Intelligent flow reactor and method for high-yield continuous synthesis of piperidine

Abstract

The present invention relates to the technical field of reactors, and discloses an intelligent flow reactor and method for the high-yield continuous synthesis of piperidine, wherein the intelligent flow reactor for the high-yield continuous synthesis of piperidine comprises a left support sleeve, and also comprises a circular sleeve and a sandwich shell fixedly connected to the left support sleeve, a plurality of barrier strips and re-route strips are all fitted with the outer wall of the synthesis tube and have the same curvature, a single barrier strip and re-route strip form a microchannel with the synthesis tube, and the shaft disc changes the flow path of the microchannel through the barrier strip and re-route strip. By driving the barrier strip and re-route strip to rotate through the shaft disc, the flow path of the fluid can be optimized according to the reaction requirements, the length and width of the reaction channel can be adjusted, the resistance is changed to control the change in the flow rate of the reaction liquid, and local stagnation and uneven flow can be effectively avoided. At the same time, a single drive is used to control the rotation of the shaft disc, and the action of the barrier strip and re-route strip is coordinated to realize the reaction process conversion without interrupting production, thereby improving the production effect.

Description

Technical Field

[0001] The present invention relates to the technical field of reactors, and in particular to an intelligent flow reactor and a method for continuously synthesizing piperidine with high yield. Background Art

[0002] Piperamide is an important organic compound in the fields of medicine, pesticides, etc. Its synthesis usually uses intelligent flow reactors, that is, it is synthesized through microchannels inside the reactor, mainly relying on the mass transfer and heat transfer, precise reaction control and continuous production advantages of microchannel reactors.

[0003] However, in the prior art, the reaction channels of existing traditional reactors are usually designed with a fixed length and manufactured, and the internal flow channel structure is difficult to change. In actual production needs, according to the reaction conditions of the reaction liquid, it is necessary to extend the length of the reaction channel to meet the longer reaction path and reaction medium residence time required for a specific chemical reaction. However, the existing reactor can only achieve this by increasing the overall equipment size and extending the shell length, which not only seriously reduces the utilization rate of the production space, but also leads to a significant increase in the cost of equipment manufacturing, installation, commissioning and long-term maintenance. It is not only extremely difficult to implement and the cost is high, but also easily subject to the limitations of the original site, which will cause the production line to stop for a long time, making subsequent improvements to the reactor extremely difficult. In terms of reaction process control, chemical reactions have different requirements for fluid flow states and heat transfer efficiency, and existing reactors cannot be flexibly adjusted according to the dynamic changes in reaction conditions. Taking the nitration reaction of piperidine as an example, the flow channel length is single, which makes it very easy for the fluid to have local stagnation or uneven flow in the reactor, resulting in an imbalance in the distribution of reactants, making it difficult to achieve fast and efficient heat extraction, and easily leading to local excessive temperatures, which not only triggers side reactions but also poses a safety hazard. At the same time, since the fixed flow channel structure cannot optimize the flow path of the fluid, the uneven distribution will cause over-reaction in some areas or insufficient reaction in some areas, seriously affecting the overall performance of the reaction and the stability of product quality. Summary of the Invention

[0004] The object of the present invention is to provide an intelligent flow reactor and method for the high-yield continuous synthesis of piperidine, so as to solve the problem that the reaction channel of the reactor affects the reaction of the reaction liquid.

[0005] On the one hand, the present invention proposes: an intelligent flow reactor for high-yield continuous synthesis of piperidine, comprising a left support sleeve, a circular sleeve and an interlayer shell fixedly connected to the left support sleeve, a right support sleeve fixedly connected to one end of the interlayer shell, a material dividing piece fixedly connected to the circular sleeve, a shaft disk rotatably connected to the inside of the material dividing piece, a synthesis tube arranged inside the right support sleeve, a barrier strip and a diameter-changing strip fixedly connected to the shaft disk at both left ends, and an inner sleeve shell located inside the synthesis tube and fixedly connected to the right support sleeve, the inner sleeve shell being fixedly connected to the inside of the right support sleeve, the right support sleeve being fitted with the shaft disk, a plurality of barrier strips and diameter-changing strips being arranged at equal angles, a plurality of the barrier strips and diameter-changing strips being fitted with the outer wall of the synthesis tube and having the same curvature, a microchannel being formed between a single barrier strip and diameter-changing strip and the synthesis tube, and the shaft disk changing the flow path of the microchannel through the barrier strips and diameter-changing strips.

[0006] Furthermore, a reaction module is set on the surface of the synthetic tube, and the reaction module includes multiple groups of reaction modules connected end to end, and the reaction module includes a straight arc plate, a double-track plate, a single-track plate, a long arc bar and a short arc bar. The straight arc plate is located on the left side of the double-track plate and the single-track plate, the long arc bar is located between the single-track plate and the double-track plate, and the short arc bar is located between the barrier bar and the double-track plate.

[0007] Furthermore, a sealing strip and a blocking strip are fixedly connected to the blocking strip, and the blocking strip is located at an initial position when it is attached to the double-track plate.

[0008] Furthermore, a connecting strip and a splicing strip are fixedly connected to the diversion strip, the connecting strip is fitted with the left end of the single-track plate, and the splicing strip is fitted with the right end of the single-track plate. The spacing between the diversion strip and the straight arc plate is greater than the spacing between the connecting strip and the double-track plate. The sealing strip is located on the left side of the connecting strip, and the blocking strip is located on the right side of the splicing strip.

[0009] Furthermore, there are multiple reaction modules, which are distributed in an array at equal angles to the center of the synthesis tube on the outer tube wall of the synthesis tube. Multiple collection plates are arranged at equal angles on the right outer wall of the synthesis tube, and the right side of the collection plate is the collection area.

[0010] Furthermore, a plurality of closing blocks are provided on the outside of the synthetic tube, the double-track plate and the barrier strip are both provided with short arc openings, the short arc strip is located in the two short arc openings, the double-track plate and the single-track plate are both provided with long arc openings, the long arc strip is located in the two long arc openings, and when the connecting strip is fitted with the double-track plate, the center line of the distance between the double-track plate and the barrier strip coincides with the center line of the short arc strip.

[0011] Furthermore, the material dividing member includes a material dividing ring arranged inside the circular sleeve, and a material guide plate fixedly connected to the material dividing ring, the material guide plate is fixedly connected to the circular sleeve, and a plurality of material guide openings are opened on the material guide plate at equal angles.

[0012] Furthermore, the shaft disc includes a rotating shaft rotatably connected to the inside of the circular sleeve, and a circular disc fixedly connected to one end of the rotating shaft, the other end of the rotating shaft extends to the outside of the left support sleeve, and a plurality of guide grooves are opened on the circular disc at equal angles, the material guide port is interconnected with the guide groove, and the guide groove is interconnected with the microchannel and the number of the two is the same.

[0013] Furthermore, the top and bottom of the sandwich shell are respectively fixedly connected with a feed port and a discharge port, the feed port is communicated with the inside of the distribution ring, the discharge port is communicated with the aggregate area, one side of the circular sleeve is fixedly connected with an inner water inlet and an outer water inlet, a conduit is fixedly connected to the inner shell, the conduit passes through the arc-shaped opening, the conduit is connected to the inner water inlet, and the outer water inlet is connected to the inner layer of the sandwich shell.

[0014] Another aspect of the present invention provides a method for continuously synthesizing piperidine with high yield, using an intelligent flow reactor for continuously synthesizing piperidine with high yield, comprising the following steps:

[0015] Step 1: Dissolve piperonal in an organic solvent to form a homogeneous reaction solution.

[0016] Step 2: The reaction liquid is delivered to the inside of the material distribution piece at a stable flow rate through a metering pump, and then enters the microchannel on the surface of the synthesis tube to allow the reaction liquid to fully contact and react.

[0017] Step 3: Adjust the reaction temperature inside the synthesis tube through external heating or cooling devices.

[0018] Step 4: Use the shaft disk to drive the barrier strips and the diameter-changing strips as needed to adjust the channel length and size, change the flow rate and affect the residence time of the reaction liquid in the microchannel.

[0019] Step 5: The low-boiling point organic solvent and unreacted raw materials are first evaporated and removed, and then a high-purity piperidine product is obtained by vacuum distillation.

[0020] Beneficial effects of the present invention:

[0021] By driving the barrier strips and the rerouting strips to rotate through the shaft disc, the flow path of the fluid can be optimized according to the reaction requirements, the length and width of the reaction channel can be adjusted, the resistance can be changed to control the change in the flow rate of the reaction liquid, and local stagnation and uneven flow can be effectively avoided, making the distribution of the reactants more uniform. At the same time, a single drive is used to control the rotation of the shaft disc, coordinated with the movement of the barrier strips and the rerouting strips, so that the reaction process can be converted without interrupting production, thereby improving production efficiency.

[0022] By rotating and offsetting the barrier strips and the diameter-changing strips, and cooperating with the straight arc plates, double-channel plates, and single-channel plates fixed on the surface of the synthesis tube, the length, cross-sectional shape, and flow path of the microchannel can be quickly changed. This purely mechanized structural design does not require complex control. Only through the relative movement of mechanical parts, the reaction path can be switched and adjusted within seconds, meeting the differentiated requirements of residence time, flow rate, and mixing effect in different reaction stages. It reduces the cost and difficulty of equipment modification and will not cause long-term shutdown of the production line, providing convenience for the continuous production of piperidine.

[0023] By forming an annular distribution system with a material distribution piece, the reaction liquid is evenly distributed and introduced with low resistance. At the same time, the double-layer heat exchange structure composed of the sandwich shell and the inner shell can accurately control the reaction temperature through the internal and external circulating coolant channels, so that the entire synthesis process can run continuously and stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the three-dimensional structure of the intelligent flow reactor of the present invention from a first perspective;

[0025] Figure 2 Schematic diagram of the structure of the synthetic tube of the present invention;

[0026] Figure 3 This is a schematic structural diagram of the material distribution ring and the shaft disc of the present invention;

[0027] Figure 4 For the present invention Figure 2 A magnified schematic diagram of point A in the middle;

[0028] Figure 5 A top view of the overall structure of the intelligent flow reactor of the present invention;

[0029] Figure 6 For the present invention Figure 5 Cross-sectional view at the middle BB;

[0030] Figure 7 It is a structural schematic diagram of the disc of the present invention;

[0031] Figure 8 It is a structural schematic diagram of the circular sleeve of the present invention;

[0032] Figure 9 This is a state diagram of the movement of the diverter strip and the barrier strip of the present invention.

[0033] In the picture:

[0034] 1. Left support sleeve; 2. Round sleeve; 21. Inner water inlet; 22. Outer water inlet; 3. Sandwich shell; 31. Feed inlet; 32. Discharge outlet; 4. Right support sleeve; 5. Material dividing piece; 51. Material dividing ring; 52. Material guide plate; 501. Material guide port; 6. Shaft plate; 61. Rotating shaft; 62. Round plate; 621. Guide groove; 601. Arc port; 7. Synthetic pipe; 71. Straight arc plate; 72. Double-channel plate; 73. Single-channel plate; 74. Long arc strip; 75. Short arc strip; 701. Aggregate plate; 702. Aggregate area; 8. Barrier strip; 81. Seal strip; 82. Block strip; 9. Diameter-changing strip; 91. Connecting strip; 92. Splicing strip; 10. Inner shell; 101. Conduit; 11. Closing block; 12. Short arc port; 13. Long arc port. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0036] Example 1, refer to Figures 1-9 , which is the first embodiment of the present invention, provides an intelligent flow reactor for high-yield continuous synthesis of piperidine, comprising a left support sleeve 1, a circular sleeve 2 and an interlayer shell 3 fixedly connected to the left support sleeve 1, a right support sleeve 4 fixedly connected to one end of the interlayer shell 3, a material dividing piece 5 fixedly connected to the circular sleeve 2, a shaft disc 6 rotatably connected to the inside of the material dividing piece 5, a synthesis pipe 7 arranged inside the right support sleeve 4, a barrier strip 8 and a diameter-changing strip 9 both of which are fixedly connected to the shaft disc 6 at their left ends, and an inner sleeve shell 10 located inside the synthesis pipe 7 and fixedly connected to the right support sleeve 4, the inner sleeve shell 10 is fixedly connected to the inside of the right support sleeve 4, the right support sleeve 4 is fitted with the shaft disc 6, a plurality of barrier strips 8 and diameter-changing strips 9 are arranged at equal angles, the plurality of barrier strips 8 and diameter-changing strips 9 are fitted with the outer wall of the synthesis pipe 7 and have the same curvature, a microchannel is formed between a single barrier strip 8 and diameter-changing strip 9 and the synthesis pipe 7, and the shaft disc 6 changes the flow path of the microchannel through the barrier strips 8 and diameter-changing strips 9.

[0037] Among them, the shaft disc 6 can be driven by a stepper motor. At the same time, the stepper motor needs to be equipped with a subdivision driver to further subdivide the step angle, thereby realizing rotation at different angles such as five or ten degrees. A pulse servo motor can also be used instead. At the same time, an interlayer is provided in the interlayer shell 3, and a coolant or heating medium can be passed between the interlayer and the inner shell 10 and the synthesis tube 7 to realize the control of the reaction temperature. At the same time, the circular sleeve 2 and the interlayer shell 3 can be directly welded by laser cladding technology, so that the joint surface is free of defects such as pores and cracks.

[0038] Reference Figure 1-Figure 3A reaction module is set on the surface of the synthesis tube 7, and the reaction module includes multiple groups of reaction modules connected end to end. The reaction module includes a straight arc plate 71, a double-channel plate 72, a single-channel plate 73, a long arc bar 74 and a short arc bar 75. The straight arc plate 71 is located on the left side of the double-channel plate 72 and the single-channel plate 73, the long arc bar 74 is located between the single-channel plate 73 and the double-channel plate 72, and the short arc bar 75 is located between the barrier bar 8 and the double-channel plate 72.

[0039] Specifically, the curvature of the straight arc plate 71 matches and fits the inner wall of the sandwich shell 3, and the double-track plate 72, the single-track plate 73, the long arc strip 74 and the short arc strip 75 are also tightly fitted with the sandwich shell 3 to ensure sufficient sealing effect. A channel is formed between the double-track plate 72 and the single-track plate 73, and a channel is formed again between the double-track plate 72 and the barrier strip 8, so that there are flow channels on both sides of the single-track plate 73.

[0040] Reference Figure 2-Figure 4 The barrier strip 8 is fixedly connected to a sealing strip 81 and a barrier strip 82. When the barrier strip 8 is attached to the double-channel plate 72, the barrier strip 8 is in the initial position, so that the channel between the double-channel plate 72 and the barrier strip 8 is blocked. At this time, the reaction liquid will only flow through the double-channel plate 72 and the single-channel plate 73. At this time, the reaction liquid passes through this microchannel in a laminar flow state and stays in the synthesis tube 7 for about 80 seconds.

[0041] Reference Figure 2-Figure 5 The diameter-changing strip 9 is fixedly connected to a connecting strip 91 and a splicing strip 92. The connecting strip 91 is in contact with the left end of the single-lane plate 73, and the splicing strip 92 is in contact with the right end of the single-lane plate 73 to ensure sealing. The distance between the diameter-changing strip 9 and the straight arc plate 71 is greater than the distance between the connecting strip 91 and the double-lane plate 72. The sealing strip 81 is located on the left side of the connecting strip 91, and the blocking strip 82 is located on the right side of the splicing strip 92. At the same time, the double-lane plate 72 is located between the blocking strip 8 and the single-lane plate 73.

[0042] Specifically, when the shaft disc 6 rotates, the blocking strip 8 and the re-routing strip 9 will rotate synchronously with it, and the positions of the two will also change accordingly. At this time, the blocking strip 8 will drive the sealing strip 81 and the blocking strip 82 to move synchronously, and the re-routing strip 9 will drive the connecting strip 91 and the splicing strip 92 to move synchronously. Taking the blocking strip 8 in the initial position as an example, assuming that the shaft disc 6 rotates six degrees at this time, the re-routing strip 9 will approach the straight arc plate 71, narrowing the gap between the two, and the connecting strip 91 and the splicing strip 92 will directly fit with the double-channel plate 72, blocking the passage between the double-channel plate 72 and the single-channel plate 73. At this time, the blocking strip 8 is no longer fitted with the double-channel plate 72, thereby extending the path. The reaction liquid can only pass through the path between the blocking strip 8 and the double-channel plate 72, and at the same time reduce the distance between the re-routing strip 9 and the straight arc plate 71, enhance the mixing degree, and make the flow channel cross-sectional area change continuously, thereby achieving precise control of the fluid flow rate and residence time, and the reaction time is about 120s.

[0043] In addition, the shaft disk 6 can also be controlled to rotate three degrees. While reducing the distance between the diameter-changing strip 9 and the straight arc plate 71, the passage between the double-channel plate 72 and the single-channel plate 73 can also be opened at the same time to form a dual path, which will be reunited at the next passage to enhance the reaction effect. It can achieve diversion, disperse the reaction heat into two channels, reduce the heat load in a single channel, and make the reaction temperature in the two channels more uniform. When reunited, the fluid is evenly mixed, avoiding local overheating, improving the safety and quality of the reaction liquid, and allowing the reaction liquid to pass quickly through the two channels after diversion. It is mainly used to shorten the residence time of the reaction liquid. When the reaction time needs to be extended and the mixing degree needs to be enhanced, the channel between the barrier strip 8 and the double-channel plate 72 can be directly used.

[0044] When the barrier strip 8 is in the initial position, the distance between the rerouting strip 9 and the straight arc plate 71 may be 3 mm, and the distance between the connecting strip 91 and the double track plate 72 may be 2 mm.

[0045] Reference Figure 2-Figure 6 There are multiple reaction modules, and they are distributed in an equiangular array on the outer tube wall of the synthesis tube 7 with the center of the synthesis tube 7. Multiple gathering plates 701 are arranged at equal angles on the right outer wall of the synthesis tube 7. The right side of the gathering plate 701 is the gathering area 702, thereby forming multiple microchannel paths. The number of gathering plates 701 is equal to the number of equiangular arrays of reaction modules, that is, the equiangular arrays of reaction modules are twelve, then the number and position of the gathering plates 701 correspond one to one, and at the same time, the sealing strip 81 and the blocking strip 82 are both fitted with the straight arc plate 71. At the same time, the width of the straight arc plate 71, the double-channel plate 72 and the single-channel plate 73 is greater than the moving distance of the connecting strip 91 and the splicing strip 92, forming an effective sealing structure.

[0046] Among them, the collection plate 701 is located between the collection area 702 and the microchannel on the surface of the synthesis tube 7. The reaction liquid flowing out of multiple microchannels will converge in the collection area 702 after passing through the collection plate 701. The collection plate 701 is used to ensure that the reaction liquid is evenly gathered in the collection area 702.

[0047] Reference Figure 2-Figure 6 A plurality of closing blocks 11 are provided on the outside of the synthetic tube 7. Both the double-track plate 72 and the barrier strip 8 are provided with short arc openings 12. The short arc strip 75 is located in the two short arc openings 12. Both the double-track plate 72 and the single-track plate 73 are provided with long arc openings 13. The long arc strip 74 is located in the two long arc openings 13. When the connecting strip 91 is fitted with the double-track plate 72, the midline of the distance between the double-track plate 72 and the barrier strip 8 coincides with the midline of the short arc strip 75.

[0048] In addition, each connection part is sealed with a polytetrafluoroethylene sealing ring, which can withstand a temperature range of 20° C. to 200° C. and has good pressure resistance. At the same time, the material of the closing block 11 is also polytetrafluoroethylene.

[0049] Specifically, the long arc bars 74 and the short arc bars 75 are used to buffer and block the reaction liquid to enhance the mixing effect.

[0050] Reference Figure 2-Figure 6 The assembly method of the dividing piece 5 and the circular sleeve 2 can be fixed with conventional screws, which is convenient for disassembly and maintenance. The dividing piece 5 includes a dividing ring 51 arranged inside the circular sleeve 2, and a guide plate 52 fixedly connected to the dividing ring 51. The guide plate 52 is fixedly connected to the circular sleeve 2, and a plurality of guide ports 501 are opened on the guide plate 52 at equal angles.

[0051] Specifically, the material distribution ring 51 and the material guide plate 52 are combined into an annular material distribution system, so that the reaction liquid is evenly distributed in the circumferential direction, reducing flow deviation. At the same time, the multiple material guide ports 501 can be gradually expanded, effectively reducing the local resistance of the reaction liquid when it enters the microchannel, avoiding eddy currents and pressure losses caused by sudden changes in flow rate, and at the same time helping the reaction liquid to achieve preliminary mixing before entering the microchannel, thereby improving the uniformity of the reaction liquid distribution.

[0052] Reference Figure 2-Figure 6 The shaft disc 6 includes a rotating shaft 61 rotatably connected to the inside of the circular sleeve 2, and a disc 62 fixedly connected to one end of the rotating shaft 61. The other end of the rotating shaft 61 extends to the outside of the left support sleeve 1. A plurality of guide grooves 621 are opened at equal angles on the disc 62. The material guide port 501 is interconnected with the guide grooves 621, and the guide grooves 621 are interconnected with the microchannels, and the number of the two is the same.

[0053] Specifically, the rotating shaft 61 is driven by a motor to rotate, so that the disc 62 drives the barrier strip 8 and the diameter-changing strip 9 to realize the change of the microchannel. At the same time, the guide groove 621 is connected with the material guide port 501 and the microchannel, and the reaction liquid will enter the guide groove 621 from the material guide port 501 and finally enter the microchannel, avoiding the retention and leakage of the reaction liquid at the connection point, and ensuring that the reaction liquid can efficiently and stably enter the microchannel for reaction.

[0054] Reference Figures 1-9 The top and bottom of the sandwich shell 3 are respectively fixedly connected with a feed port 31 and a discharge port 32. The feed port 31 is communicated with the inside of the distribution ring 51, and the discharge port 32 is communicated with the aggregate area 702. One side of the circular sleeve 2 is fixedly connected with an inner water inlet 21 and an outer water inlet 22. A conduit 101 is fixedly connected to the inner shell 10. The conduit 101 passes through the arc-shaped opening 601 to avoid interference between the disc 62 and the conduit 101. The conduit 101 is connected to the inner water inlet 21, and the outer water inlet 22 is connected to the inner layer of the sandwich shell 3. The inner water inlet 21 and the outer water inlet 22 are used to form an internal and external circulation to adjust the overall temperature balance of the reactor. The inner water inlet 21 will pass the water flow through the conduit 101 and transport it to between the inner shell 10 and the synthesis pipe 7.

[0055] The working principle of the present invention is as follows: the reaction liquid is transported to the feed port 31 at the top of the sandwich shell 3 through an external pipeline, and then enters the distribution ring 51, and passes through multiple guide ports 501 on the guide plate 52, enters the corresponding guide groove 621 on the disc 62, and then enters the guide groove 621 between the straight arc plate 71 and the diameter-changing strip 9 to complete the preliminary distribution and introduction of the reaction liquid. At the same time, the internal water inlet 21 transports the coolant through the conduit 101 to between the inner shell 10 and the synthesis tube 7 to control the temperature inside the microchannel reaction, while the external water inlet 22 transports the coolant to the interlayer of the sandwich shell 3 to adjust the overall temperature balance of the entire reactor to ensure that the reaction is carried out at an appropriate temperature, avoid side reactions or reduce reaction efficiency due to abnormal temperature, at this time, the barrier strip 8 is in the initial position, it is in contact with the double-channel plate 72, blocking the channel between the double-channel plate 72 and the barrier strip 8, and the reaction liquid only passes through the channel between the double-channel plate 72 and the single-channel plate 73, and the single-channel plate 73 is close to the straight arc Plate 71, at this time the flow channel is relatively short, the reaction liquid passes through quickly, as the reaction proceeds, the position of the barrier strip 8 and the rerouting strip 9 can be adjusted before the reaction, or dynamically adjusted during the reaction according to the situation of the reaction liquid. By using external drive, the shaft disk 6 rotates a certain angle, the barrier strip 8 and the rerouting strip 9 rotate synchronously, and the rerouting strip 9 approaches the straight arc plate 71, the distance between the two is reduced, increasing the resistance to the reaction liquid, changing the cross-sectional area of ​​the flow channel, and thus controlling the fluid flow rate, so that the reaction liquid is fully mixed in the microchannel, and the connecting strip 91 and the splicing strip 92 are attached to the double-channel plate 72, blocking the passage between the double-channel plate 72 and the single-channel plate 73. At the same time, the barrier strip 8 is separated from the double-channel plate 72, and the reaction liquid flows through the channel between the barrier strip 8 and the double-channel plate 72, extending the reaction path and the residence time. After the reaction is completed, the reaction liquid flows out of each microchannel and passes through the collecting plate 701 on the right outer wall of the synthesis tube 7 in sequence, converges to the collecting area 702, and is then discharged through the discharge port 32 at the bottom of the sandwich shell 3.

[0056] Example 2, refer to Figures 1-9 , which is a second embodiment of the present invention, provides a method for continuously synthesizing piperidine with high yield, using an intelligent flow reactor for continuously synthesizing piperidine with high yield, comprising the following steps:

[0057] Step 1: Dissolve piperonal in an organic solvent to form a homogeneous reaction solution.

[0058] Step 2: The reaction liquid is delivered to the interior of the material distribution member 5 at a stable flow rate by a metering pump, and then enters the microchannel on the surface of the synthesis tube 7, so that the reaction liquid can fully contact and react.

[0059] Step 3: Adjust the reaction temperature inside the synthesis tube 7 through an external heating or cooling device.

[0060] Step 4: Use the shaft disc 6 to drive the barrier strips 8 and the diameter-changing strips 9 as needed to adjust the channel length and size, change the flow rate, and affect the residence time of the reaction liquid in the microchannel.

[0061] Step 5: The low-boiling point organic solvent and unreacted raw materials are first evaporated and removed, and then a high-purity piperidine product is obtained by vacuum distillation.

[0062] 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 the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An intelligent flow reactor for high-yield continuous synthesis of piperidine, comprising a left support sleeve (1), characterized in that: The invention also includes a circular sleeve (2) and a sandwich shell (3) fixedly connected to the left support sleeve (1), a right support sleeve (4) fixedly connected to one end of the sandwich shell (3), a material distributor (5) fixedly connected to the circular sleeve (2), a shaft disc (6) rotatably connected to the inside of the material distributor (5), a synthetic pipe (7) arranged inside the right support sleeve (4), a barrier strip (8) and a diameter-changing strip (9) both of which are fixedly connected to the shaft disc (6) at their left ends, and an inner sleeve shell (10) located inside the synthetic pipe (7) and fixedly connected to the right support sleeve (4), wherein the inner sleeve shell (10) is fixedly connected to the inside of the right support sleeve (4), and the right The support sleeve (4) is fitted with the shaft disc (6), and a plurality of the barrier strips (8) and the re-diameter strips (9) are arranged at equal angles. The plurality of barrier strips (8) and the re-diameter strips (9) are fitted with the outer wall of the synthesis tube (7) and have the same curvature. A microchannel is formed between a single barrier strip (8) and the re-diameter strip (9) and the synthesis tube (7). The shaft disc (6) changes the flow path of the microchannel through the barrier strips (8) and the re-diameter strips (9). The barrier strips (8) and the re-diameter strips (9) are driven by the shaft disc (6) according to demand, thereby adjusting the length and size of the channel, changing the flow rate and affecting the residence time of the reaction liquid in the microchannel.

2. The intelligent flow reactor for the high-yield continuous synthesis of piperidine according to claim 1, wherein: A reaction module is provided on the surface of the synthesis tube (7), and the reaction module includes a plurality of reaction modules connected end to end. The reaction modules include a straight arc plate (71), a double-track plate (72), a single-track plate (73), a long arc bar (74) and a short arc bar (75). The straight arc plate (71) is located on the left side of the double-track plate (72) and the single-track plate (73), the long arc bar (74) is located between the single-track plate (73) and the double-track plate (72), and the short arc bar (75) is located between the barrier bar (8) and the double-track plate (72).

3. The intelligent flow reactor for the high-yield continuous synthesis of piperidine according to claim 2, wherein: A sealing strip (81) and a blocking strip (82) are fixedly connected to the blocking strip (8), and the blocking strip (8) is located at an initial position when it is in contact with the double-track plate (72).

4. The intelligent flow reactor for the high-yield continuous synthesis of piperidine according to claim 3, wherein: The diversion strip (9) is fixedly connected to a connecting strip (91) and a splicing strip (92), wherein the connecting strip (91) is in contact with the left end of the single-track plate (73), and the splicing strip (92) is in contact with the right end of the single-track plate (73). The spacing between the diversion strip (9) and the straight arc plate (71) is greater than the spacing between the connecting strip (91) and the double-track plate (72). The sealing strip (81) is located on the left side of the connecting strip (91), and the blocking strip (82) is located on the right side of the splicing strip (92).

5. The intelligent flow reactor for the high-yield continuous synthesis of piperidine according to claim 4, wherein: There are a plurality of reaction modules, which are arranged in an array at equal angles around the center of the synthesis tube (7) on the outer tube wall of the synthesis tube (7); a plurality of collection plates (701) are arranged at equal angles on the right outer wall of the synthesis tube (7); the right side of the collection plate (701) is a collection area (702); The number and position of the sealing strip (81), the blocking strip (82), the connecting strip (91), the splicing strip (92) and the single-track plate (73) correspond one to one, and the sealing strip (81) and the blocking strip (82) are both fitted with the straight arc plate (71).

6. The intelligent flow reactor for the high-yield continuous synthesis of piperidine according to claim 4, wherein: The synthetic tube (7) is provided with a plurality of closing blocks (11) on the outside. The double-track plate (72) and the barrier strip (8) are both provided with short arc openings (12). The short arc strip (75) is located in the two short arc openings (12). The double-track plate (72) and the single-track plate (73) are both provided with long arc openings (13). The long arc strip (74) is located in the two long arc openings (13). When the connecting strip (91) is fitted to the double-track plate (72), the center line of the distance between the double-track plate (72) and the barrier strip (8) coincides with the center line of the short arc strip (75).

7. The intelligent flow reactor for the high-yield continuous synthesis of piperidine according to claim 1, wherein: The material dividing member (5) comprises a material dividing ring (51) arranged inside the circular sleeve (2), and a material guide plate (52) fixedly connected to the material dividing ring (51), wherein the material guide plate (52) is fixedly connected to the circular sleeve (2), and a plurality of material guide openings (501) are formed on the material guide plate (52) at equal angles.

8. The intelligent flow reactor for the high-yield continuous synthesis of piperidine according to claim 7, wherein: The shaft disc (6) comprises a rotating shaft (61) rotatably connected to the inside of the circular sleeve (2), and a circular disc (62) fixedly connected to one end of the rotating shaft (61), the other end of the rotating shaft (61) extends to the outside of the left support sleeve (1), and a plurality of guide grooves (621) are formed on the circular disc (62) at equal angles, the material guide port (501) is interconnected with the guide grooves (621), and the guide grooves (621) are interconnected with the microchannels, and the number of the guide grooves (621) and the microchannels is the same.

9. The intelligent flow reactor for the high-yield continuous synthesis of piperidine according to claim 8, wherein: The top and bottom of the sandwich shell (3) are fixedly connected with a feed port (31) and a discharge port (32), respectively. The feed port (31) is communicated with the inside of the distribution ring (51), and the discharge port (32) is communicated with the aggregate area (702). One side of the circular sleeve (2) is fixedly connected with an inner water inlet (21) and an outer water inlet (22). A conduit (101) is fixedly connected to the inner sleeve shell (10), and the conduit (101) passes through the arc-shaped opening (601). The conduit (101) is connected with the inner water inlet (21), and the outer water inlet (22) is connected with the inner layer of the sandwich shell (3).

10. A method for continuous synthesis of piperidine with high yield, using the intelligent flow reactor for continuous synthesis of piperidine with high yield as claimed in claim 1, characterized in that: The following steps are involved: Step 1: dissolving piperonal in an organic solvent to form a homogeneous reaction solution; Step 2: The reaction liquid is transported to the interior of the material distribution member (5) at a stable flow rate by a metering pump, and then enters the microchannel on the surface of the synthesis tube (7) to allow the reaction liquid to fully contact and react; Step 3: adjusting the reaction temperature inside the synthesis tube (7) by an external heating or cooling device; Step 4: Use the shaft disc (6) to drive the barrier strip (8) and the diameter-changing strip (9) as needed to adjust the channel length and size, change the flow rate, and affect the residence time of the reaction liquid in the microchannel; Step 5: The low-boiling point organic solvent and unreacted raw materials are first evaporated and removed, and then a high-purity piperidine product is obtained by vacuum distillation.

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