JPH0329842B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a blast furnace wall repair method for repairing a damaged portion of a blast furnace wall using a monolithic refractory.

In general, blast furnace lining refractories are exposed to temperature fluctuations due to operational changes, high-temperature corrosive gases, and impact and abrasion from the charge, resulting in spalling, wear and tear.
It is easy to cause various phenomena such as collapse and falling off.

In particular, for damage to the furnace wall from the middle to the bottom of the shaft, the life of the furnace can be extended by cooling means such as staves, but cooling means such as staves are not often used for the upper part of the shaft, making it difficult to protect the furnace wall. It raises the issue from the front.

In addition, as the reducing gas in the furnace is prevented from rising uniformly in the circumferential direction of the furnace, turbulence tends to occur, and a mixed layer of coke and sinter is also likely to form, resulting in increased fuel consumption and uneven reduction of the charge. In some cases, this can lead to a decrease in productivity.

As a means to solve such problems, the contents in the furnace are reduced in size to expose the damaged part of the furnace wall, and a long refractory spray nozzle is installed from the top manhole or movable armor part. A method is known in which the damaged area is repaired by inserting construction equipment into the furnace and spraying refractories onto the damaged area.

However, with this method, the adhesion of the sprayed refractory is poor due to the furnace walls being contaminated by fine coke, sintered ore, etc., and the desired durability cannot be achieved. Since the work must be carried over a long distance and must be carried out in small quantities, it takes a long time to repair the work, which causes the remaining furnace wall to cool down, resulting in deterioration of the structure.

On the other hand, there is also known a method in which a pre-formed panel is hung from the furnace top opening, attached to the area to be repaired via a support tube, and filled with monolithic refractories from outside the furnace. In the case of this construction method, both the reliability and construction accuracy of the refractory are greatly improved, but if the panel falls off, the monolithic refractory filled in the gap between the panel and the furnace wall repair part will not be able to support the support structure. Therefore, there is a concern that they will drop out relatively early.

In addition, there is a concern that the monolithic refractories will fall off first, causing a so-called back wind to circulate around the back of the panel, damaging the panel. Although this is an excellent construction method, it does have the above-mentioned concerns.

The present invention has been developed in view of the above-mentioned situation, and is characterized in that when repairing a blast furnace wall, the inner surface of the furnace wall is formed after lowering the contents of the furnace to a level below the repaired area. A formwork is provided at the site, and a monolithic refractory support member with at least one end supported by the furnace shell is provided, and the monolithic refractory is placed in the space formed by the formwork and the remaining furnace wall surface. To provide a method for repairing a blast furnace wall, which is superior in terms of repair time, construction area, accuracy, and maintenance of the strength of existing furnace materials, and has excellent durability after construction.

As a result of various studies prior to the completion of the present invention, the present inventors focused on forming the furnace wall surface portion with a monolithic refractory layer in which supporting members are arranged like aggregates, and the present invention I saw its completion.

That is, in the present invention, after the contents of the furnace are lowered to a level below the furnace wall repair area, a formwork made of, for example, wood, plastic, ceramics, or metal is inserted into the furnace wall inner surface forming area from the furnace mouth opening. It is hung on the iron skin and fixed to the wall. The supporting member for fixing the formwork may be a protrusion for holding the refractory (irregular shape), a member with increased supporting power, a stud-like member, an anchor brick, or the like.

A monolithic refractory is press-fitted and filled into the space formed by the above-mentioned formwork and the steel shell or the remaining furnace wall through the refractory filling port or directly during a wind break or after restarting operation. Since this monolithic refractory is firmly held by the steel shell through the support member, its durability is significantly improved and the life of the furnace can be significantly extended.

An embodiment of the present invention will be described below based on the drawings.

Figure 1 is an enlarged vertical cross-sectional view of the upper part of the blast furnace, showing the situation in which the charge 1 has been reduced in size to the level below the furnace wall repair area a.
The furnace wall on the right (facing the drawing) is a schematic diagram of the implementation of the present invention before the present invention is implemented.

In the figure, 2 is a furnace top manhole, 3 is a deck, 4 is an iron shell, 5 is an ore support, 6 is a furnace wall brick, 7 is a stave cooler, and 8 is a bell, all of which are known. Since this is just a configuration, the explanation will be omitted.

9 is a formwork, which extends from the furnace top manhole part 2 to the deck 3.
It is suspended in the furnace using a winch 14 and wire 15 provided above. As described above, the formwork 9 is made of metal, wood, plastic, ceramics, etc., and is provided in an appropriate shape such as a plate shape or a net shape.

In addition, when using it as a mesh formwork, it is a matter of course that the size of the mesh is determined in consideration of the particle size of the filler (unshaped refractory material). In addition, the width of the formwork is regulated by the size of the opening at the top of the furnace, and the length and length are determined by the area of the area to be repaired, the time required for furnace repair, etc.
The number of sheets is determined. Further, the shape of the mold is not limited to a flat plate, but may be curved along the cross-sectional shape of the furnace wall. A locking tool 10 for hanging in the furnace and a tension wire 11 are attached to the formwork a. Instead of this tension wire 11, a wire made of bendable rings connected by rods, a chain, etc. can also be used.

The formwork 9 constructed as described above is loaded into a furnace according to the following procedure. First, as shown in Fig. 1, the charge is lowered (reduced in scale) below the furnace wall repaired area a and the air is rested. A plurality of formworks 9 joined together are suspended from the furnace top opening 2 into the furnace, and the lower end of the furnace wall repaired part a is opposed to the repaired part,
Wire 11 is inserted through the furnace body opening 16 using a jig.
Pull it towards the iron skin side.

Next, as shown in FIG. 2, the space between the steel shell 13 and the formwork 9 is maintained, and the filler 17 is held. Next, a stud-shaped support 12 is inserted from outside the furnace.
At this time, if the formwork 9 is made of iron, it can be joined by welding, or the formwork 9 and the support 12 can be joined even if the threads are cut in advance. In addition, the support 12
A hook method or the like can also be used for fixing the frame and the formwork 9. After the stud-shaped supports 12 are attached to the formwork 9, support wires 18 such as lath-shaped wire mesh may be stretched around the stud-like supports 12 in order to further increase the holding power of the back-filling refractory. This support wire 18 is a wire mesh,
Barbed wire, spiral shaped objects, etc. can be used, and for the refractory (indeterminate shape) holding method, a refractory product such as an anchor brick supported at one end by a steel shell can be used.

On the other hand, for the joint portion of the formwork 9, the shape shown in FIG. 3 is used based on the particle size structure, viscosity, and other physical properties of the backfilling refractory 17. For example, wire mesh 20, combination of fiber and iron plate 21, quick hardening refractory 22
Seals and hook-and-loop joints 23 can be used.

After installing the formwork 9 as described above, the iron skin 13
Filling refractory material 17 is filled through the injection port 20 that penetrates through. This refractory material 17 can be made of various materials such as siamolyte, high alumina, carbonaceous, carbon, and basic. In addition, the particle size composition ranges from coarse particles like concrete to fine particles like mortar, and the filling properties and
It can be used in consideration of workability, durability, and leak resistance. For example, the amorphous filler 17 whose particle size is adjusted by mixing approximately 20% of coarse grains of about 20 mm can be supported by the coarse grains even if there is a gap between the form frames 9, preventing leakage of intermediate grains and fine grains. I can do it. Therefore, it is desirable to use this material for the entire repaired area between the formwork 9 and the furnace wall brick 6, but in order to prevent leakage from the repaired lower part between the formwork 9 and the furnace wall brick 6, it is necessary to It is also possible to construct the irregularly shaped filler 17 with a particle composition and use the irregularly shaped filler 17 with a particle size composition of about 10 mm or less on the upper part. In addition, the space between the stave 7 and the formwork 9 is filled and solidified in advance with the fast-setting refractory 22, and at the same time, the fast-setting refractory 22 is sprayed onto the joint of the formwork 9, followed by an amorphous filler containing coarse particles. 17, there will be no leakage of the monolithic refractory 17 from the formwork 9. on the other hand,
Even when a wire mesh type formwork 9 is used, the monolithic refractory 17 can be filled without leakage by blending an appropriate amount of coarse particles larger than the mesh and adjusting the hardening. Furthermore, if the quick-hardening refractory 22 is applied between the plate-shaped formworks 9 or between the stave 7 and the formwork 9, and after hardening, a commercially available monolithic refractory 17 is applied, the refractory can be filled without causing leakage.

The refractory 17 is filled by mixing it with a carrier liquid such as water or oil and pouring or press-fitting it, or by mixing a dry refractory with a carrier gas such as air or nitrogen gas and blowing it in. construction method is used. The pressurized ports 20 that have been filled are sequentially sealed. The filling operation with the back filling refractories 17 is carried out after all the formworks 9 have been installed, but it can also be carried out when all the formworks 9 of the same height have been installed in the circumferential direction.

The refractory 17 press-fitted as described above is filled without leaking and forms a strong furnace wall. and,
Even after the formwork 9 falls off, it is fixed by the supports installed on the steel shell 13, so that a furnace wall structure that is less likely to be damaged by the subsequent operating atmosphere can be created. In this way, the damaged part of the furnace wall is corrected to an arbitrary profile and is strongly protected by the refractory 17 having a supporting structure. Moreover, this protective structure reduces the strength of the furnace body due to the opening of the shell. Deterioration can also be sufficiently reinforced.

By carrying out the present invention as described above, a strong furnace wall can be created because the damaged part of the furnace wall is supported by the support structure held from the steel shell with the filled refractory having excellent heat resistance, impact resistance, and corrosion resistance. It is possible,
Durability is significantly improved and reactor life can be significantly extended.

The required repair area and thickness can be repaired quickly and efficiently, making it possible to significantly shorten downtime.

Because the furnace profile can be adjusted arbitrarily and with high precision, the rising reducing gas is balanced between the furnace core and the furnace periphery, preventing turbulence and preventing the formation of a mixed layer of coke and sintered ore. can. Therefore,
The charge is returned in a well-balanced manner, making it possible to improve productivity and reduce the fuel ratio.

Various effects such as these can be obtained, and stable and efficient operations can be maintained.

[Brief explanation of drawings]

Figures 1 to 4 show examples of the present invention. Figure 1 is a sectional view of the upper part of the blast furnace, Figure 2 is a partially enlarged sectional view, Figure 3 is an example of a mold sealing method, and Figure 4 is after repair. FIG. a: Furnace wall repair part, 2: Furnace top opening, 6: Furnace wall brick, 9: Formwork, 11: Wire, 12: Refractory support hardware, 16: Furnace body opening, 17: Irregular shape for filling Refractory, 18: Lath for supporting refractory, 19: Iron plate for sealing steel skin, 20: Refractory filling hole, 21: Wire mesh for sealing formwork.

Claims (1)

[Claims] 1. When repairing the blast furnace wall, after lowering the contents of the furnace to a level below the area to be repaired,
A formwork is provided in the area where the inner surface of the furnace wall will be formed, and a monolithic refractory support member with at least one end supported by the furnace shell is provided, and an unformed refractory is provided in the space formed by the formwork and the remaining furnace wall surface. A method for repairing a blast furnace wall, characterized by filling it with a shaped refractory.