natural limit to the spraying thickness, improvements are desired. The method of attaching a fired refractory board or stave cooler to the front of the remaining brick refractory is to press fit the refractory and deposits on the uneven top surface of the remaining brick, and then press-fit the fired refractory board or stave cooler to the front surface of the remaining brick refractory. The gap between the back and the back is filled with impurities,
Because it is a press-fitted/filled layer with foreign matter mixed in, it is difficult to obtain dense, low-porosity properties, and there are drawbacks to durability.
During operation, it is easy to see the actual situation in this press-fit filling section.

The present invention solves the above-mentioned drawbacks, and after removing the remaining bricks and refractory material from the damaged part of the furnace wall and exposing the steel shell, the steel shell, such as a thin, staple-type cooling plate, is After installing the protective cooling plate and spraying the monolithic refractory material from inside the furnace to the joints and ends of the group of protective cooling plates, spray the monolithic refractory material from outside the furnace to prevent leakage of the press-fit material. This is a furnace repair method that improves durability, maintains the furnace profile over a long period of time, and protects the heat insulation of the iron shell by press-fitting and filling the furnace body.

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

Figure 1 shows how the steel 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. Fig. 1 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 the exposed part 3 of the iron skin after the remaining bricks 8 of the furnace wall brick section have been removed to expose the iron skin.
In this state, the iron skin protection type cooling plate 4 is attached and fixed. The iron shell protection type cooling plate 4 has a cast-in water cooling pipe 1o cast into a metal block 9, and is equipped with a precast monolithic refractory material 11, a lip 12 supporting the same, and a stud 13 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. (As a guide, 3~
Approximately 15'01ffl in 4 years When installing the iron shell protection type cooling plate 4 to the damaged part of the furnace wall, residual bricks 8 or deposits inside the furnace remain, which becomes a hindrance to precise press-fitting and filling described later. Therefore, these must be removed 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 rod support tube 15 that supports the rod are suspended from a furnace top opening 14 into the furnace by a hanging member 21, and a steel shell protection type cooling plate 4 is planned to be added. The turning operation wire 22 is operated to turn the turning operation wire 22. 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 removed by impacting and rotating the pit 16 via the rod 17 by a drive device 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, in order to prevent the actual situation on the back side of the steel shell protected type cooling plate, a monolithic refractory material is press-fitted and filled. Shows how to seal by spraying and ends.

With the 4 groups of iron shell protection type cooling plates installed and fixed at the mounting site, as shown in the figure, the end seal plate 5-26 at the end and the joint overlapping plate 27 at the joint part are installed, as shown in the figure.
After spraying the monolithic refractory material from inside the furnace with the spray nozzle 7 to prevent leakage of the press-in material, the press-fit material of the monolithic refractory material is press-fitted through the injection port 5 attached to the steel shell 24.

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, and hot spots, deformations, and cracks in the steel shell will be prevented. The blast furnace body can be maintained in a healthy condition and stable operations can be continued.

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 monolithic refractory material into the gap between the back surface and the back surface, not only can insulation protection of the steel skin be ensured for a long period of time, but also the furnace profile can be restored and a mixed layer of coke and sintered iron can be formed. Since this can also be prevented, more stable operations can be achieved.

In addition, if the steel skin protection type cooling plate starts to wear out, it is repaired by spraying using a thermal spraying repair device, but at this time, the lip part serves as a support for the spraying material, and the adhesion rate and durability of the spraying material are reduced. improve. 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 drawings]

Figures 1 (a) and (b) show the installation of a shell-protecting cooling plate to a damaged part of the blast furnace wall. (a) shows an example of a stave blast furnace, and (b) shows an example of a cooling plate blast furnace. show. FIGS. 2(A) and 2(B) 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. ■...Stave blast furnace, 2...Cooling plate blast furnace, 3...
・Exposed steel shell part, 4... Steel shell protected cooling plate, 5... Stave, 6... Cooling plate, 7... Spray nozzle,
8...Remaining brick, 9...Hardware block, 1o medium cast water cooling pipe, 11...Precast monolithic refractory material, 12...Riff, 13...Stud, 14...Furnace top opening Part, 15... Rod support tube, 16... Bit, ]7... Rod, 18... Adherence, 19...
Reduction level, 2o... Drive device, 21... Suspension member, 22... Swivel operation wire, 23... Support beam,
24 Steel shell, Z5... Pressure inlet, 26... End seal plate, 27... Joint overlapping plate,
Ah... press-in material. Agent accountant Tomoyuki Yabuki (1 other person)

Claims (1)

[Claims] When repairing the furnace wall by reducing the size of the charge and resting the blast furnace wall, the remaining refractory on the back side of the shell in the repaired area is removed to expose the back side of the shell, and the exposed part of the shell is A cooling plate for protecting the steel shell is arranged and fixed in the furnace, and the joints and ends of the group of cooling plates for protecting the steel shell are spray-formed with monolithic refractories,
A blast furnace wall repair method characterized by injecting monolithic refractories into the gap between the shell protection cooling plate and the back surface of the shell through an injection port from the surface of the shell outside the furnace.