A waste gas denitration device and process for metallurgical industry

Abstract

The application relates to the technical field of waste gas treatment, and discloses a waste gas denitration device for metallurgical industry and a process, wherein the waste gas denitration device for metallurgical industry comprises a main pipe, branch pipes arranged on the two sides of the main pipe, a spraying pipe and a gas mixing assembly arranged at the bottom of the branch pipe, the spraying pipe specifically comprises an upper connecting pipe arranged at the bottom of the branch pipe, a lower connecting pipe arranged at the end of the upper connecting pipe away from the branch pipe, and a nozzle arranged at the end of the lower connecting pipe away from the upper connecting pipe. The waste gas denitration device for metallurgical industry is provided with a cleaning assembly, when the nozzle is blocked, water supply is stopped to input ammonia water, meanwhile, a driving element drives a piston element to move downwards, the ammonia water in the vertical long side and the horizontal short side of the lower connecting pipe is sucked into a suction tank, impurities and crystals inside the nozzle are sucked into the suction tank together with the ammonia water, the impurities and the crystals in the nozzle are precipitated downwards, so that the impurities and the crystals blocked inside the nozzle can be cleaned, and the nozzle can be prevented from being blocked to affect the spraying work.

Description

Technical Field

[0001] This invention relates to the field of waste gas treatment technology, and in particular to a waste gas denitrification device and process for the metallurgical industry. Background Technology

[0002] The metallurgical industry is a crucial foundation of the national economy, but its production processes generate large amounts of waste gas. This waste gas is complex in composition and contains numerous pollutants, posing significant threats to the environment and human health. Nitrogen oxides (NOx) are a major component of the waste gas from the metallurgical industry. x The emissions of metallurgical waste gas not only cause environmental problems such as acid rain and photochemical smog, but also endanger human health. Therefore, denitrification is one of the key links in the treatment of metallurgical waste gas.

[0003] Currently, selective non-catalytic reduction (SNCR) is one of the commonly used waste gas denitrification technologies in the metallurgical industry. Its principle involves injecting a reducing agent (such as ammonia) into the waste gas under high-temperature conditions, causing the reducing agent to chemically react with nitrogen oxides, converting them into harmless nitrogen and water. In this technology, the spray system, as the core component for reducing agent injection, directly affects the denitrification efficiency. The spray system typically consists of a storage tank, a transfer pump, pipelines, and spray nozzles. Ammonia is pressurized by the transfer pump and then transported through pipelines to the spray nozzles, where it is atomized and sprayed into the waste gas to mix and react with nitrogen oxides.

[0004] Patent publication number CN118384692A discloses a chemical waste gas desulfurization and denitrification system, including a purification tower body with an air inlet on the side of the bottom and an air outlet on the top. It also includes a slow-speed rotating spray purification unit located inside the purification tower body, above the air inlet, with its rotation direction perpendicular to the waste gas flow direction. A turbulence unit is installed on the slow-speed rotating spray purification unit to agitate the gas at the center and edge of the vortex in its rotation direction. This chemical waste gas desulfurization and denitrification system effectively reduces the waste gas flow rate through the slow-speed rotating spray purification unit. Combined with the turbulence unit and the rotational design of the spray pipe, it achieves thorough mixing and contact between the waste gas and the spray solvent, effectively improving desulfurization and denitrification efficiency. Simultaneously, the turbulence unit, through a negative pressure fan and air duct design, further enhances the uniformity and efficiency of waste gas treatment.

[0005] The existing technology has the following drawbacks:

[0006] In practical applications, the spray nozzles of the spray system are prone to clogging, causing numerous problems for the stable operation of the denitrification unit. This problem is not accidental, but rather caused by the combined effect of multiple factors. On the one hand, the waste gas from the metallurgical industry contains a large amount of dust, particulate matter, and sulfides, among other impurities. When these impurities come into contact with the sprayed ammonia water, they react chemically with the components in the ammonia water to form highly viscous salts (such as ammonium sulfate and ammonium sulfite). These salts gradually adhere to the inner wall of the spray nozzle and the nozzle orifice as the ammonia water flows, accumulating over time and eventually causing the nozzle orifice to shrink or even become completely blocked. On the other hand, the ammonia water is not 100% pure and contains other impurities. Furthermore, the ammonia water needs to be sprayed in a high-temperature environment, so some of the ammonia water evaporates before or during spraying, causing impurities to precipitate and potentially crystallize. These crystallized impurities are also prone to depositing at the spray nozzle, exacerbating the clogging. Summary of the Invention

[0007] Given the problem of pipe blockage in existing technologies, a waste gas denitrification device and process for the metallurgical industry are proposed.

[0008] This application provides a waste gas denitrification device and process for the metallurgical industry, the purpose of which is to remove blockages in pipelines.

[0009] The technical solution of the present invention is as follows: a waste gas denitrification device for the metallurgical industry, comprising a main pipe, branch pipes disposed on both sides of the main pipe, an injection pipe and a gas mixing assembly disposed at the bottom of the branch pipe, wherein the injection pipe specifically comprises an upper connecting pipe disposed at the bottom of the branch pipe, a lower connecting pipe disposed at the end of the upper connecting pipe away from the branch pipe, and a nozzle disposed at the end of the lower connecting pipe away from the upper connecting pipe.

[0010] A cleaning component is provided at the connection between the upper and lower pipes. The cleaning component specifically includes a connecting pipe at the bottom of the connection between the lower and upper pipes, a suction tank at the bottom of the connecting pipe, and a piston inside the suction tank.

[0011] The upper connecting pipe is composed of a long side and a short side, forming an "L" shape. The lower connecting pipe is composed of a vertical long side, a vertical short side, and a horizontal short side, forming a "J" shape. When the lower connecting pipe is rotated up and down, its vertical short side connects to the short side of the upper connecting pipe. The suction tank is connected to the upper and lower connecting pipes through a connecting pipe. A driving component is installed below the piston component.

[0012] Furthermore, the connecting pipe is provided with a lower filter screen and an upper filter screen. The lower filter screen is a frustum shape with a thicker bottom and a thinner top, and the upper filter screen is a frustum shape with a thicker top and a thinner bottom. The upper filter screen runs through the connecting pipe from top to bottom and is secured above the connecting pipe, while the lower filter screen is secured below the connecting pipe.

[0013] Furthermore, an air exchange valve is installed at the bottom of the suction tank.

[0014] Furthermore, the driving component is a counterweight.

[0015] Furthermore, the driving component is an electrically controlled telescopic rod.

[0016] Furthermore, the gas mixing assembly specifically includes a fixing sleeve disposed on the outside of the branch pipe, a fixing pipe disposed at the bottom of the fixing sleeve, an installation pipe disposed at the bottom of the fixing pipe, a vaporization box disposed at the bottom of the installation pipe, a flow pipe disposed between the vaporization box and the injection pipe, and a suction component disposed inside the fixing pipe.

[0017] The vaporization box is connected to the branch pipe through a fixed pipe and an installation pipe, and the suction component has a built-in filter device.

[0018] Furthermore, the gas mixing assembly also includes a heating pipe that penetrates the bottom wall of the vaporization box, and an inlet located on the outside of the heating pipe;

[0019] The heating tube is closed at the lower end and connected to the internal space of the vaporization box at the upper end. The inlet is located below the internal space of the vaporization box.

[0020] Furthermore, the gas mixing assembly also includes a supplementary pipe disposed on the inner top wall of the vaporization box, the upper end of the supplementary pipe being connected to the installation pipe, and the lower end of the supplementary pipe extending into the lower space inside the vaporization box.

[0021] This invention also provides a waste gas denitrification process for the metallurgical industry, comprising the following steps:

[0022] Flue gas pretreatment: Dust in the flue gas is removed using a bag filter; flue gas temperature is adjusted;

[0023] Reducing agent preparation and spraying: Ammonia water is selected as the reducing agent. The main pipe distributes the ammonia water to numerous spray pipes through the branch pipes, atomizing the ammonia water and spraying it out to mix thoroughly with the flue gas.

[0024] Catalytic reaction: The mixed flue gas enters the SCR reactor, where ammonia water rapidly decomposes into NH3, and then, under the action of the catalyst, NO... x It undergoes a reduction reaction with NH3;

[0025] Tail-end purification and monitoring: After the flue gas from the reaction is detected by an ammonia escape monitor, it is sent into the chimney for discharge by an induced draft fan.

[0026] The beneficial effects of this invention are:

[0027] 1. By setting up a cleaning component, when the nozzle is clogged, the water supply of ammonia is stopped and a driving component moves the piston downward. During the movement of the piston, ammonia is drawn from the spray pipe through the connecting pipe. One end of the upper connecting pipe is closed and cannot be drawn, while the ammonia in the long vertical side and short horizontal side of the lower connecting pipe is drawn into the suction tank. Impurities and crystals inside the nozzle are drawn into the suction tank along with the ammonia. The impurities and crystals settle downward. Then the piston pushes upward, sending the ammonia back to the lower connecting pipe. In this way, the impurities and crystals that clog the inside of the nozzle can be cleaned, avoiding blockage and affecting the spraying operation.

[0028] 2. By setting up a lower and upper filter screen, when ammonia water flows to the suction tank, the lower filter screen will intercept impurities and crystals in the ammonia water inside the connecting pipe, thus preventing particulate matter from adhering to the inner wall of the suction tank and affecting the sliding and sealing of the piston components. The upper filter screen can prevent some impurities and crystals from flowing back to the lower connecting pipe with the ammonia water when it flows back, thus ensuring the stability of the equipment operation.

[0029] 3. By setting up a gas mixing component, ammonia water is introduced into the vaporization box. The high temperature in the denitrification tower will cause the ammonia water in the vaporization box to vaporize rapidly. Then, it enters the injection pipe through the flow pipe and completes the vaporization with the ammonia water. In this way, ammonia gas is used instead of ordinary gas, which can improve the purity of ammonia gas after vaporization, reduce the other gases mixed in, and is more conducive to the denitrification reaction of flue gas.

[0030] 4. By setting up a heating tube, ammonia water in the vaporization box flows into the heating tube through the inlet. After being heated by the heating tube, it floats up and is discharged into the space above the vaporization box. Then, more ammonia water is added to the heating tube, which improves the heating efficiency, can quickly generate ammonia gas, and ensures stable operation of the equipment. Attached Figure Description

[0031] Figure 1 This is a perspective view of the spray system of the present invention;

[0032] Figure 2 This is a schematic diagram of the injection pipe of the present invention;

[0033] Figure 3 This is a schematic diagram of the cleaning component of the present invention;

[0034] Figure 4 This is a top view of the present invention;

[0035] Figure 5 This is a bottom view of the branch pipe of the present invention;

[0036] Figure 6 For the present invention Figure 5 Sectional view at point AA;

[0037] Figure 7 For the present invention Figure 5 Sectional view at point BB;

[0038] Figure 8 This is a schematic diagram of the air-fuel mixing assembly of the present invention;

[0039] Figure 9 This is a disassembled diagram of the air-fuel mixing component of the present invention.

[0040] In the picture:

[0041] 1. Main pipe; 2. Branch pipe; 3. Spray pipe; 31. Upper connecting pipe; 32. Lower connecting pipe; 33. Nozzle; 4. Cleaning assembly; 41. Connecting pipe; 42. Suction tank; 43. Piston; 44. Air exchange valve; 45. Lower filter screen; 46. Upper filter screen; 5. Mixing assembly; 51. Fixing sleeve; 52. Fixing pipe; 53. Installation pipe; 54. Vaporization box; 55. Flow pipe; 56. Heating pipe; 57. Inlet; 58. Replenishment pipe; 59. Suction component. Detailed Implementation

[0042] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0043] Example 1, referring to Figure 1-6 The first embodiment of the present invention provides a waste gas denitrification device for the metallurgical industry, including a main pipe 1, branch pipes 2 disposed on both sides of the main pipe 1, an injection pipe 3 disposed at the bottom of the branch pipe 2 and a gas mixing component 5. The injection pipe 3 specifically includes an upper pipe 31 disposed at the bottom of the branch pipe 2, a lower pipe 32 disposed at the end of the upper pipe 31 away from the branch pipe 2, and a nozzle 33 disposed at the end of the lower pipe 32 away from the upper pipe 31.

[0044] A cleaning component 4 is provided at the connection between the upper pipe 31 and the lower pipe 32. The cleaning component 4 specifically includes a connecting pipe 41 located at the bottom of the connection end between the lower pipe 32 and the upper pipe 31, a suction tank 42 located at the bottom of the connecting pipe 41, and a piston component 43 located inside the suction tank 42.

[0045] Specifically, main pipe 1 is installed inside the denitrification tower, with one end extending through the tower and connecting to a low-temperature atmospheric pressure storage tank and an insulated transfer pump. A heating device is installed below main pipe 1 inside the denitrification tower to rapidly vaporize the injected ammonia water and accelerate the reaction. An SCR reactor is also installed inside the denitrification tower. The SCR reactor contains a catalyst layer, which promotes the reaction of ammonia and NO. xThe reactor is equipped with a rectifier grid at the top to ensure uniform distribution of the flue gas. A bag filter is installed at the inlet of the denitrification tower to remove dust from the flue gas. An ammonia slip monitor and an induced draft fan are installed at the outlet of the denitrification tower. The induced draft fan is used to send the denitrified flue gas into the chimney, and the ammonia slip monitor is used to detect and control the emitted flue gas. A row of branch pipes 2 are set on both sides of the main pipe 1, and the length of these branch pipes 2 is adaptively adjusted according to the distance to the inner wall of the denitrification tower. The branch pipes 2 are welded to the main pipe 1, and the injection pipes 3 are welded to the branch pipes 2. The upper pipe 31 is composed of a long side and a short side, forming an "L" shape. The lower pipe 32 is composed of a vertical long side, a vertical short side, and a horizontal short side, forming a "J" shape. The lower pipe 32 is rotated up and down, and its vertical short side is fixedly connected to the short side of the upper pipe 31.

[0046] A connector is provided at the connection between the upper pipe 31 and the lower pipe 32. The connecting pipe 41 is threaded to the connector, and the suction tank 42 is threaded to the connecting pipe 41. The suction tank 42 is connected to the upper pipe 31 and the lower pipe 32 through the connecting pipe 41. A driving component is provided below the piston component 43. The piston component 43 can slide inside the suction tank 42. When the piston component 43 slides down, it can evacuate the vertical long side and horizontal short side of the lower pipe 32. A ventilation valve 44 is installed at the bottom of the suction tank 42. A filter screen is installed inside the ventilation valve 44 to balance the pressure inside the suction tank 42.

[0047] By setting up the cleaning component 4, when the nozzle 33 is blocked, the water supply of ammonia is stopped and a driving component moves the piston 43 downward. During the movement of the piston 43, the ammonia in the spray pipe 3 is drawn in through the connecting pipe 41. One end of the upper pipe 31 is closed and cannot be drawn in, while the ammonia in the long vertical side and short horizontal side of the lower pipe 32 is drawn into the suction tank 42. The impurities and crystals inside the nozzle 33 are drawn into the suction tank 42 along with the ammonia. The impurities and crystals settle downward. Then the piston 43 pushes upward, sending the ammonia back to the lower pipe 32. In this way, the impurities and crystals that are blocked inside the nozzle 33 can be cleaned, avoiding blockage and affecting the spraying operation.

[0048] Specifically, a lower filter screen 45 and an upper filter screen 46 are provided inside the connecting pipe 41. The lower filter screen 45 is a frustum shape with a thicker bottom and a thinner top, and the upper filter screen 46 is a frustum shape with a thicker top and a thinner bottom. The upper filter screen 46 runs through the connecting pipe 41 from top to bottom and is held above the connecting pipe 41. The lower filter screen 45 is held below the connecting pipe 41. The lower filter screen 45 and the upper filter screen 46 are concentrically arranged, and the distance between them does not exceed five millimeters.

[0049] By setting up a lower filter 45 and an upper filter 46, when ammonia water flows to the suction tank 42, the lower filter 45 will intercept impurities and crystals in the ammonia water in the connecting pipe 41, thus preventing particulate matter from adhering to the inner wall of the suction tank 42 and affecting the sliding and sealing of the piston 43. The upper filter 46 can prevent some impurities and crystals from flowing back to the lower pipe 32 with the ammonia water when it flows back, thus ensuring the stability of the equipment operation.

[0050] Example 2, refer to Figure 6 This is the second embodiment of the present invention. The difference between this embodiment and the first embodiment is that the driving component is a counterweight. The force exerted by the counterweight on the piston 43 is greater than the force exerted by the ammonia water in the lower pipe 32 on the piston 43. Thus, when the ammonia water input stops, the counterweight can drive the piston 43 to move downward by gravity. When the ammonia water input starts, the high-speed flowing ammonia water (flow velocity 10m / s) in the upper pipe 31 and lower pipe 32 will form a low-pressure zone in the upper pipe 31 and lower pipe 32, and the piston 43 will be attracted upward. This design does not require electrical component control and can maintain stability for a long time in the relatively harsh environment inside the denitrification tower.

[0051] The remaining structure is the same as that in Example 1.

[0052] Example 3, referring to Figure 6 This is the third embodiment of the present invention. The difference between this embodiment and the first embodiment is that the driving component is an electrically controlled telescopic rod, which controls the piston component 43 to move up and down, thus making the control process more stable and more accurate.

[0053] The remaining structure is the same as that in Example 1.

[0054] Example 4, refer to Figure 4-9 This is the fourth embodiment of the present invention. The difference between this embodiment and the first embodiment is that the air-mixing component 5 specifically includes a fixing sleeve 51 disposed on the outside of the branch pipe 2, a fixing pipe 52 disposed at the bottom of the fixing sleeve 51, an installation pipe 53 disposed at the bottom of the fixing pipe 52, a vaporization box 54 disposed at the bottom of the installation pipe 53, a flow pipe 55 disposed between the vaporization box 54 and the injection pipe 3, and a suction component 59 disposed inside the fixing pipe 52.

[0055] Specifically, the fixing sleeve 51 is divided into upper and lower parts and is fixed by bolts. The fixing tube 52 is welded to the fixing sleeve 51 and the fixing tube 52 extends upward into the branch pipe 2. The upper end of the vaporization box 54 is fixed to the installation tube 53 by bolts, and the lower end is welded to the vaporization box 54. The vaporization box 54 is connected to the branch pipe 2 through the fixing tube 52 and the installation tube 53. The suction component 59 has a built-in filter device that can filter impurities in the ammonia water. Since the gas-water ratio required for atomization is approximately 1:9, the vaporization box 54 only needs to process a small amount of ammonia water, and the suction component 59 needs to process less ammonia water, which can ensure long-term use. The vaporization box 54 is made of a material with good thermal conductivity.

[0056] By setting up the gas mixing component 5, ammonia water is introduced into the vaporization box 54. The high temperature in the denitrification tower will cause the ammonia water in the vaporization box 54 to vaporize rapidly. Then, it enters the injection pipe 3 through the flow pipe 55 and completes the vaporization with the ammonia water. In this way, ammonia gas is used instead of ordinary gas, which can improve the purity of ammonia gas after vaporization, reduce the other gases mixed in it, and is more conducive to the denitrification reaction of flue gas.

[0057] The mixing assembly 5 also includes a heating pipe 56 that runs through the bottom wall of the vaporization box 54, and an inlet 57 that is opened on the outside of the heating pipe 56.

[0058] Specifically, the lower end of the heating tube 56 is closed, and the upper end is connected to the internal space of the vaporization box 54. The inlet 57 is located below the internal space of the vaporization box 54, and the heating tube 56 is made of copper alloy.

[0059] By setting up a heating tube 56, ammonia water in the vaporization box 54 flows into the heating tube 56 through the inlet 57. After being heated, the heating tube 56 floats up and is discharged into the space above the vaporization box 54. Then, ammonia water is replenished into the heating tube 56. This improves the heating efficiency, can quickly generate ammonia gas, and ensures stable operation of the equipment.

[0060] Specifically, the mixing assembly 5 also includes a replenishment pipe 58 disposed on the inner top wall of the vaporization box 54. The upper end of the replenishment pipe 58 is connected to the installation pipe 53, and the lower end of the replenishment pipe 58 extends to the lower space inside the vaporization box 54. This allows the subsequently replenished ammonia water to reach the lower end of the vaporization box 54 directly without affecting the stable circulation inside the vaporization box 54.

[0061] Example 5, refer to Figure 1 The fifth embodiment of the present invention provides: a waste gas denitrification process for the metallurgical industry, comprising the following steps:

[0062] Flue gas pretreatment: Baghouse dust collectors are used to remove more than 90% of the dust in the flue gas, and the dust concentration at the outlet is controlled below 50mg / m³; the flue gas temperature is adjusted and finally stabilized at around 400℃.

[0063] Reducing agent preparation and spraying: The reducing agent is ammonia water (industrial grade 25% concentration), which is stored in a low temperature and normal pressure storage tank (temperature controlled at 15℃ to reduce ammonia volatilization). It is transported to the main pipe 1 through the heat-insulated transfer pump. The main pipe 1 distributes the ammonia water to many spray pipes 3 through the branch pipe 2. The ammonia water is atomized into 100μm droplets and sprayed into the flue gas pipeline to mix fully with the flue gas.

[0064] Catalytic reaction: The mixed flue gas enters the SCR reactor, where ammonia water rapidly decomposes into NH3 in the high-temperature flue gas (reaction formula: NH3·H2O→NH3↑+H2O). Subsequently, under the action of the catalyst, NO... x It undergoes a reduction reaction with NH3, the core reaction being: 4NO + 4NH3 + O2 → 4N2 + 6H2O.

[0065] Tail-end purification and monitoring: After the flue gas from the reaction is detected by an ammonia escape monitor, it is sent into the chimney for discharge by an induced draft fan.

[0066] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A waste gas denitrification device for the metallurgical industry, comprising a main pipe (1), branch pipes (2) disposed on both sides of the main pipe (1), an injection pipe (3) disposed at the bottom of the branch pipes (2), and a gas mixing assembly (5), characterized in that: The spray pipe (3) specifically includes an upper pipe (31) located at the bottom of the branch pipe (2), a lower pipe (32) located at the end of the upper pipe (31) away from the branch pipe (2), and a nozzle (33) located at the end of the lower pipe (32) away from the upper pipe (31). A cleaning component (4) is provided at the connection between the upper pipe (31) and the lower pipe (32). The cleaning component (4) specifically includes a connecting pipe (41) at the bottom of the connection between the lower pipe (32) and the upper pipe (31), a suction can (42) at the bottom of the connecting pipe (41), and a piston (43) inside the suction can (42). The upper pipe (31) is composed of a long side and a short side, forming an "L" shape. The lower pipe (32) is composed of a vertical long side, a vertical short side, and a horizontal short side, forming a "J" shape. The lower pipe (32) is rotated up and down, and its vertical short side is connected to the short side of the upper pipe (31). The suction tank (42) is connected to the upper pipe (31) and the lower pipe (32) through the connecting pipe (41). A driving component is provided below the piston component (43). The connecting pipe (41) is provided with a lower filter screen (45) and an upper filter screen (46). The lower filter screen (45) is a frustum shape with a thicker bottom and a thinner top, and the upper filter screen (46) is a frustum shape with a thicker top and a thinner bottom. The upper filter screen (46) runs through the connecting pipe (41) from top to bottom and is held above the connecting pipe (41). The lower filter screen (45) is held below the connecting pipe (41).

2. The waste gas denitrification device for the metallurgical industry according to claim 1, characterized in that: A ventilation valve (44) is installed at the bottom of the suction tank (42).

3. The waste gas denitrification device for the metallurgical industry according to claim 1, characterized in that: The driving component is a counterweight.

4. The waste gas denitrification device for the metallurgical industry according to claim 1, characterized in that: The driving component is an electrically controlled telescopic rod.

5. The waste gas denitrification device for the metallurgical industry according to claim 4, characterized in that: The gas mixing assembly (5) specifically includes a fixing sleeve (51) disposed on the outside of the branch pipe (2), a fixing pipe (52) disposed at the bottom of the fixing sleeve (51), an installation pipe (53) disposed at the bottom of the fixing pipe (52), a vaporization box (54) disposed at the bottom of the installation pipe (53), a flow pipe (55) disposed between the vaporization box (54) and the injection pipe (3), and a suction component (59) disposed inside the fixing pipe (52). The vaporization box (54) is connected to the branch pipe (2) through the fixed pipe (52) and the installation pipe (53), and the suction component (59) has a built-in filter device.

6. The waste gas denitrification device for the metallurgical industry according to claim 5, characterized in that: The gas mixing assembly (5) also includes a heating pipe (56) that runs through the bottom wall of the vaporization box (54) and an inlet (57) that is opened on the outside of the heating pipe (56). The heating tube (56) is closed at the lower end and connected to the internal space of the vaporization box (54) at the upper end. The inlet (57) is located below the internal space of the vaporization box (54).

7. The waste gas denitrification device for the metallurgical industry according to claim 5, characterized in that: The gas mixing assembly (5) also includes a supplementary pipe (58) disposed on the inner top wall of the vaporization box (54). The upper end of the supplementary pipe (58) is connected to the installation pipe (53), and the lower end of the supplementary pipe (58) extends to the lower space inside the vaporization box (54).

8. A waste gas denitrification process for the metallurgical industry, employing the waste gas denitrification device for the metallurgical industry as described in claim 1, characterized in that, Includes the following steps: Flue gas pretreatment: Dust in the flue gas is removed using a bag filter; flue gas temperature is adjusted; Preparation and spraying of reducing agent: Ammonia water is selected as the reducing agent. The main pipe (1) distributes the ammonia water to many spray pipes (3) through the branch pipe (2) to atomize and spray the ammonia water, which is then fully mixed with the flue gas. Catalytic reaction: The mixed flue gas enters the SCR reactor, where ammonia water rapidly decomposes into NH3, and then, under the action of the catalyst, NO... x It undergoes a reduction reaction with NH3; Tail-end purification and monitoring: After the flue gas from the reaction is detected by an ammonia escape monitor, it is sent into the chimney for discharge by an induced draft fan.

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