A compound micro-reactor with high shear and triple-jacket jet in series

Abstract

The application provides a kind of high shear and triple tube jet flow series connection composite microreactor, belongs to microreactor technical field, including high shear pretreatment section, adapter tube, triple tube jet flow reaction section, high shear pretreatment section is equipped with feed inlet, discharge port, triple tube jet flow reaction section includes inner tube body, first middle tube, second middle tube, outer tube, inner tube body is coaxially arranged inside first middle tube, second middle tube, first middle tube, second middle tube is coaxially arranged inside outer tube, discharge port is connected with first middle tube through adapter tube.The application adopts the above-mentioned one kind of high shear and triple tube jet flow series connection composite microreactor, solves the problem that single microjet flow reactor or double tube reactor is difficult to disperse for high viscosity mixed system, mixed and heat exchange efficiency is not good and high viscosity material is easy to block in prior art.

Description

Technical Field

[0001] This invention relates to the field of microreactor technology, and in particular to a composite microreactor with high shear and three-tube jet in series. Background Technology

[0002] Against the backdrop of rapid iteration in chemical process intensification technologies, high efficiency, precision, and controllability have become core development trends in fine chemicals, pharmaceuticals, and new material synthesis. Compared to traditional batch reactors, microchannel reactors, with their superior mass and heat transfer performance and compact, precise reaction control advantages, are gradually replacing traditional reaction equipment and are widely used in various multi-stage, multiphase, and highly selective complex reaction systems, effectively meeting the diverse and high-quality chemical production needs of today. Among them, microjet reactors, as the mainstream microchannel reaction equipment, rely on the strong shearing effect generated by high-speed jets to achieve efficient dispersion of fluids at the microscale, possessing outstanding technical advantages in improving fluid mixing efficiency.

[0003] Currently, single microjet reactors and conventional double-tube jet reactors are the mainstream equipment for processing high-viscosity materials. However, both types of existing equipment have significant technical shortcomings when dealing with complex mixed systems that are high in viscosity and prone to agglomeration, making it difficult to meet the requirements of high-quality production. First, the single-jet dispersion mode has extremely poor adaptability to high-viscosity materials, easily causing uneven distribution of droplet and bubble sizes within the system, forming local mixing dead zones, significantly reducing the uniformity of material mixing, and directly affecting the uniformity of the final product quality. At the same time, existing equipment cannot simultaneously consider the gas-phase dissolution, liquid-phase mass transfer, and solid-phase contact efficiency of multiphase reactions, severely limiting the reaction rate and reaction selectivity.

[0004] While existing dual-tube reactors have improved mass and heat transfer to some extent through structural optimization, shortening fluid diffusion distance, increasing phase interface contact area, and utilizing vortex and jet oscillations to disrupt the laminar boundary layer, core technical challenges remain unresolved. Firstly, the single-jet mixing method cannot adapt to the process requirements of complex sequential reactions and spatially stepwise feeding. Secondly, for concentration-sensitive reactions, the dual-tube structure struggles to maintain a stable concentration distribution, easily leading to localized overheating and decreased reaction selectivity. Thirdly, the equipment's adaptability to high-viscosity systems is insufficient, resulting in difficulties in material dispersion and mixing, and a tendency for blockages during operation, hindering improvements in heat exchange and mixing efficiency.

[0005] In summary, existing single microjet reactors and double-tube reactors generally suffer from technical shortcomings such as poor dispersion and mixing in high-viscosity systems, low mass transfer and heat exchange efficiency, and easy material blockage. They cannot meet the needs of efficient, stable, and precise reaction production of complex high-viscosity chemical systems in modern chemical industry. There is an urgent need to develop new reactor structures to solve the above-mentioned technical problems. Summary of the Invention

[0006] The purpose of this invention is to provide a composite microreactor with high shear and three-tube jet in series, which solves the problems of difficulty in dispersing high-viscosity mixed systems, poor mixing and heat exchange efficiency, and easy clogging of high-viscosity materials in the existing single microjet reactor or double-tube reactor.

[0007] To achieve the above objectives, the present invention provides a composite microreactor with high shear and three-tube jet in series, comprising a high shear pretreatment section, a connecting pipe, and a three-tube jet reaction section. The high shear pretreatment section is provided with an inlet and an outlet. The three-tube jet reaction section includes an inner tube, a first middle tube, a second middle tube, and an outer tube. The inner tube is coaxially disposed inside the first and second middle tubes, and the first and second middle tubes are coaxially disposed inside the outer tube. The outlet is connected to the first middle tube through the connecting pipe.

[0008] Preferably, the high-shear pretreatment section includes a main drive shaft, a stator, and a rotor. The stator is coaxially disposed inside the high-shear pretreatment section, and the rotor is coaxially disposed inside the stator. The rotor is fixedly connected to the main drive shaft.

[0009] Preferably, an annular gap is formed between the stator and the rotor, with a gap size of 0.1–3.0 mm, and the main drive shaft drives the rotor to rotate at a linear velocity of 10–50 m / s.

[0010] Preferably, the inner tube body includes a first inner tube and a second inner tube, the first inner tube and the second inner tube are coaxially connected, and the end of the second inner tube is connected to the inner tube outlet pipe.

[0011] Preferably, the first inner tube has evenly distributed circular holes on its wall, with an inner diameter of 0.1–5 mm, and the holes are evenly distributed along the axial and circumferential directions of the first inner tube.

[0012] Preferably, a spiral wire turbulence-inducing insert is coaxially fixed inside the second inner tube. The spiral wire turbulence-inducing insert is a spiral metal wire, and the spiral direction of the spiral wire turbulence-inducing insert matches the fluid flow direction.

[0013] Preferably, a first inner annular gap is formed between the first middle tube and the first inner tube, a second inner annular gap is formed between the second middle tube and the second inner tube, and an outer annular gap is formed between the outer tube and the first middle tube and the second middle tube.

[0014] Preferably, the dimensions of the first inner annular gap, the second inner annular gap, and the outer annular gap are all 0.5–1.5 mm.

[0015] Preferably, the second middle tube has a second middle tube inlet pipe and a second middle tube outlet pipe on its side wall, and the outer tube has an outer tube inlet pipe and an outer tube outlet pipe on its side wall.

[0016] Preferably, the three-tube jet reaction section is a straight tube structure, with no diameter change, no bends, and no inner wall protrusions.

[0017] Therefore, the present invention employs the above-mentioned high-shear composite microreactor with three-tube jet series connection, and the technical effects are as follows: 1. Solve the dispersion problem of high viscosity systems and suppress clogging: The high-shear pretreatment section uses high-speed shearing through the narrow annular gap (0.1-3.0mm) between the rotor and stator to pre-homogenize high viscosity and easily agglomerated materials into micron-sized particles, breaking the initial laminar flow; the three-tube straight pipe design has no diameter change bends, and together with the low-resistance fluid after pre-crushing, it completely avoids the clogging of microchannel orifices, solving the pain points of uneven dispersion of high viscosity materials, local dead zones, and easy clogging in traditional reactors.

[0018] 2. Multi-stage enhanced mixing for millisecond-level uniform mixing: Employing a three-stage mixing process of "high-shear premixing + circular orifice jet + helical turbulence": The high-shear section pre-homogenizes the mixture; the first inner tube's uniform circular orifice (0.1-5mm) generates a high-speed jet, enhancing turbulence; the second inner tube's helical wire insert forces the fluid into a helical motion, extending the path and repeatedly segmenting and recombining. This eliminates mixing dead zones, significantly improving mixing uniformity and solving the problems of low mixing efficiency, uneven concentration distribution, and poor selectivity in traditional jet / double-tube reactors.

[0019] 3. High-efficiency heat exchange with dual annular gaps: The three sets of tubes form a second inner annular gap and an outer annular gap dual cooling channel, dissipating heat simultaneously from both the inside and outside of the reaction zone, significantly expanding the heat exchange area; the spiral flow disrupts the heat transfer boundary layer, enhancing convective heat transfer and rapidly removing the heat from the highly exothermic reaction. This effectively suppresses local overheating and the aggravation of side reactions, maintaining a uniform and stable temperature field, and solving the problems of poor heat exchange efficiency, easy hot spot runaway, and decreased product selectivity in traditional equipment. Attached Figure Description

[0020] Figure 1 This is a front view of a composite microreactor with high shear and three-tube jet in series according to the present invention; Figure 2 This is a schematic diagram of the structure of a high-shear pretreatment section in this invention; Figure 3 This is a schematic diagram of a partial stator-rotor structure of the high-shear pretreatment section in this invention; Figure 4 This is a schematic diagram of the three-pipe section structure in this invention; Figure 5 This is a schematic diagram showing the arrangement of the circular hole in the first inner tube of the present invention; Figure 6 This is an enlarged schematic diagram of the spiral wire turbulence-disrupting plug in the second inner tube of the present invention.

[0021] Figure Labels 1. High-shear pretreatment section; 11. Main drive shaft; 12. Stator; 13. Rotor; 2. Feed inlet; 3. Discharge outlet; 4. Connecting pipe; 5. Inner tube body; 51. Inner tube flow area; 511. Circular hole; 512. Spiral wire turbulence insert; 52. Inner tube discharge pipe; 6. First intermediate tube; 61. First inner annular gap; 62. Second inner annular gap; 621. Second intermediate tube discharge pipe; 622. Second intermediate tube feed pipe; 7. Outer tube; 71. Outer annular gap; 711. Outer tube discharge pipe; 712. Outer tube feed pipe; 8. Second intermediate tube; 9. Second inner tube. Detailed Implementation

[0022] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0024] Example 1 like Figures 1-6 As shown, the present invention provides a composite microreactor with high shear and three-tube jet in series. This composite microreactor is composed of a high shear pretreatment section 1 and a three-tube jet reaction section coupled in series axially. The whole is arranged in a coaxial linear arrangement, forming an integrated reaction unit of "shear homogenization-jet mixing-spiral enhancement-high efficiency heat exchange-anti-clogging transport", which can effectively solve the problems of difficult dispersion, low mixing and heat exchange efficiency, and easy clogging of high viscosity systems.

[0025] The high-shear pretreatment section 1 is the core pretreatment module at the front end of the device, combining the functions of crushing and homogenizing with pressurization and energy supply. It consists of a main drive shaft 11, a stator 12, a rotor 13, a cylindrical outer shell, a feed inlet 2, and a discharge outlet 3. It is the core component for material shearing and crushing, pre-homogenization, and providing the pressure and kinetic energy required for the jet. The material is forced to be sheared and crushed through the annular gap between the rotor 13 and the stator 12, achieving pre-homogenization and obtaining initial kinetic energy.

[0026] The cylindrical outer shell is a sealed pressure-bearing shell with a feed inlet 2 coaxially opened on one end wall for introducing high-viscosity materials to be reacted. Inside the shell, a stator 12 is coaxially nested, and a rotor 13 is coaxially mounted within the central cavity of the stator 12. The rotor 13 is rigidly connected to the main drive shaft 11, which passes through the end wall of the shell and connects to an external drive mechanism, driving the rotor 13 to rotate at a high speed of 10–50 m / s. A 0.1–3.0 mm annular shearing gap is formed between the inner wall of the stator 12 and the outer wall of the rotor 13, forming the core area for material shearing and crushing. A discharge port 3 is radially opened on the side wall of the cylindrical outer shell for discharging the sheared and homogenized material.

[0027] Material enters the cylindrical shell through inlet 2, undergoes high-speed shearing and homogenization in the annular gap between stator 12 and rotor 13, and is then discharged through outlet 3. The continuous conveying from feeding, shearing and homogenization to discharge is completed via connecting pipe 4. Outlet 3 is precisely connected to the inlet end of the first middle pipe 6 of the three-tube jet reaction section via connecting pipe 4, achieving axial connection between the pretreatment section and the reaction section. During this process, the high-speed rotation of rotor 13 acts like a built-in booster pump, converting mechanical energy into fluid pressure and kinetic energy, providing the necessary pressure foundation for the subsequent jet from the circular orifice 511, thus completing the energy relay from mechanical shearing to jet mixing.

[0028] The rotor 13-stator 12 in the high-shear section is used to perform strong shearing and crushing on the high-viscosity material at the inlet, breaking the initial droplet state and breaking it into smaller droplets, so that the material is mixed more evenly and quickly, effectively preventing the blockage of the micro-holes 511 in the subsequent microchannel, while increasing the interface area and enhancing the heat transfer effect.

[0029] The three-tube jet reaction section is a coaxially nested multi-layered tube structure, employing a straight tube design throughout, with no diameter changes, bends, or inner wall protrusions, avoiding the accumulation of high-viscosity materials and preventing secondary blockage. It consists of an inner tube body 5 (including a first inner tube and a second inner tube 9), a first middle tube 6, a second middle tube 8, and an outer tube 7, all coaxially nested. Internally, it forms multi-stage annular flow channels and heat exchange channels, with uniform annular gap dimensions of 0.5–1.5 mm. The first middle tube 6 and the second middle tube 8 are separated. Fluid flows from the high-shear pretreatment section 1 into the first middle tube 6, is jetted through the circular hole 511 on the first inner tube, and then flows into the spiral wire interference insert section inside the second inner tube 9. Jet mixing and turbulence enhancement are achieved through the circular hole 511 and the spiral wire turbulence insert 512, axially connected and progressively linked with the high-shear pretreatment section 1.

[0030] The inner tube 5 is a three-section coaxial connected structure, including the first inner tube in the front section and the second inner tube 9 in the rear section. The internal cavity is the main channel for material mixing, and the outside forms an inner annular flow channel with the middle tube.

[0031] The first inner tube has evenly spaced circular holes 511 (inner diameter 0.1–5 mm) in both the axial and circumferential directions. The uniform distribution of these holes reduces dead zones, minimizes localized erosion wear, reduces flow deviation and eddy currents, improves distribution uniformity, and extends equipment life. The inner diameter of the through holes, within the 0.1–5 mm range, ensures that the fluid ejected from the through holes has sufficient velocity and pressure, creating a significant jet effect. This jet effect generates strong disturbance and shearing forces on the fluid within the first inner tube, effectively promoting mixing. Its front end is connected to the feed end of the first middle tube 6 via a connecting pipe 4, and its rear end is rigidly connected coaxially to the second inner tube 9, enabling continuous axial transport of fluid from the first inner tube to the second inner tube 9.

[0032] The second inner tube 9 is coaxially equipped with a spiral wire turbulence-inducing insert 512 (a spiral metal wire), the spiral direction of which matches the fluid flow direction. The insert forces the fluid to move in a spiral motion, extending the flow path, prolonging the residence time, and increasing the opportunity for component contact and diffusion; it effectively disrupts the laminar boundary layer, increases local turbulence, and enhances shear and momentum exchange, allowing the high-viscosity fluid to continuously segment, fold, and reassemble. At the same time, it disrupts the heat transfer boundary layer, weakens thermal resistance, enhances radial exchange between hot and cold fluids, and increases the convective heat transfer coefficient; its end is connected to the inner tube outlet pipe 52 for discharging the mixed reaction material; a second inner annular gap 62 is formed between the outer wall of the second inner tube 9 and the inner wall of the second middle tube 8, serving as a heat exchange channel for the cooling medium.

[0033] The inner tube body 5 forms a continuous reaction flow channel inner tube domain 51, which is coaxially connected to the inner cavities of the first inner tube and the second inner tube 9. The front section receives high-pressure jet fluid through evenly distributed circular holes 511 on the wall of the first inner tube, forming a high-intensity turbulent mixing zone. The rear section has a built-in spiral wire turbulence-inducing insert 512 to force the fluid to move forward in a spiral, continuously enhancing turbulence and convective heat transfer. This domain is the core area for material jet mixing, spiral enhancement, and reaction. The channel cross-section is uniform, and the entire straight pipe has no diameter change, effectively eliminating dead zones, reducing the resistance of high-viscosity materials, avoiding blockage, and significantly improving mixing uniformity, heat exchange efficiency, and reaction stability.

[0034] The central tube assembly is composed of a first central tube 6 and a second central tube 8, which are coaxially connected and nested on the outside of the inner tube body 5 and the inside of the outer tube 7, realizing the integration of flow channel partitioning and heat exchange functions.

[0035] The front end of the first intermediate tube 6 is sealed and connected to the outlet 3 of the high-shear pretreatment section 1 via the connecting pipe 4, and the rear end is coaxially connected to the second intermediate tube 8. A first inner annular gap 61 is formed between its inner wall and the outer wall of the first inner tube, serving as a high-pressure storage channel for the sheared material. Fluid enters the interior of the first inner tube through the circular hole 511 via this channel. The outer wall of the first intermediate tube 6 and the front section of the inner wall of the outer tube 7 form the front section of the outer annular gap 71. The front end of the second intermediate tube 8 is connected to the first intermediate tube 6, and the rear end is closed. The side walls are radially opened with a second intermediate tube inlet pipe 622 and a second intermediate tube outlet pipe 621 for the cooling medium to enter and exit the second inner annular gap 62. The rear section of the outer wall of the second intermediate tube 8 and the rear section of the inner wall of the outer tube 7 form the rear section of the outer annular gap 71, which is connected to the front section to form an integral outer annular gap 71.

[0036] The outer tube 7 is a coaxial integral cylindrical shell, nested outside the first middle tube 6 and the second middle tube 8, forming the outermost structure of the device. The outer tube 7 has radially opened outer tube inlet pipe 712 and outer tube outlet pipe 711 on its side wall, which are used for the cooling medium to enter and exit the outer annular gap 71, and together with the second inner annular gap 62, they form an inner and outer double-layer heat exchange system.

[0037] After the material is discharged from the outlet 3 of the high shear pretreatment section 1, it flows sequentially through the connecting pipe 4, the first middle pipe 6, and the first inner annular gap 61, and then is injected into the interior of the first inner pipe through the round hole 511. Subsequently, it enters the second inner pipe 9 with the built-in spiral wire turbulence insert 512, and is finally output from the inner pipe outlet pipe 52. The whole process realizes the stepwise mixing of material shearing, jetting and spiral reinforcement.

[0038] The heat exchange system employs a double-layer structure. In the inner layer, the cooling medium enters through the feed pipe 622 of the second middle tube, passes through the second inner annular gap 62, and exits through the discharge pipe 621 of the second middle tube, achieving internal cooling of the reaction fluid within the second inner tube 9. In the outer layer, the cooling medium enters through the feed pipe 712 of the outer tube, passes through the outer annular gap 71, and exits through the discharge pipe 711 of the outer tube, achieving external cooling of the fluid outside the middle tube. This double-layer heat exchange significantly expands the heat exchange area and enhances heat dissipation efficiency. For strongly exothermic reactions, it can effectively suppress local hot spots, avoid side reactions, improve product selectivity, and reduce thermal stress, ensuring the long-term safe and stable operation of the equipment.

[0039] At the component level, the outermost tube 7 serves as the outermost layer, with the first and second middle tubes 6 and 8 coaxially nested inside as the middle layers, and the innermost layer being the inner tube body 5. These three layers radially form a three-level annular structure: a first inner annular gap 61, a second inner annular gap 62, and an outer annular gap 71. Axially, the high-shear pretreatment section 1 connects to the first middle tube 6 via a connecting pipe 4, and then is sequentially connected in series with the second middle tube 8 and the inner tube outlet pipe 52. Each component achieves leak-free fluid transport through sealed connections. Functionally, the material sequentially undergoes shear homogenization, jet mixing, spiral reinforcement, double-layer heat exchange, and straight-tube anti-clogging, progressing layer by layer and synergistically coupled to form a complete composite micro-reaction system.

[0040] The working process of the composite microreactor proposed in this invention is as follows: High-viscosity materials enter the high-shear pretreatment section 1 through inlet 2. Within a narrow annular gap of 0.1–3.0 mm between stator 12 and rotor 13, the materials are subjected to intense shearing, compression, stretching, and tearing by the high-speed rotating rotor 13 at a linear velocity of 10–50 m / s. Large-scale aggregates are broken down into micron-sized particles, the initial laminar flow is disrupted, and pre-homogenization is completed. Simultaneously, rotor 13 acts as a built-in booster pump, converting mechanical energy into fluid pressure and kinetic energy to power the subsequent jet and effectively prevent microchannel blockage.

[0041] During operation, high-viscosity materials enter the annular gap between rotor 13 and stator 12 through the feed pipe. This annular gap is extremely narrow, confining the material within a tiny channel space upon entry. The high-speed rotating rotor 13 applies strong centrifugal and shear forces to the material. Under these conditions, the material undergoes intense compression, stretching, tearing, and impact within the narrow annular gap. This composite stress field effectively disrupts the strong intermolecular forces in the high-viscosity system, breaking its initial laminar flow state and initially breaking large-scale agglomerates or high-viscosity fluid clumps into micron- or even submicron-sized particles or droplets, thereby achieving pre-homogenization of the material.

[0042] After homogenization, the high-pressure material enters the first middle pipe 6 of the three-pipe section through the outlet 3 and connecting pipe 4. After filling the first inner annular gap 61, it is driven by pressure and enters the interior of the first inner pipe at high speed through the axially and circumferentially uniformly distributed circular holes 511 with an inner diameter of 0.1–5 mm on the wall of the first inner pipe. This generates a strong jet effect, forming high-intensity turbulence and achieving millisecond-level efficient mixing. The uniform distribution of the circular holes 511 effectively reduces flow dead angles, reduces local wear, and improves the uniformity of jet distribution.

[0043] The pre-homogenized material has smaller characteristic dimensions and a more uniform distribution, which creates favorable conditions for its subsequent entry into the microchannel jet region—the initial flow resistance of the material is significantly reduced, and the risk of blockage during the jet process is also reduced. Simultaneously, the high-speed rotating rotor 13 acts like a built-in "booster pump," imparting high initial kinetic energy and flow velocity to the material through centrifugal force and rotational kinetic energy. This kinetic energy boost allows the sheared and crushed material to overcome pipe resistance and local pressure drop, smoothly flowing out of the outlet 3 and into the subsequent three-tube jet reaction section. In other words, the high-shear pretreatment section 1 not only completes the functions of material crushing and homogenization but also provides the necessary pressure and velocity foundation for subsequent jet mixing and helical intensification through an "energy relay" mechanism, achieving efficient connection and coordinated operation between different functional sections of the entire reaction system.

[0044] Subsequently, the mixed fluid flows along the first inner tube and smoothly flows into the second inner tube 9 through the connecting structure between the first inner tube and the second inner tube 9. At the instant of flowing into the second inner tube 9, the fluid enters the initial section of the second inner tube 9 from the end of the first inner tube. At this time, the fluid already has a certain flow velocity and turbulence, providing a good flow basis for subsequent helical reinforcement.

[0045] After being mixed by the jet, the fluid enters the second inner tube 9 and is forced into a spiral motion by the internal spiral filament turbulence-inducing insert 512. This insert, positioned along the interior of the second inner tube 9, applies radial and circumferential guiding torques to the flowing fluid, forcing it to deviate from its original axial linear trajectory and form a continuous spiral path. This spiral motion significantly increases the actual flow path length of the fluid, prolonging the residence time of the same unit volume of fluid within the tube, thereby increasing the opportunities for contact and diffusion between different components within the fluid. Simultaneously, the spiral motion effectively disrupts the laminar boundary layer, inducing turbulent flow and greatly enhancing the local turbulence level. This turbulence enhancement effect caused by the forced spiral motion significantly increases the shear rate and momentum exchange frequency between fluids, causing the high-viscosity system to be continuously segmented, folded, and reassembled during flow, effectively breaking the initial laminar state of the high-viscosity fluid and further enhancing the mixing effect.

[0046] In terms of heat exchange, guided by the spiral wire interference insert, the fluid continuously tumbles and mixes radially and axially within the pipe, causing frequent positional exchanges between the hot and cold fluids near the pipe wall and the fluid in the central region, thus significantly reducing the thermal resistance effect of the heat transfer boundary layer. This dynamic fluid exchange behavior directly enhances the convective heat transfer coefficient, allowing the heat generated by the reaction to be carried away by the cooling medium more rapidly. In summary, the process of fluid flowing from the first inner pipe into the second inner pipe 9 through the connecting structure achieves a smooth transition from jet mixing to spiral enhancement. By forcing spiral motion, the spiral wire interference insert achieves dual optimization of mixing effect and heat exchange performance in high-viscosity reaction systems, significantly improving the overall efficiency of the reactor.

[0047] In the heat exchange system, cooling water enters the second inner annulus 62 and outer annulus 71 from the second middle pipe inlet pipe 622 and the outer pipe inlet pipe 712, respectively, forming a double-layer cooling channel that dissipates heat simultaneously from both the inner and outer sides of the reaction zone. Cooling medium is introduced from the inlet pipes of the second inner annulus 62 cooling channel and the outer annulus 71 cooling channel, respectively. The cooling medium flows axially along the channel, exchanging heat thoroughly with the walls of the second inner pipe 9 and the second middle pipe 8. Because the two channels are located on the inner and outer sides of the reaction zone, respectively, the cooling medium can absorb heat generated in the reaction zone from both directions simultaneously, forming a three-dimensional heat dissipation network.

[0048] This dual-annular-gap cooling structure significantly expands the effective heat exchange area. Compared to traditional single-layer cooling structures, the heat exchange area in this embodiment is greatly increased. Simultaneously, the dual cooling channels allow the cooling medium to rapidly remove reaction heat from both directions, significantly improving the heat dissipation capacity per unit volume. Under the same cooling medium flow rate and temperature conditions, the heat dissipation efficiency of this embodiment is significantly improved compared to a single-layer cooling structure.

[0049] For strongly exothermic reactions, the intense heat release during the reaction process can easily lead to a sharp rise in local temperature, forming "hot spots." If the temperature of these hot spots gets out of control, it can not only exacerbate side reactions and reduce product selectivity, but in severe cases, it can also lead to runaway reactions or safety accidents. In this embodiment, the dual cooling channels of the second inner annular gap 62 and the outer annular gap 71 can simultaneously provide forced cooling to the wall of the reaction region, allowing the heat from the reaction to be rapidly absorbed and carried away by the cooling medium. This effectively suppresses abnormal local temperature increases and maintains the uniformity and stability of the temperature field in the reaction region.

[0050] This heat dissipation enhancement method has multiple beneficial effects: First, precise temperature control can effectively prevent the overheating and decomposition of the reaction medium or the occurrence of side reactions, avoiding the decrease in selectivity caused by local overheating and significantly improving the yield of the target product; second, a stable temperature environment is conducive to the reaction proceeding towards the target product, avoiding uneven product distribution caused by temperature fluctuations, thereby significantly improving the selectivity of the target product; third, effective heat dissipation can reduce the thermal stress of the equipment, reduce the risk of pipe cracking or seal failure caused by thermal fatigue, and ensure the long-term safe operation of the equipment; finally, the reaction is always maintained within the ideal temperature range, which can achieve better reaction kinetic conditions and improve reaction efficiency.

[0051] The entire three-pipe system employs a straight, bend-free, and diameter-free design, ensuring low-resistance and stable transport of high-viscosity materials throughout the process. This prevents stagnation, accumulation, and secondary blockages, guaranteeing continuous and stable system operation. Finally, the mixed and reacted material is discharged through the inner pipe outlet 52, marking the end of the entire process.

[0052] Therefore, this invention employs a composite microreactor consisting of a high-shear section and a three-tube jet reaction section connected in series. The high-shear section utilizes a stator-rotor narrow annular gap for high-speed shearing to pre-homogenize high-viscosity materials and provide jet kinetic energy. The three-tube section adopts a coaxial nested straight tube structure, with jet mixing enhanced by uniform circular holes in the inner tube, and spiral flow forced by helical wire turbulence inserts further improving turbulence and heat transfer. Furthermore, the heat transfer area is significantly increased and heat dissipation and temperature control are enhanced through internal and external double annular gap cooling channels. The overall structure combines efficient shear dispersion, multi-stage turbulent mixing, precise heat transfer, and anti-clogging conveying functions, effectively solving the technical problems of difficult dispersion, low mixing and heat transfer efficiency, and easy clogging in high-viscosity systems, significantly improving reaction efficiency, product selectivity, and operational stability.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A composite microreactor with high shear and three-tube jet in series, characterized in that, It includes a high-shear pretreatment section, a connecting pipe, and a three-tube jet reaction section. The high-shear pretreatment section is equipped with an inlet and an outlet. The three-tube jet reaction section includes an inner tube, a first middle tube, a second middle tube, and an outer tube. The inner tube is coaxially arranged inside the first and second middle tubes, and the first and second middle tubes are coaxially arranged inside the outer tube. The outlet is connected to the first middle tube through a connecting pipe.

2. The composite microreactor with high shear and three-tube jet series connection as described in claim 1, characterized in that, The high-shear pretreatment section includes a main drive shaft, a stator, and a rotor. The stator is coaxially located inside the high-shear pretreatment section, and the rotor is coaxially located inside the stator. The rotor is fixedly connected to the main drive shaft.

3. The composite microreactor with high shear and three-tube jet series connection according to claim 2, characterized in that, An annular gap is formed between the stator and the rotor, with a gap size of 0.1–3.0 mm. The main drive shaft drives the rotor to rotate at a linear velocity of 10–50 m / s.

4. The composite microreactor with high shear and three-tube jet series connection according to claim 1, characterized in that, The inner tube body includes a first inner tube and a second inner tube. The first inner tube and the second inner tube are coaxially connected, and the end of the second inner tube is connected to the inner tube outlet pipe.

5. The composite microreactor with high shear and three-tube jet series connection according to claim 4, characterized in that, The first inner tube has evenly spaced circular holes on its wall, with an inner diameter of 0.1–5 mm. These holes are evenly distributed along the axial and circumferential directions of the first inner tube.

6. The composite microreactor with high shear and three-tube jet series connection according to claim 4, characterized in that, The second inner tube has a coaxially fixed spiral wire turbulence-inducing insert, which is a spiral metal wire with the spiral direction matching the fluid flow direction.

7. A composite microreactor with high shear and three-tube jet series connection according to claim 4, characterized in that, A first inner annular gap is formed between the first middle tube and the first inner tube, a second inner annular gap is formed between the second middle tube and the second inner tube, and an outer annular gap is formed between the outer tube and the first middle tube and the second middle tube.

8. A composite microreactor with high shear and three-tube jet series connection according to claim 7, characterized in that, The dimensions of the first inner annular gap, the second inner annular gap, and the outer annular gap are all 0.5–1.5 mm.

9. A composite microreactor with high shear and three-tube jet series connection according to claim 1, characterized in that, The second middle tube has a second middle tube inlet pipe and a second middle tube outlet pipe on its side wall, and the outer tube has an outer tube inlet pipe and an outer tube outlet pipe on its side wall.

10. A composite microreactor with high shear and three-tube jet series connection according to claim 1, characterized in that, The three-tube jet reaction section has a straight tube structure with no diameter change, no bends, and no inner wall protrusions.

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