A blast furnace blow-off tuyere and a method for blowing off and blowing in the tuyere, and a blast furnace tuyere blocking device

Abstract

This invention relates to the field of blast furnace ironmaking technology, and in particular to a method and device for sealing and reopening tuyeres during blast furnace shutdowns and restarts. The invention utilizes pre-made tuyere sealing material (water-based clay) that has been baked and hardened. The device is truncated cone-shaped, with a truncated cone-shaped groove at the end facing outwards, and its thickness in the center is less than its edge thickness. Before restarting blast, the pre-made device is pushed into the tuyere sleeve to seal the tuyere. When reopening the tuyere, simply tapping the center of the device will cause it to crack, allowing it to detach and fall into the furnace under wind pressure. This invention provides a tight seal, is not easily blown open by wind pressure, and the device does not adhere to the tuyere sleeve. The reopening operation is labor-saving and quick, significantly reducing operation time and facilitating rapid blast restoration. This invention uses less clay, reducing ironmaking costs, is applicable to various sizes of tuyere sleeves, and is easy to operate.

Description

Technical Field

[0001] This invention relates to the field of blast furnace ironmaking technology, and in particular to a method and device for blocking tuyeres during blast furnace shutdown and restarting blast furnace. Background Technology

[0002] During blast furnace production, shutdowns are scheduled according to the equipment's usage cycle for regular replacement or maintenance, typically requiring an annual overhaul and three quarterly shutdowns. After blast furnace maintenance and subsequent restart, several tuyeres are temporarily sealed with water-based taphole clay to facilitate rapid reconstruction of the proper gas flow within the furnace. The traditional method of sealing tuyeres involves using a pusher to directly push the water-based taphole clay to the end of the tuyer sleeve. To ensure a tight seal and prevent it from being blown open, a large amount of taphole clay is usually used, with the clay typically extending at least 150mm from the front of the tuyer sleeve. Simultaneously, as the blast furnace gradually increases its blast volume, the workers at the furnace front must gradually pry open the sealed tuyeres based on changes in furnace pressure, blast volume, furnace temperature, and slag / iron discharge. However, the longer the tuyeres are sealed, the stronger the adhesion between the taphole clay and the sleeve, and the higher the hardening and strength of the clay, leading to greater difficulty and longer processing time for the workers. This not only affects the blast furnace blasting and furnace condition recovery process, but also significantly increases the risk of high-temperature and high-pressure gas splashing faced by furnace workers during the tuyeres process as the furnace air volume and air pressure gradually increase.

[0003] To address the aforementioned problems, a novel method for temporarily sealing tuyeres during blast furnace shutdowns has been invented. This method not only saves on taphole clay and ensures a tight seal on the tuyeres, but more importantly, regardless of how much time has passed since blast furnace restarts, furnace operators can clear the tuyeres effortlessly, significantly reducing operation time. It also avoids delays in clearing the tuyeres that could affect blast furnace ventilation and furnace condition recovery, and significantly reduces the risk of furnace operators suffering burns from high-temperature, high-pressure gases during operation. Summary of the Invention

[0004] To address the technical problems of high consumption of taphole clay and difficulty in clearing the tuyeres due to the adhesion of taphole clay to the sleeve during blast furnace shutdown in existing technologies, this invention provides a method and device for blocking and clearing the tuyeres during blast furnace shutdown and restart.

[0005] Therefore, the present invention provides the following technical solution:

[0006] A method for blocking and reopening tuyeres during blast furnace shutdown includes the following steps: S1. A prefabricated air-blocking device using water-based clay is used, and the prefabricated air-blocking device is baked and hardened (pre-formed and hardened to avoid sticking to the air-blocking sleeve after re-airing, making it easier to pry open later). S2. Before the blast furnace is re-vented, the prefabricated and hardened tuyere blocking device is pushed into the tuyere sleeve using a mud-pushing tool to complete the sealing. S3. When it is necessary to open the tuyeres after the blast furnace is restarted, the middle part of the tuyeres blocking device is struck to crack the middle part of the device. The whole device falls off into the furnace under the action of air pressure (the opening operation is labor-saving and fast, significantly shortens the tuyeres opening time, and is conducive to the rapid restoration of blast furnace air supply).

[0007] Furthermore, the external dimensions of the air vent blocking device are matched with the inner diameter of the air vent sleeve (ensuring a tight seal while facilitating easy insertion of the air vent sleeve).

[0008] Furthermore, in step S1, the baking temperature is 1500-2000℃ and the baking time is 1-2 hours (to fully harden the air-blocking device and increase its strength, so that it can seal tightly and is easy to crack by knocking).

[0009] Furthermore, the air-blocking device is generally shaped like a frustum, with its diameter gradually decreasing along the axial direction; the end of the air-blocking device facing outward from the furnace is provided with a frustum-shaped groove, so that the thickness of the middle part of the device is less than the thickness of the edge (the middle part is weak and easily cracked, while the edge has high strength to ensure the sealing effect, making it easy to poke open and reliable to seal).

[0010] Furthermore, the mud-pushing tool includes a mud-pushing rod and a mud-pushing disc. The mud-pushing disc is fixedly installed at one end of the mud-pushing rod, and the diameter of the mud-pushing disc is adapted to the diameter of the end face of the frustum-shaped groove facing into the furnace (the mud-pushing disc can stably push the air-blocking device, and the force is uniform during the pushing process, making it less likely to damage the device).

[0011] A blast furnace tuyere plugging device applied to the method is provided. The device is made of water-based taphole clay and hardened by baking. It is shaped like a frustum and its diameter gradually decreases along the axial direction. The end of the device facing outward is provided with a frustum-shaped groove, so that the thickness of the middle part of the device is less than the thickness of the edge (the whole device is prefabricated and hardened, does not adhere to the tuyere sleeve, and can be broken and detached as a whole by knocking the middle part, reducing the labor intensity of furnace workers and the risk of high temperature splashing).

[0012] Advantages and positive effects of the present invention: This application utilizes pre-prepared water-based clay to create a tuyere plugging device, which is then baked and hardened. This prevents the device from sticking to the inner wall of the tuyere sleeve after it is pushed in. This eliminates the need for laborious tuyere plugging by furnace workers, significantly reducing the tuyere plugging time and improving operational efficiency. The significantly shortened tuyere plugging time avoids delays in blast furnace blasting and furnace condition recovery, facilitating a rapid return to normal blast furnace production.

[0013] The air vent blocking device has a thin center and thick edges, making it easy to crack in the center when hit. The whole device can quickly fall off under the action of air pressure inside the furnace, which significantly reduces the risk of workers in front of the furnace being burned by high temperature and high pressure gas splashes and improves work safety.

[0014] Compared with the traditional method of directly filling the blast furnace with clay, the present invention adopts a prefabricated integral tuyere blocking device, which makes the amount of clay used more controllable and less, saves clay consumption, and reduces the production cost per ton of iron in the blast furnace.

[0015] This application is simple to operate and highly practical. It is applicable to various specifications of tuyeres with diameters of 120mm, 125mm, and 130mm, and has good versatility, making it easy to promote and apply on-site in blast furnaces. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a side sectional view of the air-blocking device provided by the present invention.

[0018] Figure 2 This is a front view of the air-blocking device provided by the present invention.

[0019] Figure 3 A top view of the air vent blocking device provided by the present invention.

[0020] Figure 4 This is a structural diagram of a mud-pushing tool.

[0021] Figure 5 This is the main view of the blast furnace tuyeres.

[0022] Figure 6 This is a sectional view of the small sleeve of the blast furnace tuyeres.

[0023] Figure 7 Front view of the tuyere blocking device being inserted into the small sleeve of the blast furnace tuyere.

[0024] Figure 8 A cross-sectional view of the tuyeres plugging device inserted into the small sleeve of the blast furnace tuyeres.

[0025] Figure 9 A cross-sectional view of the device used to break the air vent blockage with a steel chisel.

[0026] In the diagram: 1. Groove; 2. Push rod; 3. Push disc; 4. Air vent blocking device; 5. Air vent sleeve; 6. Steel rod. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0028] This invention provides a method for blocking the tuyeres during blast furnace shutdown and for clearing the tuyeres during blast furnace restart, such as... Figure 5-8 As shown, it includes the following steps: S1. A prefabricated air-blocking device 4 using water-based clay is used, and the prefabricated air-blocking device 4 is then baked to harden it; the baking temperature is 1500-2000℃, and the baking time is 1-2 hours. Figure 1-3 As shown, the external dimensions of the air-blocking device match the inner diameter of the air-blocking sleeve. The air-blocking device is shaped like a frustum, with its diameter gradually decreasing along the axial direction. The end of the air-blocking device facing outward from the furnace is provided with a frustum-shaped groove 1, so that the thickness in the middle of the device is less than the thickness at the edge.

[0029] S2. Before the blast furnace is restarted, a mud-pushing tool is used to push the prefabricated and hardened tuyere-blocking device into the tuyere sleeve 5 to complete the sealing; such as Figure 4 As shown, the mud-pushing tool includes a mud-pushing rod 2 and a mud-pushing disc 3. The mud-pushing disc 3 is fixedly installed at one end of the mud-pushing rod 2, and the diameter of the mud-pushing disc 3 is adapted to the diameter of the end face of the frustum-shaped groove 1 facing into the furnace.

[0030] S3. When it is necessary to open the air vent after the air is restored, the middle part of the air vent blocking device is struck to crack the middle part of the device, and the whole device falls off into the furnace under the action of air pressure.

[0031] The present invention also provides a blast furnace tuyere blocking device for use in the methods of blocking tuyeres during blast furnace shutdown and restarting blast furnace ventilation. The device is made of water-based clay and hardened by baking. It is shaped like a frustum and its diameter gradually decreases along the axial direction. The end of the device facing outward is provided with a frustum-shaped groove 1, so that the thickness of the middle part of the device is less than the thickness of the edge.

[0032] Working principle: This invention uses water-based clay to make an integral tuyere blocking device, which is then baked and hardened. This allows the device to achieve sealing by simply matching its shape after being pushed into the blast furnace tuyere sleeve, without sticking to the inner wall of the tuyere sleeve.

[0033] After the blast furnace is re-pumped, air pressure is formed inside the furnace. Because the tuyeres are equipped with a frustum-shaped groove in the center, the thickness of the center is less than the thickness of the edges. Figure 9As shown, when the middle part of the device is lightly tapped with steel rod 6, the middle part cracks and breaks first; after the device cracks, the air pressure inside the furnace acts on the whole device, causing it to fall off quickly and be blown into the furnace, thus quickly completing the tuyeres opening operation.

[0034] The entire process does not require vigorous shoveling, making it labor-saving and quick. It also avoids the problems of traditional clay sealing, such as difficulty in shoveling and easy splashing that can cause injury, due to the adhesion caused by high-temperature sintering.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for blocking the tuyeres during blast furnace shutdown and clearing the tuyeres during blast furnace restart, characterized in that, Includes the following steps: S1. A prefabricated air-blocking device using water-based clay is used, and the prefabricated air-blocking device is baked and hardened. S2. Before the blast furnace is re-vented, the prefabricated and hardened tuyere blocking device is pushed into the tuyere sleeve using a mud-pushing tool to complete the sealing. S3. When it is necessary to open the air vent after the air is restored, the middle part of the air vent blocking device is struck to crack the middle part of the device, and the whole device falls off into the furnace under the action of air pressure.

2. The method for blocking and reopening tuyeres during blast furnace shutdown as described in claim 1, characterized in that, The external dimensions of the air vent blocking device are matched with the inner diameter of the air vent sleeve.

3. The method for blocking and reopening tuyeres during blast furnace shutdown as described in claim 1, characterized in that, In step S1, the baking temperature is 1500-2000℃ and the baking time is 1-2 hours.

4. The method for blocking and reopening tuyeres during blast furnace shutdown as described in claim 1, characterized in that, The air-blocking device is generally shaped like a frustum, with its diameter gradually decreasing along the axial direction; the end of the air-blocking device facing outward from the furnace is provided with a frustum-shaped groove (1), so that the thickness of the middle part of the device is less than the thickness of the edge.

5. The method for blocking and reopening tuyeres during blast furnace shutdown as described in claim 4, characterized in that, The mud-pushing tool includes a mud-pushing rod (2) and a mud-pushing disc (3). The mud-pushing disc (3) is fixedly installed at one end of the mud-pushing rod (2). The diameter of the mud-pushing disc (3) is adapted to the diameter of the end face of the frustum-shaped groove (1) facing into the furnace.

6. A blast furnace tuyeres plugging device applied to the method described in any one of claims 1-5, characterized in that, The device is made of water-based clay and hardened by baking. It is shaped like a frustum and its diameter gradually decreases along the axial direction. The device has a frustum-shaped groove (1) at one end facing out of the furnace, so that the thickness of the middle part of the device is less than the thickness of the edge.

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