JPS59100203A - Method for repairing wall of blast furnace - Google Patents

Abstract

PURPOSE:To shorten the time for suspension of draft, to improve the durability of a repaired part, and to prolong the life of a blast furnace by repairing the damaged part of the wall of the furnace with a castable refractory contg. supporting members arranged in the form of aggregate so as to complete repairing in a short time. CONSTITUTION:A burden 1 in a blast furnace is dropped to a level below a part (a) to be repaired. A flask 9 is placed at a position for forming the inside of the wall of the part (a), and an interval is kept between the iron shell 13 and the flask 9. Stud-shaped members 12 for supporting a castable refractory are arranged, and the flask 9 and the members 12 are joined together. A castable refractory 17 is then packed in the space between the flask 9 and the remaining wall.

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, the refractory lining of a blast furnace is exposed to temperature fluctuations due to operational changes, high-temperature corrosive gases, and impact and abrasion caused by charges, so it is susceptible to various phenomena such as spalling, wear, collapse, and falling off.

In particular, for damage to the furnace wall from the middle part of the shaft to the part This raises issues from a protection perspective.

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 furnace contents are
The damaged part of the furnace wall is exposed through so-called downsizing, the air is rested, and a long refractory spray nozzle or construction equipment is inserted into the furnace from the top manhole or movable armor part, and the damaged part of the furnace wall is refracted. A method of spray repairing objects is known.

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 at a relatively early stage.

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 was made in view of the above-mentioned situation, and its characteristics include: when repairing the blast furnace wall,
After lowering the contents of the furnace to a level below the repaired area,
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. To provide a method for repairing a furnace wall of a blast furnace, which consists in filling a shaped refractory, is excellent in repair time, construction area, precision, and maintaining the strength of existing furnace materials, and is excellent in 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 it completed.

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 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, a member with increased supporting force, a stud-like member, an anchor brick, or the like for holding the refractory (irregular shape).

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 part a. The wall is a schematic diagram of the implementation of the invention before the invention is implemented, and the furnace wall on the right (facing the drawing) is a schematic diagram of the implementation of the invention.

In addition, 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 staple cooler, and 8 is a bell, all of which are known. Since this is just a configuration, the explanation will be omitted.

A formwork 9 is suspended from the furnace top manhole 2 into the furnace using a winch 14 and a wire 15 provided on the deck 3. 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.

Note that when used 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 (monomorphic refractory). Further, the width of the mold is regulated by the size of the furnace top opening, and the length and number of molds are determined by the area of the part to be repaired, the furnace repair time, etc. Furthermore, the shape of the mold is not limited to a flat plate, and 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 port, a bendable ring connected with a rod, 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 then the air is rested. A plurality of joined formworks 9 are suspended into the furnace from the furnace top opening 2 and are placed opposite the repaired portion at the lower end of the furnace wall repaired portion a, using a jig through the furnace body opening 16. and pull the wire port toward the iron skin.

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. Further, a hook method or the like may be adopted for fixing the support 12 and the formwork 9. After the stud-shaped support 12 is attached to the formwork 9, a support wire 18 such as a lath-shaped wire mesh may be stretched around it in order to further increase the holding power of the back-filling refractory.

The support wire 18 can be made of wire mesh, barbed wire, a spiral shape, or the like, and a refractory product such as an anchor brick with one end supported by an iron shell can be used to hold the refractory (indeterminate shape).

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, a combination of fibers and steel plates 21, seals with fast-hardening refractories 22 and hook-shaped joints 23 can be used.

After the formwork 9 is installed as described above, the filling refractory 17 is filled through the injection port 20 that penetrates the iron skin 13.

The refractory 17 can be made of various materials such as chamotte, high alumina, carbonaceous, carbon, and basic materials. In addition, the particle size structure can range from coarse particles like concrete to fine particles like mortar, taking into account fillability, workability, durability, and leak resistance.

For example, the amorphous filler 17 whose particle size is adjusted by mixing about 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, and prevent 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 bricks 6, but in order to prevent leakage from the repaired lower part between the formwork 9 and the furnace wall bricks 6, it is necessary to use this material in the repaired lower part. Amorphous filler with particle mixture 1
7, and an irregularly shaped filler 17 having a particle size of about 10 mm or less may be used on the upper part. In addition, the space between the staple tape 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 irregular filler containing coarse particles. If you construct 17,
Leakage of the monolithic refractory 17 from the formwork 9 is completely eliminated.

On the other hand, even when a wire mesh formwork 9 is used, by blending an appropriate amount of coarse particles larger than the mesh and adjusting the hardening,
The monolithic refractory 17 can be filled without leaking. Further, a quick-hardening refractory 22 is installed between the plate-shaped formwork 9 or between the staple 7 and the formwork 9, and after hardening, a commercially available monolithic refractory 1
If step 7 is carried out, it can be filled without causing any 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 work with the back filling refractories 17 is carried out after all the formworks 9 are installed, but only the formworks 9 of the same height are
It can also be carried out once all the rings 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. 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, such a protective structure prevents the strength of the furnace body from deteriorating due to openings in the shell. can be sufficiently reinforced.

By carrying out the present invention as described above, (1) filling the damaged part of the furnace wall with a refractory material having excellent heat resistance, impact resistance, and corrosion resistance;
Because it is supported by a support structure held from the steel shell, it is possible to create a strong furnace wall, which significantly improves durability and significantly extends the life of the furnace.

(2) The required repair area and thickness can be repaired quickly and efficiently, making it possible to significantly shorten wind down time.

(3) Since the furnace profile can be adjusted arbitrarily and with high precision, the rising reducing gas flows in balance between the furnace core and the furnace periphery, preventing the generation of turbulence and the formation of a mixed layer of coke and sintered ore. can be prevented. 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 the drawing]

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.

Claims (1)

[Claims] When repairing a blast furnace wall, after lowering the contents in the furnace to a level below the repaired area, a formwork is installed at the area where the inner surface of the furnace wall is formed, and a framework is installed with at least one end supported by the furnace shell. A method for repairing a blast furnace wall, which comprises disposing a shaped refractory support member and filling a space formed by an earlier formwork and a remaining wall surface with an unshaped refractory.