Tuyere for blast furnace

Abstract

To provide a tuyere for a blast furnace incorporating a pipe serving as a cooling water circulation passage.SOLUTION: A tuyere for a blast furnace includes a tuyere body part, a passage formed surrounded by the tuyere body part, a pipe built inside the tuyere body part, a supply port for supplying cooling water to the pipe, and a discharge port for discharging the cooling water circulated through the pipe. The pipe circulates the inside of the tuyere body part and serves as a cooling water circulation passage for circulating the cooling water. The pipe is an independent member incorporated in the tuyere body part.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a blast furnace tuyere that is used in a blast furnace used in steel manufacturing and the like and has high durability against the heat of the blast furnace. [Background technology]

[0002] In steelmaking, a blast furnace is used to reduce the raw material iron ore to obtain molten pig iron. The raw material iron ore is fed into the blast furnace through an inlet, and heat is supplied through another inlet to raise the temperature inside the furnace to the melting point. The molten pig iron is removed from the blast furnace and then processed as required.

[0003] The heat source, hot air and fine coal powder, is fed into the inlet that supplies the heat. A component called a tuyere is attached to this inlet, and the hot air and fine coal powder are fed through this tuyere.

[0004] The tuyere is the entrance through which hot air and fine coal powder are introduced, and is in an environment where it comes into contact with the molten iron and slag generated inside the blast furnace. In this environment, the dripping molten iron and slag are likely to cause damage to the tuyere.

[0005] In addition, since the tuyere is exposed to high heat and is used while being partially inserted into the blast furnace, the tuyere is exposed to high temperatures and is highly affected by the heat. The tuyere is exposed to the possibility of wear and tear due to the thermal effects and mechanical wear.

[0006] Thermal effects can cause the tuyere itself to heat up, increasing the effects of mechanical wear on the tuyere, which can lead to its failure.

[0007] Blast furnaces require continuous operation, such as 24 hours a day, and long-term operation, such as continuing this continuous operation for a specified period of time. When operating for a long period of time, regular or irregular maintenance is required, and if the tuyere is significantly worn during this maintenance, it will be necessary to replace the tuyere.

[0008] In the above-mentioned environment where mechanical wear and thermal influences are high, the tuyere is often worn and needs to be replaced. Frequent replacement of the tuyere increases the running cost of the blast furnace. Furthermore, if it takes time to replace the tuyere, the operation shutdown period for the blast furnace during maintenance may be longer than expected, which may reduce the operating capacity of the blast furnace.

[0009] On the other hand, there are cases where the tuyere is damaged before the maintenance period arrives, making it difficult to use. When this happens, it can no longer continue to function as a tuyere, and the blast furnace must be shut down to replace the tuyere. The blast furnace must be shut down until the tuyere can be replaced, which results in downtime from lowering the temperature, replacing it, and then raising the temperature again, increasing production costs.

[0010] Of course, it may affect the processes before and after the steelmaking process in the blast furnace, and it may affect the quality of the pig iron produced in the blast furnace. It may also increase the workload of the workers.

[0011] Furthermore, in order to replace the tuyere, it is necessary to prepare a new tuyere, secure workers to replace the tuyere, and so on, in addition to shutting down the blast furnace. Such work requires additional time and costs. These work times and costs also have a negative impact on the operation of the entire steel plant.

[0012] In addition to mechanical wear, the tuyere is required to have high durability against thermal influences. In particular, it is preferable to be able to prevent damage caused by temperature rise during use in a blast furnace as much as possible.

[0013] Under these circumstances, a tuyere technology that circulates cooling water to suppress temperature rise has been proposed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0014] [Patent Document 1] JP2012-153973 Public Relations Summary of the Invention [Problem to be solved by the invention]

[0015] Patent Document 1 discloses a tuyere for an iron and steel industry furnace having a body portion with a blowing line running through the center, the body portion consisting of a truncated conical trunk portion having a main body flow passage inside and a protrusion portion protruding from the body portion, a cover portion connected to the protrusion portion so that a tip body flow passage is formed between the cover portion and the outer peripheral surface of the protrusion portion, an outer shell cooling flow passage is formed on the inside, and the outer shell portion is connected to surround the cover portion.

[0016] The tuyere of Patent Document 1 is characterized by having a cooling water circulation passage inside the body part that is the outer periphery of the center of the tuyere. By providing a cooling water circulation passage and continuing to circulate cooling water through it, it is possible to suppress the temperature rise of the tuyere inserted in the blast furnace. This is because the cooling water circulating through the cooling water circulation passage removes heat from the tuyere and cools it. The aim is to suppress the temperature rise of the tuyere and suppress wear of the tuyere due to the temperature rise.

[0017] Here, the tuyere of Patent Document 1 is manufactured by casting a plurality of members, which are integrated by welding at necessary welding points. By integrating the members, gaps formed in the members become cooling water circulation paths. The diagram of Patent Document 1 shows the state in which the cooling water circulation path is formed by welding the plurality of members together.

[0018] A tuyere has been proposed in which a plurality of such members (manufactured by casting) are integrated at welding points to form a cooling water circulation passage.

[0019] However, the welded type tuyere described in Reference 1 had the following problems:

[0020] (1) High manufacturing costs Since each of the multiple components must be manufactured by casting, the cost of manufacturing the parts increases. In addition, since each component must be manufactured and then welded together, the total manufacturing time increases, which increases costs. In addition, the increase in manufacturing processes also increases manufacturing costs.

[0021] Another disadvantage is that the total manufacturing time increases.

[0022] (2) Welded parts have low thermal conductivity and durability The tuyere, which is integrated by welding, is inserted into the blast furnace for use. As mentioned above, the tuyere is subjected to mechanical and thermal loads and is therefore exposed to the possibility of breakage. In this case, the welded parts are structurally inferior in thermal conductivity and durability. For this reason, breakage may occur at the welded parts during use.

[0023] (3) If the outer periphery is damaged, it cannot be used. As in Patent Document 1, the cooling water circulation path is formed by welding multiple members together. In other words, the cooling water circulation path is formed by structure. Therefore, if the outer periphery is damaged, the cooling water circulation path becomes exposed. In the case of a tuyere as shown in the figure in Patent Document 1, if the outer periphery is worn away, the formed cooling water circulation path becomes exposed.

[0024] If the cooling water circuit is exposed, it can lead to the problem of the supplied cold water entering the blast furnace. In addition, the cooling water circuit will no longer function, leading to the problem of losing the cooling function. As a result, when the outer periphery is damaged to the point where the cooling water circuit is exposed, the tuyere becomes unusable.

[0025] As described above, there are problems with the prior art tuyere.

[0026] SUMMARY OF THE PRESENT EMBODIMENT In order to solve these problems, an object of the present invention is to provide a tuyere for a blast furnace having a built-in pipe serving as a cooling water circulation path. [Means for solving the problem]

[0027] In view of the above problems, the present invention provides a blast furnace tuyere comprising a tuyere body and A passage formed by being surrounded by the tuyere main body; A pipe installed inside the tuyere main body; a supply port for supplying cooling water to the pipe; and a discharge port for discharging the cooling water circulated through the pipe. The pipe serves as a cooling water circulation path for circulating the cooling water through the inside of the tuyere main body, The pipe is an independent member that is built into the tuyere body. Effect of the Invention

[0028] The blast furnace tuyere of the present invention can be constructed from a pipe that serves as a cooling water circulation path and a tuyere body that is cast with the pipe built in. This reduces the number of parts and the cost of parts. In addition, the tuyere can be manufactured by placing the pipe in a mold for the tuyere and injecting molten raw materials into it for casting. This shortens the time required for manufacturing, and reduces the effort, time, and cost.

[0029] In addition, since welding is not required, there are no welded parts, which have low thermal conductivity and durability. This reduces bottlenecks in thermal conductivity and durability, improving overall durability.

[0030] Furthermore, even if the outer periphery is damaged, the cooling water circulation path can maintain its function because it is a pipe. This means that even if the outer periphery is damaged, the cooling function is maintained and the tuyere can continue to be used. As a result, the operating time of the blast furnace can be extended, which also leads to reduced steelmaking costs. [Brief description of the drawings]

[0031] [Figure 1] 1 is an external perspective view of a blast furnace tuyere according to an embodiment of the present invention; [Diagram 2] FIG. 2 is an internal perspective view of a blast furnace tuyere according to an embodiment of the present invention. [Diagram 3]FIG. 2 is a development view of a blast furnace tuyere according to an embodiment of the present invention. [Figure 4] FIG. 2 is a side view of a blast furnace tuyere according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] The blast furnace tuyere according to the first aspect of the present invention comprises a tuyere body, A passage formed by being surrounded by the tuyere main body; A pipe installed inside the tuyere main body; a supply port for supplying cooling water to the pipe; and an outlet for discharging the cooling water circulating through the pipe, The pipe serves as a cooling water circulation path for circulating the cooling water through the inside of the tuyere main body, The pipe is an independent member that is built into the tuyere body.

[0033] This configuration ensures that cold water circulates through the tuyere body, reducing the manufacturing process and manufacturing costs. In addition, even if the tuyere body is damaged, the pipe remains, so the cold water circulation through the pipe can be maintained.

[0034] In a blast furnace tuyere according to a second aspect of the present invention, in addition to the features of the first aspect, the pipe circulates so as to circle the tuyere main body.

[0035] With this configuration, the cold water circulates in a circular manner, and the cooling capacity of the tuyere main body can be increased.

[0036] A third aspect of the present invention provides a blast furnace tuyere according to the first aspect of the present invention, wherein the pipe is made of any one of copper, iron, nickel, aluminum, titanium, and an alloy of one or more of these.

[0037] This configuration can increase the cooling capacity by circulating the cooling water through the pipes, and can also expand the variations.

[0038] In the blast furnace tuyere according to a fourth aspect of the present invention, in addition to the features of the first aspect, the inner diameter of the pipe is 10 mm to 50 mm.

[0039] This configuration makes it possible to achieve a balance between the circulation of cooling water and the cooling capacity. In addition, it is also possible to ensure that the cooling water can be easily installed in the tuyere body.

[0040] In the blast furnace tuyere according to a fifth aspect of the present invention, in addition to the features of the first aspect, at least one of the inside diameter, cross-sectional shape and cross-sectional area of ​​the pipe varies depending on the position of the pipe.

[0041] This configuration can increase the cooling capacity.

[0042] A sixth aspect of the present invention provides a blast furnace tuyere according to the first aspect of the present invention, wherein the arithmetic mean roughness of the inner surface of the pipe is 1.5 μm to 2.5 μm.

[0043] This configuration allows the cooling water to circulate smoothly.

[0044] In the blast furnace tuyere according to a seventh aspect of the present invention, in addition to the features of the first aspect, the surface roughness of the inner surface of the pipe is lower than the surface roughness of the portion where the tuyere body and the pipe contact each other.

[0045] This configuration allows the cooling water to circulate smoothly while increasing the cooling water's ability to remove heat.

[0046] In the blast furnace tuyere according to an eighth aspect of the present invention, in addition to the features of the first aspect, a plurality of the pipes are built into the tuyere body.

[0047] This configuration increases the variety of cold water circulation paths and improves cooling capacity.

[0048] In a blast furnace tuyere according to a ninth aspect of the present invention, in addition to any one of the first to eighth aspects, the pipe is built in when the tuyere main body is formed.

[0049] This structure allows the pipe to be easily and reliably built into the tuyere body, reducing manufacturing costs and simplifying the manufacturing process.

[0050] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0051] (Embodiment)

[0052] (Overview) 1 is a perspective view of the appearance of a blast furnace tuyere in an embodiment of the present invention. Since this is a view of the appearance, the internal structure is not shown. It is shown in order to grasp the entire blast furnace tuyere of the present invention.

[0053] As shown in Fig. 1, a blast furnace tuyere 1 comprises a tuyere main body 2 and a passage 3 formed by being surrounded by the tuyere main body 2. Although not shown in Fig. 1 because it is present inside and on the back side, a pipe is built into the inside of the tuyere main body 2 and is provided with a supply port for supplying cooling water to the pipe and a discharge port for discharging the cooling water that has been circulated through the pipe.

[0054] The blast furnace tuyere 1 has a shape as shown in Fig. 1 and is inserted into a predetermined position in a steel blast furnace for use. Hot air and fine coal powder required for the steel blast furnace are supplied through a passage 3.

[0055] 2 is an internal perspective view of a blast furnace tuyere in an embodiment of the present invention, which is shown in a perspective state so that the internal structure of the blast furnace tuyere 1 can be seen.

[0056] The blast furnace tuyere 1 comprises a tuyere main body 2, a passage 3, a pipe 4, a supply port 5, and a discharge port 6. The tuyere main body 2 constitutes the form of the blast furnace tuyere 2. The tuyere main body 2 is cylindrical as shown in Figs. 1 and 2, and is surrounded by the tuyere main body 2 to form a passage 3. The passage 3 serves to supply hot air and fine coal powder, etc., into the inside of the steelmaking blast furnace.

[0057] The pipe 4 is built into the tuyere main body 2. In the built-in state, the pipe 4 has a structure that circulates inside the tuyere main body 2. This circulating structure allows the pipe 4 to circulate the cooling water. In other words, the pipe 4 serves as a cooling water circulation path that circulates the cooling water inside the tuyere main body 2. This allows the tuyere main body 2 to be cooled.

[0058] The pipe 4 is built into the tuyere body 2, but is an independent member from the tuyere body 2, which is different from the case where a gap formed when the tuyere body is formed serves as a cooling water circulation path as explained in the prior art. That is, in the blast furnace tuyere 1 of the embodiment, the cooling water circulation path is an independent member from the tuyere body 2.

[0059] The supply port 5 supplies cooling water to the pipe 4. The discharge port 6 discharges the cooling water that has been supplied from the supply port 5 and circulated through the pipe 4. The cooling water circulates continuously inside the pipe 4 via the supply port 5 and the discharge port 6. This continuous circulation of cooling water keeps the blast furnace tuyere 1 used in the steel-making blast furnace cooled.

[0060] Continuing this cooling can increase the durability of the blast furnace tuyere 1 against heat that it receives while being inserted into an iron-making blast furnace and used. The increased heat resistance can reduce the possibility of damage caused by the heat it receives.

[0061] (Advantages over conventional technology tuyere 1: manufacturing cost and effort) The blast furnace tuyere 1 in the embodiment is manufactured by placing a pipe 4 in a mold corresponding to the tuyere body 2 and pouring molten metal for forming the tuyere body 2 into the mold. That is, the pipe 4 serving as a cooling water circulation path is formed inside the tuyere body 2 by casting.

[0062] Compared to the manufacturing process of assembling and welding a plurality of members together as described in the prior art, this method requires fewer manufacturing steps and fewer members, which reduces manufacturing costs.

[0063] Furthermore, in the case of conventional techniques in which multiple components are assembled, there is a possibility that the individual components may not be welded together reliably due to differences in manufacturing precision. In this case, the quality of the final tuyere may vary, and in some cases the product may be treated as a defective product. In other words, the yield rate decreases. This has a negative impact on the total cost and manufacturing capacity.

[0064] In contrast, the blast furnace tuyere of the embodiment does not require combining multiple parts, so there is no need to consider the accuracy of the combination. This increases the quality stability of the final product and increases the yield. As a result, the total manufacturing cost can be reduced and the manufacturing capacity can be increased.

[0065] (Advantage 2 over conventional tuyere technology: High durability) The conventional tuyere is manufactured by welding together a number of cast components. In this assembly, the gaps created based on the shapes of the components become the cooling water circulation paths. In this case, the gaps created by the inner shape of the outer peripheral component become the cooling water circulation paths.

[0066] Due to this structure, if the tuyere is subjected to mechanical wear and thermal load and the outer circumference is damaged, the cooling water circulation path will be exposed to the surface. If it is exposed, the cooling water will leak to the outside and the cooling function will stop completely. Also, if cooling water is being supplied, there will be a problem that the cooling water will enter the blast furnace from the exposed part.

[0067] In contrast, in the blast furnace tuyere 1 of the embodiment, even if the outer periphery of the tuyere body 2 is damaged, the built-in pipe 4 remains. The inside of the pipe 4 is not exposed. Therefore, the cooling water circulation function is maintained. In other words, the cooling function is maintained. Of course, since it is not exposed, it is also possible to prevent the cooling water from entering the blast furnace.

[0068] (Advantage 3 over conventional tuyere technology: High degree of freedom in cooling water circulation)

[0069] Here, the cooling capacity of the cooling water circulating in the cooling water circuit formed by pipe 4 is proportional to the flow rate of the circulating cooling water. The higher the flow rate, the higher the cooling capacity. With a constant flow rate, the flow rate varies depending on the inner diameter of pipe 4. If the inner diameter is small, the flow rate will be high, and if the inner diameter is large, the flow rate will be low. In this case, a small inner diameter means high pressure loss and a high flow rate. Conversely, a large inner diameter means low pressure loss and a low flow rate.

[0070] For this reason, there is a limit to how much the supply capacity can be increased in order to increase the cooling capacity, so the flow rate, which is a factor in determining the cooling capacity, can be increased by reducing the inner diameter of the pipe 4.

[0071] In addition, when there is no need for high cooling capacity (at the blast furnace tuyere itself or at the blast furnace tuyere portion), the inner diameter of pipe 4 can be increased to reduce the flow rate and provide a margin between pressure loss and the capacity of the supply pump.

[0072] In conventional tuyere technology, which combines multiple components, it is necessary to form a cooling water circulation path according to the shape of the components. Therefore, the shape of the cooling water circulation path is restricted and the degree of freedom is not high. For this reason, it is difficult to change the inner diameter of the cooling water circulation path.

[0073] In contrast, in the blast furnace tuyere 1 of the present invention, the pipe 4 built into the tuyere body 2 serves as a cooling water circulation path. This reduces the dependency on the members that constitute the tuyere body 2. In addition, since the pipe 4 only needs to be formed as a pipeline, there is a high degree of freedom in its formation. This has the advantage of providing a high degree of freedom in the shape, structure, inner diameter, circulation path, etc. of the cooling water circulation path, compared to the prior art.

[0074] That is, in the case of the present invention in which the cooling water circulation path is constituted by the pipes 4, there is a high degree of freedom in designing the shape and inner diameter of the pipes 4, and the flow rate, which is the basis of the cooling capacity, can be controlled in the design. The ability to control the flow rate by the shape and inner diameter allows for a wider variety of cooling capacities.

[0075] In addition, there is a degree of freedom in the materials and finishing quality of the pipes 4. In addition to the above-mentioned shape and structure, these materials can also control the flow rate of the cooling water circulating through the pipes 4 (in other words, the pressure loss can be controlled). Being able to control the flow rate means being able to control the cooling capacity. In other words, the variety of cooling capacity can be increased by changing the materials and finishing quality.

[0076] In this way, the blast furnace tuyere 1 of the present invention, in which the cooling water circulation passage is constituted by the pipes 4, can have a variety of cooling capacities.

[0077] (pipe) As described above, the pipe 4 forms a cooling water circulation path inside the tuyere body 2. The pipe 4 circulates the cooling water to cool the blast furnace tuyere 1. To enhance this cooling effect, the pipe 4 may circulate so as to circle around the tuyere body 2. FIG. 2 shows that the pipe 4 has a structure in which it circles around the tuyere body 2.

[0078] Of course, the number of revolutions may be more than one revolution, or may be less than one revolution. This may be appropriately selected depending on the size and shape of the tuyere main body 2. Other circulation paths may be used instead of revolutions.

[0079] The pipe 4 forms a cooling water circulation path, and therefore circulates the cooling water inside. The pipe 4 is built into the tuyere main body 2, and therefore the cooling water circulation through the pipe 4 becomes the cooling water circulation inside the tuyere main body 2.

[0080] The blast furnace tuyere 1 is inserted into a predetermined portion of a blast furnace for use. Therefore, the blast furnace tuyere 1 is subjected to a thermal load in addition to a physical load. Due to this thermal load, the blast furnace tuyere 1 is exposed to a risk of wear and tear.

[0081] In this state, the cooling water circulates through the pipes 4 to cool the tuyere body 2. Since the tuyere body 2 is the entire outer shape of the blast furnace tuyere 1, the degree of thermal load can be reduced by cooling the tuyere body 2. This can reduce the risk and degree of wear due to thermal load.

[0082] Moreover, the pipe 4 is provided so as to circle around inside the tuyere main body 2. This circulating configuration allows the cooling water to circulate around inside the tuyere main body 2. This circulation allows the cooling water to efficiently remove heat from the tuyere main body 2 and to discharge the removed heat by drainage.

[0083] Cooling water is continuously supplied to the pipe 4, circulates inside the tuyere main body 2, and then discharged. By repeating this supply, circulation, and discharge, the heat that the tuyere main body 2 receives from the blast furnace can be continuously discharged to the outside.

[0084] In addition, the pipe 4 is connected to a supply port 5 for supplying cooling water and a discharge port 6 for discharging the circulated cooling water (the ends of the pipe 4 may be the supply port 5 and the discharge port 6, or the pipe 4 may be connected to the supply port 5 and the discharge port 6 as separate components).

[0085] With this configuration, the pipe 4 can continuously circulate the cooling water in the tuyere main body 2. This circulation makes it possible to continuously cool the tuyere main body 2 which is subjected to a thermal load.

[0086] (Tuyere body) The tuyere main body 2 is an element that forms the outer shape of the tuyere 1 for a blast furnace.

[0087] The tuyere body 2 may be made of any metal, and copper is used as an example. Copper has high thermal conductivity, and the heat received from the blast furnace can be efficiently conducted to the pipe 4, and can be effectively connected to the exhaust heat by the cooling water circulation in the pipe 4.

[0088] Another advantage is that it is easy to manufacture by casting. Although copper has been described above as an example of the material, it is not intended to exclude other materials.

[0089] (supply and discharge ports) The supply port 5 is an inlet for supplying cooling water to the pipe 4 which serves as a cooling water circulation path. It is connected to an external cooling water supply device to supply cooling water to the pipe 4. The supply port 5 may be provided on the bottom surface of the tuyere main body 2, or may be provided internally and connected to a pipeline from the cooling water supply device.

[0090] By connecting to a cooling water supply device or the like, cooling water is continuously supplied to the pipes 4. The water pressure at the time of supply causes the cooling water to circulate inside the pipes 4. As it circulates, it removes heat from the tuyere main body 2 via the pipes 4. The cooling water that has absorbed and moved and received heat is circulated and discharged from the discharge port 6.

[0091] The outlet 6 is a portion for discharging the circulated cooling water. Similar to the supply inlet 5, the outlet 6 may be provided on the bottom surface of the tuyere main body 2, or may be provided inside and connected to a pipeline therein.

[0092] The outlet 6 is connected to a pipeline, and the cooling water is discharged to a drainage area or the like at the end of the pipeline. Of course, the discharged wastewater may be cooled and reused as cooling water circulating inside the pipe 4 again.

[0093] The supply port 5 and the discharge port 6 may be disposed at appropriate positions depending on the supply and discharge of cooling water. Since the supply and discharge of cooling water are involved, the supply port 5 and the discharge port 6 may be appropriately separated from each other. Alternatively, they may be disposed close to each other based on the structure of the cooling water supply device.

[0094] The supply port 5 and the discharge port 6 may be elements of both ends of the pipe 4. Alternatively, further members may be attached to the respective ends, and these members may serve as the supply port 5 and the discharge port 6.

[0095] Furthermore, when a plurality of pipes 4 are built into the tuyere body 2 as described below, there are also a plurality of supply ports 5 and discharge ports 6.

[0096] (Pipe variations) The pipe 4 circulates cooling water, which is an important element for cooling the tuyere main body 2 and enhancing the durability of the blast furnace tuyere 1.

[0097] The pipe 4 is preferably made of a metal or an alloy, because it is easy to manufacture and to incorporate into the tuyere body 2. Here, the pipe 4 is also preferably made of any one of copper, iron, nickel, aluminum, titanium, and an alloy of one or more of these metals.

[0098] These materials have high thermal conductivity and can efficiently remove heat from and cool the tuyere body 2. In addition, all of the materials can be easily manufactured into components such as pipes 4, and are highly adaptable in terms of material costs and manufacturing costs.

[0099] In addition, it has good affinity with the tuyere body 2, and even when the pipe 4 is placed in a casting mold and the molten metal for forming the tuyere body 2 is poured in, the pipe 4 is less adversely affected.

[0100] For this reason, it is preferable to select such a material, although other materials may be selected as necessary.

[0101] It is also preferable that the inner diameter of the pipe 4 is 10 mm to 50 mm. With this inner diameter, the flow rate is appropriately controlled, and the heat is efficiently removed from the tuyere main body 2 by the circulation of the cooling water.

[0102] Here, the inner diameter of the pipe 4 used may vary depending on the blast furnace tuyere 1 depending on the specifications of the blast furnace in which the blast furnace tuyere 1 is used, the performance required of the blast furnace tuyere 1, the usage environment, the size of the blast furnace tuyere 1, etc. For example, the inner diameter of the pipe 4 of a certain blast furnace tuyere A is 20 mm, and the inner diameter of the pipe 4 of another blast furnace tuyere B is 30 mm. As described above, at the same supply pressure, the flow rate of the cooling water differs depending on the inner diameter of the pipe 4. If cooling water is supplied at the same supply pressure, the flow rate of the blast furnace tuyere A is greater, and the cooling capacity of the blast furnace tuyere A is higher.

[0103] Conversely, since the pressure loss at the blast furnace tuyere B is low, it is easier to ensure a margin with the upper limit capacity of the supply pump.

[0104] In this way, it is also preferable to change the inner diameter of the pipe 4 according to the performance and specifications required for the blast furnace tuyere 1. This creates a variety of options that can provide blast furnace tuyere 1 with different cooling capacities corresponding to the performance and specifications.

[0105] In addition, with this inner diameter, it can be built into the tuyere main body 2 without any problems. With the size of the blast furnace tuyere 1, a reasonable inner diameter increases the yield rate during manufacturing and has little effect on the durability and strength during use.

[0106] In addition, with an inner diameter of this order, it is easy to appropriately form the wound shape of the pipe 4. In particular, the pipe 4 has a configuration in which it bends and wounds inside the tuyere main body 2, as shown in FIG.

[0107] 3 is a development view of a blast furnace tuyere in an embodiment of the present invention. The blast furnace tuyere is shown in a developed state, making the internal structure easier to understand.

[0108] As shown in Fig. 3, the pipe 4 has a curved interior. Even when having such a structure, it is preferable that the inside diameter is within the above-mentioned range.

[0109] Of course, the inner diameter of the pipe 4 may be other than that described above depending on the size and material of the tuyere main body 2. Also, the inner diameter and material of the pipe 4 may be selected depending on the usage mode of the blast furnace tuyere 1.

[0110] (Changes in inner diameter of pipes, etc.) It is also preferable that at least one of the inner diameter, cross-sectional shape, and cross-sectional area of ​​the pipe 4 differs depending on the position of the pipe 4. For example, the inner diameter at one position of the pipe 4 is larger than the inner diameter at another position. Alternatively, the cross-sectional shape at one position of the pipe 4 is circular, but the cross-sectional shape at another position is elliptical (or polygonal). Alternatively, the cross-sectional area at one position of the pipe 4 is larger than the cross-sectional area at other positions. It is also preferable that the differences depend on the position of the pipe 4.

[0111] In this way, by varying at least one of the inner diameter, cross-sectional shape, and cross-sectional area depending on the position of the pipe 4, it is possible to change the flow rate depending on the position of the pipe 4. For example, the flow rate is fast in one position and slow in another position. In areas of the tuyere main body 2 where high cooling capacity is required, the flow rate is increased and cooling capacity is improved by reducing the inner diameter or cross-sectional area of ​​the pipe 4. On the other hand, in areas of the tuyere main body 2 where high cooling capacity is not required, the inner diameter or cross-sectional area of ​​the pipe 4 can be increased.

[0112] For example, in order to increase the flow rate in a portion where the external thermal load is large, the inner diameter and cross-sectional area may be made smaller, and in a portion where the external thermal load is not large, the inner diameter and cross-sectional area may be made relatively larger.

[0113] Since the pipes 4 can be manufactured separately from the tuyere body 2, it is possible to vary at least one of the inside diameter, cross-sectional shape, and cross-sectional area depending on the portion. This was difficult to do with the conventional tuyere in which the cooling water circulation path is formed by combining structural members.

[0114] These features allow for more versatile and multifaceted cooling capabilities, and more customized cooling capabilities.

[0115] Alternatively, it is also preferable that the inner diameter and cross-sectional area of ​​the bent portion of the pipe 4 are larger than those of other positions, so as to prevent the circulation of the cooling water from being hindered throughout the entire pipe 4. Rather than controlling the flow rate depending on the portion, the inner diameter and cross-sectional area are changed to smooth the flow of the cooling water throughout the entire pipe 4. In addition, the cross-sectional area of ​​the pipe 4 can be freely controlled, allowing for a high degree of freedom in design.

[0116] (Arithmetic mean roughness inside the pipe)

[0117] It is also preferable that the arithmetic mean roughness inside the pipe 4 is 1.5 μm to 2.5 μm. Cooling water circulates inside the pipe 4. At this time, in cooling the tuyere main body 2, it is important that the cooling water circulates smoothly.

[0118] Cooling water is supplied from the supply port 5 and circulated. The cooling water circulates based on the supply pressure of the cooling water. At this time, pressure loss occurs in the pipe 4 with respect to the circulation of the cooling water. The pipe 4 is bent and curved inside the tuyere main body 2, so that the pressure loss in the circulation of the cooling water also increases in this respect.

[0119] In this regard, by setting the arithmetic mean roughness of the inside of the pipe 4 in the range of 1.5 μm to 2.5 μm as described above, which is smaller than the 4 μm or more of the cast surface, the circulation of cooling water becomes smoother and pressure loss is reduced.

[0120] It is also preferable that the surface roughness of the inner surface of the pipe 4 is smaller than the surface roughness of the wall surface (part) of the tuyere body 2 that contacts the pipe 4. This allows the cooling water to circulate smoothly while ensuring sufficient fixation of the pipe 4 to the tuyere body 2.

[0121] That is, the pipe 4 is securely built into the tuyere body 2. In addition, the circulation of the cooling water becomes smooth. These factors combine to increase the cooling capacity.

[0122] In addition, the cooling water circulates smoothly inside the pipe 4, and the surface roughness of the pipe 4 is small, which increases the heat transfer between the pipe 4 and the tuyere body 2. These two factors combine to increase the cooling capacity of the cooling water circulating inside the pipe 4.

[0123] (Multiple pipes included)

[0124] The tuyere main body 2 may incorporate a plurality of pipes 4. Although Fig. 2 and other figures show a state in which one pipe 4 is incorporated, a plurality of pipes 4 may be incorporated.

[0125] By incorporating multiple pipes 4, the amount of cooling water circulating inside the tuyere main body 2 and the number of circulation routes are increased, further improving the cooling capacity. For example, it is also preferable to incorporate the pipes in a mutually complementary manner, such as having one pipe 4 go around one side of the tuyere main body 2 and another pipe 4 go around the other side of the tuyere main body 2. By incorporating the pipes in such a mutually complementary manner, the cooling water can circulate thoroughly inside the tuyere main body 2.

[0126] Alternatively, one pipe 4 may be configured to go around the inside of the tuyere main body 2 and the other pipe 4 may be configured to go around the outside of the tuyere main body 2, so that the pipes 4 go around both the inside and outside in the thickness direction. This allows the inside and outside of the tuyere main body 2 to be cooled, respectively.

[0127] By incorporating a plurality of pipes 4, the circulation paths of the cooling water inside the tuyere main body 2 become more diverse, and the cooling capacity is increased.

[0128] In addition, since the cooling water circulation path can be formed by a plurality of pipes 4, the shape (bent or curved shape) of each pipe 4 can be simplified. This can reduce the manufacturing cost of the pipes 4. In addition, the strength and durability of the pipes 4 can be increased.

[0129] Furthermore, a circulation path that is difficult to configure using a single pipe 4 can be configured using a plurality of pipes 4. As a result, a complex circulation path can be configured, and the cooling capacity can be increased.

[0130] The multiple pipes 4 may each have a different inner diameter, material, shape, etc. It is sufficient to combine multiple pipes 4 having inner diameters and shapes suitable for forming a circulation path that enhances cooling capacity. For example, the inner diameter of one pipe 4 may be smaller than the inner diameter of the other pipes 4, thereby optimizing the circulation path.

[0131] Unlike the conventional technology, the cooling water circulation path can be formed by incorporating the pipe 4, so it is possible to incorporate multiple pipes 4. As a result, it is possible to form a complex cooling water circulation path with high cooling capacity more easily than with the conventional technology, and therefore it is possible to increase the variety of cooling capacity.

[0132] Here, when multiple pipes 4 are built in, there is an advantage that the multiple pipes 4 can be arranged without interfering with each other by changing the cross-sectional shape of the pipe 4. This is also true in the case of a circulation structure with a single pipe 4.

[0133] (Built-in pipe)

[0134] Fig. 4 is a side view of a blast furnace tuyere in an embodiment of the present invention. The inside is shown in a see-through state from the side. As shown in Fig. 4, a pipe 4 is built into the tuyere main body 2.

[0135] The pipe 4 may be built in when the tuyere main body 2 is formed. For example, the tuyere main body 2 is manufactured by pouring molten metal into a mold. During this casting, the pipe 4 is set in the mold, and the pipe 4 is cast in. In this way, the pipe 4 may be built in the tuyere main body 2.

[0136] FIG. 4 shows the result of such a manufacturing process.

[0137] By casting the pipe 4 during the casting process of the tuyere main body 2, the pipe 4 can be easily and reliably built in.

[0138] Of course, the pipe 4 may be built in by other methods.

[0139] As described above, multiple pipes 4 may be built in this way. In addition, since the shape of the pipes 4 can be configured at the beginning, the blast furnace tuyere 1 can be easily manufactured. Of course, the pipes 4 only need to be prepared at the beginning, which also simplifies the manufacturing process. As a result, the yield is improved.

[0140] The blast furnace tuyere described in the embodiment is merely an example for explaining the gist of the present invention, and includes modifications and alterations that do not deviate from the gist of the present invention. [Explanation of symbols]

[0141] 1 Tuyere for blast furnace 2. Tuyere body 3. Passage 4. Pipes 5 Supply inlet 6 Outlet

Claims

1. A tuyere body portion, A passage formed by being surrounded by the tuyere main body; A pipe installed inside the tuyere main body; a supply port for supplying cooling water to the pipe; and a discharge port for discharging the cooling water circulated through the pipe. The pipe serves as a cooling water circulation path for circulating the cooling water through the inside of the tuyere main body, The pipe is an independent member built into the tuyere body,

2. The tuyere for a blast furnace according to claim 1 , wherein the pipe circulates around the tuyere body.

3. 2. The tuyere for a blast furnace according to claim 1, wherein the pipe is made of any one of copper, iron, nickel, aluminum, titanium and alloys of one or more of these.

4. The tuyere for a blast furnace according to claim 1, wherein the inner diameter of the pipe is 10 mm to 50 mm.

5. 2. The tuyere for a blast furnace according to claim 1, wherein at least one of an inner diameter, a cross-sectional shape, and a cross-sectional area of ​​said pipe varies depending on a position of said pipe.

6. The tuyere for a blast furnace according to claim 1, wherein the arithmetic mean roughness of the inner surface of the pipe is 1.5 μm to 2.5 μm.

7. 2. The tuyere for a blast furnace according to claim 1, wherein the surface roughness of the inner surface of the pipe is lower than the surface roughness of a portion where the tuyere body and the pipe contact each other.

8. The tuyere of claim 1 , wherein a plurality of said pipes are built into said tuyere body.

9. The tuyere for a blast furnace according to claim 1 , wherein the pipe is built in when the tuyere main body is formed.

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