Gas-based shaft furnace direct reduction iron recovery production device

Abstract

The utility model belongs to the technical field of low-carbon metallurgy, and provides a gas-based shaft furnace direct reduction iron recovery production device which comprises a shaft furnace body used for producing direct reduction iron, a charging unit and a recovery unit are arranged at the top of the shaft furnace body, and a discharging unit is arranged at the bottom of the shaft furnace body; the material distributing unit comprises an inlet, a first outlet and a second outlet, the inlet is connected with the material discharging unit, the first outlet is used for discharging qualified direct reduced iron, and the second outlet is used for discharging unqualified direct reduced iron; and the conveying unit is connected with the second outlet and is used for conveying the unqualified direct reduced iron to the recovery unit. According to the scheme, the problems of high production energy consumption, dust pollution, low smelting efficiency, heat loss and the like in the recovery treatment process of the unqualified direct reduced iron in the prior art can be effectively avoided.

Description

Technical Field

[0001] This utility model belongs to the field of low-carbon metallurgical technology, and in particular relates to a gas-based vertical shaft furnace direct reduced iron recovery production device. Background Technology

[0002] Gas-based shaft furnaces are the main reaction units used for producing direct reduced iron (DRI). During the start-up process, the reducing gas needs time to reach the required temperature, pressure, and composition for production. The ore pellets entering the furnace also need time for preheating and reduction reactions before becoming DRI with the required metallization rate. Therefore, from start-up to production, a certain amount of substandard DRI (i.e., DRI with insufficient reduction reaction and substandard metallization rate) will be discharged from the gas-based shaft furnace DRI production unit.

[0003] In the commonly used gas-based vertical shaft furnace direct reduction metallurgical process both domestically and internationally, the following process is typically used to recycle substandard direct reduced iron (DRI) discharged during the furnace start-up process: First, the substandard DRI is transported to a temporary stockpile via a discharge system and a finished product conveying system. Then, the substandard DRI is stored in the temporary stockpile until it cools to room temperature. Finally, the substandard DRI is reloaded into the raw material processing system, where it undergoes screening, spraying, and other treatments along with raw material pellets before being re-charged into the furnace for smelting. This recycling process suffers from several drawbacks: the substandard DRI requires long-distance transportation, resulting in high energy consumption; multiple transfers generate dust, causing environmental pollution; continuous contact between the substandard DRI and oxygen and moisture in the air leads to re-oxidation, resulting in low smelting efficiency after being recycled; and the substandard DRI needs to cool to room temperature before being re-charged, causing heat loss. Utility Model Content

[0004] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a gas-based vertical shaft furnace direct reduced iron recovery production device to solve the above problems.

[0005] To achieve the above and other related objectives, this utility model provides a gas-based vertical shaft furnace direct reduced iron recovery production apparatus, comprising:

[0006] The vertical shaft furnace body is used to produce direct reduced iron. The top of the vertical shaft furnace body is equipped with a charging unit and a recycling unit, and the bottom of the vertical shaft furnace body is equipped with a discharging unit.

[0007] The material distribution unit includes an inlet, a first outlet, and a second outlet. The inlet is connected to the discharge unit. The first outlet is used to discharge qualified direct reduced iron, and the second outlet is used to discharge unqualified direct reduced iron.

[0008] A conveying unit, connected to the second outlet, is used to convey substandard direct reduced iron to the recycling unit.

[0009] Optionally, the conveying unit includes a conveying tank, a first conveying pipe is provided between the conveying tank and the distributing unit, a first sealing shut-off valve is provided on the first conveying pipe, a second conveying pipe is provided at the output end of the conveying tank, a feeding valve is provided on the second conveying pipe, and a second sealing shut-off valve is provided between the feeding valve and the output end of the second conveying pipe.

[0010] Optionally, the conveying tank is equipped with an air supply unit, which is used to provide conveying air for the unqualified direct reduced iron in the conveying tank.

[0011] Optionally, the gas supply unit includes a nitrogen gas source and a pressurizing pipe and a pneumatic conveying pipe respectively connected to the nitrogen gas source. The pressurizing pipe is connected to the top of the conveying tank and is equipped with a pressurizing valve. The pneumatic conveying pipe is connected to the output end of the second conveying pipe and is equipped with a shut-off valve. The pneumatic conveying pipe is connected to the recovery unit.

[0012] Optionally, the conveying tank is also connected to a first dust removal device via a first pressure relief pipe, and a first pressure relief valve is provided on the first pressure relief pipe.

[0013] Optionally, the first pressure relief pipe is connected to the top of the delivery tank.

[0014] Optionally, the recycling unit includes a recycling tank, the pneumatic conveying pipe is connected to the top of the recycling tank, a third sealing shut-off valve is provided on the pneumatic conveying pipe, a material distributor is provided between the recycling tank and the vertical furnace body, the material distributor is connected to the recycling tank through a third conveying pipe, and a fourth sealing shut-off valve is provided on the third conveying pipe.

[0015] Optionally, the recycling tank is connected to a second dust removal device via a second pressure relief pipe, and a second pressure relief valve is provided on the second pressure relief pipe.

[0016] Optionally, the second pressure relief pipe is connected to the top of the recovery tank.

[0017] As described above, the gas-based vertical shaft furnace direct reduced iron recovery production device of this utility model has the following beneficial effects:

[0018] In this scheme, raw materials enter the shaft furnace body through the charging unit for direct reduction reaction. The resulting direct reduced iron (DRI) is then depressurized through the discharge unit and enters the distribution unit. Substandard DRI enters the conveying unit from the second outlet of the distribution unit and is pneumatically conveyed to the recovery unit, where it re-enters the shaft furnace body for direct reduction reaction. This entire process enables the reuse of substandard DRI. Substandard DRI does not require long-distance transport; instead, it is directly conveyed to the recovery unit via the conveying unit, resulting in short transport distances, low transport costs, low energy consumption, and minimal heat loss. The recovery of substandard DRI via pneumatic conveying occurs entirely within a closed container or pipeline, only in contact with nitrogen gas, ensuring cleanliness and environmental friendliness, preventing re-oxidation, and improving the smelting efficiency after recovery. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the gas-based vertical shaft furnace direct reduced iron recovery production device in this embodiment of the present invention. Detailed Implementation

[0020] The reference numerals in the accompanying drawings include:

[0021] 1. Charging unit; 2. Recycling tank; 3. Distributor; 4. Fourth sealing shut-off valve; 5. Vertical furnace body; 6. Discharge unit; 7. Distribution unit; 8. First conveying pipe; 9. First sealing shut-off valve; 10. Conveying tank; 11. Feeding valve; 12. Second sealing shut-off valve; 13. Nitrogen source; 14. Pressurizing pipe; 15. Pressurizing valve; 16. Shut-off valve; 17. Pneumatic conveying pipe; 18. Third sealing shut-off valve; 19. Second pressure relief valve; 20. Second dust removal equipment; 21. First pressure relief valve; 22. First dust removal equipment; 23. Second conveying pipe; 24. Qualified direct reduced iron conveying and processing unit; 25. Third conveying pipe; 26. First pressure relief pipe; 27. Second pressure relief pipe.

[0022] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0023] This utility model provides a gas-based vertical shaft furnace direct reduced iron recovery production device, such as... Figure 1 As shown.

[0024] In one exemplary embodiment of this application, a gas-based vertical shaft furnace direct reduced iron recovery production apparatus is provided, comprising:

[0025] The vertical furnace body 5 is used to produce direct reduced iron. A feeder 3 is installed at the top of the vertical furnace body 5. A charging unit 1 and a recovery tank 2 are connected to the feeder 3. A discharge unit 6 is installed at the bottom of the vertical furnace body 5.

[0026] The material distribution unit 7 includes an inlet, a first outlet, and a second outlet. The inlet is connected to the discharge unit 6. The first outlet is used to separate qualified direct reduced iron, and the second outlet is used to separate unqualified direct reduced iron.

[0027] The conveying unit, connected to the second outlet, is used to convey substandard direct reduced iron to the recycling tank 2.

[0028] For example, the recycling tank 2 and the fabric distributor 3 are connected by a third conveying pipe 25. A fourth sealing shut-off valve 4 is provided on the third conveying pipe 25. By opening or closing the fourth sealing shut-off valve 4, the connection or blockage between the recycling tank 2 and the fabric distributor 3 can be achieved.

[0029] In this embodiment, the raw material is pressurized in the charging unit 1, and then enters the vertical shaft furnace body 5 through the distributor 3 for direct reduced iron (DRI) reaction. The produced DRI is then depressurized through the discharge unit 6 and enters the distribution unit 7. Unqualified DRI enters the conveying unit from the second outlet of the distribution unit 7, and is conveyed to the recovery tank 2. It then re-enters the vertical shaft furnace body 5 through the distributor 3 for DRI reaction. This entire process enables the reuse of unqualified DRI. Unqualified DRI does not require long-distance transport; instead, it is directly transported to the recovery unit via the conveying unit. This results in a short transport distance, low transport costs, low energy consumption, and minimal heat loss. Unqualified DRI is recovered via pneumatic conveying. The entire process is conducted within a closed container or pipeline, only in contact with the transported nitrogen gas, making it clean and environmentally friendly, preventing re-oxidation, and improving the smelting efficiency after recovery.

[0030] For example, the charging unit 1 contains unreacted raw materials, and the recovery tank 2 is used to hold substandard direct reduced iron (DRI). The distributing unit 7 includes a three-way distributor, used to switch the outlet according to the quality of the conveyed DRI. When qualified DRI is discharged, the system switches to open the first outlet and close the second outlet; if substandard DRI is discharged, the system switches to close the first outlet and open the second outlet. The quality of the DRI can be determined manually or based on the reaction time of the shaft furnace body 5.

[0031] For example, the direct reduced iron produced within a preset time after the vertical shaft furnace body 5 is opened is determined to be unqualified direct reduced iron, and the material distribution unit 7 is controlled to distribute the material by means of timers or other methods.

[0032] In an exemplary embodiment, the conveying unit includes a conveying tank 10, a first conveying pipe 8 is provided between the conveying tank 10 and the distributing unit 7, a first sealing shut-off valve 9 is provided on the first conveying pipe 8, a second conveying pipe 23 is provided between the conveying tank 10 and the pneumatic conveying pipe 17, a feeding valve 11 is provided on the second conveying pipe 23, and a second sealing shut-off valve 12 is provided between the feeding valve 11 and the output end of the second conveying pipe 23.

[0033] For example, the conveying tank 10 includes a feeding state, a pressurizing state, and a conveying state. In the feeding state, the first sealing shut-off valve 9 is open, and the second sealing shut-off valve 12 and the feed valve 11 are closed. In the pressurizing state, the first sealing shut-off valve 9, the feed valve 11, and the second sealing shut-off valve 12 are closed. In the conveying state, the first sealing shut-off valve 9 is closed, and the feed valve 11 and the second sealing shut-off valve 12 are open.

[0034] In this embodiment, during the conveying of substandard direct reduced iron in the conveying tank 10, pressurization is required for conveying. To facilitate pressurization, a first sealing shut-off valve 9 and a second sealing shut-off valve 12 are provided to block and seal the input and output of the conveying tank. The feed valve 11 is used to open after pressurization is stopped, so as to convey the substandard direct reduced iron to the pneumatic conveying pipe 17.

[0035] In one exemplary embodiment, a gas supply unit is provided on the conveying tank 10, which is used to provide conveying gas for the defective direct reduced iron in the conveying tank.

[0036] In this embodiment, the gas supply unit provides the conveying gas for conveying unqualified direct reduced iron to the conveying tank 10.

[0037] In an exemplary embodiment, the gas supply unit includes a nitrogen gas source 13 and a pressurizing pipe 14 and a pneumatic conveying pipe 17 respectively connected to the nitrogen gas source 13. The pressurizing pipe 14 is connected to the conveying tank 10 and is provided with a pressurizing valve 15. The pneumatic conveying pipe 17 is connected to the output end of the second conveying pipe 23 and the recovery tank 2, and is provided with a shut-off valve 16.

[0038] In this embodiment, when the substandard direct reduced iron is located in the conveying tank 10, the first sealing shut-off valve 9 and the second sealing shut-off valve 12 are closed first, the pressurization valve 15 is opened, and nitrogen is introduced into the conveying tank 10 until the conveying tank 10 reaches the working pressure, and then the pressurization valve 15 is closed; then the shut-off valve 16 is opened, and the conveying nitrogen gas flow is introduced into the pneumatic conveying pipe 17; finally, the second sealing shut-off valve 12 and the feed valve 11 are opened in sequence to discharge the substandard direct reduced iron in the conveying tank 10 into the pneumatic conveying pipe 17 through the second conveying pipe 23.

[0039] In an exemplary embodiment, the conveying tank 10 is also connected to a first dust removal device 22 via a first pressure relief pipe 26, and a first pressure relief valve 21 is provided on the first pressure relief pipe 26.

[0040] It should be noted that after the unqualified direct reduced iron is output from the conveying tank 10, it is necessary to depressurize it in order to facilitate the subsequent conveying of unqualified direct reduced iron.

[0041] For example, the conveying tank 10 also includes a pressure relief state. After the conveying state ends, the first sealing shut-off valve 9, the feed valve 11 and the second sealing shut-off valve 12 are closed, the first pressure relief valve 21 is opened, and the conveying tank 10 is switched to the pressure relief state to release the pressure in the conveying tank 10 to atmospheric pressure.

[0042] In one exemplary embodiment, the pressurization pipe 14 is connected to the top of the delivery tank 10.

[0043] In this embodiment, in order to facilitate pressurization of the delivery tank 10, the pressurization pipe 14 is connected to the top of the delivery tank 10.

[0044] In an exemplary embodiment, the first pressure relief pipe 26 is connected to the top of the delivery tank 10.

[0045] In this embodiment, in order to facilitate the pressure relief of the conveying tank 10, the first pressure relief pipe 26 is connected to the top of the conveying tank 10.

[0046] In an exemplary embodiment, a pneumatic conveying pipe 17 is provided between the gas supply unit and the recovery tank 2, and a shut-off valve 16 is provided on the pneumatic conveying pipe 17.

[0047] In this embodiment, the substandard direct reduced iron enters the pneumatic conveying pipe 17 from the conveying tank 10 through the second conveying pipe 23, and is conveyed by the nitrogen gas flow in the pneumatic conveying pipe 17, so that the substandard direct reduced iron enters the recovery tank 2 through the pneumatic conveying pipe 17.

[0048] In an exemplary embodiment, the recovery tank 2 is connected to a second dust removal device 20 via a second pressure relief pipe 27, and a second pressure relief valve 19 is provided on the second pressure relief pipe 27.

[0049] In this embodiment, during the pneumatic conveying process of unqualified direct reduced iron, nitrogen is continuously introduced into the recovery tank 2, which will cause the gas pressure in the recovery tank 2 to increase. In order to avoid hindering the continued conveying of unqualified direct reduced iron, the recovery tank 2 is equipped with a second pressure relief pipe 27 and a second pressure relief valve 19 to discharge the conveyed nitrogen to the second dust removal equipment 21 for dust removal treatment.

[0050] In one exemplary embodiment, the second pressure relief pipe 27 is connected to the top of the recovery tank 2.

[0051] In this embodiment, in order to facilitate pressure relief, the second pressure relief pipe 27 is connected to the top of the recovery tank 2.

[0052] In an exemplary embodiment, a discharge unit 6 is provided between the inlet of the material distribution unit 7 and the discharge port at the bottom of the vertical furnace body 5.

[0053] In this embodiment, the unqualified direct reduced iron produced by the vertical furnace body 5 enters the discharge unit 6 for depressurization, so that the discharge unit 6 is reduced to atmospheric pressure, so that the unqualified direct reduced iron can enter the conveying tank 10.

[0054] For example, after the unqualified direct reduced iron comes out of the vertical furnace body 5, it directly enters the discharge unit 6 and is reduced to atmospheric pressure. Then, the first sealing shut-off valve 9 is opened and the second sealing shut-off valve 12 and the feed valve 11 are closed, so that the conveying tank 10 is switched to the feeding state. The three-way distributor is switched to discharge from the second outlet to transport the unqualified direct reduced iron into the conveying tank 10. After the non-conforming direct reduced iron (DRI) has been conveyed, the first sealing shut-off valve 9, feed valve 11, shut-off valve 16, second sealing shut-off valve 12, and first pressure relief valve 21 are closed. The pressurizing valve 16 is opened, switching the conveying tank 10 to pressurization mode. After pressurization, the pressurizing valve 16 is closed, and the third sealing shut-off valve 18, shut-off valve 16, second sealing shut-off valve 12, and feed valve 11 are opened sequentially, switching the conveying tank 10 to conveying mode for pneumatic conveying of the non-conforming DRI. After all the non-conforming DRI has been conveyed out of the conveying tank 10, the second sealing shut-off valve 12 and feed valve 11 are closed, and the first pressure relief valve 22 is opened, switching the conveying tank to pressure relief mode. The third sealing shut-off valve 18 and shut-off valve 16 remain open, allowing the nitrogen source 13 to continue providing pneumatic power for the conveying of the non-conforming DRI, ensuring that all the non-conforming DRI is conveyed to the recovery tank 2 via the pneumatic conveying pipe 17. After a batch of substandard direct reduced iron (DRI) enters the recovery tank 2, the second pressure relief valve 19 is closed, while the third sealing shut-off valves 18 and 16 remain open until the air pressure in the recovery tank 2 and the material distributor 3 are consistent. Then, the third sealing shut-off valves 18 and 16 are closed. When the air pressure in the recovery tank 2 and the material distributor 3 are consistent, the fourth sealing shut-off valve 4 between the recovery tank 2 and the material distributor 3 is opened, allowing the substandard DRI in the recovery tank 2 to enter the material distributor 3 and then into the vertical furnace body 5 for direct reduction reaction.

[0055] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A gas-based shaft furnace direct reduced iron recovery production device, characterized in that, The utility model relates to a vertical furnace body for producing direct reduction iron, which is provided with a charging unit and a recovery unit at the top and a discharging unit at the bottom. The utility model relates to a vertical furnace body for producing direct reduction iron, which is provided with a charging unit and a recovery unit at the top and a discharging unit at the bottom. The utility model relates to a vertical furnace body for producing direct reduction iron, which is provided with a charging unit and a recovery unit at the top and a discharging unit at the bottom. The utility model relates to a vertical furnace body for producing direct reduction iron, which is provided with a charging unit and a recovery unit at the top and a discharging unit at the bottom.

2. The apparatus for gas-based shaft furnace direct reduced iron recovery production according to claim 1, characterized in that, The utility model relates to a vertical furnace body for producing direct reduction iron, which is provided with a charging unit and a recovery unit at the top and a discharging unit at the bottom.

3. The apparatus for gas-based shaft furnace direct reduced iron recovery production according to claim 2, characterized in that, The utility model relates to a vertical furnace body for producing direct reduction iron, which is provided with a charging unit and a recovery unit at the top and a discharging unit at the bottom.

4. The apparatus according to claim 3, wherein the apparatus is characterized by: The utility model relates to a vertical furnace body for producing direct reduction iron, which is provided with a charging unit and a recovery unit at the top and a discharging unit at the bottom.

5. The apparatus for gas-based shaft furnace direct reduced iron recovery production according to claim 3, characterized in that, The utility model relates to a vertical furnace body for producing direct reduction iron, which is provided with a charging unit and a recovery unit at the top and a discharging unit at the bottom.

6. The apparatus for gas-based shaft furnace direct reduced iron recovery production according to claim 5, characterized in that, The utility model relates to a vertical furnace body for producing direct reduction iron, which is provided with a charging unit and a recovery unit at the top and a discharging unit at the bottom.

7. The apparatus according to claim 4, wherein the apparatus is characterized by: The utility model relates to a vertical furnace body for producing direct reduction iron, which is provided with a charging unit and a recovery unit at the top and a discharging unit at the bottom.

8. The apparatus for gas-based shaft furnace direct reduced iron recovery production according to claim 7, characterized in that, The utility model relates to a vertical furnace body for producing direct reduction iron, which is provided with a charging unit and a recovery unit at the top and a discharging unit at the bottom.

9. The apparatus for gas-based shaft furnace direct reduced iron recovery production according to claim 8, characterized in that, The utility model relates to a vertical furnace body for producing direct reduction iron, which is provided with a charging unit and a recovery unit at the top and a discharging unit at the bottom. The utility model relates to a vertical furnace body for producing direct reduction iron, which is provided with a charging unit and a recovery unit at the top and a discharging unit at the bottom. The utility model relates to a vertical furnace body for producing direct reduction iron, which is provided with a charging unit and a recovery unit at the top and a discharging unit at the bottom. The utility model relates to a vertical furnace body for producing direct reduction iron, which is provided with a charging unit and a recovery unit at the top and a discharging unit at the bottom. The utility model relates to a vertical furnace body for producing direct reduction iron, which is provided with a charging unit and a recovery unit at the top and a discharging unit at the bottom.

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