JP2021134415A - Stave replacing method and stave - Google Patents

Abstract

To provide a method for replacing a stave which can prevent breakage of a water supply and drainage pipe and has high workability, and a stave.SOLUTION: Provided is a method for replacing a pre-replacement stave having a gas seal structure other than a combing structure with a replacement stave. The replacement stave includes a stave body, a water supply and drain pipe, and a protective pipe. A stave replacing method includes a step of removing the pre-replacement stave from an iron skin of a blast furnace, a step of inserting a water supply/drain pipe and a protective pipe into an opening of the iron skin of the blast furnace for the pre-replacement stave from the inside of the furnace, and a step of making a combing structure by joining one end of a side plate to the outer periphery of the opening of the iron skin of the blast furnace and joining a seal plate to the other end of the side plate and the protective pipe on the outside of the furnace. The invention also relates to a stave comprising a stave body, a water supply and drainage pipe, a protective pipe, and a combing structure. The protective pipe is reduced in diameter from the stave body toward the furnace inner side surface of the blast furnace iron skin between the stave body and the furnace inner side surface of the blast furnace iron skin.SELECTED DRAWING: Figure 2

Description

The present invention relates to a method for exchanging stave and a stave.

In recent blast furnaces, a stave cooler (hereinafter, simply referred to as a stave) is often used in order to protect the iron skin of the blast furnace from high temperature gas or the like in the blast furnace. A cooling water channel for flowing a refrigerant (for example, water) is formed in the stave, and the stave cooled by the refrigerant protects the blast furnace iron skin from high temperature gas or the like in the furnace.

The water supply / drainage pipe for flowing the refrigerant penetrates the opening of the blast furnace iron skin, and there is a gap between the blast furnace iron skin and the water supply / drainage pipe. Since the gas inside the furnace is extremely hot (for example, about 1200 ° C.), the sealing member for the gas inside the furnace that closes the gap is the outer surface of the blast furnace iron skin so that the gas inside the furnace is not released to the outside of the furnace through this gap. It is provided in. In addition to the function of sealing the gas in the furnace, the member is required to have a function of absorbing thermal deformation of the stave that may occur when exposed to high temperature gas.

As a member for sealing the gas in the furnace and absorbing thermal deformation, a telescopic tube type stave 11 provided with a telescopic tube 12 (also referred to as a "compensator") as shown in FIG. 4 is known ( For example, Patent Document 1). The expansion pipe 12 is joined to the outer surface of the furnace of the blast furnace iron skin 5, and its bellows structure makes it possible to absorb the displacement of the water supply / drainage pipe 4 due to the thermal deformation of the stave body 2. Further, in many cases, in order to suppress thermal deformation of the stave body 2, a method of fixing the stave body 2 to the blast furnace iron skin 5 by using a fixing member 13 (for example, a bolt) as shown in FIG. 4 is adopted. NS.

As another member for sealing the gas in the furnace and absorbing thermal deformation, a combing structural type stave 1 having a combing structure 10 (also referred to as a “combing box”) as shown in FIG. 5 is known. (For example, Patent Document 2). The combing structure 10 includes a side plate 8 and a seal plate 9 and is joined to the outer surface of the blast furnace iron skin 5. Then, the combing structure 10 makes it possible to absorb the displacement of the water supply / drainage pipe 4 due to the thermal deformation of the stave body 2. Further, in the combing structure type stave 1, a protective pipe 7 is installed so as to surround the water supply / drainage pipe 4, and the combing structure 10 is installed on the protective pipe 7. Also in the combing structural type stave 1, in order to suppress the thermal deformation of the stave main body 2, a method of fixing the stave main body 2 to the blast furnace iron skin 5 by using the fixing member 13 may be adopted.

Japanese Unexamined Patent Publication No. 2014-173095 JP-A-2007-308747

For example, in the telescopic pipe type stave 11 as shown in FIG. 4, when the plurality of fixing members 13 cannot completely restrain the thermal deformation of the stave body 2, the water supply / drainage pipe 4 is loaded, and as a result, the telescopic pipe 12 is damaged. Invitation may cause gas in the furnace to leak, or the water supply / drainage pipe 4 itself may be damaged and the cooling function may be lost. In particular, those made of copper or a copper alloy having a large length of the stave body 2 are significantly affected by thermal deformation and are likely to be subjected to a heat load, and as a result, the expansion tube 12 is more likely to be damaged. .. If the expansion pipe 12 is damaged, the water supply / drainage pipe 4 is damaged and the stave body 2 cannot be cooled. There is a risk that cracks will occur and the operation itself will not be able to continue, and the impact will be immeasurable.

On the other hand, for example, in the combing structure type stave 1 shown in FIG. 5, since the double pipe structure of the water supply / drainage pipe 4 and the protection pipe 7 is adopted, the strength of the joint portion of the water supply / drainage pipe 4 with the stave main body 2 is high. Therefore, even if the fixing member 13 cannot completely restrain the thermal deformation of the stave body 2, it can be supported by the water supply / drainage pipe 4 and the protection pipe 7, so that the protection pipe 7 may be damaged or the water supply / drainage pipe 4 may be damaged. Can be lowered.

Therefore, the present invention relates to a stave replacement method and a stave that can improve workability while preventing damage to the water supply / drainage pipe when replacing a stave having a gas seal structure other than the combing structure such as a telescopic pipe with a combing structure type stave. The purpose is to provide.

The gist of the present invention is as follows.
(1)
This is a method of replacing a stave that has a gas seal structure other than the combing structure and replaces the pre-replacement stave with a replacement stave.
The replacement stave includes a stave body having a cooling water channel inside, at least one water supply / drainage pipe joined to the stave body, and protection joined to the stave body and the water supply / drainage pipe so as to surround the water supply / drainage pipe. Equipped with a tube and
The process of removing the pre-replacement stave from the blast furnace iron skin,
The step of inserting the water supply / drainage pipe and the protection pipe from the inside of the furnace into the opening of the blast furnace iron skin for the pre-replacement stave, and
On the outside of the furnace, one end of the side plate is joined to the outer peripheral portion of the opening of the blast furnace iron skin so as to surround the protective tube, and the seal plate is joined to the other end of the side plate and the protective tube to form a combing structure. A method of exchanging a stave, which comprises a step of performing.
(2)
The protective tube is characterized in that the diameter is reduced from the stave main body toward the inner side surface of the blast furnace iron skin between the stave main body and the inner side surface of the iron skin of the blast furnace (1). ) How to replace the stave.
(3)
The water supply / drainage pipe is characterized in that the diameter is reduced from the stave main body toward the inner side surface of the blast furnace iron skin between the stave main body and the inner side surface of the iron skin of the blast furnace (1). ) Or (2).
(4)
The method for replacing a stave according to any one of (1) to (3), wherein the thickness of the seal plate is less than 5 mm.
(5)
The method for replacing a stave according to any one of (1) to (4), wherein at least one of the water supply / drainage pipes is arranged near the upper and lower ends of the stave body.
(6)
The stave according to any one of (1) to (5), wherein the outer diameter of the water supply / drainage pipe included in the replacement stave is smaller than the outer diameter of the water supply / drainage pipe included in the pre-replacement stave. method of exchange.
(7)
The method for replacing a stave according to any one of (1) to (6), wherein the stave body is made of copper or a copper alloy.
(8)
The method for replacing a stave according to any one of (1) to (7), wherein the length of the stave body is more than 2.5 m.
(9)
With the main body of the stave
At least one water supply / drainage pipe joined to the stave body,
A protective pipe with one end joined to the stave body and the other end joined to the water supply / drainage pipe so as to surround the water supply / drainage pipe.
With a combing structure with side plates and seal plates,
The stave is characterized in that the protective tube has a diameter reduced from the stave main body in the extending direction of the protective tube.
(10)
The stave according to (9), wherein the water supply / drainage pipe has a diameter reduced from the main body of the stave toward the extending direction of the water supply / drainage pipe.
(11)
The stave according to (9) or (10), wherein the thickness of the seal plate is less than 5 mm.
(12)
The stave according to any one of (9) to (11), wherein at least one of the water supply / drainage pipes is arranged near the upper and lower ends of the stave body.
(13)
The stave according to any one of (9) to (12), wherein the stave body is made of copper or a copper alloy.
(14)
The stave according to any one of (9) to (13), wherein the length of the stave body is more than 2.5 m.

According to the stave replacement method and the stave according to the present invention, the opening of the blast furnace iron skin used for the existing stave is diverted, that is, the existing stave is used as a new combing structure without changing the size of the opening. It can be replaced with a type stave. Therefore, on-site work on the opening is not substantially required, and it is possible to reduce the work load and improve on-site workability. By improving the workability at the site, it becomes possible to complete the work within the limited shutdown period (wind break period) of the blast furnace. Further, by using the combing structure together with the double pipe structure, it is possible to reduce the risk of damage to the water supply / drainage pipe.

The schematic diagram of the combing structural type stave which installed the replacement stave and the combing structure which concerns on this invention is shown. A part of the combing structural type stave shown in FIG. 1 is shown. It is the same figure as FIG. 2, and shows the schematic diagram of another example combing structural type stave which concerns on this invention. The schematic diagram of the conventional telescopic tube type stave is shown. The schematic diagram of the conventional combing structural type stave is shown.

Hereinafter, some embodiments according to the present invention will be described with reference to the drawings. However, these descriptions are intended merely to illustrate preferred embodiments of the invention and are not intended to limit the invention to such particular embodiments.

[How to replace the stave]
The method for replacing a stave according to the present invention (hereinafter, referred to as “the present replacement method”) is a method for replacing a pre-replacement stave having a gas seal structure other than the combing structure with a replacement stave. The gas seal structure other than the combing structure is not particularly limited, and examples thereof include a telescopic tube 12 as shown in FIG. Hereinafter, a case where the pre-replacement stave is the telescopic tube type stave 11 and the replacement stave is the combing structural type stave 1 will be described as an example.

In this replacement method, when the telescopic tube type stave 11 is replaced with a replacement stave, the outer diameter of the protective tube 7 is typically substantially equal to the outer diameter of the water supply / drainage pipe 4 provided in the telescopic tube type stave 11, for example. The difference is within ± 10%. Therefore, the strength of the protective pipe 7 of the replacement stave against tension and bending is about the same as that of the water supply / drainage pipe 4 provided in the telescopic pipe type stave 11, and damage to the water supply / drainage pipe 4 can be prevented.

For example, as shown in FIG. 1, the replacement stave according to the present invention surrounds a stave main body 2 having a cooling water channel 3 inside, at least one water supply / drainage pipe 4 joined to the stave main body 2, and a water supply / drainage pipe 4. As described above, the stave main body 2 and the protective pipe 7 joined to the water supply / drainage pipe 4 are provided. Generally, the replacement stave is carried to the site where the stave replacement work is performed with the water supply / drainage pipe 4 and the protection pipe 7 (hereinafter collectively referred to as “piping”) joined to the stave main body 2.

(Process to remove the stave before replacement)
In this step, the pre-replacement stave is removed from the blast furnace iron skin 5. The pre-replacement stave has a gas seal structure other than the combing structure, and is, for example, a telescopic tube type stave 11 as shown in FIG. When removing the telescopic pipe type stave 11, after removing the telescopic pipe 12 on the outside of the furnace, the water supply / drainage pipe 4 is pulled out from the opening 6 of the blast furnace iron skin 5 inside the furnace, and the telescopic pipe type stave 11 is pulled out from the blast furnace iron skin 5. Can be removed from.

(Process of inserting the pipe into the opening)
After removing the pre-replacement stave as described above, the pipe of the replacement stave is inserted into the opening 6 of the blast furnace iron skin 5 from the inside of the furnace. The opening 6 of the blast furnace iron skin 5 is an opening 6 for the stave before replacement. That is, in this replacement method, the opening 6 of the blast furnace iron skin 5 used in the pre-replacement stave can be used as it is when the replacement stave is attached without changing the size of the opening 6. can. In other words, this replacement method may not include the step of changing the outer diameter or size of the opening 6 of the blast furnace iron skin 5.

In this replacement method, since the opening 6 of the blast furnace iron skin 5 for the pre-replacement stave can be used as it is, a high load work such as expanding the size of the opening 6 does not occur. Therefore, the work load at the site is greatly reduced and the workability is improved. As a result, the combing structural stave 1 can be installed in a short time, and the stave replacement work can be easily completed within the limited wind break period.
More specifically, for example, when replacing the telescopic pipe type stave 11 with the combing structural type stave 1, the inner diameter of the water supply / drainage pipe 4 provided in the telescopic pipe type stave 11 is provided in order to allow the refrigerant to flow through the stave body 2 at a sufficient flow velocity. It is usual to use a water supply / drainage pipe 4 having the same inner diameter as the above. In this case, since the combing structural type stave 1 has a double pipe structure of a water supply / drainage pipe 4 and a protective pipe 7, the outer diameter of the pipe passing through the opening 6 becomes large, and the opening 6 is enlarged to insert the pipe. Needs may arise. However, since it takes a lot of time to process the opening 6, it is not preferable from the viewpoint of workability. On the other hand, in this replacement method, as described above, the opening 6 used in the telescopic tube type stave 11 is used as it is without changing the dimensions of the opening 6, so that the opening 6 is processed. Is not particularly necessary, and the result is that the workability is greatly improved. Further, since the protective pipe 7 has an outer diameter equivalent to that of the water supply / drainage pipe 4 provided in the telescopic pipe type stave 11, it is possible to prevent the water supply / drainage pipe 4 from being damaged.

Further, since the combing structure 10 is attached to the outer peripheral portion of the opening 6, if the opening 6 of the blast furnace iron skin 5 is enlarged to install the combing structure 10, the adjacent combing structures 10 may interfere with each other. .. Moreover, if the opening 6 of the blast furnace iron skin 5 is enlarged, the strength of the blast furnace iron skin 5 itself may decrease, which is not preferable in practice. On the other hand, in this replacement method, since the dimensions of the openings 6 of the blast furnace iron skin 5 are not changed at all, the combing structure 10 can be reliably attached to each opening 6 without interference, and the blast furnace iron skin 5 can be securely attached. The strength can also be guaranteed.
In the blast furnace iron skin 5 for the pre-replacement stave, in order to cool the operating surface over a wide range, a cooling water channel 3 is provided along the length direction of the stave main body 2, and a plurality of water supply and drainage are provided near the upper and lower ends of the stave main body 2. The pipes 4 may be joined, that is, the plurality of openings 6 of the blast furnace iron skin 5 may be arranged linearly in a perforated manner in the vicinity of the upper and lower ends of the stave body 2. In particular, when the openings 6 of the blast furnace iron skin 5 are arranged in such a perforation pattern, there is a design restriction that it is difficult to expand the outer diameter of the openings 6 from the viewpoint of the strength of the blast furnace iron skin 5. In this replacement method, by using a protective pipe 7 having an outer diameter substantially equal to the outer diameter of the water supply / drainage pipe 4 provided in the pre-replacement stave, the combing structure 10 is used without changing the dimensions of the opening 6 of the blast furnace iron skin 5. It is possible to secure the strength of the blast furnace iron skin 5 by attaching the above.

(Step of forming a combing structure: Step of joining the side plate to the outer peripheral portion of the opening of the blast furnace iron skin)
After inserting the pipe into the opening 6 of the blast furnace iron skin 5 from the inside of the furnace, one end of the side plate 8 is joined to the outer peripheral portion of the opening 6 of the blast furnace iron skin 5 so as to surround the protective pipe 7 on the outside of the furnace. It is possible to perform this process before inserting the pipe, but if it is performed after inserting the pipe, the position of the side plate 8 can be determined according to the position of the pipe, so the positional relationship between the pipe and the side plate can be adjusted. preferable. As described above, in this exchange method, since the opening 6 of the blast furnace iron skin 5 is not enlarged, the side plate 8 can be installed without interfering with the adjacent opening 6.

(Step of forming a combing structure: Step of joining the seal plate to the other end of the side plate and the protective tube)
After joining one end of the side plate 8 to the outer peripheral portion of the opening 6 of the blast furnace iron skin 5, the seal plate 9 is joined to the other end of the side plate 8 and the protective pipe 7 to form the combing structure 10. Therefore, the combing structure 10 includes a side plate 8 and a seal plate 9. By this step, the combing structural type stave 1 shown in FIGS. 1 to 3 is installed on the blast furnace iron skin 5.

-Stave main body The stave main body 2 is provided with a cooling water channel 3 for flowing a refrigerant (for example, water) inside. The path and dimensions of the cooling water channel 3 can be arbitrarily determined depending on the dimensions of the stave body 2 and the required cooling capacity. The stave body 2 is preferably made of copper or a copper alloy from the viewpoint of thermal conductivity and the like. The length dimension of the stave main body 2 (dimension in the vertical direction in FIG. 1) is not particularly limited, but is, for example, more than 1.0 m and less than 3.0 m. The length of the stave body 2 is preferably more than 2.5 m. If the length of the stave body 2 is large and / or if the stave body 2 is made of copper or a copper alloy, the thermal deformation during blast furnace operation becomes larger and the piping is likely to be displaced. It is advantageous to use the combing structure 10 as compared with the case of using the expansion tube 12. The width dimension (dimension in the direction perpendicular to the length dimension) and the plate thickness of the stave body 2 are not particularly limited.

-Water supply / drainage pipe As shown in FIG. 3B, the water supply / drainage pipe 4 is directed from the stave main body 2 to the inner side surface of the blast furnace iron skin 5 between the stave main body 2 and the inner side surface of the blast furnace iron skin 5. It is preferable that the diameter is reduced (the diameter is increased from the inner side surface of the blast furnace iron skin 5 toward the stave main body 2). In this case, the outer diameter of the water supply / drainage pipe 4 at the position where it is joined to the stave main body 2 is preferably 1.1 to 2.0 times the outer diameter of the water supply / drainage pipe 4 at the position where it penetrates the opening 6. It is more preferably 1.3 to 1.7 times. When the outer diameter of the water supply / drainage pipe 4 is large at the joint with the stave main body 2, it is possible to reduce the pressure loss of the refrigerant flowing inside the water supply / drainage pipe 4 at the joint. Further, if the water supply / drainage pipe 4 at the position penetrating the opening 6 is made small, it becomes easy to insert the pipe into the opening 6 with the opening 6 diverted as it is.

The number of water supply / drainage pipes 4 joined to one stave main body 2 is not particularly limited, but four or more are preferable. Alternatively, the number of water supply / drainage pipes 4 can be determined so as to be arranged at regular intervals (for example, 200 mm) according to the width dimension of the stave. By arranging the water supply and drainage pipes at regular intervals, it is possible to uniformly cool the entire stave body 2. The material of the water supply / drainage pipe 4 is not particularly limited, but is preferably made of stainless steel in order to prevent corrosion.

Preferably, at least one of the water supply / drainage pipes 4 may be arranged near the upper and lower ends of the stave body 2. "Near the upper and lower ends of the stave body 2" means the length between the upper end or the lower end of the stave body 2 and the central axis of the water supply / drainage pipe 4 closest to the end with respect to the length dimension of the stave body 2. It means that the ratio is 0.05 or less. When the water supply / drainage pipe 4 is arranged near the upper and lower ends of the stave body 2, a cooling water channel 3 can be formed in substantially the entire inside of the stave body 2, improving the cooling capacity of the stave and uniformly cooling the stave. can do. On the other hand, the fixing member 13 cannot be provided near the upper and lower ends of the stave body 2, and the piping position is likely to be displaced due to thermal deformation of the stave body 2. Even in such a case, it is advantageous to use the combing structure 10 as compared with the case of using the telescopic tube 12.

Preferably, the outer diameter of the water supply / drainage pipe 4 provided in the replacement stave is smaller than the outer diameter of the water supply / drainage pipe 4 provided in the pre-replacement stave (for example, the telescopic pipe type stave 11). If the outer diameter of the water supply / drainage pipe 4 of the replacement stave is small, the outer diameter of the protective pipe 7 can be reduced accordingly, so that it becomes easy to insert the pipe into the opening 6 at the site. Workability is improved. If the outer diameter of the water supply / drainage pipe 4 provided in the replacement stave becomes small, the pressure loss increases and the amount of refrigerant supplied to the stave body 2 decreases. This point is the output of the pump that supplies the refrigerant to the water supply / drainage pipe 4. The amount of refrigerant supplied may be secured by increasing the amount of refrigerant.

-Protective pipe The protective pipe 7 is installed so as to surround the water supply / drainage pipe 4, one end thereof is joined to the stave main body 2 and the other end is joined to the water supply / drainage pipe 4. The protection pipe 7 can function to prevent the water supply / drainage pipe 4 from being directly exposed to the high temperature gas in the furnace. Therefore, the protective pipe 7 is typically installed so as to surround all of the water supply and drainage pipes 4 in the furnace. Here, "surrounding" means that the protective pipe 7 surrounds the entire outer circumference of the water supply / drainage pipe 4 with a certain gap, at least inside the furnace. The term "surrounding" is also used when used between other members. The material of the protective tube 7 is not particularly limited, but is preferably made of stainless steel or carbon steel for high temperature piping. Further, in order to reduce the difference in thermal expansion, it is more preferable that the materials of the water supply / drainage pipe 4 and the protection pipe 7 are the same.

As shown in FIGS. 3A and 3B, the protective tube 7 is provided between the stave main body 2 and the inner side surface of the blast furnace iron skin 5 from the stave main body 2 to the inner side surface of the blast furnace iron skin 5. It is preferable that the diameter is reduced toward the direction (the diameter is increased from the inner side surface of the blast furnace iron skin 5 toward the stave main body 2). The outer diameter of the protective tube 7 at the position where it is joined to the stave body 2 is preferably 1.1 to 2.0 times the outer diameter of the protective tube 7 at the position where it penetrates the opening 6. It is more preferable that it is ~ 1.7 times. When the protective tube 7 is enlarged at the joint with the stave main body 2, the outer peripheral length of the joint of the protective tube 7 is increased and the joint distance with the stave main body 2 is extended, so that the strength in the longitudinal direction is increased. .. Further, by increasing the diameter of the protective tube 7 at the joint portion, a larger moment of inertia of area can be obtained, and the strength in the bending direction is increased. Further, since the protective pipe 7 has a reduced diameter from the stave main body 2 toward the inner side surface of the blast furnace iron skin 5, it is easy to insert the pipe into the opening 6 with the opening 6 diverted as it is. Become. Therefore, by reducing the diameter of the protective pipe 7, it is possible to increase the strength of the protective pipe 7, prevent the water supply / drainage pipe 4 from being damaged more effectively, and further improve the workability.

In general, the openings 6 for the water supply / drainage pipe 4 are often densely packed on the iron skin 5 of the blast furnace. Therefore, by diverting the openings 6 as they are in this replacement method, each opening 6 has a combing structure. 10 can be installed reliably. On the other hand, since the pipes can be arranged relatively freely inside the blast furnace iron skin 5, as described above, the protective pipe 7 and / / regardless of the outer diameter of the pipe at the position penetrating the opening 6. Alternatively, the outer diameter of the joint portion of the water supply / drainage pipe 4 with the stave main body 2 can be determined relatively freely, and therefore the strength of the pipe can be ensured and the pressure loss can be prevented from decreasing.

The method for reducing the diameter of the protection pipe 7 and the water supply / drainage pipe 4 is not particularly limited, but may be, for example, a connecting pipe connecting flange (reducer). It is preferable that the connecting pipe connecting flange is made of the same material as the member whose diameter is reduced in order to make the heat load uniform.

-Combing structure In the present invention, the combing structure 10 includes a side plate 8 and a seal plate 9. The combing structure 10 may be composed of only the side plate 8 and the seal plate 9. Further, a donut-shaped flange-shaped plate that absorbs the misalignment between the opening 6 of the blast furnace iron skin 5 and the pipe may be provided between the side plate 8 and the seal plate 9.

-Side plate The side plate 8 is generally a tubular plate, and after the pipe is inserted into the opening 6, one end thereof is the outer surface of the blast furnace iron skin 5 and is joined to the outer peripheral portion of the opening 6, and the other end. Is joined to the seal plate 9. The tubular shape is not limited to a cylindrical shape, and may be, for example, a square tubular shape. When forming one combing structure 10 for two pipes, the side plate 8 can be oval tubular, and when forming one combing structure 10 for three pipes, the side plate 8 is triangular. It can be tubular. The material of the side plate 8 is not particularly limited, but is preferably steel. The thickness of the side plate 8 is not particularly limited, but is preferably 6 to 10 mm, for example, 9 mm.

-Seal plate The seal plate 9 is a plate having an opening inside, and can be, for example, a donut-shaped plate. The seal plate 9 is a part of the inner side surface of the seal plate 9 after the pipe of the replacement stave is inserted into the opening 6 and one end of the side plate 8 is installed on the outer peripheral portion of the opening 6 of the blast furnace iron skin 5. Is joined to the side plate 8 and the end face of the opening is joined to the protective tube 7. The material of the seal plate 9 is not particularly limited, but steel is preferable. The thickness of the seal plate 9 is not particularly limited, but is preferably less than 5 mm, for example, 4.5 mm. If it is less than 5 mm, the seal plate before the joint with the stave body 2 of the pipe is damaged when the pipe is displaced due to a large thermal deformation of the stave body 2, especially when the pipe is displaced in the longitudinal direction. 9 can be made to break. If the seal plate 9 is preferentially damaged in this way, repair can be performed only by replacing the seal plate 9 accessible from outside the furnace, and the repair work time can be greatly reduced and the workability is improved.

-Fixing member A fixing member 13 for more firmly fixing the stave main body 2 and the blast furnace iron skin 5 can be provided. The fixing member 13 can function to suppress thermal deformation of the stave body 2 during blast furnace operation. Although one fixing member 13 is shown at the same position in FIGS. 1 to 5, the position and number of the fixing members 13 may be appropriately set according to the dimensions of the stave body 2 and the like. can. When the stave body 2 is long (more than 2.5 m), the number of fixing members 13 should be increased because the thermal deformation during blast furnace operation is large. For example, the number of bolts can be eight. ..

-Blast furnace iron skin In this replacement method, the blast furnace iron skin 5 has an opening 6 used for a pre-replacement stave (for example, a telescopic tube type stave 11). In addition, the dimensions of the opening 6 are not changed throughout the entire process of this replacement method.

In the present invention, the method of joining each member is not particularly limited, and examples thereof include welding and bolt connection, and welding is preferable. In addition, additional parts may be appropriately used in joining the members in order to facilitate the work.

[Stave]
The stave according to the present invention (hereinafter referred to as “the stave”) surrounds a stave main body 2 having a cooling water channel 3 inside, at least one water supply / drainage pipe 4 joined to the stave main body 2, and a water supply / drainage pipe 4. As described above, one end is provided with the stave main body 2, the other end is provided with a protective pipe 7 joined to the water supply / drainage pipe 4, and a combing structure 10 having a side plate 8 and a seal plate 9. Further, in this stave, the protective tube 7 is reduced in diameter from the stave main body 2 in the extending direction of the protective tube 7. Here, the "extending direction" of the protective pipe 7 is a direction from the stave main body 2 toward the blast furnace iron skin 5, and is a direction from the left side to the right side on FIG.

In this stave, the outer protective tube 7 of the double pipe structure is reduced in diameter from the stave main body 2 in the extending direction of the protective tube 7, so that the joint portion of the protective tube 7 with the stave main body 2 is formed. Since the outer peripheral length is increased and the bonding distance with the stave body 2 is extended, the strength in the longitudinal direction is increased. Further, by increasing the outer diameter of the protective tube 7 at the joint portion, a larger moment of inertia of area can be obtained, and the strength in the bending direction is increased. Further, since the outer diameter of the protective pipe 7 at the position penetrating the opening 6 of the blast furnace iron skin 5 is smaller than the outer diameter of the joint portion, when the pipe is inserted into the opening 6, the opening 6 is opened. It can be used as it is without expansion, improving workability. Therefore, by using this stave, the strength of the protective pipe 7 is improved, it is possible to prevent the water supply / drainage pipe 4 from being damaged, and further, the pipe can be easily inserted into the existing opening 6 of the blast furnace iron skin 5. It is possible to improve the workability.

Preferably, the water supply / drainage pipe 4 is reduced in diameter from the stave main body 2 in the extending direction of the water supply / drainage pipe 4. That is, the outer diameter of the water supply / drainage pipe 4 is large at the joint with the stave main body 2. Then, the pressure loss of the refrigerant flowing inside the water supply / drainage pipe 4 at the joint can be reduced. Further, if the water supply / drainage pipe 4 at the position penetrating the opening 6 is made small, it becomes easy to insert the pipe into the opening 6 in a state where the opening 6 is diverted as it is.

The stave body 2, the water supply / drainage pipe 4, the protective pipe 7, and the combing structure 10 (side plate 8 and the seal plate 9) in the stave independently include a part or all of the embodiments described in the above-described replacement method. can do.

The present invention can be used for exchanging stave in a high temperature furnace such as a blast furnace for iron making.

1 Combing structural type stave 2 Stave body 3 Cooling water channel 4 Water supply and drainage pipe 5 Blast furnace iron skin 6 Opening 7 Protective pipe 8 Side plate 9 Seal plate 10 Combing structure 11 Telescopic pipe type stave 12 Telescopic pipe 13 Fixing member

Claims (14)

This is a method of replacing a stave that has a gas seal structure other than the combing structure and replaces the pre-replacement stave with a replacement stave.
The replacement stave includes a stave body having a cooling water channel inside, at least one water supply / drainage pipe joined to the stave body, and protection joined to the stave body and the water supply / drainage pipe so as to surround the water supply / drainage pipe. Equipped with a tube and
The process of removing the pre-replacement stave from the blast furnace iron skin,
The step of inserting the water supply / drainage pipe and the protection pipe from the inside of the furnace into the opening of the blast furnace iron skin for the pre-replacement stave, and
On the outside of the furnace, one end of the side plate is joined to the outer peripheral portion of the opening of the blast furnace iron skin so as to surround the protective tube, and the seal plate is joined to the other end of the side plate and the protective tube to form a combing structure. A method of exchanging a stave, which comprises a step of performing. The claim is characterized in that the protective tube has a diameter reduced from the stave main body toward the inner side surface of the blast furnace iron skin between the stave main body and the inner side surface of the iron skin of the blast furnace. The method for exchanging the stave according to 1. The claim is characterized in that the water supply / drainage pipe has a diameter reduced from the stave main body toward the inner side surface of the blast furnace iron skin between the stave main body and the inner side surface of the iron skin of the blast furnace. The method for exchanging the stave according to 1 or 2. The method for replacing a stave according to any one of claims 1 to 3, wherein the thickness of the seal plate is less than 5 mm. The method for replacing a stave according to any one of claims 1 to 4, wherein at least one of the water supply and drainage pipes is arranged near the upper and lower ends of the stave body. The stave according to any one of claims 1 to 5, wherein the outer diameter of the water supply / drainage pipe included in the replacement stave is smaller than the outer diameter of the water supply / drainage pipe included in the pre-replacement stave. method of exchange. The method for replacing a stave according to any one of claims 1 to 6, wherein the stave body is made of copper or a copper alloy. The method for replacing a stave according to any one of claims 1 to 7, wherein the length of the stave body is more than 2.5 m. The main body of the stave, which has a cooling water channel inside,
At least one water supply / drainage pipe joined to the stave body,
A protective pipe with one end joined to the stave body and the other end joined to the water supply / drainage pipe so as to surround the water supply / drainage pipe.
With a combing structure with side plates and seal plates,
The stave is characterized in that the protective tube has a diameter reduced from the stave main body in the extending direction of the protective tube. The stave according to claim 9, wherein the water supply / drainage pipe has a diameter reduced from the main body of the stave toward the extending direction of the water supply / drainage pipe. The stave according to claim 9 or 10, wherein the thickness of the seal plate is less than 5 mm. The stave according to any one of claims 9 to 11, wherein at least one of the water supply and drainage pipes is arranged in the vicinity of the upper and lower ends of the stave body. The stave according to any one of claims 9 to 12, wherein the stave body is made of copper or a copper alloy. The stave according to any one of claims 9 to 13, wherein the length of the stave body is more than 2.5 m.

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