JP3045461B2 - Repair method of damaged part of blast furnace wall - Google Patents

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 or worn.

[0002]

2. Description of the Related Art Ore and coke charged from the upper part of a blast furnace gradually undergo a reduction reaction under a high-pressure and high-temperature state while moving downward, and become molten pig iron and slag. In this process, the refractory in the furnace is melted down due to chemical change, physical wear and the like, gradually decreases in thickness, and eventually disappears.

[0003] For example, a stave is provided and fixed as a means for cooling the refractory between the furnace refractory and the furnace shell.
When the refractory is extinguished, the stave may be exposed directly to the hot furnace interior material, causing erosion wear and even damage to the cast-in cooling tube therein. When the stave as a cooling means for the refractory inside the furnace is broken in this way, the furnace steel shell is directly subjected to a high heat load and cracks are generated, so that the CO inside the furnace is damaged.
The gas leaks out of the furnace and becomes an unsafe state, and a defect is present in the strength, and the life of the blast furnace is significantly shortened. Therefore, when renovating the blast furnace, all the staves that play an important role in cooling the furnace body are usually replaced.

[0004] However, in the intermediate renovation of the blast furnace due to reduced scale wind, it is generally required that the cost be reduced in a short period of time. Therefore, a healthy stave is left as it is, and only the damaged stave is repaired. Or will be replaced. For example, Japanese Unexamined Patent Publication No. 60-2607 discloses a repair stave 20 having a precast refractory 23 on a stud 22 attached to the inside of a furnace of a stave main body 21 as shown in FIG. It is arranged and fixed on the exposed portion of the removed furnace shell 24. In this state, after spraying an irregular refractory from inside the furnace with a spray nozzle 29 to the mechanical seal portions of the end seal plate 26 and the overlapping plate 27 to prevent leakage of the press-fit material, the furnace steel 24 Press the irregular-shaped refractory through the press-fit port 25
Are disclosed which are repaired by forming

[0005]

If the repair stave 20 disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 60-2607 can be used, the furnace shell 24 can be heat-insulated and protected. However, the stave body of the repair stave is used. Since the gap (vertical joint) between the furnace steel and the furnace shell 24 is large, it is necessary to form the press-fitting material 28 by supplying a large amount of irregular refractory to the vertical joint. For this reason, not only does the work time for press-fitting the irregular shaped refractory uniformly into the gaps become long, but also when the irregular shaped refractory cannot be uniformly filled all over, there is a risk of insufficient insulation protection. .

The present invention solves the above-mentioned problems of the prior art and, when repairing a damaged part of a furnace wall with furnace interior materials by reducing windage, repair work is performed in a short time with good workability using a repair stave. It is possible to reduce the application of head pressure of irregular shaped refractory to the mechanical seal applied to the horizontal joint formed on the outer periphery of the repair stave, and to ensure sufficient heat insulation protection, It is another object of the present invention to provide a method for repairing a damaged portion of a blast furnace wall having excellent repair efficiency.

[0007]

In order to achieve the above object, the present invention provides a method for repairing a blast furnace wall by lowering a furnace interior charge to a portion below a damaged portion of the furnace wall by reducing windage of the furnace. A precast refractory is provided on the inside of the furnace of the stave body at the furnace wall damaged portion where the refractory remaining at the damaged portion or the furnace wall damaged portion is removed to expose the furnace shell, and the furnace shell is provided on the outside of the furnace. A required number of repair staves in which a mechanical seal is applied to the inside end of a precast refractory and a side joint formed on the outer periphery of the repair stave so that a flowable gap of an amorphous refractory is formed therebetween. After arranging and fixing, the irregular number of refractory supply ports are arranged on the upper and lower sides of the furnace steel in correspondence with the upper and lower parts of each repair stave arranged and fixed in the required number, First, the refractory for pouring from the lower refractory supply port Said lower amorphous by pouring
From refractory feed opening into the gap and the lateral joint of the lower charge <br/> Hama to the refractory layer formed pouring, then spray the spraying for monolithic refractories from the upper side of the monolithic refractory feed opening A procedure for forming a sprayed refractory layer capable of supporting a next casting head refractory pouring head pressure on the casting refractory layer by filling the casting refractory layer is sequentially performed from the lower stage to the upper repair stave. This is a method for repairing a damaged portion of a blast furnace wall, which is performed repeatedly.

In addition, when the furnace interior is lowered below the furnace wall damage portion by the reduced scale wind to repair the blast furnace wall, the furnace wall damage portion or the refractory remaining in the furnace wall damage portion is removed. A precast refractory is provided inside the furnace of the stave body at the furnace wall damaged part where the furnace steel is exposed, and a gap through which the amorphous refractory can flow is formed between the furnace steel and the outside of the furnace. After the required number of repair staves in which a mechanical seal has been applied and fixed at the furnace inner end of the precast refractory and the side joint formed on the outer periphery of the repair stave are fixed and then the required number is provided. Irregular refractory supply ports are provided on the upper and lower sides of the furnace shell corresponding to the upper and lower parts of each fixed repair stave. The lower side is undefined by spraying a fixed refractory
To form a spray refractory layer was <br/> filled from the form refractory feed opening into the gap and the lateral joint of the lower, then poured monolithic refractories for pouring from the top of the monolithic refractory feed opening A method for repairing a damaged portion of a blast furnace wall, wherein the procedure for forming a refractory layer by pouring onto the sprayed refractory layer and forming the refractory layer from the lower stage to the upper stage is sequentially and repeatedly performed. is there.

[0009]

According to the present invention, there is provided a stave for repair in which a precast refractory is provided inside the furnace of the stave body and a precast refractory is provided with a flowable gap of an irregular refractory between the furnace and the outside of the furnace. To repair damaged furnace walls. In this way, there is a thick precast refractory between the stave body and the furnace steel, and the gap (vertical joint) between the repair stave and the furnace steel is uniform, allowing the flow of irregular shaped refractories. The dimensions are set to the minimum necessary size for performing a sufficient filling.

[0010] Therefore, the amount of irregular refractory supplied from the pouring port provided in the furnace steel shell can be reduced, so that the work time required for filling can be greatly reduced. Further, in the present invention, the irregular refractory supply ports are arranged on the upper and lower sides of the furnace shell corresponding to the upper and lower parts of each repair stave, and the lower irregular refractory supply ports are arranged from the lower irregular refractory supply ports. By supplying a castable refractory with good fluidity, it is filled completely and uniformly from the lower refractory supply port to the joint formed on the outer periphery of the repair stave. An object layer can be formed.

In the state where the cast refractory layer is formed in this way, a blowing refractory having a lower fluidity than the upper refractory supply port is filled by spraying to fill the refractory layer. A spraying refractory layer having a large holding force is formed in the gap in the above. Since the sprayed refractory layer supports the head pressure of the next casting irregular shaped refractory, the head pressure applied to the mechanical seal applied to the outer end of the joint formed on the outer periphery of the repair stave is applied to the mechanical seal. Can be reduced. As a result, it is possible to prevent seal leakage due to inadequate sealing of the cast refractory from the mechanical seal.

[0012] Further, when filling the amorphous refractory, the procedure is such that the amorphous refractory for spraying is first filled by spraying, and then the amorphous refractory for casting is filled by casting. The time required for the filling operation can be reduced by utilizing the fact that the solidification time of the blowing refractory is shorter than that of the refractory.

[0013]

【Example】

(Embodiment 1) Hereinafter, the configuration and operation of the present invention will be described based on an embodiment. FIG. 1 is a longitudinal 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, a repair stave 1 used in the present invention is provided with a precast refractory 3 inside a furnace of a stave body 2 made of cast iron, as in the prior art. On the outside, a precast refractory 4 having a thickness capable of forming a gap S through which an amorphous refractory can flow between the furnace refractory 7 and the furnace shell 7 is provided. It should be noted that protective tubes 6 are connected to the upper and lower portions of the stave body 2, and the cast water cooling tubes 5 are buried through the protective tubes 6 by casting.

Further, an upper refractory supply port 13 and a lower refractory supply port 12 on the furnace shell 7 are provided with upper and lower refractory supply ports 12 corresponding to the upper and lower portions of the repair stave 1, respectively. It is located between them. When repairing the blast furnace wall by lowering the furnace interior material 8 below the damaged furnace wall generated in the blast furnace shaft due to the reduced scale wind, the damaged existing stave is removed, and the remaining furnace fire resistance is further removed. The material is removed to expose the back surface of the furnace shell 7. A repair stave 1 prepared in advance is suspended via a wire from a furnace top manhole or an opening formed by separately cutting a furnace top iron skin, and is hung down while rewinding a winch to face the repair part.

After the upper and lower protective tubes 6 connected to the repair stave 1 are inserted into the upper and lower pipe seats 9 provided on the furnace shell 7, a gap S between the repair stave 1 and the furnace shell 7 is formed. The refractory is fixed to the upper and lower pipe seats 9 via the protective tube 6 by adjusting the size so that the flow of the amorphous refractory becomes possible. After the required number of repair staves 1 are arranged and fixed in the furnace wall repair section in this way, the existing stave 1A arranged adjacent to the repair stave 1 and the repair stave 1 adjacent to the upper side are connected. A mechanical seal 10 provided with a seal material such as a seal plate is applied to a furnace inner end portion of the horizontal joint formed therebetween. When the mechanical seal 10 alone is not sufficient, a seal holding plate (not shown) may be fixed to the precast refractory 3 inside the furnace and reinforced outside the mechanical seal 10.

After arranging the staves in this manner, an irregular refractory for pouring is supplied from the lower irregular refractory supply port 12 disposed on the furnace shell 7 by pouring or press-fitting. The gap between the repair stave 1 and the furnace shell 7 below the irregular-shaped refractory supply port 12 and the surrounding joints are filled with the irregular-shaped cast refractory to form a poured refractory layer 14. Thus, after pouring into the vicinity of the level of the lower refractory supply port 12 and filling the refractory, it is switched to the upper refractory supply port 13 disposed above the refractory supply port 13, and from there, the refractory for spraying is formed. The sprayed refractory layer 15 is formed by pumping the material and filling the vertical joints above the poured refractory layer 14.

When the irregular shaped refractory for spraying is filled to the vicinity of the upper level of the irregular shaped refractory supply port 13, the furnace shell corresponding to the repairing stave 1 provided above the repairing stave 1 is provided. The refractory is poured from the lower refractory supply port 12 provided at the lower side 7 and filled by pouring. At this time, the head pressure of the amorphous refractory supplied by pouring is supported by the sprayed refractory layer 15. For this reason, the head pressure of the cast refractory can be reduced from acting on the mechanical seal 10 below.
The occurrence of seal leakage can be prevented.

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

[0020]

[Table 1]

As shown in Table 1, the cast refractory used in the present invention was adjusted so that the hardening time was extended to 3 to 5 hours to prevent it from solidifying and clogging in the middle of a supply hose or the like. Was used. Other properties were also good, the amorphous refractory layer 14 could be formed under uniform filling, and the curing time after filling was 5.5 hours. on the other hand,
Since the sprayed refractory hardens in a short time to form the sprayed refractory layer 15, it is possible to support the head pressure of the cast refractory filled above it at an early stage. . As a result, it is possible to reduce the pressure acting on the mechanical seal 10 packed in the lower horizontal joint,
The casting refractory can prevent the seal from leaking due to the mechanical seal 10 being pushed out, so that the casting refractory can be uniformly filled.

Assuming that the thickness of the stave body 2 is 240 mm, the thickness of the precast refractory 3 inside the furnace is 150 mm, and the thickness of the precast refractory 4 outside the furnace is 400 mm, the height and width of each stage are determined in consideration of the size of the repair part. Repair of damaged furnace wall was performed by combining repair staves of various sizes. In a typical repair stave, the weight of the cast iron stave body was 5140 kg, the weight of the precast refractory used on the front and back was 2556 kg, and the total weight was 7496 kg.

In the above-described embodiment, the case where the irregular refractory for pouring is filled by pouring from the lower irregular refractory supply port 12 disposed in the furnace shell 7 has been described. Since the formation of the refractory layer 15 can reduce the head pressure of the casting refractory acting on the mechanical seal, the casting refractory can be press-fitted within an allowable limit without extruding the mechanical seal. . Thereby, more uniform filling of the refractory layer 14 can be achieved. (Embodiment 2) The repair stave 1 and the irregular refractory supply ports 12 and 13 of the first embodiment are the same, but first, the part to be located at the lowermost layer is sprayed from the irregular refractory supply port. Amorphous refractories were filled by spraying. Immediately after the filling, the irregular refractory for pouring was poured to fill the gap S.

This operation was sequentially repeated to complete the filling of the gap S. Since the lowermost layer is filled with irregular-shaped refractories sequentially, the initial sealing is a problem.In the case of casting and filling of irregular-shaped refractories for casting, after a certain amount of solidification,
It is necessary to start the next construction to prevent leakage of the refractory. In this example, since the spraying operation is performed with the refractory for spraying in the first filling, the solidification is fast in the construction by spraying, and the refractory for the next pouring can be poured immediately after the spray filling is completed. Therefore, there is an advantage that the repair work can be continuous.

The present invention can be applied to repair a damaged part of a furnace wall of a blast furnace provided with a cooling means different from a stave, for example, a cooling box.

[0026]

As described above, according to the present invention, a precast refractory is provided not only on the inside of the furnace of the stave body but also on the outside of the furnace, and the gap between the repair stave and the furnace shell is not reduced. It is a necessary minimum that allows the flow of fixed refractories. Therefore, the required number of repair staves are installed and fixed in the furnace wall repair section, and the refractory joint formed by the repair stave and the furnace steel to be constructed and the horizontal joint formed around the repair stave are irregularly shaped refractories. Since only a small amount is required, the repair work time required for filling can be greatly reduced.

[0027] In addition, the cross joints formed around the repair stave can be uniformly filled up to the corners by supplying a flowable irregular shaped refractory with good fluidity. Since the head pressure of the cast refractory is supported by the sprayed refractory layer, the pressure acting on the mechanical seal below is reduced, and it is possible to prevent leakage of the seal due to the mechanical seal being pushed into the furnace. .

The combination of the cast refractory layer and the sprayed refractory layer allows the refractory material to be filled all over, so that the furnace shell can be insulated and protected during the operation of the blast furnace, and the repair stave and the furnace iron can be filled. Since the back wind flowing between the hull and the skin can be reliably prevented, the life of the blast furnace wall can be extended.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a repair structure of a blast furnace wall using staves according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a repair structure of a blast furnace wall using a stave according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Repair stave 2 Stave main body 3 Precast refractory (furnace inside) 4 Precast refractory (furnace outside) 5 Cast-in water cooling tube 6 Protective tube 7 Furnace steel 8 Furnace interior 9 Tube seat 10 Mechanical seal 11 Seal holding plate 12 Irregular refractory supply port (lower side) 13 Irregular refractory supply port (upper side) 14 Pouring refractory layer 15 Spray refractory layer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C21B 7/10 C21B 7/06 F27D 1/16

Claims (2)

(57) [Claims] When the furnace interior is lowered below the furnace wall damage portion by the reduced scale wind to repair the blast furnace furnace wall, the furnace wall damage portion or the refractory remaining in the furnace wall damage portion is removed. A precast refractory is provided inside the furnace of the stave body at the furnace wall damaged part where the furnace steel is exposed, and a gap through which the amorphous refractory can flow is formed between the furnace steel and the outside of the furnace. After the required number of repair staves with a mechanical seal applied to the furnace inner end of precast refractory and side joints formed on the outer periphery of the repair stave are fixed and fixed,
The irregular refractory supply ports are arranged on the upper and lower sides of the furnace shell corresponding to the upper and lower parts of the repair staves which are provided and fixed in the required number, and first, the lower irregular refractory is provided. Inject the irregular shaped refractory from the supply port into the lower irregular
The refractory layer formed pouring by <br/> filled from the form refractory feed opening into the gap and the lateral joint of the lower, then spray the spraying for monolithic refractories from the upper side of the monolithic refractory feed opening The procedure of forming a sprayed refractory layer capable of supporting the next casting head refractory pouring head pressure on the poured refractory layer by filling the casting refractory layer is sequentially performed from the lower stage to the upper repair stave. A method for repairing a damaged part of a blast furnace wall, which is repeatedly performed. 2. When the furnace interior charge is lowered below the furnace wall damage portion by the reduced scale wind to repair the blast furnace furnace wall, the furnace wall damage portion or the refractory remaining in the furnace wall damage portion is removed. A precast refractory is provided inside the furnace of the stave body at the furnace wall damaged part where the furnace steel is exposed, and a gap through which the amorphous refractory can flow is formed between the furnace steel and the outside of the furnace. After the required number of repair staves with a mechanical seal applied to the furnace inner end of precast refractory and side joints formed on the outer periphery of the repair stave are fixed and fixed,
The irregular refractory supply ports are arranged on the upper and lower sides of the furnace shell corresponding to the upper and lower parts of the repair staves which are provided and fixed in the required number, and first, the lower irregular refractory is provided. said lower amorphous resistance by spraying the spray for monolithic refractories from the supply port
To form a spray refractory layer is filled from the fire was feed opening into the gap and the lateral joint of the lower, then the filled by pouring the casting for monolithic refractories from the upper side of the monolithic refractory feed opening A method for repairing a damaged portion of a blast furnace wall, wherein a procedure of forming a refractory layer by pouring onto a sprayed refractory layer is sequentially and repeatedly performed on a repair stave from a lower stage to an upper stage.