JP3702571B2 - Protective liner for the blast furnace hearth - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a protective liner for a blast furnace furnace port, and in particular, is a protective liner that covers a stave, which is a cooling wall provided in the blast furnace furnace port, to enhance its durability and extend its life.
[0002]
[Prior art]
The inner wall of the blast furnace mouth portion is required to have wear resistance because the raw material collides when the raw material is charged from the top of the furnace or the raw material slides down the furnace wall surface due to a charge drop during operation. Further, since it is exposed to a high-temperature gas having an average of 300 ° C. to 400 ° C., durability is also required. Therefore, for example, as shown in FIG. 7, wear resistance is applied to the inner surface of the iron skin 1 where the raw material 3 charged into the furnace collides from a furnace top charging device (not shown) such as a bell or a bellless chute. An ore receiver 2, also known as a wear ring plate (hereinafter simply referred to as a wear ring 2) made of a material, is provided so that the raw material 3 collides with the wear ring 2 to protect the iron skin 1. Yes. The wear ring 2 is connected to the iron skin 1 via a support metal 4, and a refractory castable 5 is filled in the gap with the iron skin 1.
[0003]
However, in blast furnace operation, operation failure sometimes occurs, and high-temperature gas such as 800 ° C. to 1000 ° C. may reach the furnace port 6, and even temporarily, exceeds the heat resistance temperature of the wear ring 2. It can be a condition like this. Therefore, during the operation period of the blast furnace for a long time, the wear ring 2 is inevitably cracked, worn or peeled off. For this reason, the life of the blast furnace was about several years after firing. If damage to the blast furnace furnace port occurs, the distribution of the charge in the furnace becomes unstable and the gas flow distribution in the furnace deteriorates, reducing the ore reduction status and reducing productivity. The iron shell 1 itself of the furnace port 6 itself is thermally deformed and cracked, causing gas leakage and the like to shorten the life of the blast furnace itself.
[0004]
In order to cope with such a problem of the blast furnace furnace opening, various devices have been conventionally made. For example, JP-A-49-39503 and JP-A-61-9508 disclose that a cooling water pipe is disposed in the wear ring 2 to cool the wear ring body or to replace the wear ring 2. The use of stave 9 is disclosed. This prevents the main body from reaching the heat-resistant temperature or higher when the operation is not successful, and is effective in extending the life of the furnace port 6. Recently, in order to suppress damage due to heat and wear of the wear ring 2 and the stave 9 and to improve durability, as shown in FIG. 5 and FIG. 6, a protection composed of a plate-like member covering the inner surface of the furnace. A liner 7 is used.
[0005]
However, although the protective liner 7 shown in FIGS. 5 and 6 is supported on the upper blast furnace core 1 by a chain (usually two) 8, the raw material 3 collides with the liner 7 or the high temperature is high. When exposed to gas, the chain 8 is often deformed or cut. Further, since the protective liner 7 is a so-called single piece, a stress is generated by a thermal shock of a high-temperature gas, and cracks and deformation occur. Therefore, between the protective liner 7 and the stave 9 or the wear ring 2 on the back surface. A gap is formed, and the stave 9 and the wear ring 2 are directly exposed to the hot gas in the furnace, which causes damage. Therefore, as seen from the situation that the life extension of the furnace body and incidental equipment has recently progressed and the life of the entire blast furnace exceeds 10 years and reaches 20 years, the above-mentioned techniques are not sufficient. is there.
[0006]
[Problems to be solved by the invention]
In view of such circumstances, an object of the present invention is to provide a protective liner for a blast furnace furnace port part capable of further extending the life of the furnace port part.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the inventor intensively reviewed the drawbacks of the conventional protective liner and concluded that it is mainly in the support function. The present invention was completed in consideration of the improvement and the relaxation of the thermal stress.
That is, the present invention is a protective liner composed of a plate-like member that covers the furnace inside of a stave installed at the furnace port portion position of the blast furnace iron skin, and the upper end of the plate-like member is a Г-type flange, A protective liner for a blast furnace furnace port portion, wherein a tension means is attached to a part of a plate-like member, and the tension means is fixed to the outer surface of the iron skin. It is.
[0008]
Further, the present invention is the protective liner for a blast furnace furnace port portion, wherein the pulling means is passed through a protective cylinder penetrating the stave or as a chain. Further, according to the present invention, the plate-shaped member is divided into a plurality of parts in the vertical direction, and each of them is pin-engaged with each other, or the plate-shaped member is made of a cast alloy steel, It is also a protective liner for the department.
[0009]
In the present invention, since the protective liner for the stave disposed at the blast furnace opening is structured as described above, the support of the liner is strengthened. Even when exposed to a high-temperature gas, since the amount of deformation due to thermal expansion is suppressed by the divided structure, the thermal stress is relieved. As a result, compared to conventional protective liners, its durability is greatly improved, not only extending the life of the stave, but also allowing the blast furnace itself to operate for a long time.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a situation in which a protective liner 7 according to the present invention is attached to a stave 9 disposed at the furnace port 6. As shown in FIG. 4, the stave 9 is disposed around the furnace port portion 6, and the protective liner 7 is mainly composed of a plate-like member 7 that covers the surface of the stave 9 inside the furnace.
[0011]
First, according to the present invention, the upper end of the plate-like member 7 is bent into a Γ shape to form the flange portion 10 and is suspended on the upper end surface of the stave 9. Further, as shown in FIG. 2, a tension means 11 for pulling the plate-like member 7 toward the outside of the furnace and locking it to the iron shell 1 of the blast furnace is provided at the center of the plate-like member 7 in the width direction. is there. Further, as shown in FIG. 3, the same pulling means 11 is attached to the upper end of the flange portion 10. The tension means 11 is housed in a cylinder 12 made of a heat resistant material so as to block heat from the high temperature gas. In the present invention, the cylinder 12 itself extends to the outside of the iron skin 1 through the through hole 13 provided in the stave 9 so as not to be exposed to the high temperature gas. The rear end of the cylinder 12 is opened so that the tension of the tension means 11 can be adjusted from the outside of the iron skin 1. However, this opening is normally closed with a cap 14. Since the structure as described above is employed, the protective liner 7 according to the present invention has a stronger support at a higher temperature than the conventional one, and has increased durability.
[0012]
The material of the plate-like member 7 is preferably alloy steel, and more preferably a cast product with high Cr and high Ni. The pulling means 11 may be a combination of the above-mentioned links, and a chain is usually sufficient.
Next, in the present invention, in addition to the above structure, the plate-like member 7 is divided into a plurality of parts in the vertical direction. This is because when the plate-like member 7 is thermally expanded at a high temperature, the amount of expansion is suppressed and the generation of thermal stress is alleviated. Thereby, deformation and crack generation of the plate-like member 7 are suppressed, and durability is further increased. That is, the result of adopting the protective liner 7 shown in FIG. 5 in the furnace port portion of the 5000 m ³ class blast furnace is as follows. It has a lifetime of 5-6 years. Since the present invention has improved the drawbacks of the conventional protective liner 7 as described above, it is expected that there will be at least a 2-3 times longer life. In the above-mentioned 5000 m ³ class blast furnace, the top gas temperature is usually 150 ° C., and the raw material 3 is made up of a total of 20,000 to 25,000 tons / day of ore and coke using a bell-less charging device. It is charged at a pace.
[0013]
【The invention's effect】
As described above, according to the present invention, the protective liner for the blast furnace furnace port portion, which has conventionally been only 5 to 6 years, can greatly extend its life. As a result, the life of the blast furnace is extended to be almost the same as before, and replacement and repair during operation of the blast furnace are unnecessary, which is expected to greatly contribute to blast furnace operation.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a protective liner according to the present invention attached to a stave of a furnace port portion.
FIG. 2 is a view taken in the direction of arrows AA in FIG.
FIG. 3 is a view taken along arrow BB in FIG. 1;
FIG. 4 is a plan view showing a stave arrangement of a furnace port portion.
FIG. 5 is a longitudinal sectional view showing a protective liner attached to a conventional stave.
FIG. 6 is a longitudinal sectional view showing a protective liner attached to a conventional wear ring plate.
FIG. 7 is a longitudinal sectional view explaining attachment of a waring plate.
[Explanation of symbols]
1 Iron skin 2 Ore receiving hardware (wearing)
3 Raw Material 4 Support Metal 5 Castable 6 Furnace Port 7 Protective Liner (Plate Member)
8 Chain 9 Stave 10 Hook 11 Pulling means 12 Tube 13 Through hole 14 Cap

Claims (5)

A protective liner made of a plate-like member that covers the furnace inside of the stave installed at the furnace port position of the blast furnace iron skin,
The upper end of the plate-shaped member is a Γ-shaped flange, the flange is suspended from the upper end surface of the stave, and a tension means is attached to a part of the plate-shaped member, and the tension means is attached to the outer surface of the iron skin. A protective liner for a blast furnace furnace opening, which is fixed. 2. A protective liner for a blast furnace furnace opening according to claim 1, wherein the pulling means is passed through a protective cylinder penetrating the stave. 3. A protective liner for a blast furnace furnace opening according to claim 1 or 2, wherein the pulling means is a chain. The protective liner for a blast furnace furnace port according to any one of claims 1 to 3, wherein the plate-like member is divided into a plurality of parts in the vertical direction and each is pin-engaged with each other. The protective liner after the blast furnace furnace opening according to claim 1, wherein the plate-like member is a cast product of alloy steel.

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