JPH0660331B2 - Blast furnace wall structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to a furnace wall structure having an excellent function of a blast furnace.

(Prior art) Generally, the blast furnace wall is exposed to physical factors such as wear due to contact with the charge, thermal shock due to operating temperature fluctuations, joint breakage due to expansion and contraction, or the intrusion of CO gas, alkali vapor, and zinc vapor. It can also be damaged by chemical factors such as carbon deposition, alkaline bursting, and zinc immersion.

Conventionally, various measures have been taken to suppress these damages.For example, chemical damage and damage due to thermal shock are mainly dealt with by selecting the material of the brick forming the furnace wall. Recently, high-purity alumina bricks, C-SiC bricks, β-SiC bricks, SiC bricks having Si ₃ N ₄ bonds, or high-alumina bricks with spall-resistant aggregates have been used.

On the other hand, with respect to the expansion of the furnace wall structure, for expansion in the vertical direction, a compressible filler is inserted between the bricks adjacent in the vertical direction, or a void is formed above.
Further, with respect to expansion in the furnace radial direction, the expansion is absorbed by mortar joints interposed between the bricks adjacent in the furnace radial direction, the stamp material with the iron skin-brick interposed, and the iron skin. It is common to have

(Problems to be Solved by the Invention) In the above conventional general furnace wall structure, in particular, since there is no structure that sufficiently absorbs expansion in the furnace circumferential direction, bricks in the furnace circumferential direction are generated between each other. Expansion stress also acts in the radial direction of the furnace, resulting in excessive expansion and contraction stress in the radial direction of the furnace, and in addition to repeated expansion and contraction due to operating temperature fluctuations, not only bricks but also stamp materials and mortar joints are destroyed. However, there is a drawback that the bricks are likely to fall off and the furnace wall lining function is easily lost.

As an attempt to eliminate such drawbacks, for example, Jitsuko Sho 51-4
There is a device of 967 publication.

This invention absorbs the expansion of bricks by interposing carbon fiber moldings solidified with synthetic resin between the refractory bricks at appropriate places of the refractory bricks forming the furnace wall, and at the same time leaks gas in the furnace. It can be said that it is considerably improved as compared with the conventional general furnace wall structure.

However, the carbon fiber molded body in this invention has a drawback that it cannot withstand long-term use because it does not have sufficient heat resistant adhesive strength.

The present invention has been made to solve the above-mentioned conventional drawbacks.

(Means for Solving the Problem) The present invention is a furnace wall structure of a blast furnace in which a furnace wall is formed of a plurality of rows of refractory bricks in the furnace radial direction, and a group of refractory bricks forming the furnace wall is divided into a plurality of blocks. In a blast furnace wall structure in which a compressible mortar is divided between adjacent blocks in the circumferential direction of the furnace, the compressive stress is 2 to 30 as the compressible mortar.
Those in kg / cm ² has a compressible rate of 10% to 70%, to maintain the adhesion flexural strength of the refractory bricks after compressible to 5Kg / cm ² or more,
For example, Al with excellent heat resistance and alkali resistance and good shrinkability
₂ O ₃ -C, S _i O ₂ -C, MgO-C, etc. carbon-bonded refractory oxide-based shrinkable mortar, or SiC-C, etc. carbon-bonded refractory non-oxide-based shrinkable mortar With a thickness of 1.0-10 m
It is characterized in that it is interposed by m and oil paper is interposed on the sliding surface between adjacent blocks in the furnace radial direction, and in particular it effectively absorbs the expansion in the circumferential direction and the furnace wall Relieves the expansion stress as a whole, refractory bricks, stamp materials, especially joints, refractory bricks can withstand compression when expanded and the refractory bricks can maintain sufficient adhesiveness even when contracted, and the joint function over a long period of time. This is to maintain the furnace wall lining structure in a stable manner.

The present invention will be described in detail below based on the embodiment shown in FIG.

FIG. 1 shows an example in which the furnace wall structure of the present invention is adopted in the shaft portion of a large blast furnace using a cooling plate, and the inside of the shaft iron shell 1 is stamped 2 in the furnace radial direction. 3 rows of refractory bricks consisting of refractory bricks 3, 4 and 5 (a) (b)
(C) is arranged, and the lining layer A consisting of these three rows of refractory brick layers (a), (b), and (c) is circumferentially divided into a plurality of blocks B ₁ ,
It is divided into B ₂ , ..., B _n . And this block B ₁ , B ₂
The expansion absorption mortar 6 is interposed between them.

As shown in Table 1, the expansion-absorbing mortar 6 is based on a mixture of 80% alumina powder and 20% natural scaly graphite particles, mixed with porous fibers and tar / pitch powder, and further hardened. The resin particles are used as a solvent, and water and alcohol are added and kneaded.

And this is formed by ironing.

As is well known, the expansion amount of refractory bricks varies depending on the temperature, and in the furnace wall of the blast furnace shaft portion, there is a distribution that it is larger inside the furnace where the temperature is higher and smaller on the iron shell side where the temperature is lower.

Therefore, the expansion allowance may be set according to the distribution of the expansion amount, but in general, there are many cases where the expansion amount is set based on the expansion amount at the inner temperature of the refractory brick.

Also in this example, the thickness of the expansion absorption mortar as the expansion allowance was set based on the average expansion amount of the refractory brick.

The set thickness of the expansion absorption mortar as the expansion allowance is the second
As shown in the figure, when the average expansion amount of the refractory brick layer is set to L _0, and in order to absorb this expansion amount L ₀ , for example, when an expansion absorption mortar having a compressibility of 50% with a compressive stress of 110 kg / cm ² is used It will be good to set it to 2L ₀ .

Forming the furnace wall of the shaft part of the blast furnace in this embodiment 3
The average expansion amount L ₀ of the refractory brick layer consisting of rows in the circumferential direction is about 2
It is 50 mm, and 50 mm of this is absorbed by the normal mortar interposed between the refractory bricks, the shrinkage of the stamp material, the expansion of the iron shell, etc., so the remaining 200 mm is absorbed by the expansion absorption mortar.

The expansion absorption mortar used here is 1 as shown in FIG.
Since it has a compressibility of 50% with a compressive stress of 0 kg / cm ^2, the initial set total thickness (at the time of building) was 400 mm.

In this embodiment, a group of refractory bricks forming a refractory brick layer is divided into 100 blocks in the circumferential direction in a substantially even manner, and an expansion absorption mortar 6 having a thickness of 4 mm is interposed between the blocks during construction.
It was set to 2 mm after expansion and absorption.

Since the facing surfaces between the blocks are uneven surfaces with the side surface of each refractory brick as a unit, the expansion absorbing mortar is independently and discontinuously interposed between the facing refractory bricks.

In order to facilitate sliding due to expansion and contraction of the refractory brick, an oil paper 9 to which ordinary mortar is applied is interposed as sliding joints on the sliding surfaces between the opposing blocks formed by the unevenness.

Incidentally, 7 and 8 are usually mortars.

As described above, in the blast furnace wall structure of the present invention, the refractory brick layer is divided into a plurality of blocks in the furnace circumferential direction through the expansion absorption mortar, and the expansion is absorbed in each block unit.

The blast furnace adopting the thus constructed furnace wall structure maintains a stable structure even after 5 years from the start of firing and is operating smoothly without the occurrence of a reddish skin accident due to back wind.

In this embodiment, the refractory brick group is divided only in the furnace circumferential direction, but it may be divided in the furnace height direction as well.

The carbon-bonded oxides and non-oxides used in the present invention include, for example, Al ₂ O ₃ -C in the present embodiment, as well as SiO ₂ -C, MgO-C,
Oxides etc., or a _{SiC-C, Si 3 N 4} -C non-oxide such as an oxide of these carbon bond, although non-oxide are also those produced in naturally, Al ₂ O ₃ In the case of -C, it is generally obtained by mixing alumina powder and carbon powder and firing this at a high temperature.

(Effect of the Invention) In the blast furnace wall structure of the present invention, the expansion of the refractory bricks in the furnace circumferential direction is completely absorbed by the expansion absorption mortar in each block unit, and the carbon bonds generated in the process firmly bond the blocks to each other. On the back side, that is, in the furnace radial direction, it is not necessary to provide an expansion and absorption allowance, and a sound back lining can be provided.

Further, since the carbon bond is formed in the expansion-absorbing mortar joint after the expansion absorption, it has the same heat-resistant adhesive strength as ordinary mortar, so that the function as the furnace wall does not deteriorate as compared with the conventional structure.

On the other hand, refractory bricks are usually united with mortar in block units, and the behavior of expansion and contraction is in block units.Because the expansion absorption mortar interposed between each block absorbs all, each refractory brick It has an excellent effect such that joint defects due to ordinary mortar during the period hardly occur.

[Brief description of drawings]

FIG. 1 is a partially cutaway three-dimensional explanatory view showing one embodiment of the blast furnace wall structure of the present invention, FIG. 2 is a graph showing the relationship between the expansion amount of refractory bricks and the contraction amount of expansion absorption mortar, and FIG. The figure is a graph showing the contractibility of the expansion-absorption mortar in the example of the present invention. 1: Iron skin, 2: Stamp material, 3, 4, 5: Refractory brick, 6: Expansion absorption mortar, 7, 8: Normal mortar, 9: Oil paper.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsushi Kasai 1-1-1 Edamitsu, Yawatahigashi-ku, Kitakyushu, Fukuoka Pref. , U) Actual development Sho 47-37702 (JP, U)

Claims (1)

[Claims] 1. A furnace wall structure of a blast furnace in which a furnace wall is formed of a plurality of rows of refractory bricks in a radial direction of the furnace, wherein a group of refractory bricks forming the furnace wall is divided into a plurality of blocks and adjacent in the furnace circumferential direction. In a blast furnace wall structure in which a compressible mortar is interposed between the blocks, as the compressible mortar, carbon-bonded refractory oxide-based compressible mortar or carbon-bonded refractory non-oxide-based compressible A blast furnace wall structure characterized by using a heat-resistant mortar and interposing oil paper on the sliding surface between adjacent blocks in the furnace radial direction.