Cooling structure for blast furnace

Abstract

To provide a cooling structure for a blast furnace that properly cools the bosh part of a blast furnace, maintains the ideal profile of a utilization surface, and achieves more stable blast furnace operation.SOLUTION: A cooling structure for a blast furnace comprises a front coolant constituting the furnace wall on the furnace inner side at least in the bosh part of the blast furnace and a rear coolant having therein a flow path on which a cooling medium is supplied, disposed on the furnace outer side of the front coolant, and cooling the front coolant. The rear coolant may be disposed in direct contact with the front coolant. Furthermore, a heat-conducting material formed from an unshaped material may be provided between the rear coolant and the front coolant.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cooling structure for a blast furnace. [Background technology]

[0002] Conventionally, stave and cooling plate systems have been used as cooling structures for the morning glory portion of a blast furnace. For example, Patent Documents 1 and 2 disclose stave-type cooling structures. Furthermore, Patent Documents 3 and 4 disclose cooling structures using cooling plates. A combination of the stave and cooling plate systems has also been proposed. For example, Patent Document 5 discloses a cooling structure in which a cooling body (cooling plate) is arranged above the tuyere and a stave is arranged in the morning glory portion above it. Furthermore, Patent Document 6 discloses a cooling structure in which a stave is arranged on the steel shell side and a cooling body (cooling plate) is arranged on the furnace inside of the stave, and a similar structure is also disclosed in the aforementioned Patent Document 4.

[0003] These cooling structures are used to cool the furnace walls and maintain the profile of the furnace working surface in the bosh section of the blast furnace. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-115007 [Patent Document 2] Patent No. 4757960 [Patent Document 3] Japanese Patent Application Publication No. 8-199211 [Patent Document 4] Japanese Patent Application Laid-Open No. 2005-194567 [Patent Document 5] Japanese Patent Application Laid-Open No. 2005-248209 [Patent Document 6] Japanese Patent Publication No. 2020-66771 Summary of the Invention [Problem to be solved by the invention]

[0005] The above-mentioned conventional cooling structure was insufficient in its function of maintaining the ideal shape of the working surface in the morning glory section throughout blast furnace operation. Specifically, with the stave system, if a cooling pipe inside the stave was damaged, it was difficult to replace the damaged cooling pipe. Therefore, when damage occurred, cooling was not performed around the damaged area, and the area was damaged by heat from inside the furnace and deformed into a concave shape. As a result, it was sometimes impossible to maintain the ideal profile. Furthermore, if the cooling pipe was positioned closer to the outside of the furnace to prevent damage, cooling was insufficient, and the ideal profile was also not obtained.

[0006] The cooling plate system allows for the replacement of each damaged cooling plate. However, the cooling plate system involves distributing multiple cooling plates in a staggered pattern, with the gaps between them filled with refractory to form the working surface of the furnace wall. Therefore, when the refractory wears out, the working surface becomes uneven. Therefore, even with the cooling plate system, it is difficult to maintain the ideal profile of the working surface over the long term.

[0007] In addition, even in cooling structures that combine staves and cooling plates, the problems with the stave system and cooling plate system described above have still not been resolved, making it difficult to maintain an ideal profile of the morning glory portion.

[0008] Therefore, the present application aims to provide a cooling structure for a blast furnace that properly cools the morning glory portion of the blast furnace to maintain an ideal profile of the operating surface and realize more stable operation of the blast furnace. [Means for solving the problem]

[0009] The present application has been made to solve the above problems, and its gist is as follows.

[0010] (1) a front cooling body constituting a furnace wall inside the furnace at least in the morning glory portion of the blast furnace; a rear cooling body having a flow path therein through which a cooling medium is supplied, the rear cooling body being disposed outside the furnace of the front cooling body and cooling the front cooling body; A cooling structure for a blast furnace.

[0011] (2) The cooling structure for a blast furnace according to (1) above, wherein the rear cooling body is disposed in direct contact with the front cooling body.

[0012] (3) A cooling structure for a blast furnace according to (1) above, characterized in that a heat conductive material formed of an unshaped material is present between the rear cooling body and the front cooling body.

[0013] (4) A cooling structure for a blast furnace as described in (1) above, further comprising a support part having a support tool that supports the front cooling body and a tensile force applying means that pulls the support tool toward the outside of the furnace.

[0014] (5) The cooling structure for a blast furnace according to (4) above, wherein the tension applying means includes a spring disposed on the outer side of the steel shell of the blast furnace. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a blast furnace cooling structure that properly cools the morning glory portion of the blast furnace to maintain an ideal profile of the operating surface and realize more stable blast furnace operation. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram showing the configuration of a cooling structure of a blast furnace according to an embodiment. FIG. [Figure 2] 1 is a diagram showing a configuration of a cooling structure of a blast furnace according to an embodiment as viewed from outside the furnace. FIG. [Figure 3] FIG. 2 is a partial cross-sectional view taken along the line AA in FIG. [Figure 4] FIG. 2 is a partial cross-sectional view taken along the line BB in FIG. 1, and is a schematic diagram showing the structure of a support portion of the front cooling body. DETAILED DESCRIPTION OF THE INVENTION

[0017] (First embodiment) The cooling structure of a blast furnace according to this embodiment will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the cooling structure of a blast furnace according to this embodiment. More specifically, it is a vertical cross-sectional view of the tuyere and morning glory of the blast furnace. FIG. 2 is a diagram showing a part of the configuration of the cooling structure according to this embodiment as seen from the outside of the blast furnace. FIG. 3 is a partial cross-sectional view at the position AA in FIG. 1.

[0018] The cooling structure 1 of this embodiment is arranged in the morning glory portion 50 above the tuyere 24. The cooling structure 1 of this embodiment is not limited to the range of the morning glory portion 50, and may be arranged above the morning glory portion 50 or below the tuyere 24.

[0019] The cooling structure 1 comprises a front cooling body 2 and a rear cooling body 4. The front cooling body 2 constitutes the furnace wall on the inside of the furnace at least in the morning glory section 50 of the blast furnace. The rear cooling body 4 has a flow path 4c inside through which a cooling medium is supplied and flows, is placed outside the furnace of the front cooling body 2, and cools the front cooling body 2 by heat conduction from the front cooling body 2. The cooling structure 1 can also comprise a support part 6. The support part 6 is a mechanism that supports the front cooling body 2. Each part will be explained in more detail below.

[0020] The forward cooling body 2 may be arranged in the furnace wall within the furnace in a range from the position above the tuyere 24 to the position of the upper end of the morning glory section 50. The forward cooling body 2 preferably constitutes the entire furnace wall of the morning glory section 50, but may also constitute a portion. When it is a portion, the forward cooling body 2 may be arranged in a partial range in the height direction of the morning glory section 50, may be arranged in a partial range in the circumferential direction, or may be arranged dispersedly in the morning glory section 50. When it is a portion of the morning glory section 50, it is preferable that 50% or more of the furnace wall of the morning glory section 50 is composed of the forward cooling body 2. By having 50% or more, the morning glory section 50 can be cooled more effectively. Furthermore, it is more preferable that 80% or more of the furnace wall of the morning glory section 50 is composed of the forward cooling body 2, which can cool the morning glory section 50 even more effectively.

[0021] The surface of the front cooling body 2 is inclined in a direction approaching the center of the furnace body as it moves downward in the blast furnace. The inclination angle of the surface of the front cooling body 2 is set to form an ideal profile on the working surface of the morning glory section 50. For example, the front cooling body 2 can be arranged at an inclination such that the angle between the surface and the horizontal plane is in the range of 70° to 80°.

[0022] The front cooling body 2 is preferably made of a material with excellent thermal conductivity. Specifically, the front cooling body 2 is preferably made of copper, a copper alloy, or a material with a thermal conductivity equivalent to that of copper or a copper alloy. For example, an aluminum-based alloy can be used as a material with a thermal conductivity equivalent to that of copper or a copper alloy.

[0023] The front cooling body 2 is a plate-shaped member, and is preferably a solid material in order to obtain higher thermal conductivity. The front cooling body 2 does not need to have flow paths for the cooling medium, as formed in the rear cooling body 4. The thickness of the front cooling body 2 is not particularly limited, but can be, for example, in the range of 100 mm to 300 mm.

[0024] The forward cooling body 2 may have any appropriate width. For example, it may be the same width as the distance between the centers of adjacent tuyere assemblies inside the furnace (the tuyere-to-tuyere dimension), or it may be a width obtained by dividing the distance between the centers of the tuyere assemblies at both ends of four consecutive tuyere assemblies by two (1.5 times the tuyere-to-tuyere dimension). Multiple forward cooling bodies 2 of appropriate width can be arranged in the circumferential direction of the blast furnace. Multiple forward cooling bodies 2 may also be arranged in the height direction. Figure 1 shows an example in which two rows are arranged vertically within the bosh section 50. The dimensions (on the furnace surface side) of the multiple forward cooling bodies 2 may be the same or different. In this way, multiple forward cooling bodies 2 are arranged circumferentially to form the furnace wall in the bosh section 50.

[0025] The front cooling bodies 2 are not limited to being arranged in two vertical rows in the morning glory section 50, but may be divided into a larger number and arranged in the vertical direction, or may be arranged in a single vertical row. Furthermore, the multiple front cooling bodies 2 may be arranged in a lattice pattern with their positions aligned in the circumferential and vertical directions, or may be arranged alternately in a staggered pattern such as a staggered pattern. Furthermore, in FIG. 1, the front cooling bodies 2 are arranged from above the refractory material 26 around the tuyere 24, but this is not limiting, and the front cooling bodies 2 may be arranged in close proximity to the tuyere 24.

[0026] The front cooling body 2 may have a rear cooling body support 2a on its back side. The rear cooling body support 2a supports the tip 4a of the rear cooling body 4 at a predetermined position on the front cooling body 2. The structure of the rear cooling body support 2a is not particularly limited as long as it can support the rear cooling body 4 without shifting, but it can have a structure into which the tip 4a of the rear cooling body 4 is inserted. Specifically, the rear cooling body support 2a can be a member (e.g., a frame-shaped member) extending outside the furnace. Since the tip surface of the rear cooling body 4 is inclined and a force acts to shift it vertically, it is sufficient that the rear cooling body support 2a be formed at least above and below the tip 4a. The rear cooling body support 2a may be made of the same material as the front cooling body 2 or a material with equivalent thermal conductivity. This allows for thermal conduction and cooling from the rear cooling body support 2a when the periphery of the tip 4a comes into contact.

[0027] Furthermore, the front cooling body 2 may have a support part connecting part 2b on its back surface side. The tip of a support part 6 that supports the front cooling body 2 is fixed to the support part connecting part 2b. As will be described later, the support part 6 supports the front cooling body 2 while pulling it toward the outside of the furnace. Therefore, the support part 6 is fixed by the support part connecting part 2b so that it does not come off the front cooling body 2. The support part connecting part 2b can be fixed, for example, by forming a screw hole in the support part connecting part 2b and screwing in a support part 6 with a thread formed therein. The support part connecting part 2b may be formed so as to protrude outward from the front cooling body 2 as shown in FIG. 1 , or may be formed within the front cooling body 2.

[0028] The rear cooling body 4 absorbs heat from the front cooling body 2 to cool the front cooling body 2. In this embodiment, the rear cooling body 4 is disposed in direct contact with the front cooling body 2. Specifically, the front end 4a of the rear cooling body 4 inside the furnace is in contact with the back surface of the front cooling body 2, and extends in the furnace radial direction from the front end 4a to the outside of the steel shell 20 on the outside of the furnace. The rear cooling body 4 can be a plate-like member that is rectangular in plan view, as shown in FIG. 3 .

[0029] The rear cooling body 4 is preferably made of a material with excellent thermal conductivity, and is preferably made of copper or a copper alloy, or a material with a thermal conductivity equivalent to that of the front cooling body 2. It may be made of the same material as the front cooling body 2 or a different material.

[0030] A flow path 4c through which a cooling medium flows is formed inside the rear cooling body 4. The cooling medium is supplied from one inlet of the flow path 4c, flows through the rear cooling body 4, absorbs heat from the front cooling body 2, and is discharged from the other outlet. Various known media can be used as the cooling medium, and water, for example, can be used.

[0031] The cooling medium may be supplied to each of the multiple rear cooling bodies 4 in parallel, or the cooling medium may be supplied by connecting the flow paths 4c of the multiple rear cooling bodies 4 in series. In FIG. 2, as an example of connecting the flow paths 4c in series, part of the piping 4d connecting the flow paths 4c is shown by a broken line. As shown in FIG. 2, among the rear cooling bodies 4 arranged in a staggered pattern, diagonally adjacent rear cooling bodies 4 may be connected by the piping 4d, or vertically adjacent rear cooling bodies 4 may be connected by the piping 4d. When connecting rear cooling bodies 4 in series, it is sufficient to connect an appropriate number of rear cooling bodies 4 within a range that allows sufficient cooling with the supplied cooling medium.

[0032] The rear cooling body 4 is disposed such that the tip 4a of the rear cooling body 4 is in close contact with the back surface of the front cooling body 2 so as to conduct heat between the rear cooling body 4 and the front cooling body 2. In this embodiment, the rear cooling body 4 is disposed in surface contact (metal-to-metal contact) with the front cooling body 2. That is, the two are disposed in direct contact. This allows heat to be efficiently transferred from the front cooling body 2 to the rear cooling body 4, thereby cooling the front cooling body 2. As described above, heat can also be transferred from the point where the rear cooling body support part 2a and the tip 4a of the rear cooling body 4 are in contact with each other, allowing for cooling. Each rear cooling body 4 may be disposed so as to be in contact with only one corresponding front cooling body 2. Alternatively, the rear cooling body 4 may be disposed so as to be in contact across multiple front cooling bodies 2. In this case, one rear cooling body can cool multiple front cooling bodies 2 that are adjacent in the horizontal or vertical direction.

[0033] In this way, the rear cooling body 4 is not fixed to the front cooling body 2 by a fastening member or the like, but is in contact with the front cooling body 2, which ensures reliable cooling and also makes it easy to replace the rear cooling body 4 and improves maintainability. In other words, even if the rear cooling body 4 breaks down, it can be removed simply by pulling out the broken rear cooling body 4. Furthermore, when installing a new rear cooling body 4, it is sufficient to insert the new rear cooling body 4 until the tip 4a comes into close contact with the front cooling body 2.

[0034] To facilitate the removal and insertion of the rear cooling body 4, it is preferable that the rear cooling body 4 has a shape that extends in the furnace radial direction, in other words, a shape that extends horizontally in the direction of the central axis of the blast furnace. Furthermore, it is preferable that the rear cooling body 4 has a tapered shape in which the cross section narrows toward the tip 4a. Even a slight tapered shape makes removal and insertion easier, allowing for more efficient replacement.

[0035] The support part 6 supports the front cooling body 2. At least one, preferably two, and more preferably four support parts 6 are arranged for one front cooling body 2, and support the front cooling body 2. The support part 6 supports the front cooling body 2 while pulling it towards the outside of the furnace, in order to reliably maintain contact between the front cooling body 2 and the rear cooling body 4.

[0036] An example of the structure of the support part 6 is shown in Figure 4. Figure 4 is a partial cross-sectional view taken along the line BB in Figure 1, showing the structure of the support part 6 in a plan view. The support part 6 includes a support 6a, a spring 6b, and a connecting plate 6c. The support 6a supports the front cooling body 2. The spring 6b and the connecting plate 6c work together to provide a tensile force applying means that pulls the support 6a toward the outside of the furnace.

[0037] As described above, the tip of the support 6a is fixed to the support connection part 2b of the front cooling body 2. The rear end of the support 6a on the outside of the furnace is fixed to the connection plate 6c. The spring 6b is arranged between the steel shell 20 and the connection plate 6c on the outside of the furnace. The spring 6b pulls the support 6a toward the outside of the furnace via the connection plate 6c, so that a tensile force acts on the front cooling body 2 toward the outside of the furnace. The support 6a is, for example, a columnar member, and may be cylindrical or rectangular. Furthermore, the support 6a is not limited to being columnar, and may be a plate-like support extending in the radial direction of the furnace.

[0038] Furthermore, with the configuration in which the front cooling body 2 is supported by being pulled toward the outside of the furnace by the support part 6, stable contact between the front cooling body 2 and the rear cooling body 4 can be maintained throughout the operation of the blast furnace. Specifically, during operation of the blast furnace, the heat of the blast furnace causes the support part 6 and various surrounding parts to expand. For this reason, if the front cooling body 2 is simply fixed to the steel shell 20 or the like using only the support tool 6a without providing a mechanism such as a tension force applying means, the expansion of the support tool 6a may push the front cooling body 2 toward the inside of the furnace and cause it to be displaced in a direction away from the rear cooling body 4. If the front cooling body 2 separates from the rear cooling body 4, cooling cannot be performed.

[0039] In contrast to this, in this embodiment, by supporting the front cooling body 2 while pulling it toward the outside of the furnace with a tensioning force applying means such as spring 6b, it is possible to maintain the state in which the front cooling body 2 is in pressure contact with the rear cooling body 4 even if the support 6a etc. expands. Therefore, continuous and stable cooling is possible.

[0040] The support part 6 may be formed of any steel material that is heat resistant to the heat of the blast furnace, such as SM steel, SC steel, SUS steel, or SS steel. The tensile force applying means is not limited to the spring 6b, and may be any mechanism that can apply a tensile force. For example, a hydraulic, pneumatic, or electric actuator may be used to apply a tensile force toward the outside of the furnace. The mechanism connecting the support 6a and the spring 6b is not limited to the connecting plate 6c, and may be any other suitable mechanism.

[0041] As another configuration, a stave 22 similar to that of the prior art may be arranged between the front cooling body 2 and the steel shell 20, as shown in FIG. 1. By arranging the stave 22, in combination with the cooling structure 1, the morning glory portion 50 can be cooled more reliably. Since the stave 22 is arranged on the outer side of the furnace than the front cooling body 2, it is protected from the heat inside the blast furnace and damage can be prevented. Note that the stave 22 does not have to be arranged.

[0042] 1, the space 40 other than the front cooling body 2, the rear cooling body 4, the steel shell 20, and the staves 22 may be filled with a monolithic refractory such as a castable refractory. Between the rear cooling body 4 and the support part 6 (support 6a), which may move in the furnace radial direction, and the monolithic refractory, there may be a gap large enough to allow movement.

[0043] According to the present embodiment described above, the front cooling body 2 is continuously and stably cooled by the rear cooling body 4 during blast furnace operation, and the ideal profile at the time of blast furnace construction can be maintained as the working surface of the morning glory section 50. Furthermore, since the front cooling body 2, which is most exposed to heat, is a simple plate-shaped member, damage to internal piping, etc., does not occur as with staves, and the profile can be maintained for a longer period of time. Furthermore, since the rear cooling body 4 is simply placed in contact with the front cooling body 2, even if it is damaged, only the damaged rear cooling body 4 can be easily replaced.

[0044] Furthermore, when the front cooling body 2 is made of a copper panel, the cooling structure 1 of this embodiment allows the front cooling body 2 to be cooled without exceeding the heat-resistant temperature of copper (approximately 1100°C). The same is true for copper alloys. Therefore, the profile of the bosh portion 50 can be reliably maintained throughout the operation of the blast furnace.

[0045] In this embodiment, the cooling structure 1 has been described as being arranged in the bosh portion 50, but this is not limited to this, and it may be installed as a furnace wall other than the bosh portion 50.

[0046] (Second embodiment) A second embodiment will now be described. In this embodiment, the front cooling body 2 and the rear cooling body 4 are arranged to be thermally conductive via a thermally conductive material made of an amorphous material. This embodiment differs from the first embodiment in that the front cooling body 2 and the rear cooling body 4 are not in direct contact with each other.

[0047] Specifically, in this embodiment, a thermally conductive material made of an amorphous material with excellent thermal conductivity is provided between the tip 4a of the rear cooling body 4 and the front cooling body 2. Heat from the front cooling body 2 is transferred to the rear cooling body 4 via the thermally conductive material, thereby cooling the front cooling body 2. If a rear cooling body support part 2a is provided on the back surface of the front cooling body 2, a thermally conductive material may also be provided between the rear cooling body support part 2a and the rear cooling body 4.

[0048] The amorphous material constituting the thermally conductive material can be any amorphous material with excellent thermal conductivity, such as copper powder paste or carbon paste.

[0049] According to this embodiment, the space between the front cooling body 2 and the rear cooling body 4 is filled with a highly thermally conductive material without any gaps, so that heat from the front cooling body 2 can be efficiently transferred to the rear cooling body 4 for cooling. [Explanation of symbols]

[0050] 1, 100 cooling structure 2 Front cooling body 4 Rear cooling body 4c Flow path 6 Support part 6a Support 6b Spring 20 Ironhide 26 Refractories 24 Tuyere 50 Morning Glory Club

Claims

1. A front cooling body constituting a furnace wall inside the furnace at least in the morning glory portion of the blast furnace; a rear cooling body having a flow path therein through which a cooling medium is supplied, the rear cooling body being disposed outside the furnace of the front cooling body and cooling the front cooling body; A cooling structure for a blast furnace.

2. The cooling structure for a blast furnace according to claim 1 , wherein the rear cooling body is disposed in direct contact with the front cooling body.

3. 2. The cooling structure of a blast furnace according to claim 1, wherein a heat conductive material formed of an unshaped material is provided between the rear cooling body and the front cooling body.

4. 2. The cooling structure for a blast furnace according to claim 1, further comprising a support part having a support tool that supports the front cooling body and a tensile force applying means that pulls the support tool toward the outside of the furnace.

5. 5. The cooling structure of a blast furnace according to claim 4, wherein the tension applying means includes a spring disposed on the outer side of the steel shell of the blast furnace.

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