A device for recycling waste flue gas to prepare coal powder

Abstract

This utility model relates to the field of pulverized coal preparation, and more particularly to a pulverized coal preparation device for recovering and utilizing waste flue gas. The device includes a coal mill and a pulverized coal drying unit. The pulverized coal drying unit includes a first air conveying pipe. The coal mill is equipped with a first conveying pipe connected to the pulverized coal drying unit. The pulverized coal drying unit is equipped with a second conveying pipe connected to a pulverized coal silo. A third conveying pipe is located at the lower end of the pulverized coal silo and is connected to a pulverized coal injection tank. The pulverized coal injection tank is equipped with a nitrogen pipe connected to a nitrogen supply unit, and a pulverized coal injection pipe. This utility model has the advantage of using high-temperature waste flue gas to dry pulverized coal, replacing a hot blast stove and reducing energy consumption.

Description

Technical Field

[0001] This utility model relates to the field of coal powder preparation, and in particular to a coal powder preparation device for the recovery and utilization of waste flue gas. Background Technology

[0002] Blast furnace pulverized coal preparation is a key step in blast furnace ironmaking. By processing raw coal into pulverized coal that meets the requirements and injecting it into the blast furnace, coke consumption can be effectively reduced, the smelting process optimized, and economic benefits improved. The blast furnace pulverized coal process includes: raw coal storage, grinding and drying, sorting and collection, conveying and injection. Grinding and drying refer to the process where raw coal enters a vertical coal mill for drying and grinding, and then hot air is used to fully exchange heat with the pulverized coal to dry it. Existing hot air sources generally use dedicated hot blast stoves to provide hot air, which consumes energy. During blast furnace ironmaking, a large amount of high-temperature waste gas is generated. Therefore, it is necessary to design a pulverized coal preparation device that uses high-temperature waste gas to dry pulverized coal, replacing the hot blast stove and reducing energy consumption. Summary of the Invention

[0003] The purpose of this invention is to provide a waste flue gas recovery and utilization coal powder preparation device, which has the advantages of using high-temperature waste flue gas to dry coal powder, replacing hot blast stoves and reducing energy consumption.

[0004] The technical solution adopted is as follows:

[0005] A waste flue gas recovery and utilization coal powder preparation device includes a coal mill and a coal powder drying device. The coal powder drying device includes a first air conveying pipe. The coal mill is provided with a first conveying pipe connected to the coal powder drying device. The coal powder drying device is provided with a second conveying pipe. The second conveying pipe is connected to a coal powder silo. A third conveying pipe is provided at the lower end of the coal powder silo. The third conveying pipe is connected to a pulverized coal injection tank. The pulverized coal injection tank is provided with a nitrogen pipe. The nitrogen pipe is connected to a nitrogen supply unit. The pulverized coal injection tank is provided with a coal injection pipe.

[0006] Preferably, the lower end of the pulverized coal drying device is provided with a segmented wheel feeder connected to the second conveying pipe.

[0007] Preferably, the first air duct is connected to a bag filter, and the bag filter is equipped with a flue gas duct.

[0008] Preferably, the third conveying pipe is equipped with an ash discharge valve.

[0009] Compared to existing technologies, the advantages are:

[0010] This invention utilizes the high-temperature waste flue gas generated during steelmaking to dry pulverized coal. Compared to using a hot blast stove to dry pulverized coal, it achieves heat recovery and utilization of the high-temperature waste flue gas, while reducing the energy consumption of the hot blast stove. Attached Figure Description

[0011] Figure 1 This is a three-dimensional structural diagram of a waste flue gas recovery and utilization coal powder preparation device according to the present invention.

[0012] Figure 2 This is a front view structural diagram of a waste flue gas recovery and utilization coal powder preparation device according to this utility model.

[0013] In the diagram: 1. Coal mill; 2. Pulverized coal drying device; 3. First air conveyor pipe; 4. Bag filter dust collector; 5. Flue gas duct; 6. Pulverized coal injection pipe; 7. First conveying pipe; 8. Second conveying pipe; 9. Pulverized coal silo; 10. Ash discharge valve; 11. Third conveying pipe; 12. Pulverized coal injection tank; 13. Nitrogen pipe; 14. Nitrogen supply unit; 15. Divider wheel feeder. Detailed Implementation

[0014] The present invention will be further described below with reference to specific embodiments, such as... Figures 1 to 2 As shown:

[0015] Example 1: A waste flue gas recovery and utilization coal powder preparation device includes a coal mill 1 and a coal powder drying device 2. The coal powder drying device 2 includes a first air conveying pipe 3. High-temperature waste flue gas generated during the steelmaking process is transported from the first air conveying pipe 3 to the coal powder drying device 2. The coal mill 1 is equipped with a first conveying pipe 7 connected to the coal powder drying device 2. The coal mill 1 grinds coal into coal powder, and the ground coal powder is transported from the first conveying pipe 7 to the coal powder drying device 2, where the high-temperature waste flue gas is used to dry the coal powder.

[0016] The pulverized coal drying device 2 is equipped with a second conveying pipe 8, which is connected to a pulverized coal silo 9. The second conveying pipe 8 conveys the dried pulverized coal into the pulverized coal silo 9. A third conveying pipe 11 is provided at the lower end of the pulverized coal silo 9, which is connected to a spray tank 12. The pulverized coal in the pulverized coal silo 9 is conveyed to the spray tank 12 through the third conveying pipe 11. The spray tank 12 temporarily stores the pulverized coal. The spray tank 12 is equipped with a nitrogen pipe 13, which is connected to a nitrogen supply unit 14.

[0017] The nitrogen supply unit 14 is existing technology and will not be described in detail here. The nitrogen supply unit 14 delivers high-pressure nitrogen to the injection tank 12. The injection tank 12 is equipped with a pulverized coal injection pipe 6, which is connected to the blast furnace. The pulverized coal in the injection tank 12 enters the blast furnace through the pulverized coal injection pipe 6.

[0018] Example 2: A waste flue gas recovery and utilization coal powder preparation device, including a coal mill 1 and a coal powder drying device 2. The coal powder drying device 2 includes a first air conveying pipe 3, which is connected to a bag filter 4. The bag filter 4 is equipped with a flue gas pipe 5. The high-temperature waste flue gas generated during the steelmaking process is transported from the flue gas pipe 5 to the bag filter 4. The bag filter 4 removes dust from the high-temperature waste flue gas, and after dust removal, it enters the coal powder drying device 2 through the first air conveying pipe 3.

[0019] The coal mill 1 is equipped with a first conveying pipe 7 connected to the coal powder drying device 2. The coal mill 1 grinds coal into coal powder, and the ground coal powder is conveyed from the first conveying pipe 7 to the coal powder drying device 2, where the coal powder is dried using high-temperature waste flue gas.

[0020] The pulverized coal drying device 2 is equipped with a second conveying pipe 8. The lower end of the pulverized coal drying device 2 is equipped with a segmented wheel feeder 15 connected to the second conveying pipe 8. The second conveying pipe 8 is connected to a pulverized coal silo 9. The second conveying pipe 8 conveys the dried pulverized coal into the pulverized coal silo 9. The lower end of the pulverized coal silo 9 is equipped with a third conveying pipe 11. The third conveying pipe 11 is equipped with an ash discharge valve 10. The third conveying pipe 11 is connected to a spray tank 12. The pulverized coal in the pulverized coal silo 9 is conveyed to the spray tank 12 through the third conveying pipe 11. The spray tank 12 temporarily stores the pulverized coal. The spray tank 12 is equipped with a nitrogen pipe 13. The nitrogen pipe 13 is connected to a nitrogen supply unit 14.

[0021] The nitrogen supply unit 14 is existing technology and will not be described in detail here. The nitrogen supply unit 14 delivers high-pressure nitrogen to the injection tank 12. The injection tank 12 is equipped with a pulverized coal injection pipe 6, which is connected to the blast furnace. The pulverized coal in the injection tank 12 enters the blast furnace through the pulverized coal injection pipe 6.

[0022] The working principle is as follows:

[0023] High-temperature waste gas generated during steelmaking enters the bag filter 4 from the flue gas duct 5. After being filtered by the bag filter 4, it enters the pulverized coal drying device 2 from the first air conveyor duct 3. At the same time, the coal mill 1 conveys the ground pulverized coal to the pulverized coal drying device 2. After the high-temperature waste gas dries the pulverized coal, it is fed by the dividing wheel feeder 15 and conveyed from the second conveyor pipe 8 to the pulverized coal silo 9. The pulverized coal in the pulverized coal silo 9 is conveyed to the injection tank 12 by the third conveyor pipe 11. The injection tank 12 temporarily stores the pulverized coal. The nitrogen supply unit 14 delivers high-pressure nitrogen to the injection tank 12. The pulverized coal in the injection tank 12 enters the blast furnace through the pulverized coal injection pipe 6. Compared with using a hot blast stove to dry the pulverized coal, the heat of the high-temperature waste gas is recovered and utilized, while reducing the energy consumption of the hot blast stove.

[0024] The above embodiments are merely preferred embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model. Any non-substantial changes and substitutions made by those skilled in the art based on this utility model shall fall within the scope of protection claimed by this utility model.

Claims

1. A device for preparing pulverized coal for waste flue gas recovery and utilization, characterized in that: The device includes a coal mill (1) and a coal powder drying device (2). The coal powder drying device (2) includes a first air conveying pipe (3). The coal mill (1) is provided with a first conveying pipe (7) connected to the coal powder drying device (2). The coal powder drying device (2) is provided with a second conveying pipe (8). The second conveying pipe (8) is connected to a coal powder silo (9). The lower end of the coal powder silo (9) is provided with a third conveying pipe (11). The third conveying pipe (11) is connected to a pulverized coal injection tank (12). The pulverized coal injection tank (12) is provided with a nitrogen pipe (13). The nitrogen pipe (13) is connected to a nitrogen supply unit (14). The pulverized coal injection tank (12) is provided with a coal injection pipe (6).

2. The waste flue gas recovery and utilization coal powder preparation device as described in claim 1, characterized in that: The lower end of the coal powder drying device (2) is equipped with a segmented wheel feeder connected to the second conveying pipe (8).

3. The waste flue gas recovery and utilization coal powder preparation device as described in claim 1, characterized in that: The first air duct (3) is connected to a bag filter (4), and the bag filter (4) is equipped with a flue gas duct (5).

4. The waste flue gas recovery and utilization coal powder preparation device as described in claim 1, characterized in that: The third conveying pipe (11) is equipped with an ash discharge valve (10).

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