2-methylpyridine ammoxidation fixed bed catalytic reactor and catalytic reaction system

Abstract

The invention discloses a 2-methylpyridine ammoxidation fixed bed catalytic reactor and a catalytic reaction system, and belongs to the technical field of efficient catalysis. Comprising a tower body, a mixed gas inlet is formed in the top of the tower body, a mixed gas outlet is formed in the bottom of the tower body, a plurality of catalyst laminar flow pipes and a plurality of baffle plates are arranged in an inner cavity of the tower body, a plurality of arc-shaped jacketed pipes are horizontally arranged on the outer wall of the tower body in a surrounding mode, and one axial end of each arc-shaped jacketed pipe is a closed end; the other axial end of the arc-shaped jacketed pipe is a fused salt inlet, a plurality of communicating holes are formed in the connecting face of the outer wall of the tower body and the arc-shaped jacketed pipe, and a fused salt outlet is further formed in the outer wall of the tower body. Fused salt fluid is annularly and uniformly distributed at the fused salt inlet through the arc-shaped jacketed pipe, the flow field disturbance and bias flow phenomena caused by a traditional tangential inlet are avoided, the flowing stability of the fused salt fluid is improved, formation of a local flowing isolation area is eliminated, heat accumulation is reduced, the heat transfer uniformity is improved, and the catalytic efficiency is improved.

Description

Technical Field

[0001] The invention relates to a 2-methylpyridine ammoxidation fixed-bed catalytic reactor and a catalytic reaction system, belonging to the technical field of high-efficiency catalysis. Background Art

[0002] 2-Cyanopyridine is an important organic synthesis intermediate, widely used in the manufacture of medicines, pesticides, dyes and other fine chemical products. The development of efficient, environmentally friendly and economical methods for the production of 2-cyanopyridine is essential to meet the growing market demand. Traditional synthetic routes usually involve the use of highly toxic cyanides, which not only burdens the environment, but also increases production costs and safety hazards. In contrast, the catalytic ammoxidation method using 2-methylpyridine as raw material shows many advantages.

[0003] This method uses 2-methylpyridine to react with ammonia and oxygen under the action of a catalyst to generate the target product 2-cyanopyridine. This synthetic route has a wide range of raw materials, low cost, and avoids the use of toxic chemicals, greatly reducing environmental impact and safety risks. Due to its high yield, low cost and environmental protection characteristics, the catalytic ammoxidation method has great application prospects in the industrial production of 2-cyanopyridine, providing a clean and economical new route for the commercial production of this important intermediate.

[0004] In the catalytic ammoxidation method using 2-methylpyridine as raw material, air, ammonia and methylpyridine as reactants undergo a series of complex chemical reactions under the action of a catalyst to finally generate 2-cyanopyridine product. This reaction pathway is the core and key step in the entire process. The 2-methylpyridine ammoxidation reactor used in the prior art is as follows: Figure 7 As shown, the process of catalytic ammoxidation using 2-methylpyridine as a raw material according to the 2-methylpyridine ammoxidation reactor is as follows:

[0005] In the upstream mixer, air, ammonia and methylpyridine are precisely proportioned and mixed evenly to form a pre-reaction gas. The pre-reaction gas is evenly diffused into multiple catalyst laminar flow tubes filled with catalysts through the inlet inverted cone hole distributor. As a high-temperature heat carrier, the molten salt enters the reactor shell tangentially through the upper and lower double-tube tangents, and forms a circulation in the shell side through the arched baffles in the pipeline, indirectly heating the mixed gas in the reaction tube, promoting its reaction with the catalyst to generate the target product. The molten salt is transported to the outlet at the top of the reactor to discharge the reactor, and then flows back to the molten salt pool to form a closed loop.

[0006] In actual operation, the molten salt enters the reactor shell tangentially through two double-tube tangents. However, the fixed-bed catalytic reactor system adopts an up-and-down opposed layout of four tangential inlets, which will lead to uneven flow distribution at the inlet, which is very likely to cause the formation of local flow isolation zones and heat accumulation, resulting in adverse rheological and thermodynamic effects.

[0007] Tangential entry will give the fluid a larger tangential velocity component. Due to the intensification of flow field disturbance and unevenness, it is very easy to induce complex secondary flow phenomena such as eddy current and backflow, which will not only significantly increase the flow resistance, but also lead to additional energy dissipation and reduced heat transfer efficiency. After tangential entry, the fluid needs to turn 90 degrees to flow along the tube bundle, and the turning process will produce a large pressure loss. At the same time, it may cause uneven flushing of the tube bundle by the fluid, affecting the heat exchange efficiency.

[0008] The molten salt streamlines at the upper and lower inlets will also have a hedging phenomenon, resulting in a strong swirl bath and reflux zone inside the shell, which seriously destroys the originally expected circulation flow field, thereby causing unfavorable flow patterns such as fluid pre-retention and diversion in the heat mixing area. This flow field disturbance causes uneven heat transfer in the shell, and some pipelines cannot obtain sufficient heat transfer.

[0009] Baffles force the fluid to pass through the reactor in a tortuous path, which can cause uneven distribution of the fluid on the reactor cross section. In the upstream area close to the baffle, the fluid velocity is high and the impact is more severe, which may lead to a local high heat transfer coefficient. Downstream of the baffle, the fluid velocity will slow down, causing a slower flow. This reduction in velocity will reduce the heat transfer efficiency in the downstream area because a lower flow rate means a lower heat transfer coefficient. Due to changes in fluid velocity and turbulence, the heat exchange in the reactor is not uniform, and local heat exchange dead zones may occur, forming a significant temperature gradient.

[0010] The uneven distribution of the shell temperature field will directly affect the catalytic reaction process in the laminar flow tube, reduce the utilization efficiency and selectivity of the catalyst, and then lead to a decrease in the overall reaction performance and product yield. In addition, the uneven distribution of the shell temperature field may lead to local overheating or low temperature areas, accelerate equipment corrosion and aging, and have low operational safety. Traditional fixed-bed catalytic reactor control mostly adopts empirical control and lacks intelligent optimization functions.

[0011] Therefore, how to achieve uniform distribution of temperature field during the fixed-bed catalytic reaction of 2-methylpyridine ammoxidation and improve the efficiency of the fixed-bed catalytic reaction of 2-methylpyridine ammoxidation has become a technical problem to be solved urgently by those skilled in the art. Summary of the invention

[0012] In order to solve the existing problems of uneven temperature field distribution during the reaction process caused by tangential entry of molten salt into the reactor during the fixed-bed catalytic reaction of 2-methylpyridine ammoxidation, the present invention provides a 2-methylpyridine ammoxidation fixed-bed catalytic reactor and a catalytic reaction system.

[0013] As one aspect of the present invention, a 2-methylpyridine ammoxidation fixed-bed catalytic reactor is provided, comprising: a tower body, a mixed gas inlet is arranged at the top of the tower body, a mixed gas outlet is arranged at the bottom of the tower body, a plurality of catalyst laminar flow tubes and a plurality of baffles are arranged in the inner cavity of the tower body, a plurality of arc-shaped jacketed tubes are arranged horizontally around the outer wall of the tower body, one axial end of the arc-shaped jacketed tube is a closed end, and the other axial end of the arc-shaped jacketed tube is a molten salt inlet, a plurality of connecting holes are provided on the connecting surface between the outer wall of the tower body and the arc-shaped jacketed tube, and a molten salt outlet is also arranged on the outer wall of the tower body.

[0014] Furthermore, the baffle is an arched baffle, which is horizontally arranged in the inner cavity of the tower body, and the relative positions of the plurality of arc-shaped jacketed tubes are arranged in sequence from top to bottom and spaced left and right, and the arched baffles and the arc-shaped jacketed tubes are arranged one by one, and the first arched baffle to the penultimate arched baffle from top to bottom are all arranged to be co-chord with the corresponding arc-shaped jacketed tube, and the chord of the last arched baffle from top to bottom is coplanar with the chord of the last arc-shaped jacketed tube in the vertical direction, but not coplanar in the horizontal direction.

[0015] Furthermore, the communicating hole is arranged to be inclined upward from the inner wall of the tower body to the outer wall of the tower body.

[0016] Furthermore, the communicating hole is inclined upward at an angle of 10° to 20° from the outer wall of the tower body to the inner wall of the tower body.

[0017] Furthermore, a nozzle is installed in the connecting hole, and the nozzle is used to send the molten salt in the arc-shaped jacket tube into the inner cavity of the tower body.

[0018] Furthermore, the communicating holes are distributed in a form of being dense in the middle and sparse on both sides.

[0019] As another aspect of the present invention, a 2-methylpyridine ammoxidation fixed bed catalytic reaction system is provided, comprising a flow measurement module, a temperature measurement module, a data processing module, a control module, a feedback regulation module and the above-mentioned 2-methylpyridine ammoxidation fixed bed catalytic reactor;

[0020] The 2-methylpyridine ammoxidation fixed bed catalytic reactor is respectively connected to a flow measurement module, a temperature measurement module and a feedback regulation module, the flow measurement module and the temperature measurement module are respectively connected to a data processing module, the data processing module is connected to a control module, and the control module is connected to a feedback regulation module;

[0021] The 2-methylpyridine ammoxidation fixed bed catalytic reactor is used to catalyze 2-methylpyridine, air and ammonia through molten salt and catalyst to prepare 2-cyanopyridine;

[0022] The flow measurement module is used to monitor the molten salt flow rate of each molten salt inlet in real time and transmit the molten salt flow rate data to the data processing module;

[0023] The temperature measurement module is used to monitor the temperature of each preset temperature measurement point in the 2-methylpyridine ammoxidation fixed bed catalytic reactor in real time, and transmit the temperature data to the data processing module;

[0024] The data processing module is used to analyze the temperature distribution according to the temperature information, obtain the temperature distribution result, calculate the temperature error between the temperature data and the corresponding preset target temperature, and calculate the actual molten salt flow rate ratio according to the molten salt flow rate data corresponding to each molten salt inlet;

[0025] The control module is used to calculate the molten salt flow rate adjustment amount of each molten salt inlet according to the temperature error, the actual molten salt flow rate ratio and the temperature distribution result, and to generate a corresponding molten salt flow rate adjustment signal according to the molten salt flow rate adjustment amount;

[0026] The feedback regulation module is used to regulate the molten salt flow rate of the corresponding molten salt inlet according to each molten salt flow rate regulation signal.

[0027] Furthermore, the control module adopts a PID control algorithm.

[0028] The beneficial effects of the present invention are:

[0029] (1) The present invention provides a design of a uniformly distributed annular feed structure for the arc-shaped jacketed tube in a fixed-bed catalytic reactor for 2-methylpyridine ammoxidation, which allows the molten salt fluid to be uniformly distributed in an annular direction at the molten salt inlet into the inner cavity, which can avoid the flow field disturbance and bias caused by the traditional tangential inlet, improve the flow stability of the molten salt fluid, and eliminate the formation of local flow isolation zones, reduce heat accumulation, reduce the adverse effects of rheology and thermodynamics, improve the uniformity of heat transfer, ensure that the catalytic reaction is carried out under the best conditions, improve the efficiency of the catalytic reaction in the catalyst laminar flow tube, and improve the utilization rate of the catalyst, thereby improving the overall reaction performance and product yield. In addition, the temperature field distribution can be optimized, the overheating and low temperature areas inside the equipment can be reduced, the risk of equipment corrosion and aging can be effectively reduced, the service life of the equipment can be extended, and the safety of operation can be improved.

[0030] (2) The 2-methylpyridine ammonia oxidation fixed-bed catalytic reaction system provided by the present invention can monitor the molten salt flow rate and reaction temperature in real time, automatically adjust the molten salt flow rate according to the monitoring results, and change the flow rate ratio of each molten salt inlet, thereby optimizing the temperature field distribution in the shell side, making the temperature distribution more uniform, optimizing the reaction conditions, and improving the reaction effect and efficiency. It also realizes automatic monitoring and optimization control of the system, overcomes the limitations of traditional empirical control, and improves the operational safety and efficiency of the 2-methylpyridine ammonia oxidation fixed-bed catalytic reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0032] Figure 1 This is a schematic structural diagram of a fixed-bed catalytic reactor for 2-methylpyridine ammoxidation provided by an embodiment of the present invention;

[0033] Figure 2 is a schematic diagram of a connecting hole provided by an embodiment of the present invention;

[0034] Figure 3 is another schematic diagram of a connecting hole provided by an embodiment of the present invention;

[0035] Figure 4 Schematic diagram of a nozzle provided in an embodiment of the present invention.

[0036] Figure 5 This is a schematic structural diagram of a fixed-bed catalytic reaction system for 2-methylpyridine ammoxidation provided by an embodiment of the present invention;

[0037] Figure 6 It is a schematic diagram of a fixed-bed catalytic reaction system for 2-methylpyridine ammoxidation provided by an embodiment of the present invention.

[0038] Figure 7 It is a schematic diagram of the simplified structure of an existing 2-methylpyridine ammoxidation fixed-bed catalytic reactor provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0040] The embodiment of the present invention provides a fixed-bed catalytic reactor for 2-methylpyridine ammoxidation, such as Figure 1 and Figure 2As shown, it includes: a tower body 1, a mixed gas inlet 2 is arranged on the top of the tower body 1, and a mixed gas outlet 3 is arranged on the bottom of the tower body 1; the inner cavity of the tower body 1 is provided with a plurality of catalyst laminar flow tubes (not shown in the figure) and a plurality of baffles 4, and the outer wall of the tower body 1 is horizontally surrounded by a plurality of arc-shaped jacketed tubes 5, one axial end of the arc-shaped jacketed tube 5 is a closed end 51, and the other axial end of the arc-shaped jacketed tube 5 is a molten salt inlet 52, a plurality of connecting holes 6 are provided on the connecting surface between the outer wall of the tower body 1 and the arc-shaped jacketed tube 5, and the outer wall of the tower body 1 is also provided with a molten salt outlet 7.

[0041] Specifically, in the embodiment of the present invention, an inverted cone-shaped hole distributor 8 is further arranged below the mixed gas inlet 2. After the mixed gas of air, ammonia and 2-methylpyridine enters the mixed gas inlet 2, it evenly enters the catalyst laminar flow tube filled with catalyst through the inverted cone-shaped hole distributor 8. The molten salt as a heat carrier flows through the annular pipe diameter of the arc-shaped jacket pipe 5 horizontally arranged around the outer wall of the tower body 1, enters the inner cavity of the tower body 1 through the connecting hole 6, and forms a circulation in the shell side through the baffle 4, indirectly heating the mixed gas in the catalyst laminar flow tube, promoting its reaction with the catalyst to generate the target product 2-cyanopyridine, and then the molten salt is transported to the molten salt outlet 7 to discharge from the reactor, and then refluxes to the molten salt pool to form a closed loop cycle.

[0042] The arc-shaped jacket tube 5 adopts a uniformly distributed annular feeding structure design, which allows the molten salt fluid to be evenly distributed in the molten salt inlet 52 to enter the inner cavity, which can avoid the flow field disturbance and bias caused by the traditional tangential inlet, improve the flow stability of the molten salt fluid, and eliminate the formation of local flow isolation zones, reduce heat accumulation, reduce the adverse effects of rheology and thermodynamics, improve the uniformity of heat transfer, ensure that the catalytic reaction is carried out under the best conditions, improve the efficiency of the catalytic reaction in the catalyst laminar flow tube, and improve the utilization rate of the catalyst, thereby improving the overall reaction performance and product yield. In addition, it can also optimize the temperature field distribution, reduce the overheating and low temperature areas inside the equipment, effectively reduce the risk of equipment corrosion and aging, extend the service life of the equipment, and improve the safety of operation.

[0043] Furthermore, if Figure 1 As shown, the baffle 4 is an arched baffle, which is horizontally arranged in the inner cavity of the tower body 1, and the relative positions of a plurality of arc-shaped jacketed tubes 5 are arranged in sequence from top to bottom and at intervals on the left and right, and the arched baffles and the arc-shaped jacketed tubes 5 are arranged in a one-to-one correspondence, and the first arched baffle to the penultimate arched baffle from top to bottom are all arranged to be co-chordal with the corresponding arc-shaped jacketed tube 5, and the chord of the last arched baffle from top to bottom is coplanar with the chord of the last arc-shaped jacketed tube 5 in the vertical direction, but not coplanar in the horizontal direction.

[0044] Specifically, the baffle 4 provided in the embodiment of the present invention is not only an arched baffle, but also a single arched baffle. By setting the molten salt inlet 52 to be introduced from the notch of the arched baffle, the first arched baffle to the penultimate arched baffle from top to bottom are all set to be co-chord with the corresponding arc-shaped jacket tube 5, thereby avoiding the direct collision of the molten salt streamlines at the upper and lower molten salt inlets, reducing the intensity of the flow field disturbance, which reduces the flow resistance and reduces the additional energy dissipation caused by complex secondary flow phenomena such as eddy currents and backflows, thereby improving the heat transfer efficiency. In addition, the chord of the last arched baffle from top to bottom is coplanar with the chord of the last arc-shaped jacket tube 5 in the vertical direction, but not coplanar in the horizontal direction, which can avoid insufficient heat exchange efficiency in the bottom area.

[0045] Furthermore, if Figure 2 As shown, the communication hole 6 is arranged to be inclined upward from the outer wall of the tower body 1 to the inner wall of the tower body.

[0046] Specifically, the embodiment of the present invention provides a certain tangential velocity component to the incoming molten salt fluid by setting the connecting hole 6 upwardly inclined from the outer wall of the tower body 1 to the inner wall of the tower body, effectively offsetting the uneven flow of the molten salt caused by the structure of the baffle 4. It ensures that the flow volume of the entire cross section of the arc-shaped jacket pipe 5 is balanced, avoids the occurrence of local overheating or low temperature problems, and further improves the uniformity of heat exchange.

[0047] Furthermore, if Figure 3 As shown, the upward inclination angle of the connecting hole 6 from the inner wall of the tower body 1 to the outer wall of the tower body is 10° to 20°.

[0048] When the upward inclination angle of the connecting hole 6 is between 10° and 20°, it can provide the molten salt fluid with a suitable tangential velocity component, avoiding the tangential velocity being too small, which is insufficient to offset the uneven flow of the molten salt caused by the structure of the baffle 4, and avoiding the tangential velocity being too large, which will cause flow field disturbances and induce eddy currents, backflows and other phenomena.

[0049] Furthermore, if Figure 3 and Figure 4 As shown, a nozzle 9 is installed in the connecting hole 6 , and the nozzle 9 is used to send the molten salt in the arc-shaped jacket tube 5 into the inner cavity of the tower body 1 .

[0050] Specifically, the nozzle 9 for spraying the molten salt fluid is provided in the connecting hole 6 so that the molten salt fluid can be further evenly distributed.

[0051] Furthermore, the communicating holes 6 are distributed in a form of being dense in the middle and sparse on both sides.

[0052] Specifically, the communicating holes 6 are distributed in a form of being dense in the middle and sparse on both sides, so as to achieve a balanced distribution of the flow rate on the cross section corresponding to the entire arc-shaped jacket pipe 5 and the tower body 1 .

[0053] Another embodiment of the present invention provides a 2-methylpyridine ammoxidation fixed bed catalytic reaction system 10, see Figure 5 and Figure 6 , including a flow measurement module 11, a temperature measurement module 12, a data processing module 13, a control module 14, a feedback regulation module 15 and the above-mentioned 2-methylpyridine ammoxidation fixed bed catalytic reactor 16;

[0054] The 2-methylpyridine ammoxidation fixed bed catalytic reactor 16 is respectively connected to the flow measurement module 11, the temperature measurement module 12 and the feedback regulation module 15, the flow measurement module 11 and the temperature measurement module 12 are respectively connected to the data processing module 13, the data processing module 13 is connected to the control module 14, and the control module 14 is connected to the feedback regulation module 15;

[0055] The 2-methylpyridine ammoxidation fixed bed catalytic reactor 16 is used to catalyze 2-methylpyridine, air and ammonia by using molten salt and catalyst to prepare 2-cyanopyridine;

[0056] The flow measurement module 11 is used to monitor the molten salt flow rate of each molten salt inlet in real time and transmit the molten salt flow rate data to the data processing module 13;

[0057] Specifically, the flow measurement module 11 in the embodiment of the present invention includes several flow meters, which are respectively arranged at the molten salt inlet of each arc-shaped jacketed tube of the 2-methylpyridine ammoxidation fixed bed catalytic reactor 16 to monitor the molten salt flow corresponding to each molten salt inlet in real time.

[0058] The temperature measurement module 12 is used to monitor the temperature of each preset temperature measurement point in the 2-methylpyridine ammoxidation fixed bed catalytic reactor 16 in real time, and transmit the temperature data to the data processing module 13;

[0059] Specifically, in the implementation of the present invention, the temperature measurement module 12 includes a plurality of temperature sensors, which are respectively arranged at preset temperature measurement points of the 2-methylpyridine ammonia oxidation fixed bed catalytic reactor 16 to monitor the molten salt flow rate corresponding to each molten salt inlet in real time. The number of positions of the temperature measurement points can be specifically selected according to actual needs, and the embodiment of the present invention does not make further limitations on this.

[0060] The data processing module 13 is used to analyze the temperature distribution according to the temperature information, obtain the temperature distribution result, and calculate the temperature error between the temperature data and the corresponding preset target temperature, and calculate the actual molten salt flow rate ratio according to the molten salt flow rate data corresponding to each molten salt inlet;

[0061] The control module 14 is used to calculate the molten salt flow rate adjustment amount of each molten salt inlet according to the temperature error, the actual molten salt flow rate ratio and the temperature distribution result, and to generate a corresponding molten salt flow rate adjustment signal according to the molten salt flow rate adjustment amount;

[0062] The feedback regulation module 15 is used to regulate the molten salt flow rate of the corresponding molten salt inlet according to each molten salt flow rate regulation signal.

[0063] The embodiment of the present invention actually performs feedback regulation of the molten salt flow rate through an electric regulating valve, and an electric regulating valve is provided at the molten salt inlet of each arc-shaped jacketed pipe. Specifically, the control module 14 outputs various molten salt flow rate regulation signals, which act on the corresponding electric regulating valves respectively, and the electric regulating valves adjust the opening according to the corresponding molten salt flow rate regulation signals, thereby realizing molten salt flow rate regulation.

[0064] In summary, the embodiments of the present invention can monitor the molten salt flow rate and reaction temperature in real time, automatically adjust the molten salt flow rate according to the monitoring results, change the flow rate ratio of each molten salt inlet, thereby optimizing the temperature field distribution in the shell, making the temperature distribution more uniform, optimizing the reaction conditions, and improving the reaction effect and efficiency. It also realizes automatic monitoring and optimization control of the system, overcomes the limitations of traditional empirical control, and improves the operational safety and efficiency of the 2-methylpyridine ammoxidation fixed bed catalytic reactor.

[0065] Furthermore, the control module 14 adopts a PID control algorithm.

[0066] The control module 14 provided in the embodiment of the present invention calculates the molten salt adjustment amount through the PID (Proportion Integral Differential) control algorithm. Specifically, the temperature error, the actual molten salt flow ratio and the temperature distribution result are used as input data of the PID control algorithm, and the molten salt adjustment amount is obtained by proportional regulation, integral regulation and differential regulation calculation in sequence.

[0067] Some steps in the embodiments of the present invention may be implemented using software, and the corresponding software program may be stored in a readable storage medium, such as a CD or a hard disk.

[0068] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. 2-Methylpyridine ammoxidation fixed bed catalytic reactor, characterized in that: include: A tower body, wherein a mixed gas inlet is arranged at the top of the tower body, and a mixed gas outlet is arranged at the bottom of the tower body; a plurality of catalyst laminar flow tubes and a plurality of baffles are arranged in the inner cavity of the tower body, a plurality of arc-shaped jacketed tubes are arranged horizontally around the outer wall of the tower body, one axial end of the arc-shaped jacketed tube is a closed end, and the other axial end of the arc-shaped jacketed tube is a molten salt inlet, a plurality of connecting holes are provided on the connecting surface between the outer wall of the tower body and the arc-shaped jacketed tube, and a molten salt outlet is also arranged on the outer wall of the tower body.

2. The 2-methylpyridine ammoxidation fixed bed catalytic reactor according to claim 1, characterized in that: The baffle is an arched baffle, which is horizontally arranged in the inner cavity of the tower body. The relative positions of the plurality of arc-shaped jacketed tubes are arranged in sequence from top to bottom and spaced left and right. The arched baffles and the arc-shaped jacketed tubes are arranged one by one. From the first arched baffle to the second to last arched baffle from top to bottom, they are all arranged to be co-chordal with the corresponding arc-shaped jacketed tube. The chord of the last arched baffle from top to bottom is coplanar with the chord of the last arc-shaped jacketed tube in the vertical direction, but not coplanar in the horizontal direction.

3. The 2-methylpyridine ammoxidation fixed bed catalytic reactor according to claim 1, characterized in that: The communicating hole is arranged to be inclined upward from the outer wall of the tower body to the inner wall of the tower body.

4. The 2-methylpyridine ammoxidation fixed bed catalytic reactor according to claim 3, characterized in that: The communicating hole is inclined upward at an angle of 10° to 20° from the inner wall of the tower body to the outer wall of the tower body.

5. The 2-methylpyridine ammoxidation fixed bed catalytic reactor according to claim 4, characterized in that: A nozzle is installed in the communicating hole, and the nozzle is used to send the molten salt in the arc-shaped jacket pipe into the inner cavity of the tower body.

6. The 2-methylpyridine ammoxidation fixed bed catalytic reactor according to any one of claims 1 to 5, characterized in that: The communicating holes are distributed in a form of being dense in the middle and sparse on both sides. 7.2-Methylpyridine ammoxidation fixed bed catalytic reaction system, characterized in that: It comprises a flow measurement module, a temperature measurement module, a data processing module, a control module, a feedback regulation module and a 2-methylpyridine ammoxidation fixed bed catalytic reactor according to any one of claims 1 to 6; The 2-methylpyridine ammoxidation fixed bed catalytic reactor is respectively connected to the flow measurement module, the temperature measurement module and the feedback regulation module, the flow measurement module and the temperature measurement module are respectively connected to the data processing module, the data processing module is connected to the control module, and the control module is connected to the feedback regulation module; The 2-methylpyridine ammoxidation fixed bed catalytic reactor is used to catalyze 2-methylpyridine, air and ammonia by using molten salt and catalyst to prepare 2-cyanopyridine; The flow measurement module is used to monitor the molten salt flow of each molten salt inlet in real time and transmit the molten salt flow data to the data processing module; The temperature measurement module is used to monitor the temperature of each preset temperature measurement point in the 2-methylpyridine ammoxidation fixed bed catalytic reactor in real time, and transmit the temperature data to the data processing module; The data processing module is used to analyze the temperature distribution according to the temperature information to obtain the temperature distribution result, and to calculate the temperature error between the temperature data and the corresponding preset target temperature, and to calculate the actual molten salt flow rate ratio according to the molten salt flow rate data corresponding to each of the molten salt inlets; The control module is used to calculate the molten salt flow rate adjustment amount of each molten salt inlet according to the temperature error, the actual molten salt flow rate ratio and the temperature distribution result, and to generate a corresponding molten salt flow rate adjustment signal according to the molten salt flow rate adjustment amount; The feedback regulation module is used to regulate the molten salt flow rate of the corresponding molten salt inlet according to each molten salt flow rate regulation signal.

8. The 2-methylpyridine ammoxidation fixed bed catalytic reaction system according to claim 7, characterized in that: The control module adopts PID control algorithm.

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