Hydrogenation reaction device for 2-nitro-N, 3-dimethylbenzamide

Abstract

The utility model provides a hydrogenation reaction device for 2-nitro-N, 3-dimethylbenzamide, which comprises a hydrogenation reaction kettle provided with a feed port and a discharge port, and a hydrogen tank communicated with the hydrogenation reaction kettle through a hydrogen header pipe, the hydrogen header pipe is respectively communicated with a first hydrogen branch pipe and a second hydrogen branch pipe, a first hydrogen distribution pipe is arranged at the bottom in the hydrogenation reaction kettle, a second hydrogen distribution pipe is arranged in the middle in the hydrogenation reaction kettle, the first hydrogen branch pipe is communicated with the first hydrogen distribution pipe, and the second hydrogen branch pipe is communicated with the second hydrogen distribution pipe; the sides, facing the center of the hydrogenation reaction kettle, of the first hydrogen distribution pipe and the second hydrogen distribution pipe are communicated with a plurality of aerators; a stirring unit is also arranged in the hydrogenation reaction kettle. According to the preparation method disclosed by the invention, the hydrogenation reaction efficiency of the 2-nitro-N, 3-dimethyl benzamide is improved.

Description

Technical Field

[0001] This application relates to the field of organic synthesis equipment technology, and in particular to a hydrogenation reaction apparatus for 2-nitro-N,3-dimethylbenzamide. Background Technology

[0002] 2-Amino-N,3-Dimethylbenzamide is a key intermediate in the synthesis of insecticides such as chlorantraniliprole. Chlorantraniliprole is safe for mammals and exhibits high efficiency, broad spectrum, and novel mechanism of action, thus possessing broad market potential and prospects.

[0003] Currently, the synthesis of 2-amino-N,3-dimethylbenzamide mainly involves the hydrogenation reaction of 2-nitro-N,3-dimethylbenzamide. In this process, 2-nitro-N,3-dimethylbenzamide, solvent, and catalyst are added to a hydrogenation reactor, which is then purged with nitrogen. Hydrogen is introduced, and the temperature is raised to 30-100℃ to produce 2-amino-N,3-dimethylbenzamide. However, because the materials in the hydrogenation reactor include gaseous hydrogen, liquid feedstock, and solid catalyst, and because existing hydrogenation reactors are relatively large, with hydrogen introduced from the top of the reactor, the gas, liquid, and solid phases are difficult to mix thoroughly within the reactor. This results in low efficiency of the catalytic hydrogenation reaction of 2-nitro-N,3-dimethylbenzamide, affecting the final product quality and yield. Utility Model Content

[0004] This application provides a hydrogenation reaction apparatus for 2-nitro-N,3-dimethylbenzamide to solve the problems mentioned in the background art.

[0005] This application provides a hydrogenation reaction apparatus for 2-nitro-N,3-dimethylbenzamide, including a hydrogenation reactor with an inlet and an outlet, and a hydrogen tank connected to the hydrogenation reactor via a hydrogen main pipe;

[0006] The main hydrogen pipe is connected to a first hydrogen branch pipe and a second hydrogen branch pipe. A first hydrogen distribution pipe is installed at the bottom of the hydrogenation reactor, and a second hydrogen distribution pipe is installed in the middle of the hydrogenation reactor. The first hydrogen branch pipe is connected to the first hydrogen distribution pipe, and the second hydrogen branch pipe is connected to the second hydrogen distribution pipe.

[0007] Both the first hydrogen gas distribution pipe and the second hydrogen gas distribution pipe are connected to multiple aerators on the side facing the center of the hydrogenation reactor.

[0008] The hydrogenation reactor is also equipped with a stirring unit.

[0009] Optionally, the stirring unit includes a motor, a drive shaft, a drive gear, a driven gear, a stirring shaft, and a stirring paddle;

[0010] The output end of the motor is connected to the drive shaft, which is set vertically. The drive gear fixing sleeve is placed on the drive shaft, and the driven gear fixing sleeve is placed on the outside of one end of the stirring shaft. The driven gear meshes with the drive gear. The end of the stirring shaft away from the driven gear extends vertically into the hydrogenation reactor. Multiple centrally symmetrical stirring paddles are set on the stirring shaft.

[0011] Optionally, the stirring shaft has a hollow structure, and multiple vent holes are provided on the side wall of the stirring shaft. The main hydrogen pipe is connected to the top of the stirring shaft through a third hydrogen branch pipe.

[0012] Optionally, the distance between the air outlet of the aerator and the stirring shaft is greater than the length of the stirring paddle.

[0013] Optionally, a moving unit is also provided inside the hydrogenation reactor. The moving unit includes a telescopic tube, a fixed plate, multiple telescopic cylinders, and a push rod.

[0014] The second hydrogen distribution pipe and the second hydrogen distribution pipe are connected by a telescopic pipe set in a vertical direction. The fixed plate is set on the upper part of the inner wall of the hydrogenation reactor. The fixed end of the telescopic cylinder is connected to the bottom of the fixed plate. The telescopic end of the telescopic cylinder is fixedly connected to one end of the push rod. The end of the push rod away from the telescopic cylinder is connected to the second hydrogen distribution pipe.

[0015] Optionally, a level gauge is installed inside the hydrogenation reactor.

[0016] Optionally, a pressure sensor and a venting valve are installed on the top of the hydrogenation reactor.

[0017] The hydrogenation apparatus for 2-nitro-N,3-dimethylbenzamide provided in this application realizes the hydrogenation reaction of 2-nitro-N,3-dimethylbenzamide, and has the following advantages compared with the prior art:

[0018] (1) By connecting the main hydrogen pipe to the first hydrogen branch pipe and the second hydrogen branch pipe respectively, and setting the first hydrogen distribution pipe at the bottom of the hydrogenation reactor and the second hydrogen distribution pipe in the middle, the first hydrogen branch pipe is connected to the first hydrogen distribution pipe and the second hydrogen branch pipe is connected to the second hydrogen distribution pipe. During the hydrogenation reaction, the hydrogen in the hydrogen tank is transported to the first hydrogen distribution pipe and the second hydrogen distribution pipe through the main hydrogen pipe. Then the hydrogen is output through multiple aerators. The beneficial effect of this setting is that after the hydrogen is output, it directly contacts the liquid and solid raw materials in the hydrogenation reactor and reacts. Compared with the prior art, where the hydrogen is input from the top of the hydrogenation reactor, the hydrogenation reaction device provided in this application makes the mixing of hydrogen and each reactant more uniform and can also play a stirring role on the reactants. The contact area between each material and the hydrogen is larger and the contact time is longer, which makes the hydrogenation reaction more efficient and significantly improves the quality and yield of the product.

[0019] (2) By setting the stirring shaft in the stirring unit to a hollow structure, and opening multiple vent holes on the side wall of the stirring shaft, the hydrogen main pipe is connected to the top of the stirring shaft through the third hydrogen branch pipe. Hydrogen enters the hollow structure of the stirring shaft through the hydrogen main pipe and the third hydrogen branch pipe, and is then output to the reactants through the multiple vent holes on the side wall of the stirring shaft. This further makes the mixing of hydrogen with other liquid and solid raw materials more uniform, and at the same time improves the quality of the product.

[0020] (3) A moving unit, including a telescopic pipe, a fixed plate, multiple telescopic cylinders, and a push rod, is set up to drive the second hydrogen distribution pipe to move vertically via the telescopic cylinders, so as to adapt to the reaction at different liquid levels in the hydrogenation reactor. One end of the telescopic pipe is connected to the second hydrogen distribution pipe, and the other end of the telescopic pipe is connected to the second hydrogen distribution pipe. The telescopic pipe is set vertically, which helps the second hydrogen distribution pipe to maintain vertical movement and improves the operational stability of the hydrogenation reactor. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of a hydrogenation reactor provided in one embodiment of this application;

[0023] Figure 2 A schematic diagram of the structure of the first hydrogen distribution pipe, the second hydrogen distribution pipe, the first hydrogen distribution pipe, and the second hydrogen distribution pipe provided in an embodiment of this application;

[0024] Figure 3 This is a schematic diagram of the structure of a hydrogenation reactor provided in another embodiment of this application;

[0025] Figure 4 This is a schematic diagram of the structure of a hydrogenation reactor provided in another embodiment of this application;

[0026] Figure 5 This is a schematic diagram of the structure of a moving unit provided in an embodiment of this application.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1: Hydrogen reactor; 2: Hydrogen tank; 3: Hydrogen main pipe; 6: Level gauge; 110: Inlet; 120: Outlet; 130: First hydrogen distribution pipe; 140: Second hydrogen distribution pipe; 150: Aerator; 160: Pressure sensor; 170: Vent valve; 310: First hydrogen branch pipe; 320: Second hydrogen branch pipe; 330: Third hydrogen branch pipe; 410: Motor; 420: Drive shaft; 430: Drive gear; 440: Driven gear; 450: Stirring shaft; 460: Stirring paddle; 510: Telescopic pipe; 520: Fixing plate; 530: Telescopic cylinder; 540: Flange; 550: Positioning rod; 560: Limit block. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0030] like Figure 1 and Figure 2 As shown, this application provides a hydrogenation reaction apparatus for 2-nitro-N,3-dimethylbenzamide, including a hydrogenation reactor 1 with an inlet 110 and an outlet 120, and a hydrogen tank 2 connected to the hydrogenation reactor 1 through a hydrogen main pipe 3;

[0031] The main hydrogen pipe 3 is connected to the first hydrogen branch pipe 310 and the second hydrogen branch pipe 320 respectively. The bottom of the hydrogenation reactor 1 is provided with the first hydrogen distribution pipe 130, and the middle part of the hydrogenation reactor 1 is provided with the second hydrogen distribution pipe 140. The first hydrogen branch pipe 310 is connected to the first hydrogen distribution pipe 130, and the second hydrogen branch pipe 320 is connected to the second hydrogen distribution pipe 140.

[0032] Both the first hydrogen gas distribution pipe 130 and the second hydrogen gas distribution pipe 140 are connected to multiple aerators 150 on the side facing the center of the hydrogenation reactor 1.

[0033] The hydrogenation reactor 1 is also equipped with a stirring unit.

[0034] Specifically, the reactants 2-nitro-N,3-dimethylbenzamide, solvent, catalyst, etc., are fed into the hydrogenation reactor 1 through the feed port 110. The hydrogen tank 2 contains hydrogen gas, which is used to supply hydrogen gas to the hydrogenation reactor 1 to carry out the hydrogenation reaction of 2-nitro-N,3-dimethylbenzamide to obtain 2-amino-N,3-dimethylbenzamide. After the reaction, the material is discharged through the discharge port 120.

[0035] The main hydrogen pipe 3 is connected to a first hydrogen branch pipe 310 and a second hydrogen branch pipe 320. During the hydrogenation reaction, hydrogen from the hydrogen tank 2 is transported through the main hydrogen pipe 3 to the first hydrogen distribution pipe 130 and the second hydrogen distribution pipe 140 via the first hydrogen branch pipe 310 and the second hydrogen branch pipe 320, respectively. The first hydrogen distribution pipe 130 and the second hydrogen distribution pipe 140 are arranged around the inner wall of the hydrogenation reactor 1. Then, the hydrogen is output through multiple aerators 150. During the hydrogenation reaction, the pressure of the output hydrogen will not cause the material in the hydrogenation reactor 1 to flow back. The beneficial effect of this arrangement is that the output hydrogen directly contacts the liquid and solid raw materials in the hydrogenation reactor 1 and reacts. Compared with the prior art, where hydrogen is input from the top of the hydrogenation reactor 1, the hydrogenation reaction device provided in this application makes the mixing of hydrogen and each reactant more uniform, and the contact area and contact time between each material and hydrogen are larger, thereby making the hydrogenation reaction more efficient and significantly improving the quality and yield of the product.

[0036] Furthermore, check valves are installed between the aerator 150 and the first hydrogen distribution pipe 130 and the second hydrogen distribution pipe 140 to prevent liquid backflow. At the same time, after the reaction is completed, the reacted material is discharged through the discharge port 120, and hydrogen is continuously introduced for 5-10 minutes to purge, so as to avoid material clogging of the aerator 150 or liquid backflow in the hydrogenation reactor 1.

[0037] The first hydrogen distribution pipe 130 is located at the bottom of the hydrogenation reactor 1, and the second hydrogen distribution pipe 140 is located in the middle of the hydrogenation reactor 1. This ensures a continuous supply of hydrogen regardless of the amount of reactants added. The hydrogenation reactor 1 is also equipped with a stirring unit. During the hydrogenation reaction, hydrogen is output through multiple aerators 150, which not only improves the uniformity of mixing of the materials but also stirs the reactants. Combined with the stirring unit, the uniformity of mixing of hydrogen and raw materials is further improved, thus increasing the efficiency of the hydrogenation reaction.

[0038] This application achieves the hydrogenation reaction of 2-nitro-N,3-dimethylbenzamide through the above-described scheme. The main hydrogen pipeline is connected to a first hydrogen distribution pipe and a second hydrogen distribution pipe. A first hydrogen distribution pipe is installed at the bottom of the hydrogenation reactor, and a second hydrogen distribution pipe is installed in the middle. The first hydrogen distribution pipe is connected to the first hydrogen distribution pipe, and the second hydrogen distribution pipe is connected to the second hydrogen distribution pipe. During the hydrogenation reaction, hydrogen from the hydrogen tank is transported through the main hydrogen pipeline to the first hydrogen distribution pipe and the second hydrogen distribution pipe, respectively. The hydrogen is distributed through a hydrogen gas distribution pipe, and then the hydrogen is output through multiple aerators. The beneficial effect of this setup is that the output hydrogen directly contacts and reacts with the liquid and solid raw materials in the hydrogenation reactor. Compared with the prior art, where hydrogen is input from the top of the hydrogenation reactor, the hydrogenation reactor provided in this application makes the mixing of hydrogen with each reactant more uniform and can also play a stirring role for the reactants. The contact area between each material and hydrogen is larger and the contact time is longer, thereby making the hydrogenation reaction more efficient and significantly improving the quality and yield of the product.

[0039] like Figure 3 As shown, optionally, the stirring unit includes a motor 410, a drive shaft 420, a drive gear 430, a driven gear 440, a stirring shaft 450, and a stirring paddle 460.

[0040] The output end of the motor 410 is connected to the drive shaft 420, which is vertically oriented. The drive gear 430 is fixedly mounted on the drive shaft 420, and the driven gear 440 is fixedly mounted on the outside of one end of the stirring shaft 450. The driven gear 440 meshes with the drive gear 430. The end of the stirring shaft 450 away from the driven gear 440 extends vertically into the hydrogenation reactor 1. Multiple centrally symmetrical stirring paddles 460 are mounted on the stirring shaft 450.

[0041] Specifically, the motor 410 is mounted on the top of the hydrogenation reactor 1 via a bracket. When the motor 410 is turned on, it provides power to drive the transmission shaft 420 to rotate. The transmission shaft 420 drives the drive gear 430 to rotate, which in turn drives the driven gear 440 meshing with it to rotate. The driven gear 440 drives the stirring shaft 450 to rotate, which in turn drives the stirring paddle 460 to rotate. The stirring paddle 460 stirs the reaction materials in the hydrogenation reactor 1 and works together with the hydrogen gas output from the aerator 150 to improve the efficiency of the hydrogenation reaction while stirring the reactants.

[0042] The connection between the stirring shaft 450 and the hydrogenation reactor 1 is dynamically sealed by a bearing seal, which helps to keep the reaction pressure inside the hydrogenation reactor 1 at the preset pressure. The preset pressure of the hydrogenation reaction is set according to the actual working conditions.

[0043] like Figure 3As shown, optionally, the stirring shaft 450 has a hollow structure, and multiple vent holes are provided on the side wall of the stirring shaft 450. The hydrogen main pipe 3 is connected to the top of the stirring shaft 450 through the third hydrogen branch pipe 330.

[0044] Specifically, hydrogen gas enters the hollow structure of the stirring shaft 450 through the main hydrogen pipe 3 and the third hydrogen branch pipe 330, and then exits to the reactants through multiple vent holes on the side wall of the stirring shaft 450. This further ensures more uniform mixing of hydrogen gas with other liquid and solid reactants, while improving the quality of the product. During the hydrogenation reaction, the pressure of the output hydrogen gas will not cause backflow of materials in the hydrogenation reactor 1.

[0045] After the reaction is complete, the reacted material is discharged through outlet 120, and hydrogen is continuously introduced for 5-10 minutes to purge, so as to prevent the material from clogging the outlet or the liquid in hydrogenation reactor 1 from flowing back.

[0046] Optionally, the distance between the air outlet of the aerator 150 and the stirring shaft 450 is greater than the length of the stirring paddle 460. This arrangement avoids collisions between the stirring paddle 460 and the aerator 150 during rotation, which is beneficial for the long-term stable operation of the device.

[0047] like Figure 4 As shown, optionally, a moving unit is also provided inside the hydrogenation reactor 1. The moving unit includes a telescopic tube 510, a fixed plate 520, multiple telescopic cylinders 530 and a push rod 531.

[0048] The second hydrogen distribution pipe 320 and the second hydrogen distribution pipe 140 are connected by a vertically arranged telescopic pipe 510. The fixed plate 520 is set on the upper part of the inner wall of the hydrogenation reactor 1. The fixed end of the telescopic cylinder 530 is connected to the bottom of the fixed plate 520. The telescopic end of the telescopic cylinder 530 is fixedly connected to one end of the push rod 531. The end of the push rod 531 away from the telescopic cylinder 530 is connected to the second hydrogen distribution pipe 140.

[0049] Specifically, the moving unit is used to move the second hydrogen distribution pipe 140 vertically to accommodate reactions at different liquid levels within the hydrogenation reactor 1. One end of the telescopic pipe 510 is connected to the second hydrogen branch pipe 320, and the other end of the telescopic pipe 510 is connected to the second hydrogen distribution pipe 140. The telescopic pipe 510 is vertically positioned, which facilitates the vertical movement of the second hydrogen distribution pipe 140.

[0050] Furthermore, the second hydrogen distribution pipe 320 is connected to the telescopic pipe 510 via a metal elbow, with the end of the metal elbow connected to the telescopic pipe 510 pointing vertically upwards. This helps keep the telescopic pipe 510 vertical and prevents it from shifting direction. Multiple telescopic cylinders 530 are located in the upper part of the hydrogenation reactor 1, and the telescopic ends of the multiple telescopic cylinders 530 are always above the liquid surface, not in contact with the materials inside the hydrogenation reactor 1, ensuring stable operation of the telescopic cylinders 530.

[0051] like Figure 5 As shown, further, the two ends of the telescopic pipe 510 are connected to the second hydrogen distribution pipe 320 and the second hydrogen distribution pipe 140 respectively through flanges 540. At least two vertical positioning rods 550 are provided between the upper and lower flanges 540. The bottom of the positioning rod 550 is fixedly connected to the lower flange 540, and the top of the positioning rod 550 passes through the upper flange 540, so that the positioning rod 550 can always move through the upper flange 540 when the telescopic pipe 510 is extended vertically. The length of the positioning rod 550 is greater than the maximum length of the telescopic pipe 510 when it is extended. A limit block 560 is provided at the top of the positioning rod 550. This allows the telescopic pipe 510 to maintain vertical extension and contraction without directional deviation, thereby ensuring continuous hydrogen input and improving the efficiency of the hydrogenation reaction.

[0052] Furthermore, a groove is vertically formed on the inner wall of the hydrogenation reactor 1, and a protrusion is provided on the second hydrogen distribution pipe 140 at the position corresponding to the groove. The protrusion is slidably disposed inside the groove. This arrangement ensures that when the telescopic pipe 510 extends or retracts in the vertical direction, it drives the second hydrogen distribution pipe 140 to move stably, avoiding shaking and directional deviation.

[0053] Optionally, a level gauge 6 is installed inside the hydrogenation reactor 1.

[0054] Specifically, the level gauge 6 is used to detect the liquid level in the hydrogenation reactor 1. By observing the reading of the level gauge 6, the telescopic cylinder 530 can be adjusted to extend or retract, so that the second hydrogen distribution pipe 140 is located below the liquid level in the hydrogenation reactor 1, so as to ensure a stable input of hydrogen and thus improve the efficiency of the hydrogenation reaction.

[0055] Optionally, a pressure sensor 160 and a venting valve 170 are provided on the top of the hydrogenation reactor 1.

[0056] Specifically, pressure sensor 160 is used to detect the pressure inside hydrogenation reactor 1. When the pressure reading of pressure sensor 160 is greater than or equal to the preset pressure of the device, vent valve 170 is opened to balance the pressure inside hydrogenation reactor 1, which is beneficial to the efficient and stable progress of the reaction.

[0057] The technical solution of this application will be illustrated in detail below with specific embodiments.

[0058] The operating procedure of the hydrogenation reaction apparatus for 2-nitro-N,3-dimethylbenzamide in this embodiment is as follows:

[0059] Before the hydrogenation reaction begins, hydrogen from hydrogen tank 2 is first transported through the main hydrogen pipe 3 to the hollow structures of the first hydrogen distribution pipe 130, the second hydrogen distribution pipe 140, and the stirring shaft 450 via the first hydrogen distribution pipe 310, the second hydrogen distribution pipe 320, and the third hydrogen distribution pipe 330, respectively. Hydrogen from the first hydrogen distribution pipe 130 and the second hydrogen distribution pipe 140 is output through multiple aerators 150, and hydrogen from the stirring shaft 450 is output through multiple vent holes on the side wall of the stirring shaft 450. Simultaneously, 2-nitro-N,3-dimethylbenzamide, solvent (such as one of methanol, ethanol, or propanol), catalyst, and other reaction raw materials are added to the hydrogenation reactor 1 through the feed inlet 110. After the addition is complete, the motor 410 is turned on to provide power, which drives the transmission shaft 420 to rotate. The transmission shaft 420 drives the drive gear 430 to rotate, which in turn drives the driven gear 440 meshing with it to rotate. The driven gear 440 drives the stirring shaft 450 to rotate, which in turn drives the stirring paddle 460 to rotate. The stirring paddle 460 stirs the reaction raw materials in the hydrogenation reactor 1. The reaction is carried out by jacket heating and hydrogenation reaction to obtain the product 2-amino-N,3-dimethylbenzamide. The reacted material is output through the discharge port 120.

[0060] By observing the liquid level reading on the level gauge 6, the telescopic cylinder 530 can be adjusted to extend or retract. The extension or retraction of the telescopic cylinder 530 causes the second hydrogen distribution pipe 140 to move vertically, ensuring that the second hydrogen distribution pipe 140 is below the liquid level of the material in the hydrogen reactor 1. This guarantees a stable input of hydrogen and improves the efficiency of the hydrogenation reaction. When the pressure reading on the pressure sensor 160 is greater than or equal to the preset pressure of the device (e.g., 1.2 MPa), the vent valve 170 is opened to balance the pressure inside the hydrogen reactor 1, which is beneficial for the efficient and stable progress of the reaction.

[0061] It should be noted that the detailed structure of some devices in this utility model is not described in detail, but belongs to the prior art known to those skilled in the art, so it will not be described in detail here.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A hydrogenation reaction apparatus for 2-nitro-N,3-dimethylbenzamide, characterized in that, It includes a hydrogenation reactor (1) with an inlet (110) and an outlet (120), and a hydrogen tank (2) connected to the hydrogenation reactor (1) via a hydrogen main pipe (3); The main hydrogen pipe (3) is connected to a first hydrogen branch pipe (310) and a second hydrogen branch pipe (320). A first hydrogen distribution pipe (130) is provided at the bottom of the hydrogenation reactor (1), and a second hydrogen distribution pipe (140) is provided in the middle of the hydrogenation reactor (1). The first hydrogen branch pipe (310) is connected to the first hydrogen distribution pipe (130), and the second hydrogen branch pipe (320) is connected to the second hydrogen distribution pipe (140). The first hydrogen gas distribution pipe (130) and the second hydrogen gas distribution pipe (140) are each connected to a plurality of aerators (150) on the side facing the center of the hydrogenation reactor (1). The hydrogenation reactor (1) is also equipped with a stirring unit.

2. The hydrogenation reaction apparatus for 2-nitro-N,3-dimethylbenzamide according to claim 1, characterized in that, The stirring unit includes a motor (410), a drive shaft (420), a drive gear (430), a driven gear (440), a stirring shaft (450), and a stirring paddle (460). The output end of the motor (410) is connected to the transmission shaft (420), which is vertically arranged. The driving gear (430) is fixedly sleeved on the transmission shaft (420), and the driven gear (440) is fixedly sleeved on the outside of one end of the stirring shaft (450). The driven gear (440) meshes with the driving gear (430). The end of the stirring shaft (450) away from the driven gear (440) extends vertically into the hydrogenation reactor (1). Multiple centrally symmetrical stirring paddles (460) are arranged on the stirring shaft (450).

3. The hydrogenation reaction apparatus for 2-nitro-N,3-dimethylbenzamide according to claim 2, characterized in that, The stirring shaft (450) has a hollow structure, and multiple air outlets are provided on the side wall of the stirring shaft (450). The hydrogen main pipe (3) is connected to the top of the stirring shaft (450) through a third hydrogen branch pipe (330).

4. The hydrogenation reaction apparatus for 2-nitro-N,3-dimethylbenzamide according to claim 2, characterized in that, The distance between the air outlet of the aerator (150) and the stirring shaft (450) is greater than the length of the stirring paddle (460).

5. The hydrogenation apparatus for 2-nitro-N,3-dimethylbenzamide according to any one of claims 1-4, characterized in that, The hydrogenation reactor (1) is also equipped with a moving unit, which includes a telescopic tube (510), a fixed plate (520), multiple telescopic cylinders (530) and a push rod (531). The second hydrogen distribution pipe (320) and the second hydrogen distribution pipe (140) are connected by a vertically arranged telescopic pipe (510). The fixed plate (520) is located on the upper part of the inner wall of the hydrogenation reactor (1). The fixed end of the telescopic cylinder (530) is connected to the bottom of the fixed plate (520). The telescopic end of the telescopic cylinder (530) is fixedly connected to one end of the push rod (531). The end of the push rod (531) away from the telescopic cylinder (530) is connected to the second hydrogen distribution pipe (140).

6. The hydrogenation reaction apparatus for 2-nitro-N,3-dimethylbenzamide according to claim 5, characterized in that, A level gauge (6) is installed inside the hydrogenation reactor (1).

7. The hydrogenation reaction apparatus for 2-nitro-N,3-dimethylbenzamide according to claim 6, characterized in that, The top of the hydrogenation reactor (1) is equipped with a pressure sensor (160) and a venting valve (170).

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