A special tool for plugging tuyere of blast furnace and coal injection gun system

Abstract

This utility model relates to the field of blast furnace technology, specifically to a special tool for blocking blast furnace tuyeres and a pulverized coal injection (PCI) system. The special tool for blocking blast furnace tuyeres is used to inject a sodium silicate aqueous solution into a PCI system. The PCI system includes a PCI body and a coal conveying pipeline. A branch pipe is connected to the coal conveying pipeline, and a branch valve is installed on the branch pipe to control its on / off state. The special tool includes a purge pipe, a solution tank, and a connecting pipe connected in sequence. The end of the purge pipe away from the solution tank is connected to an air compressor, and the purge pipe is detachably connected to the solution tank. The special tool is connected to the coal conveying pipeline via the branch pipe. The sodium silicate aqueous solution is blown into the PCI body by the air compressor, mixes with the pulverized coal air from the coal conveying pipeline, and is then sprayed. This eliminates the problem of discontinuous air supply and effectively prevents the PCI clogging.

Description

Technical Field

[0001] This utility model relates to the field of blast furnace technology, specifically to a special tool for blocking blast furnace tuyeres and a coal injection gun system. Background Technology

[0002] In the blast furnace ironmaking process, various reasons often necessitate temporary or long-term blocking of tuyeres to reduce smelting intensity. Currently, after blocking the tuyeres with plugging mud, a sodium silicate aqueous solution is sprayed onto the pre-filled plugging mud surface using a spray gun. When the temperature exceeds 500℃, the sodium silicate aqueous solution rapidly dehydrates to form SiO2 gel, which solidifies within 3-5 minutes, acting as a binder.

[0003] For details, see attached. Figure 1 As shown, the current pulverized coal injection system includes a feed pipe 4, a coal conveying hose 5, a pulverized coal injection gun inlet pipe 3, and a pulverized coal injection gun body 2, which are connected in sequence. The two ends of the coal conveying hose 5 are detachably connected to the feed pipe 4 and the pulverized coal injection gun inlet pipe 3 via a first quick connector 6, respectively. A first valve 7 and a second valve 8 are installed on the feed pipe 4 and the pulverized coal injection gun inlet pipe 3, respectively. Before spraying the sodium silicate aqueous solution onto the plugging surface through the spray gun, the first valve 7 and the second valve 8 need to be closed. Then, the connection between the coal conveying hose 5 and the feed pipe 4 needs to be disconnected. Next, the sodium silicate aqueous solution is injected into the open end of the coal conveying hose 5. Then, the coal conveying hose 5 is reconnected to the feed pipe 4. Finally, the first valve 7 and the second valve 8 are opened, and air is supplied simultaneously.

[0004] The current technique of using sodium silicate aqueous solution to bond water-based plugging mud to air vents has the following main disadvantages:

[0005] 1. It is necessary to interrupt the air supply of the coal injection gun. Due to the discontinuous air supply of the coal injection gun, it is easy to cause blockage of the coal injection gun, which will affect the coal injection operation after the air outlet is opened, and at the same time affect the service life of the coal injection gun.

[0006] 2. Due to the limited capacity of the coal conveying hose 5, the amount of sodium silicate solution that can be sprayed in each spraying operation is small, requiring repeated interruptions of the coal injection air and repeated filling of the coal conveying hose 5, which is cumbersome. Utility Model Content

[0007] (I) The problem to be solved by this utility model is that the technique of using sodium silicate aqueous solution to bond the air vent with water-blocking mud requires interrupting the air supply of the coal injection gun. Due to the discontinuous air supply of the coal injection gun, it is easy to cause blockage of the coal injection gun, which affects the coal injection operation after the air vent is opened, and also affects the service life of the coal injection gun. In addition, due to the limited capacity of the coal conveying hose, the amount of sodium silicate aqueous solution that can be sprayed in each spraying operation is small, which requires repeated interruption of coal injection air and repeated filling of coal conveying hose, making the operation cumbersome.

[0008] (II) Technical Solution

[0009] A special tool for blocking tuyeres in blast furnaces, the special tool for blocking tuyeres in blast furnaces is used to inject sodium silicate aqueous solution into a pulverized coal injection system, the pulverized coal injection system includes a pulverized coal injection gun body and a coal conveying pipeline, a branch pipe is connected to the coal conveying pipeline, and a branch pipe valve for controlling its on and off is installed on the branch pipe;

[0010] The special tool for blocking the blast furnace tuyeres includes a purge pipe, a solution tank, and a connecting pipe connected in sequence. The end of the purge pipe away from the solution tank is used to connect to an air compressor. The purge pipe is detachably connected to the solution tank, and the connecting pipe is detachably connected to the solution tank. The end of the connecting pipe away from the solution tank is detachably connected to the end of the branch pipe away from the coal conveying pipeline.

[0011] The solution tank is provided with an inlet pipe on its side wall, and an exhaust valve is installed on the inlet pipe to control its opening and closing.

[0012] According to one embodiment of the present invention, one end of the solution tank is connected to an air inlet pipe, and the other end is connected to an air outlet pipe. The air inlet pipe is detachably connected to the purge pipe, and the air outlet pipe is detachably connected to the connecting pipe. An air source ball valve is installed on the air inlet pipe, and an output ball valve is installed on the air outlet pipe.

[0013] According to one embodiment of the present invention, the end of the air inlet pipe away from the solution tank is connected to the purge pipe via a second quick connector, and the end of the air outlet pipe away from the solution tank is detachably connected to the connecting pipe via a third quick connector.

[0014] According to one embodiment of the present invention, the end of the connecting pipe away from the solution tank is detachably connected to the branch pipe via a fourth quick connector.

[0015] According to one embodiment of the present invention, at least one purge valve for controlling its on / off state is installed on the purge pipe.

[0016] According to one embodiment of the present invention, the inner diameter of the bottom of the solution tank gradually increases along the air outlet pipe to the air inlet pipe.

[0017] A pulverized coal injection system, including the aforementioned special tool for blocking tuyeres in a blast furnace.

[0018] The beneficial effects of this utility model are:

[0019] Compared with traditional pulverized coal injection gun systems, the pulverized coal injection gun system equipped with this special tool for blocking blast furnace tuyeres has the following advantages:

[0020] First, the special tool is connected to the coal conveying pipeline through a branch pipe. The sodium silicate aqueous solution is blown into the coal injection gun body under the action of the air compressor. It is mixed with the coal injection air in the coal conveying pipeline and then sprayed. This eliminates the problem of discontinuous air supply and effectively prevents the coal injection gun from clogging.

[0021] Secondly, because the airflow inside the pulverized coal injection gun is stable, coal dust will not accumulate due to airflow interruption, reducing maintenance frequency and replacement costs, and extending the overall service life of the pulverized coal injection gun.

[0022] Third, traditional coal conveying hoses have limited capacity (usually holding only a small amount of solution), resulting in small spray volumes each time. This necessitates repeated interruptions of the coal injection airflow for refilling (e.g., repeatedly disconnecting the hose, injecting the solution, and reconnecting). This is not only cumbersome but also increases production delays and the risk of human error. In contrast, the solution tank in this application has a much larger capacity than the coal conveying hose, allowing for the storage and spraying of more sodium silicate aqueous solution each time. This reduces the refilling frequency, allows for the coverage of a wider area of ​​the plugging surface with a single injection, and improves spraying efficiency.

[0023] Fourth, after the solution is used up, simply close the output ball valve and the gas source ball valve, open the exhaust valve to vent the gas, and the solution can be quickly re-injected through the liquid inlet pipe. Then, spraying can be resumed immediately. The whole process is completed in a few minutes. The operation is simple and does not require disconnecting the special tool for blocking the blast furnace tuyeres from the branch pipe, nor will it interrupt the coal injection air.

[0024] Fifth, it is easy to operate; a single person can complete the spraying of sodium silicate aqueous solution. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of an existing coal injection gun system;

[0027] Figure 2 A schematic diagram of the coal injection gun system provided in an embodiment of this utility model;

[0028] Figure 3 This is a structural diagram of the solution tank provided in an embodiment of the present invention.

[0029] Icons: 1. Air inlet; 2. Coal injection gun body; 3. Coal injection gun inlet pipe; 301. Branch pipe; 302. Branch pipe valve; 4. Feed pipe; 5. Coal conveying hose; 6. First quick connector; 7. First valve; 8. Second valve; 9. Sludge plug; 10. Solution tank; 11. Air inlet pipe; 12. Air outlet pipe; 13. Liquid inlet pipe; 14. Air source ball valve; 15. Output ball valve; 16. Exhaust valve; 17. Second quick connector; 18. Third quick connector; 19. Purge pipe; 20. Connecting pipe; 21. Fourth quick connector; 22. Purge valve. Detailed Implementation

[0030] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0031] Example 1:

[0032] like Figures 2-3 As shown, Embodiment 1 of this utility model provides a special tool for blocking blast furnace tuyeres. The special tool for blocking blast furnace tuyeres is used to inject sodium silicate aqueous solution into the pulverized coal injection system. The pulverized coal injection system includes a pulverized coal injection gun body 2 and a coal conveying pipeline. A branch pipe 301 is connected to the coal conveying pipeline, and a branch pipe valve 302 for controlling its opening and closing is installed on the branch pipe 301.

[0033] The special tool for blocking the blast furnace tuyeres includes a purge pipe 19, a solution tank 10, and a connecting pipe 20 connected in sequence. The end of the purge pipe 19 away from the solution tank 10 is used to connect to an air compressor. The purge pipe 19 and the solution tank 10 are detachably connected. The connecting pipe 20 and the solution tank 10 are detachably connected. The end of the connecting pipe 20 away from the solution tank 10 is detachably connected to the end of the branch pipe 301 away from the coal conveying pipeline.

[0034] The solution tank 10 is provided with an inlet pipe 13 on its side wall, and an exhaust valve 16 is installed on the inlet pipe 13 to control its opening and closing.

[0035] In this embodiment, after the sludge 9 is used to block the air outlet 1, the end of the connecting pipe 20 away from the solution tank 10 is connected to the branch pipe 301 on the coal conveying pipeline. Then, the exhaust valve 16 on the inlet pipe 13 of the solution tank 10 is opened, and sodium silicate aqueous solution is injected into the inlet pipe 13. After that, the exhaust valve 16 is closed, and the purge pipe 19 is connected to the air compressor. Then, the air compressor is turned on to start blowing air and the branch pipe valve 302 is opened at the same time. At this time, the compressed air in the purge pipe 19 blows the sodium silicate aqueous solution in the solution tank 10 out and passes through the connecting pipe 20 and the branch pipe 301 in sequence before entering the coal conveying pipeline. Finally, under the combined action of the compressed air in the coal conveying pipeline and the compressed air entering from the purge pipe 19, the sodium silicate aqueous solution is blown into the coal injection gun body 2, thereby spraying the sludge 9 in the air outlet 1.

[0036] As can be seen, in this embodiment, the special tool for blocking the blast furnace tuyere is connected to the coal conveying pipeline of the conventional pulverized coal injection system. In this way, the coal conveying pipeline of the pulverized coal injection system supplies air normally, and then the special tool for blocking the blast furnace tuyere is used to send sodium silicate aqueous solution into the coal conveying pipeline.

[0037] This allows for continuous air supply to the pulverized coal injection gun, preventing clogging and extending its lifespan. Furthermore, each spraying operation can deliver a larger volume of sodium silicate solution, and operation is simpler.

[0038] It needs to be explained that in the past, during pulverized coal injection, compressed air (carrier air) kept the pulverized coal in a suspended state. Once the air supply was interrupted, the pulverized coal lost its airflow support and quickly settled on the inner wall of the coal conveying pipeline. Moreover, the pulverized coal is easily softened by heat and adheres to the pipe wall, causing blockage. In addition, the temperature in the air outlet area 1 can reach over 2000℃. After the air supply is interrupted, the pulverized coal remaining at the nozzle head is continuously baked by the high temperature, pyrolyzing and coking to form a hard carbon layer, which easily causes blockage. This requires manual unblocking or replacement of the nozzle, increasing maintenance costs, and frequent interruptions shorten the life of the nozzle.

[0039] In this embodiment, since the coal conveying pipeline of the coal injection gun system supplies air normally throughout the entire process of spraying sodium silicate aqueous solution, the coal injection gun supplies air continuously and will not cause blockage of the coal injection gun due to interruption of air supply, thus avoiding the problem of shortened service life of the coal injection gun due to interruption of air supply.

[0040] Furthermore, it needs to be explained that during the tuyer 1 blocking operation, even though tuyer 1 has been sealed with plugging mud 9, a low airflow still needs to be maintained. This is determined by the process characteristics and safety requirements of blast furnace smelting. The specific reasons are as follows: a complete stop of airflow would cause a low-temperature dead zone to form in the blocked tuyer 1 area, causing the molten slag and iron to solidify and triggering the risk of hearth freezing. Low airflow can maintain the weak combustion of coke in this area and prevent a sudden drop in temperature. In addition, the cooling water jacket of tuyer 1 relies on internal airflow to remove heat. When the airflow is completely stopped, high-temperature furnace gas backflows (>1500℃), burning through the copper jacket of tuyer 1.

[0041] In this embodiment, as Figure 2 and Figure 3 As shown, one end of the solution tank 10 is connected to an air inlet pipe 11, and the other end is connected to an air outlet pipe 12. The axis of the air inlet pipe 11 and the axis of the air outlet pipe 12 are collinear. An air source ball valve 14 is installed on the air inlet pipe 11, and an output ball valve 15 is installed on the air outlet pipe 12. The end of the air inlet pipe 11 away from the solution tank 10 is connected to the purge pipe 19 via a second quick connector 17. The end of the air outlet pipe 12 away from the solution tank 10 is detachably connected to the first end of the connecting pipe 20 via a third quick connector 18. One end of the liquid inlet pipe 13 is sealed to the liquid inlet on the side wall of the solution tank 10.

[0042] In some embodiments, such as Figure 2 As shown, the end of the connecting pipe 20 away from the solution tank 10 is detachably connected to the branch pipe 301 via a fourth quick connector 21.

[0043] In some embodiments, at least one purge valve 22 is installed on the purge pipe 19 for controlling its on / off state.

[0044] In some embodiments, the volume of the solution tank 10 is 1L to 3L. Preferably, it is 3L.

[0045] In some embodiments, such as Figure 3 As shown, the bottom of the solution tank 10 is frustum-shaped, meaning that the inner diameter of the bottom of the solution tank 10 gradually increases from the outlet pipe 12 to the inlet pipe 11. This design makes it easier to drain the sodium silicate aqueous solution from the solution tank 10.

[0046] In some embodiments, the system further includes an injection mechanism comprising an injection pump and an injection pipe, wherein a first end of the injection pipe is connected to the injection pump, and a second end of the injection pipe is connected to the inlet pipe 13 via a flange or quick connector. Thus, the injection pump can complete the injection operation without manual injection.

[0047] It should be noted that the pressure of the high-pressure air source connected to the purge pipe 19 should be more than 100 kPa higher than the working pressure of the coal injection air in the coal injection gun, but not more than twice the working pressure of the coal injection air.

[0048] In this embodiment, after the blast furnace is shut down, the tuyeres 1 are first blocked using conventional methods with plugging mud 9, the thickness of which only needs to be about 100mm. After blocking the tuyeres 1, the tuyeres 1 are restored to the air supply state. Then, with the coal conveying pipeline in the air supply state, the special tool for blocking the blast furnace tuyeres is used... Figure 2The solution is connected to branch pipe 301 of the coal conveying pipeline as shown. Then, the exhaust valve 16 is opened and the output ball valve 15 is closed. Sodium silicate aqueous solution is injected into the solution tank 10 through the inlet pipe 13. After injection, the exhaust valve 16 is closed. When spraying the air-blocking nozzle 1 is required, the purge valve 22, air source ball valve 14, output ball valve 15, and branch pipe valve 302 are opened. The sodium silicate aqueous solution is then blown into the coal injection gun body 2 under the action of the high-pressure air source from the air compressor. Inside the coal injection gun, it mixes with the existing coal injection air and is sprayed onto the plugging mud 9, completing the air-blocking nozzle 1 spraying operation and stabilizing the plugging mud 9.

[0049] When the sodium silicate aqueous solution has been sprayed out and more needs to be sprayed, close the output ball valve 15 and the gas source ball valve 14, and open the exhaust valve 16 to vent the gas. After venting, inject sodium silicate aqueous solution back into the solution tank 10 through the liquid inlet pipe 13. After injection, close the exhaust valve 16, open the gas source ball valve 14 and the output ball valve 15, and the spraying operation can be carried out again.

[0050] In summary, compared with traditional pulverized coal injection gun systems, the pulverized coal injection gun system equipped with this special tool for blocking blast furnace tuyeres has the following advantages:

[0051] First, the special tool is connected to the coal conveying pipeline through branch pipe 301. The sodium silicate aqueous solution is blown into the coal injection gun body 2 under the action of the air compressor. It is mixed with the coal injection air of the coal conveying pipeline and then sprayed. This eliminates the problem of discontinuous air supply and effectively prevents the coal injection gun from clogging.

[0052] Secondly, because the airflow inside the pulverized coal injection gun is stable, coal dust will not accumulate due to airflow interruption, reducing maintenance frequency and replacement costs, and extending the overall service life of the pulverized coal injection gun.

[0053] Third, the traditional coal conveying hose 5 has a limited capacity (usually only able to hold a small amount of solution), resulting in a small spray volume each time. This necessitates repeated interruptions of the coal injection airflow for filling (e.g., repeatedly disconnecting the coal conveying hose 5, injecting the solution, and reconnecting). This is not only cumbersome but also increases production delays and the risk of human error. In contrast, the solution tank 10 of this application has a volume of 3L, far exceeding the capacity of the coal conveying hose 5. It can store and spray a larger amount of sodium silicate aqueous solution each time, reducing the filling frequency and allowing a single injection to cover a wider area of ​​the plugging mud 9 surface, thus improving spraying efficiency.

[0054] Fourth, after the solution is used up, simply close the output ball valve 15 and the gas source ball valve 14, open the exhaust valve 16 to exhaust the gas, and the solution can be quickly re-injected through the liquid inlet pipe 13. Then spraying can be resumed immediately. The whole process is completed in a few minutes. The operation is simple and does not require disconnecting the connection between the special tool for blocking the blast furnace tuyeres and the branch pipe 301, nor will it interrupt the coal injection air.

[0055] Fifth, it is easy to operate; a single person can complete the spraying of sodium silicate aqueous solution.

[0056] Example 2

[0057] Embodiment 2 of this utility model provides a pulverized coal injection gun system, which includes the blast furnace tuyeres plugging tool described in Embodiment 1 above. The pulverized coal injection gun system includes a coal conveying pipeline, a pulverized coal injection gun body 2, and a high-pressure gas source. The coal conveying pipeline includes a feed pipe 4, a coal conveying hose 5, and a pulverized coal injection gun inlet pipe 3 connected in sequence. The two ends of the coal conveying hose 5 are detachably connected to the feed pipe 4 and the pulverized coal injection gun inlet pipe 3 respectively via a first quick connector 6. One end of the pulverized coal injection gun inlet pipe 3 is connected to the pulverized coal injection gun body 2. The feed pipe 4 is connected to the high-pressure gas source. A first valve 7 and a second valve 8 are installed on the feed pipe 4 and the pulverized coal injection gun inlet pipe 3, respectively. Furthermore, an installation hole is opened on the side wall of the pulverized coal injection gun inlet pipe 3, and a branch pipe 301 is sealed and installed at the installation hole. A branch pipe valve 302 is installed on the branch pipe 301. The connecting pipe 20 of the blast furnace tuyeres plugging tool is detachably connected to the branch pipe 301 via a fourth quick connector 21.

[0058] In the description of this utility model, it should be noted that the terms "upper" and "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0059] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0060] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A special tool for blocking blast furnace tuyeres, characterized in that, The special tool for blocking the blast furnace tuyere is used to inject sodium silicate aqueous solution into the pulverized coal injection system. The pulverized coal injection system includes the pulverized coal injection gun body (2) and the coal conveying pipeline. A branch pipe (301) is connected to the coal conveying pipeline. A branch pipe valve (302) for controlling its opening and closing is installed on the branch pipe (301). The special tool for blocking the blast furnace tuyeres includes a purge pipe (19), a solution tank (10), and a connecting pipe (20) connected in sequence. The end of the purge pipe (19) away from the solution tank (10) is used to connect to an air compressor. The purge pipe (19) is detachably connected to the solution tank (10). The connecting pipe (20) is detachably connected to the solution tank (10). The end of the connecting pipe (20) away from the solution tank (10) is detachably connected to the end of the branch pipe (301) away from the coal conveying pipeline. The solution tank (10) is provided with an inlet pipe (13) on its side wall, and an exhaust valve (16) for controlling its opening and closing is installed on the inlet pipe (13).

2. The special tool for blocking blast furnace tuyeres according to claim 1, characterized in that, One end of the solution tank (10) is connected to an air inlet pipe (11), and the other end is connected to an air outlet pipe (12). The air inlet pipe (11) is detachably connected to the purge pipe (19), and the air outlet pipe (12) is detachably connected to the connecting pipe (20). An air source ball valve (14) is installed on the air inlet pipe (11), and an output ball valve (15) is installed on the air outlet pipe (12).

3. A special tool for blocking blast furnace tuyeres according to claim 2, characterized in that, The end of the air inlet pipe (11) away from the solution tank (10) is connected to the purge pipe (19) via a second quick connector (17), and the end of the air outlet pipe (12) away from the solution tank (10) is detachably connected to the connecting pipe (20) via a third quick connector (18).

4. A special tool for blocking blast furnace tuyeres according to claim 3, characterized in that, The end of the connecting pipe (20) away from the solution tank (10) is detachably connected to the branch pipe (301) via a fourth quick connector (21).

5. A special tool for blocking blast furnace tuyeres according to claim 4, characterized in that, At least one purge valve (22) is installed on the purge pipe (19) for controlling its on / off state.

6. A special tool for blocking blast furnace tuyeres according to claim 2, characterized in that, Along the outlet pipe (12) to the inlet pipe (11), the inner diameter of the bottom of the solution tank (10) gradually increases.

7. A coal injection gun system, characterized in that, Includes a special tool for blocking blast furnace tuyeres as described in any one of claims 1-6.

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