JPH08134519A - Stave cooler - Google Patents

Abstract

PURPOSE: To prevent an obstruction of the descent of raw material caused by the metallic ribs of a base material even after losing cast-in refractories and to make the heat deformation difficult to occur even in the end period of furnace life by forming the lines of refractory materials in the vertical direction and holding the refractory materials with the metallic ribs of the base material, in the stave cooler used for the furnace wall, etc., of a blast furnace. CONSTITUTION: In the stave cooler for cooling furnace wall integrally constituted by assembling a pipe for cooling at the outside of the furnace using a metallic base material and refractory materials at the inside of the furnace, plural lines of the refractory materials 3 are formed in the vertical direction and held with the metallic ribs 5 of the base material. For example, the refractory brick as the refractory material 3 and a spheroidal graphite cast iron as the metallic rib 5 of the base material are used. Further, a ceramic wool which can hold the compressivity and stability without melting and deteriorating even under the high temp. such as about 1300 deg.C, is used as a heat insulating material 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a stave cooler used for a furnace wall of a blast furnace.

[0002]

2. Description of the Related Art A stave cooler 6 shown in FIG. 9 which is used for a furnace wall of a blast furnace is installed inside a steel shell 10 and a refractory brick layer 15 is provided inside the stave cooler 6 to prevent the heat from rising in the furnace. A cooling device that protects the skin. In the stave cooler itself, as shown in FIG. 10, refractory bricks 12 are arranged in a horizontal row on the inner surface side, and a cooling pipe 13 for passing cooling water is integrally formed of a base metal 14 such as cast iron. This cooling pipe is shown in FIG.
As shown in FIG. 3, cooling water is passed from the stave cooler to the stave cooler thereabove through the connecting pipe 16 to form a closed circulation system including a head tank 17, a cooler 18, and a pump 19.

As a conventional technique, for example, Japanese Patent Publication No. 52-
There is a "cooler for a cooling device for a metallurgical furnace" disclosed in Japanese Patent No. 8241. As shown in FIG. 6, the feature of this technique is that a row of refractory bricks 12 insulated from a base metal bar (rib) 5 with an asbestos gasket 20 is provided across the width of a stave cooler. This is based on the idea of preventing the refractory brick from falling off by horizontally sandwiching and supporting the refractory brick with the base metal ribs. There is also an idea that the gasket between the refractory brick and the metal rib of the base metal expands and contracts when thermal deformation such as expansion and contraction occurs in the furnace due to temperature fluctuations, thereby facilitating tracking.

In actual manufacturing, two types of refractory bricks of different lengths are prepared, and bricks of different sizes are arranged so as to be close to the total length of each brick row of the stave cooler. This is because the stave coolers are arranged so as to form the shape of a truncated cone-shaped blast furnace as shown in FIG. 9, and therefore the lengths of the upper side and the lower side are different, and therefore the length of the brick row of each stave cooler is also different. This is because it is necessary to deal with the change depending on the position. Such a brick structure is a method generally used when a brick layer is provided on the inner surface of a truncated cone. Further, Japanese Patent Publication No. 52-8241 describes a structure in which a refractory brick is surrounded by grid ribs made of iron.

[0005]

The above-mentioned prior art has the following problems. The first problem is that the refractory brick disappears faster than the base metal ribs as the blast furnace goes into operation.
As a result, only the lateral base metal ribs remain on the stave working surface. Although refractory bricks are used as a general material for forming the inner wall of the furnace, the inner surface of the blast furnace wall is in a condition where the temperature changes extremely due to the upward flow of hot gas, and the brick material cannot follow this temperature change. , Gradually peeling from the inner surface of the furnace and falling off. This is one of the forms of brick wear called spalling.

FIG. 12 shows an example in which the vertical axis represents the temperature of the gas inside the furnace wall and the horizontal axis represents the time, showing the temperature fluctuations on the inner surface of the furnace wall in the actual blast furnace. In this example, it is about 40 at 3 o'clock.
Although the temperature is 0 ° C, the temperature rises sharply thereafter, and the temperature exceeds 800 ° C at 7 o'clock. In addition, a situation is shown in which during that time, the temperature is raised and lowered repeatedly within a short time.
As a result, over the years of operation of the blast furnace, the refractory brick layer inside the stave cooler disappears, and then the inner surface side of the stave cooler comes into contact with the raw materials and furnace gas, but the refractory bricks of the stave cooler will soon disappear. It disappears and only the base metal ribs arranged in the lateral direction remain. Even in the case of the grid rib, the situation in which the metal rib remains in the lateral direction is the same.

As shown in FIG. 7, the unevenness of the base metal in the lateral direction formed by the metal ribs causes the mixed layer 9 of the coke layer 7 and the ore layer 8 to be formed in the vicinity of the furnace wall when the raw material is dropped in the furnace. generate. The mixed layer is generated because the frictional resistance between the raw material and the wall surface increases due to the unevenness of the metal of the stave cooler base metal, and the raw material descent rate near the wall surface becomes slow. Generally, coke grains have a larger grain size than ores, and the coke layer has less gas pressure loss than the ore layer. In a normal blast furnace operation, the coke layers and the ore layers are charged into the furnace so that they are alternately stacked. When a mixed layer occurs near the furnace wall, the gas ventilation pressure loss in this part becomes an intermediate value between the ore layer and the coke layer, and the gas easily passes through the ore layer. Therefore, it is difficult to control the gas flow in the furnace only around the furnace wall, which disturbs the operation stability of the blast furnace and reduces the utilization rate of the gas in the furnace.

The second problem is that at the end of the life of the furnace, the lower end of the stave 6 may protrude into the furnace due to thermal deformation as shown in FIG. This also hinders the fall of the raw materials in the furnace, or becomes a source of deposits on the furnace wall, which becomes an unstable factor in the operation. Also, if the deformation is severe, the pipes for water supply and drainage may be broken, or hot gas may flow between the stave cooler and the iron shell, damaging the castable 11,
Sometimes the iron skin glows red.

An object of the present invention is to provide a stave cooler which does not cause the above-mentioned inhibition of the raw material drop by the metal ribs of the base metal even after the cast brick disappears, and is resistant to thermal deformation even at the end of the life of the furnace. That is.

[0010]

SUMMARY OF THE INVENTION The present invention is to solve the above problems and provides a stave cooler in which a base metal is used to integrally form a cooling pipe on the outside of the furnace and a refractory material on the inside of the furnace. The stave cooler is characterized by arranging a plurality of rows of refractory material in a longitudinal direction and holding the rows by a base metal rib.

[0011]

In the structure of the stave cooler of the present invention, a plurality of rows of the refractory material arranged inside the furnace are arranged in the vertical direction, and are integrally constructed so as to be held by the base metal ribs. Therefore, after the years of operation have passed and the refractory material has disappeared,
Although the base metal ribs in the vertical direction remain, the unevenness of the base metal in the vertical direction does not act as a resistance when the raw material in the furnace descends, so the raw material descending speed in the vicinity of the furnace wall does not slow down. ,
There is no mixed layer of coke layer and ore layer. Further, in the structure of the stave cooler of the present invention, since the base metal ribs remain in the vertical direction, the horizontal sectional rigidity of the stave body is higher than that of the stave cooler of the conventional structure, so that thermal deformation is less likely to occur, and the raw material descent in the furnace is reduced. It does not interfere with the above, or does not become a source of deposits on the furnace wall, contributes to stable operation maintenance, and reduces the risk of damage to the cooling pipe and red heat of the skin.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. 1 is a plan view of a stave cooler showing an embodiment of the present invention as seen from the inside of a furnace, FIG. 2 is a side view thereof, and FIG. 3 is a sectional view taken along the line AA of FIG. In the example of FIG. 1, refractory bricks are used as the refractory material 3, and spheroidal graphite cast iron is used as the base metal 1. Insulation material 4
As the material, ceramic wool is used, which does not melt and deteriorate at a high temperature of about 1300 ° C. and can maintain the compressibility and the restoring property. The thickness of the base metal rib 5 is 30 mm or more in order to secure the flow of molten metal during casting.

Generally, the stave cooler is arranged so as to form a truncated cone-shaped in-furnace profile as shown in FIG. 9, and therefore the length of the upper side and the length of the lower side are different, but the refractory brick is made of one type of mold. It can be done without increasing the number of bricks and molds. That is, the rows of the refractory bricks have the same width, and by appropriately changing the thickness of the base metal rib from the upper side to the lower side, it is possible to cope with the difference in length between the upper side and the lower side of the stave.

The cooling pipe 2 is arranged outside the furnace of the refractory material 3 and is integrally cast into the base metal 1. The base metal may be gray cast iron, heat-resistant cast iron, or heat-resistant cast steel, in addition to the spheroidal graphite cast iron described above. The refractory material may be chamotte brick, high alumina brick, or silicon carbide brick. Further, as shown in another embodiment of FIG. 4, the refractory brick layer 1
It is also possible to manufacture a double brick structure in which 5 is integrated into the stave cooler itself. In this case, the construction work of the refractory brick layer is not required, and the construction period can be shortened. When the refractory material is the brick 12, it may be integrally cast at the time of casting, or a solid brick may be inserted into the groove after the groove mold made of the metal rib is manufactured.

When the castable 25 is made of a refractory material, it is also possible to fabricate a groove mold with the metal ribs 5 as in the other embodiment of FIG. 5, then cast the castable into the groove and dry-mold it. . In this case, the stud 21 may be stood on the metal rib in order to improve the castable holding ability.

Next, the improvement of the horizontal sectional rigidity will be described.
In the case of the prior art of FIG. 6, the horizontal cross section of the stave cooler has the minimum area at the groove bottom between the base metal ribs 5,
Corresponding to the thickness h ₁ × width b of the stave cooler in the horizontal sectional view of the present invention in FIG. 3, where Z ₁ is the sectional modulus, Z
A ₁ = bh ₁ ^2/6. On the other hand, in the present invention, the thickness of the horizontal cross section is increased by the height of the base metal rib 5 to be h ₂ . Therefore, the section modulus Z ₂ is because it is Z ^₂ = bh _{2 2/6} becomes, Z ₁ <Z _2, can be cross rigidity than conventionally improved, increasing the strength against deformation.

With the stave cooler according to the above invention, the vertical metal ribs remain in the vertical direction after the refractory material disappears after the operating years have passed, but this does not become a resistance when the raw material falls in the furnace. Therefore, the problem that the mixed layer of the coke layer and the ore layer is generated and the operation stability of the blast furnace is disturbed is solved without slowing down the raw material descent rate near the furnace wall. In addition, since the horizontal cross-section rigidity of the stave cooler is improved, it may cause the material to fall in the furnace due to thermal deformation, which may cause unstable operation due to the generation of deposits, or damage to the cooling pipe or red heat of the skin. The risk can be reduced.

[0018]

As described above, according to the structure of the stave cooler of the present invention, the following excellent effects can be obtained. (1) Arrange refractory materials arranged inside the furnace in the longitudinal direction,
Since it is integrally configured to be held by the base metal, after the operating years have passed and the refractory material has disappeared, even if the base metal rib in the vertical direction remains, it does not hinder the raw material descent in the furnace. In addition, the mixed layer of coke layer and ore layer in the vicinity of the furnace wall is not generated, therefore the gas ventilation resistance in the furnace cross section can be maintained systematically controllable by the furnace top charging device, and the stability of the operation at the end of the furnace is secured. it can.

(2) The material can be smoothly dropped in the furnace even near the furnace wall, the gas ventilation resistance in the furnace cross section can be controlled by the furnace top charging device, and the optimum operating conditions can be maintained. The coke weight (coke ratio) required for production per ton can be reduced and a great economic effect can be exhibited. (3) Since the mixed layer generation near the furnace wall in the furnace is suppressed, the gas flow of the blast furnace rising along the furnace wall is reduced, and the thermal load on the stave cooler is reduced, so that the thermal shock to the stave cooler body is reduced. Is reduced, the life of the stave cooler body can be extended, and as a result, the life of the blast furnace can be extended.

(4) Since the base metal ribs remain in the vertical direction, the horizontal cross-section rigidity of the stave cooler body is increased, so that thermal deformation is less likely to occur, and therefore the raw material descent in the furnace is not hindered. It does not become a source of deposits on the wall, and the stability of operation can be maintained. (5) Since the stave cooler is less likely to be thermally deformed, damage to the water supply / drainage part of the cooling pipe can be prevented.

(6) Since the stave cooler is less likely to be thermally deformed, the joint portion between the adjacent stave coolers does not spread, and high temperature furnace gas is prevented from flowing between the stave cooler and the iron shell. Therefore, it is possible to prevent the reddish heat of the iron shell at the joints of the stave cooler, to prevent cracking of the iron shell, and to extend the life of the blast furnace. (7) When refractory bricks are used as the refractory material, the types of refractory bricks and molds are reduced, which is extremely effective in designing, manufacturing, and managing.

[Brief description of drawings]

FIG. 1 is a plan view of an example of a stave cooler according to the present invention as viewed from the inside of a furnace.

FIG. 2 is a side view of FIG.

FIG. 3 is a sectional view taken along the line AA of FIG.

FIG. 4 is a sectional view of a stave cooler according to another embodiment.

FIG. 5 is a sectional view of a stave cooler of another embodiment.

FIG. 6 is a plan view of a conventional stave cooler viewed from the inside of the furnace.

FIG. 7 is a diagram for explaining a situation in which a raw material descent in a furnace is prevented in a conventional stave cooler.

FIG. 8 is a diagram for explaining a thermal deformation state of a lower end portion of a conventional stave cooler.

[Fig. 9] Overall view of furnace wall structure of blast furnace

FIG. 10 is a perspective view of a conventional stave cooler.

FIG. 11 is a diagram showing a stave cooler cooling water circulation system.

FIG. 12 is a graph showing an example of temperature fluctuations on the inner surface of the furnace wall of the blast furnace.

[Explanation of symbols]

 1 Base Metal 2 Cooling Pipe 3 Refractory Material 4 Heat Insulating Material 5 Base Metal Rib 6 Stave Cooler 7 Coke Layer 8 Ore Layer 9 Mixed Layer 10 Iron Crust 11 Castable 12 Refractory Brick 13 Cooling Pipe 14 Base Metal 15 Fire Brick Layer 16 Connecting pipe 17 Head tank 18 Cooler 19 Pump 20 Gasket 21 Stud 25 Castable

Claims (1)

[Claims] 1. A furnace wall cooling stave cooler in which a cooling pipe is incorporated into the outside of the furnace and a refractory material is incorporated into the inside of the furnace by a base metal to integrally form a plurality of rows of the refractory material in a vertical direction. In addition, the stave cooler is characterized by being held by the metal rib of the base material.