JPH0941010A - Method for repairing damaging part of wall of blast furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the leakage of a seal by reducing a filling pressure of monolithic refractory for casting, loaded to a mechanical seal applied to side joint surrounding staves, at the time of repairing the damaged part of a furnace wall by using the stave for repairing in a blast furnace. SOLUTION: The cast monolithic refractory supplied from a monolithic refractory supplying hole 12 at the lower side is cast in the supporting condition with a sprayed refractory layer 15 supplied and cast from a monolithic refractory supplying hole 13 at the upper side in order. Therefore, the pressure acted to the mechanical seal 10 by the head pressure of the monolithic refractory is reduced and it can be prevented that the mechanical seal 10 is pushed out in the direction in the furnace and leakage of the seal is eliminated.

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 damaged portion of a blast furnace, which repairs a damaged portion of a blast furnace wall where refractories and staves have fallen off or worn.

[0002]

2. Description of the Related Art Ore and coke charged from the upper part of a blast furnace gradually move downward, and undergo a reduction reaction in a high pressure and high temperature state to become molten pig iron and slag. In this process, the refractory material in the furnace is melted and lost due to chemical changes and physical wear, and the thickness is gradually reduced until a part of the refractory material disappears.

A stave, for example, is arranged and fixed between the refractory material in the furnace and the furnace shell as cooling means for the refractory material.
When the refractory is extinguished, the stave may be directly exposed to the high temperature furnace interior inserts and undergo erosion wear, which may even damage the cast cooling tubes inside. When the stave as a cooling means for refractories in the furnace is damaged in this way, the furnace shell is directly subjected to high heat load and cracks occur, causing CO
Gas leaks out of the furnace and is in an unsafe state, and also has defects in terms of strength, which shortens the blast furnace life significantly. Therefore, when repairing the blast furnace, all staves that play an important role in cooling the furnace body are usually replaced.

[0004] However, in the intermediate renovation of the blast furnace by reduced blast, it is generally required that the cost be short and the cost is not so high. Therefore, the stave remains intact and only the damaged stave is repaired. Or it will be replaced. For example, in Japanese Patent Laid-Open No. 60-2607, a repair stave 20 having a precast refractory 23 on a stud 22 attached to the inside of a stave body 21 as shown in FIG. The removed furnace iron skin 24 is arranged and fixed on the exposed portion. In this state, after spraying an irregular shaped refractory from the inside of the furnace to the mechanical seal points of the end seal plate 26 and the overlapping plate 27 with the spray nozzle 29 to prevent leakage of the press-fit material, Irregular shaped refractory is press-fitted through the attached pressurizing port 25, and press-fitting material 28
What was repaired by forming a is disclosed.

[0005]

If the repairing stave 20 disclosed in the above-mentioned Japanese Patent Laid-Open No. 60-2607 is used, the furnace shell 24 can be heat-insulated and protected, but the stave body of the repairing stave. Since the gap (longitudinal joint) between 21 and the furnace skin 24 is large, it is necessary to form the press-fit material 28 by supplying a large amount of irregular shaped refractory material to this longitudinal joint. For this reason, not only the work time for pressurizing the irregular refractory uniformly into the gap but also the risk of insufficient insulation protection if the irregular refractory cannot be uniformly filled all the way .

The present invention solves the above-mentioned problems of the prior art, and when repairing a damaged interior wall of a furnace interior by reduced-scale deaeration, a repairing stave is used for good workability in a short time. It is possible to reduce the application of head pressure of irregular shaped refractory to the mechanical seal formed on the lateral joint formed on the outer periphery of the repair stave, and it is possible to sufficiently secure heat insulation protection, It is another object of the present invention to provide a method for repairing a damaged part of a blast furnace wall, which has excellent repair efficiency.

[0007]

SUMMARY OF THE INVENTION The present invention for achieving the above-mentioned object is intended to repair the blast furnace wall by lowering the contents inside the furnace to below the damaged part of the blast furnace wall by reduced scale deaeration. With the furnace wall damage site where the residual refractory of the damaged part or the furnace wall damaged part is removed and the furnace shell is exposed, the precast refractory is provided inside the furnace of the stave body and with the furnace shell outside the furnace. Required number of repair staves with mechanical seals on the furnace inner edge of the precast refractory and lateral joints formed on the outer periphery of the repair stave so that a flowable gap between the irregular shaped refractory is formed between them. After arranging and fixing, arranging the above-mentioned required number of fixed staves for repair corresponding to the upper and lower parts of the repair stave, and arranging the irregular refractory supply ports on the upper and lower sides of the furnace shell. First of all, the irregular refractory for pouring from the lower irregular refractory supply port. To fill the joints by pouring to form a pouring refractory layer, then from the upper irregular refractory supply port is sprayed by filling the irregular refractory for spraying on the pouring refractory layer, next time Damage to the blast furnace wall, characterized in that the procedure for forming a sprayed refractory layer capable of supporting the pouring head pressure of an indefinite shaped refractory is sequentially repeated for repair staves from the lower side to the upper side. It is a repair method.

[0008] Further, when repairing the blast furnace wall by lowering the contents inside the furnace to below the damaged part of the furnace wall by reduced-scale blast, the residual refractory material in the damaged part of the furnace wall or the damaged part of the furnace wall is removed. The precast refractory is provided inside the stave body inside the furnace wall where the furnace shell is exposed, and a flowable gap between the amorphous furnace and the furnace shell is formed outside the furnace. After fixing and fixing the required number of repair staves with a mechanical seal at the furnace inner end of the horizontal joint formed on the outer periphery of the precast refractory and the repair stave, the required number is set. Arrange unfixed refractory supply ports on the upper and lower sides of the furnace shell corresponding to the upper and lower parts of each fixed repair stave, and first from the unfixed refractory supply ports on the lower side. Filling the joints to the joints by spraying a standard refractory and spraying a refractory layer The procedure for forming a refractory layer on the sprayed refractory layer by filling the castable amorphous refractory from the upper irregular refractory supply port and then forming the refractory layer from the lower side to the upper side It is a method for repairing a damaged portion of a furnace wall of a blast furnace, which is characterized by sequentially repeating the steps for the staves for use.

[0009]

According to the present invention, there is provided a repair stave in which the precast refractory is provided inside the stave body inside the furnace, and the precast refractory is installed outside the furnace with a flowable gap between the irregular shaped refractory and the furnace shell. Used to repair the damaged part of the furnace wall. In this way, there is a thick precast refractory between the stave body and the furnace iron skin, and the gap (vertical joint) between the repair stave and the furnace iron skin is a uniform and flowable irregular refractory material. It has the minimum necessary size that can be filled.

Therefore, a small amount of amorphous refractory is supplied from the pouring port provided in the iron shell of the furnace, so that the working time required for filling can be greatly shortened. Further, in the present invention, the irregular shaped refractory supply port is arranged on the upper side and the lower side of the furnace iron shell corresponding to the upper and lower parts of each repair stave, and from the lower shaped irregular refractory supply port. By supplying a castable refractory material with good fluidity, fill the entire area from the lower-shaped irregular refractory material supply port to the joint formed on the outer periphery of the repair stave and fill it with uniform pouring fireproofness. An object layer can be formed.

In the state where the cast refractory layer is formed in this manner, a spraying castable refractory having poorer fluidity than the upper castable refractory supply port is charged by spraying to fill the cast refractory layer. A sprayed refractory layer having a large holding force is formed in the gap. Since this sprayed refractory layer supports the head pressure of the cast indeterminate refractory to be poured next, the head pressure applied to the mechanical seal applied to the outer side end of the furnace of the joint formed on the outer periphery of the repair stave. Can be reduced. As a result, it is possible to prevent the leakage of the seal due to the imperfect seal of the cast refractory material from the mechanical seal.

In addition, when filling the irregular refractory, first, the irregular refractory for spraying is filled by spraying, and then the irregular refractory for pouring is filled by pouring. The time required for the filling operation can be shortened by utilizing the fact that the solidification time of the irregular refractory for spraying is shorter than that of the irregular refractory.

[0013]

【Example】

(Embodiment 1) Hereinafter, the configuration and operation of the present invention will be described based on embodiments. FIG. 1 shows a vertical cross-sectional view after repairing a damaged portion of a furnace wall of a blast furnace according to the present invention using a repair stave.

As shown in FIG. 1, the repair stave 1 used in the present invention has a precast refractory 3 inside the furnace of a stave body 2 made of cast iron, which is the same as the conventional one. A precast refractory 4 having a thickness capable of forming a flowable gap S between the irregular shaped refractory and the furnace shell 7 is provided on the outer side. A protective pipe 6 is connected to the upper and lower sides of the stave body 2, and the casting water cooling pipe 5 is buried by casting through the protective pipe 6 as in the conventional case.

In addition, the furnace iron shell 7 is provided with an upper irregular refractory supply port 13 and a lower irregular refractory supply port 12 in the upper and lower pipe seats 9 corresponding to the upper and lower portions of the repair stave 1. It is located between them. When repairing the blast furnace wall by lowering the furnace interior contents 8 below the damaged part of the blast furnace shaft caused by reduced-scale blast, the damaged existing stave was removed, and the remaining furnace fire resistance The object is removed to expose the back surface of the furnace shell 7. A repairing stave 1 prepared in advance is suspended from a furnace top manhole or an opening formed by cutting a furnace top iron shell via a wire, and the winch is unwound and hung down to face the repair portion.

After the upper and lower protective tubes 6 connected to the repair stave 1 are inserted through the upper and lower pipe seats 9 provided in the furnace shell 7, the gap S between the repair stave 1 and the furnace shell 7 is formed. The refractory is shaped so that it can flow, and is fixed to the upper and lower pipe seats 9 through the protective pipe 6. In this way, when the required number of repair staves 1 are arranged and fixed to the furnace wall repair section, the existing staves 1A arranged adjacent to the repair staves 1 and the repair staves 1 adjacent to the upper side are fixed. A mechanical seal (10) provided with a sealing material such as a seal plate is applied to the furnace inner end portion of the horizontal joint formed between them. If the mechanical seal 10 is not sufficient, a seal retainer plate (not shown) may be fixed to the outside of the mechanical seal 10 to reinforce the precast refractory 3 inside the furnace.

After arranging the staves in this way, the amorphous refractory for pouring is supplied by pouring or press-fitting from the lower irregular refractory material supply port 12 arranged in the furnace shell 7, and the lower side is supplied. A cast refractory layer 14 is formed by filling the castable refractory in the gap between the repair stave 1 and the furnace iron skin 7 below the irregular refractory supply port 12 and in the surrounding joints. In this way, after pouring to near the level of the lower irregular refractory supply port 12 and filling the irregular refractory, switch to the upper irregular refractory supply port 13 arranged above it, and spray from this irregular refractory The sprayed refractory layer 15 is formed by pumping the material and filling the vertical joints above the poured refractory layer 14.

When the amorphous refractory for spraying is filled up to near the level of the upper irregular refractory supply port 13, the furnace iron skin corresponding to the repair stave 1 arranged above the repair stave 1 A refractory material is poured from a lower-shaped irregular refractory material supply port 12 provided in No. 7 to fill the refractory material by pouring. At this time, the head pressure of the amorphous refractory material supplied by pouring is supported by the sprayed refractory material layer 15. Therefore, it is possible to reduce the head pressure of the cast refractory that acts on the mechanical seal 10 below,
It is possible to prevent the occurrence of seal leakage.

A seal plate is applied to the joints of the repair stave, and the gap S formed between the repair stave and the furnace shell is set to 50 to 100 mm in consideration of the fluidity of the irregular refractory. Table 1 shows the amorphous refractories for pouring from the lower irregular refractory supply port 12 provided in the furnace shell 7 and the blowing irregular refractory from the upper irregular refractory supply port 13. The cast refractory layer 14 and the sprayed refractory layer 15 were formed using the properties and components. The joint gap was about 50 mm.

[0020]

[Table 1]

As shown in Table 1, the castable refractory used in the present invention is adjusted so that the curing time is extended to 3 to 5 hours in order to prevent the supply hose or the like from being solidified and clogged. Was used. Other properties are also good, and the amorphous refractory layer 14 can be formed under uniform filling, and the curing time after filling is 5.5 hours. on the other hand,
Since the sprayed amorphous refractory hardens in a short time to form the sprayed refractory layer 15, it becomes possible to quickly support the head pressure of the casting amorphous refractory filled above it. . As a result, it is possible to reduce the pressure acting on the mechanical seal 10 packed in the lower horizontal joint,
It is possible to prevent a seal leak caused by the cast-in amorphous refractory pushing out the mechanical seal 10, and it is possible to uniformly fill the cast-in irregular refractory.

The stave body 2 has a thickness of 240 mm, the furnace-side precast refractory 3 has a thickness of 150 mm, and the furnace-side precast refractory 4 has a thickness of 400 mm. The height and width of each step are taken into consideration in consideration of the size of the repaired portion. The damaged part of the furnace wall was repaired by combining repair staves of various sizes. The weight of the cast iron stave body in a typical repair stave was 5140 kg, and the weight of the precast refractory used for the front and back was 2556 kg, and the total weight was 7496 kg.

In the above-mentioned embodiment, the case was described in which the irregular refractory for pouring was filled from the lower irregular refractory supply port 12 provided in the furnace shell 7 by pouring. By forming the refractory layer 15 it is possible to reduce the head pressure of the casting indefinite refractory that acts on the mechanical seal, so it is possible to press the casting indefinite refractory into the allowable limit without pushing out the mechanical seal. . This allows more uniform filling of the refractory layer 14 to be achieved. (Embodiment 2) The repair stave 1 and the amorphous refractory supply ports 12 and 13 of Example 1 are the same, but the irregular refractory supply port is first sprayed to the portion to be located in the lowermost layer. Irregular refractories were filled by spraying. Immediately after the filling, the insulative refractory for pouring was poured to fill the gap S.

This operation was repeated successively to complete the filling of the gap S. The bottom layer is filled with amorphous refractory in order, so the initial seal is a problem, and in the pouring and filling of irregular refractory for pouring, wait for some solidification,
It is necessary to start the next construction to prevent leakage of the filled refractory. In this example, since the spraying operation with the spraying irregular shaped refractory is taken for the first filling, the solidification is quick in the construction by spraying, and it is possible to pour the next pouring refractory immediately after the completion of the spray filling. Therefore, there is an advantage that the repair work can be continued.

The present invention can also be applied to repair the damaged portion of the furnace wall of the blast furnace provided with a cooling means different from the stave, such as a cooling box.

[0026]

As described above, according to the present invention, the precast refractory is provided not only on the inside of the stave body but also on the outside of the furnace, and the gap formed between the repairing stave and the furnace iron shell is not formed. It is set as a necessary minimum to allow the flow of standard refractories. For this reason, irregular shaped refractory is formed in the longitudinal joints formed by the repair stave and the furnace steel skin after the required number of repair staves have been fixedly installed in the furnace wall repair section, and in the lateral joints formed around the repair stave. Since only a small amount of gas is required to be supplied, the repair work time required for filling can be greatly shortened.

The lateral joints formed around the repairing stave are supplied with a flowable amorphous refractory so that the filling can be evenly filled. Since the head pressure of the cast refractory is supported by the sprayed refractory layer, the pressure acting on the lower mechanical seal is reduced, and seal leakage due to pushing the mechanical seal into the furnace can be prevented. .

By combining the cast-in refractory layer and the sprayed refractory layer, it is possible to fill the irregular refractory material to every corner, so that the furnace shell can be adiabatically protected during the operation of the blast furnace, and the repair stave and furnace iron can be protected. Since the back wind that flows between the leather and the skin can be reliably prevented, the life of the furnace wall of the blast furnace is extended.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a structure for repairing a furnace wall of a blast furnace according to an embodiment of the present invention with a stave.

FIG. 2 is a transverse cross-sectional view showing a structure for repairing a furnace wall of a blast furnace according to a conventional example by a stave.

[Explanation of symbols]

 1 Repair stave 2 Stave main body 3 Precast refractory (inside the furnace) 4 Precast refractory (outside the furnace) 5 Casting water cooling pipe 6 Protective tube 7 Furnace iron skin 8 Furnace interior filling 9 Pipe seat 10 Mechanical seal 11 Seal holding plate 12 Irregular refractory supply port (lower side) 13 Irregular refractory supply port (upper side) 14 Cast refractory layer 15 Sprayed refractory layer

Claims (2)

[Claims] 1. When repairing the blast furnace wall by lowering the contents inside the furnace to below the damaged part of the furnace wall by reduced-scale deaeration, the residual refractory material in the damaged part of the furnace wall or the damaged part of the furnace wall is removed. The precast refractory is provided inside the stave body inside the furnace wall where the furnace shell is exposed, and a flowable gap between the amorphous furnace and the furnace shell is formed outside the furnace. After fixing and fixing a required number of repair staves with a mechanical seal at the furnace inner end of the horizontal joint formed on the outer periphery of the precast refractory and the repair stave,
The irregular shaped refractory supply ports are arranged on the upper side and the lower side of the furnace iron shell so as to correspond to the upper portion and the lower portion of each repair stave fixed and arranged in the required number, and first, the lower shaped irregular refractory material is provided. From the supply port, fill the irregular refractory for pouring to the joints by pouring to form a pouring refractory layer, and then fill the irregular refractory for spraying from the upper irregular refractory supply port by spraying. On the cast refractory layer, the procedure of forming a sprayed refractory layer capable of supporting the pouring head pressure of the next cast indeterminate refractory material is sequentially repeated from the lower stage to the upper stave for repair. Characteristic method of repairing damaged parts of blast furnace wall. 2. When repairing the blast furnace wall by lowering the furnace interior contents below the furnace wall damaged part by reduced-scale blast, the residual refractory material in the furnace wall damaged part or the furnace wall damaged part is removed. The precast refractory is provided inside the stave body inside the furnace wall where the furnace shell is exposed, and a flowable gap between the amorphous furnace and the furnace shell is formed outside the furnace. After fixing and fixing a required number of repair staves with a mechanical seal at the furnace inner end of the horizontal joint formed on the outer periphery of the precast refractory and the repair stave,
The irregular shaped refractory supply ports are arranged on the upper side and the lower side of the furnace iron shell so as to correspond to the upper portion and the lower portion of each repair stave fixed and arranged in the required number, and first, the lower shaped irregular refractory material is provided. Fill the joints by spraying the amorphous refractory for spraying from the supply port to form a sprayed refractory layer, and then fill the irregular refractory for pouring by pouring from the upper amorphous refractory supply port. A method for repairing a damaged portion of a furnace wall of a blast furnace, characterized in that a procedure for forming a refractory layer by pouring on the sprayed refractory layer is sequentially repeated from a lower stave to an upper stave for repair.