JPH11236611A - Blast furnace stave - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blast furnace stave which has high cracking strength, can prevent erosion, and can be manufactured at low cost. SOLUTION: In a blast furnace stave 10 used from a furnace abdomen of a blast furnace to a shaft middle section, a stave body 12 is provided.
The cooling pipes buried in the furnace are arranged in two layers from the furnace inside toward the steel shell side.
The second-stage cooling pipe 14 is disposed on the stave body 12 in a non-welded state, and is disposed on the stave body 12 by welding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for mounting a cooling pipe of a stave (also referred to as a stave cooler) used from a furnace abdomen of a blast furnace to a shaft middle section.

[0002]

2. Description of the Related Art As shown in FIGS. 3 and 4, a stave cooler 53 used as a furnace wall cooling device from a belly portion 51 of a metallurgical furnace 50 such as a blast furnace to a shaft portion middle stage 52 allows water to pass therethrough. The one provided with the cooling pipe 54 is used. 55 is the stave body, 56 is the water inlet, 5
7 denotes a water outlet. In this stave cooler, for example, as described in JP-A-58-68463,
After wrapping a low carbon steel foil material etc. in advance in a mold and arranging an iron cooling pipe, pouring the molten metal and casting it, the stave body and the cooling pipe were integrated and manufactured,
As described in JP-A-55-109557, a mold is made in the stave body so as to form a similar cavity larger than the cooling pipe, and then the cooling pipe is placed in this cavity. A blast furnace stave manufactured by injecting a metal (eg, copper, aluminum, or the like) having a low melting point and a high thermal conductivity into a hollow portion has been proposed.

[0003]

However, in a stove for a blast furnace of the type described in JP-A-58-68463, in which a cooling pipe is arranged in a mold and the cooling pipe is directly cast, a stave body and a cooling pipe are used. If cracks occur in the stave body and the cracks propagate to the cooling pipe, there is a problem that the cooling pipe is also cracked. Therefore, it has been proposed to form a heat-resistant coating around the cooling pipe in advance and then manufacture the blast furnace stave by casting. In this blast furnace stave, as the temperature of the blast furnace stave rises, the temperature of the cooling pipe does not rise because the cooling pipe is water-cooled. There is a problem that becomes worse. On the other hand, the stove for a blast furnace described in JP-A-55-109557 has a problem that it is difficult to form a cavity having a certain gap with a cooling pipe in a mold. And, even if a small gap is formed between the stave body and the cooling pipe, if the temperature rises during use, the diameter of the cooling pipe is not changed because the cooling pipe is cooled with water, but the cooling pipe of the stave body is There is a problem in that the diameter of the passage through which the passage passes is increased, and thereby the overall heat transfer efficiency is reduced. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a blast furnace stave that can prevent propagation of cracks in a mold at a specific portion, has a long life, and can be manufactured relatively inexpensively. And

[0004]

According to the present invention, there is provided a semiconductor device comprising:
The stove for a blast furnace described above is a stove for a blast furnace used from the abdomen part of the blast furnace to the middle part of the shaft part.
The cooling pipes of the first layer from the inside of the furnace are arranged in a non-welded state on the stave body, and the cooling pipes of the second layer from the inside of the furnace are welded to the stave body. It is arranged. Further, in the blast furnace stave according to claim 2, in the blast furnace stave according to claim 1, the cooling pipe of the second layer is coated in advance with a coating material, and is provided to the stave body via the coating material. Welded. Here, as the coating material, for example, a metal (for example, aluminum or copper) or a metal compound (for example,
Iron oxide).

In the stove for a blast furnace according to the first and second aspects, the cooling pipe of the first layer from the inside of the furnace is disposed in a non-welded state on the stave body. Even if the crack progresses from the inside of the furnace, the progress of the crack stops before the first-layer cooling pipe because the first-layer cooling pipe and the stave body are not fixedly joined. Therefore, no crack occurs in the first-layer cooling pipe. Instead, the heat conduction between the first-layer cooling pipe and the stave body is deteriorated. However, since the second-layer cooling pipe on the outside of the first-layer cooling pipe is welded to the stave body, the second-layer cooling pipe is welded to the stave body. The heat transferred by the cooling pipes of the eyes is absorbed, and the propagation of heat to the outside is reduced. In particular, in the blast furnace stave according to the second aspect, the cooling pipe of the second layer is welded to the stave body via the coating material. Therefore, this coating material buffers direct contact between the molten metal constituting the stave body and the second-layer cooling pipe. Then, the casting constituting the stave body and the second-layer cooling pipe form an alloy layer at the boundary between the casting and the second-layer cooling pipe, thereby preventing deterioration of the material of the cooling pipe.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view showing a blast furnace stave according to one embodiment of the present invention.
(A) is a side view thereof, (B) is a front view thereof, and FIG.
(A), (B) is sectional drawing of the cooling pipe of the blast furnace stave, respectively.

As shown in FIGS. 1A and 1B, a stave 10 for a blast furnace according to an embodiment of the present invention is a stave body made of a cast iron casting in which a refractory 11 is disposed inside a furnace. The cooling pipe 13 includes first and second cooling pipes 13 and 14 provided in two layers from the inside of the furnace toward the steel shell side. Hereinafter, these will be described in detail.

[0008] The stave body 12 is made of cast iron casting, and has a plurality of refractories 11 which are arranged at predetermined intervals and are cast in the front side thereof. The heat from the inside is cut off to some extent by the refractory 11, and the stave body 12 has a role of holding the refractory 11 at a predetermined interval. On the outside of the stave body 12 including the refractory 11, an iron shell 15 made of a thick steel plate is attached via a protrusion 16 and a bolt 17 screwed into the protrusion. In this embodiment, the stave body 12 is divided into a size of about 2 to 3 m in length, 0.9 to 1.5 m in width, and about 0.5 to 0.6 m in thickness. Etc. can be easily performed.

Inside the stave body 12, cooling pipes 13 and 14 of the first layer and the second layer are provided with a gap in two layers from the inside of the furnace toward the steel shell side. I have. The cooling pipe 13 of the first layer is shown in FIGS.
As shown in the figure, a plurality of stave bodies 12 are mainly arranged in the vertical direction, and the cooling pipes 14 of the second layer are arranged in the stave body 12 in a zigzag manner in the horizontal direction. The cooling pipes 13 and 14 of the first and second layers are made of steel pipes in this embodiment, and the ends of the cooling pipes 13 and 14 protrude from the steel shell 15 via the reinforcing member 18 to the outside. One is a water inlet and the other is a water outlet.

The first and second cooling pipes 13,
A method of embedding the 14 in the stave body 12 will be described. The first-layer cooling pipe 13 needs to be cast in a non-welded state with the stave body 12. Therefore, at the time of casting, in the first-layer cooling pipe 13, a coating layer 19 made of a heat-resistant powder or the like that does not melt even by the injected molten metal is formed. This material is preferably coated with a stable ceramic material such as alumina, but may be a heat-resistant tape (for example, a ceramic tape). It is preferable that the thickness of the heat-resistant powder layer or the heat-resistant tape is thin in terms of heat transfer. For example, the thickness is set to about 0.1 to 1 mm. As a result, the coating layer does not melt even when pouring,
As a result, the cooling pipe 13 of the first layer and the stave body 1
2 is in a non-welded state as shown in FIG.

Next, the second-layer cooling pipe 14 needs to be buried in a welded state with the stave body 12. Therefore, the molten metal may be poured into the mold while flowing the cooling gas through the cooling pipe 14 of the second layer. Thereby, the surface layer of the second-layer cooling pipe 14 is partially melted and poured, so that the solidified cast iron and the second-layer cooling pipe 14 are in a welded state. However, in this case, the boundary between the cast iron and the second-layer cooling pipe 14 becomes brittle due to the carburization of the surface of the cooling pipe, and when cracks develop from the stave body 12, the cracks are easily formed in the second layer. Propagation to the cooling pipe 14 of the eye. Therefore, on the surface of the second-layer cooling pipe 14, a material that is melted by pouring a molten metal to form a stronger alloy layer,
It is preferable to coat in advance. Examples of such a material include metals such as aluminum, iron oxide, copper, iron, and nickel, and metal compounds having a low melting point. These may be applied in the form of powder, or may be formed in a tape shape and wound around the cooling pipe 14 of the second layer. FIG. 2B shows a cross section of the cooling pipe 14 after welding.

Since the blast furnace stave 10 according to one embodiment of the present invention has the above structure, even if a crack (crack) occurs in the stave body 12 from the inside of the furnace,
Since the first-layer cooling pipe 13 and the stave body 12 are separated from each other, the crack does not propagate to the first-layer cooling pipe 13. On the other hand, since the second-layer cooling pipe 14 is closer to the shell than the first-layer cooling pipe 13 and is welded to the stave body 12, the heat transfer efficiency is improved and the stave body 12 is improved. Can be sufficiently cooled.

In the above-described embodiment, the dimensions of each part are specified and described for easy understanding. However, the present invention is not limited to these dimensions.

[0014]

According to the stove for a blast furnace according to the first or second aspect, the first and second cooling pipes are arranged in the stave body, and the inner first cooling pipe is connected to the stave body. Since it is arranged in a non-welded state, cracks of the stave body generated from the inside do not propagate to the cooling pipe 14 of the first layer. Therefore, the service life of the first-layer cooling pipe is extended, and as a result, the blast furnace stave has a long life. Since the cooling pipe of the second layer is welded to the stave body, the cooling effect is large, and the heat from the inside can be further prevented from being transmitted to the steel shell side at this portion. Especially,
After coating the surface of the second-layer cooling pipe with the coating material, the cooling pipe is cast into the stave body to form an alloy layer between the second-layer cooling pipe and the stave body. It is possible to prevent erosion of the cooling pipe of the second layer,
Moreover, the generation of a brittle alloy layer due to the contact between the second-layer cooling pipe and the stave body can be prevented.

[Brief description of the drawings]

FIG. 1 is a side view (A) and a front view (B) of a blast furnace stave according to an embodiment of the present invention.

FIG. 2A is a cross-sectional view of a blast furnace stave cooling pipe when the surface of a first-layer cooling pipe is coated with a coating material, and FIG. 2B is a cross-sectional view of a second-layer cooling pipe; It is.

FIG. 3 is an overall explanatory view of a blast furnace according to a conventional example.

FIG. 4A is a side view of a stave cooler used in a conventional blast furnace, and FIG. 4B is a front view thereof.

[Explanation of symbols]

Reference Signs List 10 blast furnace stave 11 refractory 12 stave body 13 first layer cooling pipe 14 second layer cooling pipe 15 steel shell 16 protrusion 17 bolt 18 reinforcing member 19 coating layer

Claims (2)

[Claims] 1. A blast furnace stave used from the furnace abdomen to the shaft middle of a blast furnace, wherein cooling pipes embedded in the stave body are arranged in two layers from the furnace inside toward the steel shell side. The cooling pipe of the first layer from the inside is disposed in a non-welded state on the stave body, and the cooling pipe of the second layer from the furnace side is disposed on the stave body by welding. And blast furnace staves. 2. The blast furnace stave according to claim 1, wherein the second-layer cooling pipe is previously coated with a coating material and is welded to the stave body via the coating material.