A large hydrogen-based shaft furnace reduction gas balance injection device

Abstract

This invention discloses a large-scale hydrogen-based vertical shaft furnace reducing gas uniform injection device, belonging to the field of metallurgical equipment technology. Its purpose is to improve the uniformity of reducing gas injection and ensure product quality. The technical solution is as follows: the device includes a central jet injector located at the bottom of the reduction section of the vertical shaft furnace and multiple peripheral nozzles. The peripheral nozzles are located on the inner side wall of the vertical shaft furnace and are evenly distributed along a circumference coaxial with the furnace. The inlet of each peripheral nozzle is connected to a gas supply pipe. The central jet injector is installed in the center of the vertical shaft furnace and connected to the gas supply pipe. This invention utilizes the central jet injector and peripheral nozzles to simultaneously inject reducing gas into the center and periphery of the hydrogen-based vertical shaft furnace, making the distribution of reducing gas inside the furnace more uniform. This avoids the problem of insufficient reaction of localized furnace charge due to uneven distribution of reducing gas, greatly improving the metallization rate of the furnace charge and ensuring product quality.

Description

Technical Field

[0001] This invention relates to a large-scale hydrogen-based vertical shaft furnace reducing gas equalization injection device, which can improve the metallization rate of the furnace charge in the central part of the vertical shaft furnace, and belongs to the field of metallurgical equipment technology. Background Technology

[0002] Large-scale carbon emissions contribute to the greenhouse effect, causing significant negative impacts on human life. As an energy-intensive industry, the steel industry consistently ranks among the top in my country in terms of carbon emissions, making low-carbon emission reduction imperative. Currently, my country's steel industry primarily utilizes a long blast furnace-converter process, with the blast furnace ironmaking stage generating the largest amount of carbon emissions. Therefore, energy conservation and emission reduction must be achieved through efficient production processes in the ironmaking stage. Compared to current carbon reduction-based smelting processes (where the reduction product is CO2), hydrogen reduction smelting produces H2O, does not generate carbon emissions during the reduction process, and boasts high reduction efficiency. Hydrogen-based vertical shaft furnace (hydrogen-based reactor) production technology utilizing hydrogen reduction is a new smelting process that is currently being developed globally. The gradually applied hydrogen metallurgy technology will be a crucial pathway for my country's steel industry to achieve low-carbon emission reduction.

[0003] Currently, large hydrogen-based vertical shaft furnaces typically employ dozens of nozzles densely arranged around the furnace to inject reducing gas into the furnace, ensuring a sufficient flow of reducing gas. However, due to the 5-8 m inner diameter of large vertical shaft furnaces, the reducing gas struggles to reach the center of the furnace body after entering, resulting in highly uneven metallization rates in the produced metallized charge. The metallization rate of the charge on the periphery can reach over 90%, while the metallization rate of the charge in the center of the furnace is only about 10%, severely impacting product quality. Therefore, improving the uniformity of reducing gas injection has become an urgent problem to be solved. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a large-scale hydrogen-based vertical furnace reducing gas uniform injection device to improve the uniformity of reducing gas injection and ensure product quality.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A large hydrogen-based vertical shaft furnace reducing gas equalization injection device includes a central jet device and multiple peripheral nozzles located at the bottom of the reduction section of the vertical shaft furnace. The multiple peripheral nozzles are located on the inner side wall of the vertical shaft furnace and are distributed at equal intervals along a circumference coaxial with the vertical shaft furnace. The inlet of each peripheral nozzle is connected to a gas supply pipe. The central jet device is installed in the center of the vertical shaft furnace and is connected to the gas supply pipe.

[0007] The above-mentioned large-scale hydrogen-based vertical furnace reducing gas equalization injection device includes a central jet device comprising an anti-blocking buffer cover and a jet pipe installed at the center of the vertical furnace. The anti-blocking buffer cover is a hollow frustum shape that is thicker at the top and thinner at the bottom, with its upper part closed and its bottom open. The jet pipe is placed vertically and is coaxial with the anti-blocking buffer cover. The lower end of the jet pipe is connected to the gas supply pipe, and the upper end is inserted into the anti-blocking buffer cover.

[0008] In the above-mentioned large-scale hydrogen-based vertical furnace reducing gas equalization injection device, the angle between the side generatrix of the anti-blocking buffer cover and the vertical direction is 15°~25°.

[0009] In the aforementioned large-scale hydrogen-based vertical furnace reducing gas equalization injection device, the length of the jet pipe inserted into the anti-blocking buffer cover is 2 / 3 of the depth of the inner cavity of the anti-blocking buffer cover.

[0010] The aforementioned large-scale hydrogen-based vertical furnace reducing gas equalization injection device includes a central jet device equipped with a cooling device. The cooling device comprises a circulating water tank, a circulating pump, and a circulating water pipe. The inlet of the circulating pump is connected to the outlet of the circulating water tank, and the outlet of the circulating pump is connected to the return outlet of the circulating water tank through the circulating water pipe. The circulating water pipe passes through the vertical furnace and is connected to the anti-clogging buffer cover of the central jet device to cool and fix the central jet device.

[0011] The aforementioned large-scale hydrogen-based vertical furnace reducing gas equalization injection device includes a circulating water tank equipped with a water temperature detection device, a water inlet, and a drain outlet.

[0012] The above-mentioned large-scale hydrogen-based vertical furnace reducing gas equalization injection device, the central jet device also includes a material guide hood, the material guide hood covers the top of the anti-blocking buffer hood, and the upper surface of the material guide hood is a conical surface or an arc-shaped surface.

[0013] The aforementioned large-scale hydrogen-based vertical furnace reducing gas equalization injection device has a maintenance manhole on the side wall of the furnace corresponding to the central jet injection device.

[0014] The aforementioned large-scale hydrogen-based vertical furnace reducing gas equalization injection device includes multiple central jet devices arranged radially along the furnace.

[0015] The aforementioned large-scale hydrogen-based vertical furnace reducing gas equalization injection device has multiple central jet devices arranged along a circumference coaxial with the vertical furnace.

[0016] This invention utilizes a central jetting device and peripheral nozzles to simultaneously inject reducing gas into the center and periphery of a hydrogen-based vertical shaft furnace, resulting in a more balanced distribution of reducing gas inside the furnace. This avoids the problem of insufficient reaction of localized furnace charge due to uneven distribution of reducing gas, greatly improving the metallization rate of the furnace charge and ensuring product quality. Attached Figure Description

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0018] Figure 1 This is an installation diagram of the present invention;

[0019] Figure 2 This is a schematic diagram (top view) of the central jet assembly.

[0020] Figure 3 This is a schematic diagram of the central jet device.

[0021] The following are the labels in the diagram: 1. Vertical furnace, 2. Feed port, 3. Exhaust port, 4. Reduction section, 5. Discharge port, 6. Cooling section, 7. Central jet device, 7-1. Anti-clogging buffer cover, 7-2. Jet pipe, 7-3. Material guide cover, 8. Peripheral nozzle, 9. Gas supply pipe, 10. Circulating water tank, 11. Circulating pump, 12. Water temperature detection device, 13. Water inlet, 14. Drain outlet, 15. Circulating water pipe, 16. Insulation layer, 17. Inspection manhole. Detailed Implementation

[0022] This invention addresses the problems of low reaction rate and poor product quality in the central part of existing large hydrogen-based vertical shaft furnaces by providing a reducing gas equalization injection device for large hydrogen-based vertical shaft furnaces. This device can make the reducing gas evenly distributed inside the vertical furnace, and the reducing gas concentration in the central part of the furnace body is also sufficient, thereby improving the metallization rate of the furnace charge in the central part of the vertical furnace and ensuring product quality.

[0023] See Figures 1-3 This invention mainly includes multiple peripheral nozzles 8, a central jetting device 7, and a cooling device. The furnace body of the vertical shaft furnace 1 includes a reduction section 4 and a cooling section 6. The reduction section 4 is cylindrical, and the cooling section 6 is conical. The cooling section 6 is located at the lower part of the reduction section 4. The top of the reduction section 4 is provided with a feed inlet 2 and an exhaust outlet 3, and the bottom of the cooling section 6 is provided with a discharge outlet 5. During the production process, the furnace charge enters the vertical shaft furnace through the feed inlet 2 and moves downward. After reacting with the reducing gas entering the vertical shaft furnace from the bottom of the reduction section 4, it enters the cooling section 6 and is finally discharged from the discharge outlet 5. The reducing gas reacts with the furnace charge and flows upward, eventually being discharged from the exhaust outlet 3.

[0024] Multiple peripheral nozzles 8 are located at the bottom of the reduction section 4 and are distributed at equal intervals along a circumference coaxial with the vertical furnace 1. The air inlet of the peripheral nozzle 8 is connected to the gas supply pipe 9, and the nozzle of the peripheral nozzle 8 faces the axis of the vertical furnace 1 and is inclined upward.

[0025] The central jetting device 7 includes an anti-clogging buffer cover 7-1 and a jetting pipe 7-2. The anti-clogging buffer cover 7-1 is installed at the bottom of the reduction section 4 of the vertical furnace 1, close to the axis of the furnace 1. The anti-clogging buffer cover 7-1 is a hollow frustum shape, open at the bottom and closed at the top, with the upper diameter larger than the lower diameter. The angle between the generatrix of the side of the anti-clogging buffer cover 7-1 and the vertical direction is 15°~25°. The jetting pipe 7-2 is placed vertically and coaxial with the anti-clogging buffer cover 7-1. The lower end of the jetting pipe 7-2 is connected to the gas supply pipe 9, and the upper end is inserted into the anti-clogging buffer cover 7-1. The length of the jetting pipe 7-2 inserted into the anti-clogging buffer cover 7-1 is 2 / 3 of the depth of the inner cavity of the anti-clogging buffer cover 7-1. This structure can prevent furnace charge particles from clogging the gas pipeline and avoid production accidents. At least one central jetting device 7 is provided. When there is only one central jetting device 7, it is installed at the axis of the vertical furnace 1. Figure 2 It can be seen that when multiple central jet devices 7 are installed, they can be arranged radially along the vertical furnace 1, such as... Figure 2 As shown in (a), it can also be arranged along a circumference coaxial with the vertical furnace 1, such as... Figure 2 As shown in (b).

[0026] The cooling device mainly includes a circulating water tank 10, a circulating pump 11, and a circulating water pipe 15. The inlet of the circulating pump 11 is connected to the outlet of the circulating water tank 10, and the outlet of the circulating pump 11 is connected to the return port of the circulating water tank 10 through the circulating water pipe 15. The circulating water pipe 15 passes through the vertical furnace 1. The anti-clogging buffer cover 7-1 of the central jet device 7 is fixed to the lower part of the circulating water pipe 15 through a heat-conducting connection device. When cooling water flows through the circulating water pipe 15, it cools the central jet device 7, ensuring that the central jet device 7 can operate safely for a long time in a high-temperature environment. The circulating water pipe 15 also serves to fix the central jet device 7, eliminating the need for a dedicated support bracket and reducing equipment costs. The circulating water tank 10 is also equipped with a water temperature detection device 12, a water inlet 13, and a drain outlet 14. The water temperature detection device 12 measures the temperature of the cooling water in the circulating water tank 10 in real time. When the water temperature exceeds the set value, the cooling water in the circulating water tank 10 is replaced through the water inlet 13 and the drain outlet 14 to ensure the cooling effect.

[0027] To prevent the top platform of the anti-clogging buffer cover 7-1 from obstructing the downward movement of the furnace charge, a guide cover 7-3 is installed on the upper part of each anti-clogging buffer cover 7-1. The upper surface of the guide cover 7-3 is conical or arc-shaped, allowing the furnace charge to slide down smoothly. The guide cover 7-3 also serves to prevent the upper pellets from damaging the heat-conducting connection device between the anti-clogging buffer cover 7-1 and the circulating water pipe 15.

[0028] For ease of maintenance, a maintenance manhole 17 corresponding to the central jet device 7 is provided on the side wall of the vertical furnace 1.

[0029] The following is a detailed description of the application process of this equipment, taking the production of standard 8-16 mm iron oxide pellets as an example:

[0030] After entering the vertical shaft furnace 1 through the feed inlet 2, the furnace charge moves downwards under its own gravity and is preheated in the reduction section. Reducing gas at 950℃ enters the gas supply pipe 9 at the bottom of the reduction section of the hydrogen-based vertical shaft furnace. Multiple peripheral nozzles 8 connected to the gas supply pipe 9 simultaneously inject reducing gas into the furnace. At the same time, the reducing gas enters the inner cavity of the anti-blocking buffer cover 7-1 through the jet pipe 7-2 connected to the gas supply pipe 9. Since the anti-blocking buffer cover 7-1 only has a bottom opening, the reducing gas entering the inner cavity of the anti-blocking buffer cover 7-1 flows out from the bottom opening and diffuses evenly around, reducing the furnace charge in the reduction section. Because reducing gas is injected into both the periphery and center of the vertical shaft furnace, the reducing gas is evenly distributed within the reduction section, resulting in a sufficiently high metallization rate for both the peripheral and central furnace charge, greatly improving product quality. After reduction, the metallized furnace charge undergoes carburizing and cooling in the cooling section and is discharged from the discharge port 5, producing pellets with an average metallization rate of over 92%, meeting national standards.

[0031] During the production process, the cooling device continuously supplies circulating cooling water to cool the central jet device 7, preventing it from being damaged due to prolonged exposure to high temperatures, extending its service life, and ensuring smooth production.

[0032] This device also has the advantages of simple structure, low operating cost, and convenient maintenance.

Claims

1. A large hydrogen-based shaft furnace reduction gas balance injection device, characterized in that, It includes a central jet device (7) and multiple peripheral nozzles (8) located at the bottom of the reduction section (4) of the vertical furnace (1). The multiple peripheral nozzles (8) are located on the inner side wall of the vertical furnace (1) and are distributed at equal intervals along a circumference coaxial with the vertical furnace (1). The air inlet of each peripheral nozzle (8) is connected to the gas supply pipe (9). The central jet device (7) is installed in the center of the vertical furnace (1) and connected to the gas supply pipe (9). The central jet device (7) includes an anti-blocking buffer cover (7-1) and a jet pipe (7-2) installed in the center of the vertical furnace (1). The anti-blocking buffer cover (7-1) is a hollow frustum shape with a thicker top and a thinner bottom. Its upper part is closed and its bottom is open. The jet pipe (7-2) is placed vertically and is coaxial with the anti-blocking buffer cover (7-1). The lower end of the jet pipe (7-2) is connected to the gas supply pipe (9), and the upper end is inserted into the anti-blocking buffer cover (7-1). The central jet device (7) is equipped with a cooling device, which includes a circulating water tank (10), a circulating pump (11), and a circulating water pipe (15). The inlet of the circulating pump (11) is connected to the outlet of the circulating water tank (10), and the outlet of the circulating pump (11) is connected to the return outlet of the circulating water tank (10) through the circulating water pipe (15). The circulating water pipe (15) passes through the vertical furnace (1) and is connected to the anti-blocking buffer cover (7-1) of the central jet device (7) to cool and fix the central jet device (7).

2. A hydrogen-based shaft furnace reduction gas equalization injection device according to claim 1, characterized in that, The angle between the side generatrix of the anti-blocking buffer cover (7-1) and the vertical direction is 15°~25°.

3. A hydrogen-based shaft furnace reduction gas equalization injection device according to claim 2, characterized in that, The length of the jet pipe (7-2) inserted into the anti-blocking buffer cover (7-1) is 2 / 3 of the depth of the inner cavity of the anti-blocking buffer cover (7-1).

4. A device for balanced injection of reducing gas into a large hydrogen-based shaft furnace according to claim 3, characterized in that, The circulating water tank (10) is equipped with a water temperature detection device (12), a water inlet (13) and a drain outlet (14).

5. A large-sized hydrogen-based shaft furnace reduction gas equalizing injection device according to claim 4, characterized in that, The central jet device (7) also includes a guide hood (7-3), which covers the top of the anti-clogging buffer cover (7-1). The upper surface of the guide hood (7-3) is a conical or arc-shaped surface.

6. A large-sized hydrogen-based shaft furnace reduction gas equalizing injection device according to claim 5, characterized in that, The side wall of the vertical furnace (1) is provided with a maintenance manhole (17) corresponding to the central jet device (7).

7. A large-scale hydrogen-based vertical furnace reducing gas equalization injection device according to claim 6, characterized in that, Multiple central jet devices (7) are provided, arranged radially along the vertical furnace (1).

8. A large-scale hydrogen-based vertical furnace reducing gas equalization injection device according to claim 6, characterized in that, Multiple central jet devices (7) are provided, arranged along a circumference coaxial with the vertical furnace (1).

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