Heat exchange type fluid distribution collision micro-reactor and use method and application

Abstract

The application discloses a heat exchange type fluid distribution collision micro-reactor and belongs to the technical field of exothermic chemical reaction equipment. The micro-reactor comprises a main flow pipeline, a micro-porous jet flow mixing unit and a heat exchange unit. The main flow pipeline comprises a dispersed phase liquid inlet pipe, a reaction liquid outlet pipe and a continuous phase liquid inlet pipe. A tapered flow divider, a first structure, a second structure, a third structure and a tapered flow collector are sequentially connected in the main flow pipeline. The micro-porous jet flow mixing unit comprises a continuous phase annular gap channel, a micro-pore, a continuous phase connecting pipeline and a plurality of mixing reaction tanks. The application also discloses a use method and application of the heat exchange type fluid distribution collision micro-reactor. The application significantly improves the two-phase mixing effect, greatly reduces the side reaction for fast and strong exothermic reaction, and realizes high-throughput continuous feeding through the parallel structure of the plurality of mixing reaction tanks, thereby being suitable for industrial large-scale continuous synthesis conditions.

Description

Technical Field

[0001] This invention belongs to the technical field of exothermic chemical reaction equipment, specifically relating to a heat-exchange type fluid distribution collision microreactor, its usage method, and its application. Background Technology

[0002] The synthesis of fine chemicals, pharmaceutical intermediates, and hazardous chemicals widely involves highly exothermic and rapid reaction processes such as halogenation, nitration, diazotization, and addition coupling. These reactions generally share common characteristics such as extremely fast reaction rates, huge instantaneous heat release, and stringent requirements for the microscopic mixing scale of reactants. Traditional batch reactors, relying on agitators for macroscopic mixing, have low mass transfer coefficients, and their heat exchange area is limited by jackets or coils, making it difficult to quickly remove the instantaneously released reaction heat. This easily leads to serious safety hazards such as local overheating, a surge in byproducts, and even runaway temperature control. At the same time, the intermittent operation mode is inefficient and cannot meet the demands of modern industrial production for high-throughput continuous production.

[0003] Existing microporous jet reactors, with their high specific surface area and short mass transfer distance provided by micron-sized channels, have demonstrated significant advantages in enhancing mass transfer and have been widely used. However, several technical bottlenecks remain when applied to high-throughput, highly exothermic systems. First, microporous jet reactors typically rely on a single jacket or a single heat exchange surface for heat exchange, resulting in a limited heat exchange area. Under high exothermic conditions, the temperature difference between the heat exchange medium and the reactants is insufficient, failing to remove the large amount of heat released instantaneously. This easily leads to the formation of local hot spots within the reaction system, causing a decrease in product selectivity and threatening the safe operation of the equipment. Second, while existing microporous jet or impinging flow mixers can enhance two-phase contact to some extent, most employ single-component jets or simple two-phase direct collision structures, resulting in limited shear strength, wide droplet size distribution in the two-phase dispersion, and difficulty in further improving mixing uniformity. For systems with extremely fast reaction rates, insufficient micro-mixing will directly lead to unstable reaction conversion rates and product quality. Third, when using multiple parallel mixing units for scale-up production, traditional reactors lack a reasonable fluid distribution structure. Dispersed phase feed is prone to flow deviation and uneven material distribution between mixing units, leading to inconsistent reaction conditions in different channels and poor batch-to-batch product repeatability. This severely restricts the industrial-scale application of microreactors. Fourth, to achieve uniform fluid distribution and better mixing, traditional microreactors often require that the volumetric flow rates of the two mixed fluids not differ too much. However, in actual applications, the volumetric flow rates of the fluids often differ significantly.

[0004] Therefore, the industry urgently needs a microreactor that can solve the above-mentioned technical problems. Summary of the Invention

[0005] The present invention addresses the above-mentioned problems and overcomes the shortcomings of the prior art by providing a heat-exchange type fluid distribution collision microreactor, comprising a main flow pipeline, a microporous jet mixing unit, and a heat exchange unit; The main flow pipeline includes a dispersed phase inlet pipe, a reaction liquid outlet pipe, and a continuous phase inlet pipe. A conical distributor, a first structure, a second structure, a third structure, and a conical manifold are sequentially connected within the main flow pipeline. The outer diameter of the second structure is larger than the outer diameter of the first structure. The conical distributor, the first structure, the second structure, the third structure, and the conical manifold are coaxial. The microporous jet mixing unit includes a continuous phase annular gap channel, micropores, continuously connected pipelines, and several mixing reaction tanks; the continuous phase annular gap channel is provided with micropores, which are connected to the mixing reaction tanks through continuously connected pipelines; the several mixing reaction tanks are evenly distributed circumferentially around the central axis of the second structure. A dispersed phase annular channel is provided between the main flow pipeline and the conical distributor and the first structure; a reaction liquid annular channel is provided between the main flow pipeline and the conical manifold and the third structure; the continuous phase inlet pipe is connected to several mixing reaction tanks through the continuous phase annular channel, and both ends of the mixing reaction tank are connected to the dispersed phase annular channel and the reaction liquid annular channel, respectively; the dispersed phase annular channel is connected to the dispersed phase inlet pipe, and the reaction liquid annular channel is connected to the reaction liquid outlet pipe; The small-diameter end of the conical splitter faces the dispersed phase inlet pipe, the large-diameter end of the conical splitter is fixedly connected to the first structure, the small-diameter end of the conical manifold faces the reaction liquid outlet pipe, and the large-diameter end of the conical manifold is fixedly connected to the third structure. The heat exchange unit includes an internal counter-current heat exchange device and an external heat exchange device.

[0006] Preferably, the external heat exchange device is arranged around the outer wall of the continuous phase annular gap channel and the reaction liquid annular gap channel; the internal countercurrent heat exchange device is arranged inside several mixing reaction tanks.

[0007] Preferably, the inner diameter of the dispersed phase inlet pipe is 35mm-50mm, the inner diameter of the continuous phase inlet pipe is 15mm-25mm, the inner diameter of the reaction liquid outlet pipe is 30mm-50mm, and the length of the continuously connected pipe is 5mm-10mm.

[0008] Preferably, the number of mixing reaction tanks is 15-50.

[0009] Preferably, the micropores are circular with a diameter of 0.2-0.5 mm, and the number of micropores on each mixing reaction tank is 4-21.

[0010] Preferably, the cone angle of the cone-shaped splitter is 60°, and the cone angle of the cone-shaped combiner is 60°.

[0011] Another object of the present invention is to provide a method of using the above-mentioned heat exchange type fluid distribution collision microreactor, comprising the following steps: S1: The dispersed phase fluid is introduced into the dispersed phase inlet pipe and evenly distributed to each mixing reaction tank through the conical distributor; S2: The continuous phase fluid is introduced into the continuous phase inlet pipe, and after entering the continuous phase annular gap channel, it is jetted out through micropores and continuously connected pipelines, and mixed with the dispersed phase fluid in the mixing reaction tank to form a reaction mixture. The volume flow ratio of the dispersed phase fluid to the continuous phase fluid is 1:1-1:200. S3: The reaction mixture flows through each mixing reaction tank to the reaction liquid annular channel, and then is collected by the conical manifold and discharged through the reaction liquid outlet pipe; Steps S1 and S2 are performed simultaneously, followed by step S3, or step S1 is performed first, followed by steps S2 and S3. While steps S1 to S3 are being performed, heat exchange is carried out through an internal counter-current heat exchange device and an external heat exchange device, and the flow directions of the heat exchange medium in the internal counter-current heat exchange device and the external heat exchange device are opposite.

[0012] Another object of the present invention is to provide an application of the above-mentioned heat exchange type fluid distribution collision microreactor in nitration, diazotization or halogenation reactions.

[0013] Beneficial effects of this invention: 1. This invention sets up several mixing reaction tanks evenly distributed circumferentially around the central axis of the second structure and the conical splitter. The continuous phase enters the mixing reaction tank through a high-speed jet of micropores and mixes with the dispersed phase through high-shear collision. The micron-sized micropores can cut the continuous phase into tiny liquid streams, significantly reducing the mass transfer distance between the two phases and enhancing the interface renewal efficiency. Compared with traditional microchannel and ordinary jet reactors, the shear strength of the two-phase mixing is significantly improved, and the droplet size distribution is narrower. For rapid and strongly exothermic reactions, it can significantly reduce side reactions, improve product selectivity and reaction conversion efficiency. At the same time, the multi-tank parallel structure can realize high-throughput continuous feeding, which is suitable for industrial large-scale continuous synthesis.

[0014] 2. This invention is equipped with a conical distributor and a conical confluencer. The conical distributor has a tapered, expanding shape, while the conical confluencer has a tapered, contracting structure. This allows the dispersed phase to be evenly distributed to each mixing reaction tank in the dispersed phase annular channel. The reaction liquid completes stable flow in the reaction liquid annular channel. The coordinated action with several mixing reaction tanks effectively solves the problems of feed deviation and uneven material distribution in multiple parallel reaction units. The reaction conditions in each mixing reaction tank are highly consistent, resulting in stronger batch stability of the product.

[0015] 3. The distribution method of the present invention distributes one stream of fluid in the form of a trough and another stream of fluid in the form of micropores. The size and number of troughs, as well as the diameter and number of micropores, can be adjusted according to the volumetric flow rate of the fluids, thereby achieving instantaneous uniform mixing even when the volumetric flow rates of the fluids are very different.

[0016] 4. The coordinated function of each component in this invention integrates two-phase feeding, microporous high-shear mixing, double-sided countercurrent heat exchange, and uniform material distribution and confluence functions into one unit. The integrated flow channel design results in uniform pressure drop distribution and lower energy consumption. The internal and external heat exchange channels are independent of each other, and the temperature of the internal and external heat exchange media can be controlled separately to accurately match the exothermic requirements of different stages of the reaction process. The temperature control accuracy is higher, the equipment structure is compact, and no additional mixing or heat exchange auxiliary equipment is required. It is suitable for a variety of strongly exothermic and rapid reaction systems such as nitration, diazotization, and halogenation, and has strong versatility.

[0017] 5. This invention adopts an internal and external double-layer independent counter-current heat exchange structure. The internal counter-current heat exchange device is set inside several mixing reaction tanks and close to the outer wall of the mixing reaction tank. The external heat exchange device pipe covers the outer wall of the continuous phase annular gap channel and the reaction liquid annular gap channel. The heat exchange medium flows in the opposite direction, which can simultaneously remove a large amount of heat released instantaneously from both the internal and external sides. The effective heat exchange area is more than twice that of a single-layer jacketed reactor, and the heat transfer temperature difference utilization rate is higher. It can quickly eliminate local hot spots in the reaction system, avoid the safety risks of local overheating and runaway temperature in strongly exothermic reactions, and broaden the safe operating range of the reaction.

[0018] 6. The structure of this invention achieves simultaneous enhancement of mass transfer and heat transfer. By combining the method of this invention, it overcomes the technical bottlenecks of insufficient heat exchange flux and limited shear mixing capacity of traditional microreactors. While ensuring high throughput, it also takes into account precise temperature control and efficient mixing, as well as production capacity, product quality and production safety, and has good industrial promotion value. Attached Figure Description

[0019] Figure 1 This is one of the structural schematic diagrams of a heat exchange type fluid distribution collision microreactor according to the present invention; Figure 2 This is a schematic diagram showing the flow directions of the continuous phase fluid, the dispersed phase fluid, and the reaction liquid after mixing the two phase fluids when using the heat exchange type fluid distribution collision microreactor of the present invention. In the diagram, blue represents the dispersed phase fluid, red represents the continuous phase fluid, and green represents the mixed reaction liquid fluid. Figure 3 This is a schematic diagram of the heat exchange fluid flow direction in a heat exchange type fluid distribution collision microreactor according to the present invention; Figure 4 This is a schematic diagram of the structure of the mixing reaction tank, the continuously connected pipeline, and the continuous phase annular gap channel in this invention; Figure 5 This is the second schematic diagram of the structure of the heat exchange type fluid distribution collision microreactor of the present invention; Figure 6 This is a diagram showing the overall concentration mixing simulation results in the numerical simulation test of Embodiment 1 of the present invention; Figure 7 This is a diagram showing the concentration mixing simulation results of the mixing reaction tank and continuously connected pipelines in the numerical simulation test of Embodiment 1 of the present invention; Figure 8 This is a comparison chart of the mixing uniformity corresponding to different micropore diameters in this invention.

[0020] In the diagram, 1. Dispersed phase inlet pipe; 2. Continuous phase inlet pipe; 3. Reaction liquid outlet pipe; 4. Continuous phase annular channel; 5. Continuously connected pipeline; 6. Mixing reaction tank; 7. Inlet pipe of internal countercurrent heat exchange pipeline; 8. Outlet pipe of internal countercurrent heat exchange pipeline; 9. Internal countercurrent heat exchange pipeline; 10. Inlet pipe of external heat exchange pipeline; 11. External heat exchange pipeline; 12. Outlet pipe of external heat exchange pipeline; 13. Conical distributor; 14. Dispersed phase annular channel; 15. Reaction liquid annular channel; 16. Conical manifold. Detailed Implementation

[0021] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0022] Example 1: Refer to Figures 1 to 4 As shown, this embodiment provides a heat exchange type fluid distribution collision microreactor including a main flow pipeline, a microporous jet mixing unit, and a heat exchange unit; The main flow pipeline includes a dispersed phase inlet pipe 1, a reaction liquid outlet pipe 3, and a continuous phase inlet pipe 2. The main flow pipeline is equipped with a conical distributor 13, a first structure, a second structure, a third structure, and a conical manifold 16 connected in sequence. The outer diameter of the second structure is larger than the outer diameter of the first structure. The conical distributor, the first structure, the second structure, the third structure, and the conical manifold are coaxial. The dispersed phase inlet pipe 1, the reaction liquid outlet pipe 3, the internal countercurrent heat exchange pipe 9, the horizontal section of the internal countercurrent heat exchange inlet pipe 7, the horizontal section of the internal countercurrent heat exchange outlet pipe 8, the horizontal section of the external heat exchange pipe 11, the external heat exchange pipe inlet pipe 10, and the external heat exchange pipe outlet pipe 12 are coaxially assembled and connected to achieve uniform distribution of each fluid stream and equal pressure on the reactor in the axial and circumferential directions.

[0023] The micro-hole jet mixing unit includes a continuous phase annular gap channel 4, micropores, a continuous connecting pipeline 5, and several mixing reaction tanks 6; micropores are provided on the continuous phase annular gap channel 4, and the micropores are connected to the mixing reaction tanks 6 through the continuous connecting pipeline 5; several mixing reaction tanks 6 are evenly distributed circumferentially around the central axis of the second structure. A dispersed phase annular channel 14 is provided between the main flow pipeline and the conical distributor 13 and the first structure; a reaction liquid annular channel 15 is provided between the main flow pipeline and the conical manifold 16 and the third structure; the continuous phase inlet pipe 2 is connected to several mixing reaction tanks 6 through the continuous phase annular channel 4, and both ends of the mixing reaction tank 6 are connected to the dispersed phase annular channel 14 and the reaction liquid annular channel 15 respectively; the dispersed phase annular channel 14 is connected to the dispersed phase inlet pipe 1, and the reaction liquid annular channel 15 is connected to the reaction liquid outlet pipe 3; The small-diameter end of the conical splitter 13 faces the dispersed phase inlet pipe 1, and the large-diameter end of the conical splitter 13 is fixedly connected to the first structure. The small-diameter end of the conical manifold 16 faces the reaction liquid outlet pipe 3, and the large-diameter end of the conical manifold 16 is fixedly connected to the third structure. Using heat transfer oil as the heat exchange fluid, the temperature range of the heat exchange fluid is generally -40℃ to 200℃, thus achieving environmental stability of the exothermic reaction under extreme operating conditions (-40℃ to 200℃).

[0024] Specifically, the inner diameter of the dispersed phase inlet pipe 1 is 50 mm, the inner diameter of the continuous phase inlet pipe 2 is 20 mm, the inner diameter of the reaction liquid outlet pipe 3 is 50 mm, and the length of the continuous connecting pipe 5 is 10 mm.

[0025] Specifically, there are 15 mixing reaction tanks 6.

[0026] Specifically, the micropores are circular with a diameter of 0.5 mm. Each mixing reaction tank 6 has 21 corresponding micropores arranged in three rows. The spacing between micropores in each row on the same mixing reaction tank 6 is 4 mm, and the spacing between two micropores in the same row is 1 mm.

[0027] The dispersed phase inlet pipe 1 can handle a fluid with a volumetric flow rate of 2226.6 L / H and a flow velocity of 0.315 m / s; the continuous phase inlet pipe 2 can handle a fluid with a volumetric flow rate of 2226.6 L / H and a flow velocity of 1.97 m / s; the reaction liquid outlet pipe 3 has a fluid volumetric flow rate of 4453.2 L / H.

[0028] Specifically, the cone angle of the cone-shaped splitter 13 is equal to the cone angle of the cone-shaped combiner 16, both being 60°.

[0029] like Figure 3As shown, the heat exchange unit includes an internal countercurrent heat exchange device and an external heat exchange device. The external heat exchange device is arranged on the outer wall of the continuous phase annular channel 4 and the reaction liquid annular channel 15; the internal countercurrent heat exchange device is set inside several mixing reaction tanks 6.

[0030] The internal countercurrent heat exchange device consists of an internal countercurrent heat exchange pipe inlet pipe 7, an internal countercurrent heat exchange pipe 9, and an internal countercurrent heat exchange pipe outlet pipe 8 connected in sequence. The inner diameter of the internal countercurrent heat exchange pipe inlet pipe 7, the internal countercurrent heat exchange pipe 9, and the internal countercurrent heat exchange pipe outlet pipe 8 is 20mm.

[0031] The internal countercurrent heat exchange pipe 9 is horizontally arranged in the first structure, the second structure and the third structure, and the internal countercurrent heat exchange pipe 9 is provided with an internal countercurrent heat exchange pipe outlet pipe 8 at the end of the pipe.

[0032] The external heat exchange device is enclosed outside the continuous phase annular gap channel 4, the conical manifold 16 and the reaction liquid annular gap channel 15. It is a sandwich heat exchange channel composed of external heat exchange pipe 11, external heat exchange pipe inlet pipe 10 and external heat exchange pipe outlet pipe 12.

[0033] like Figure 3 As shown, the internal heat exchange fluid is introduced through the vertical section of the inlet pipe 7 of the internal countercurrent heat exchange pipeline, first flowing into the internal countercurrent heat exchange pipeline 9, and then flowing downward out of the equipment through the vertical section of the outlet pipe 8 of the internal countercurrent heat exchange pipeline located at the end of the pipeline 9; the heat exchange fluid and the internal reaction two-phase fluid achieve countercurrent heat exchange through the pipe wall.

[0034] Meanwhile, the external heat exchange fluid is introduced into the interlayer gap between the external heat exchange pipe 11 and the outer wall of the internal component through the external heat exchange pipe inlet pipe 10. It flows upward along the interlayer, completely covering the mixing reaction tank 6 and the area of ​​the conical manifold 16. After fully exchanging heat with the internal reaction fluid on the wall, it is discharged upward through the external heat exchange pipe outlet pipe 12 at the top.

[0035] The continuous phase inlet pipe 2, the continuous phase annular gap channel 4, and the outer base of the micropore are integrally formed by welding, which can ensure that the continuous phase annular gap channel 4, the continuous connected pipe 5, and the dispersed phase annular gap channel 14 are strictly coaxial.

[0036] In this invention, except for the external heat exchange pipe inlet pipe 10, external heat exchange pipe 11, and external heat exchange pipe outlet pipe 12, which are made of stainless steel, the base material of the other components is Hastelloy.

[0037] Example 2: The rest is the same as in Example 1, except that the inner diameter of the dispersed phase inlet pipe 1 is 35 mm, the inner diameter of the continuous phase inlet pipe 2 is 15 mm, the inner diameter of the reaction liquid outlet pipe 3 is 30 mm, and the length of the continuous connecting pipe 5 is 5 mm.

[0038] The number of mixing reaction tanks 6 is 50.

[0039] The micropores are circular with a diameter of 0.2 mm. There are 4 micropores on each mixing reaction tank 6, and the distance between two micropores on the same mixing reaction tank 6 is 1 mm.

[0040] Example 3: Method of using the heat exchange type fluid distribution collision microreactor of Example 1: S1: The dispersed phase fluid is introduced into the dispersed phase inlet pipe and evenly distributed to each mixing reaction tank through the conical distributor; S2: The continuous phase fluid is introduced into the continuous phase inlet pipe, and after entering the continuous phase annular gap channel, it is jetted out through micropores and continuously connected pipelines, and mixed with the dispersed phase fluid in the mixing reaction tank to form a reaction mixture. The volume flow ratio of the dispersed phase fluid to the continuous phase fluid is 1:1. S3: The reaction mixture flows through each mixing reaction tank to the reaction liquid annular channel, and then is collected by the conical manifold and discharged through the reaction liquid outlet pipe; Steps S1 and S2 are performed simultaneously, and then step S3 is performed. While steps S1 to S3 are being performed, heat exchange is carried out through an internal counter-current heat exchange device and an external heat exchange device, and the flow directions of the heat exchange medium in the internal counter-current heat exchange device and the external heat exchange device are opposite.

[0041] Example 4: Other steps are the same as in Example 3, except that step S2 is different, and the volumetric flow rate ratio of the dispersed phase fluid to the continuous phase fluid is 1:200.

[0042] like Figure 2 As shown, the dispersed phase fluid in the dispersed phase inlet pipe 1 ( Figure 2 The fluid (blue arrow in the middle) flows through the conical distributor 13, through the dispersed phase annular gap channel 14, and into the mixing reaction tank 6; the continuous phase fluid (…) in the continuous phase inlet pipe 2… Figure 2 (Red arrow in the middle) is introduced into the continuous phase annular gap channel 4, and sprayed into the continuously connected pipeline 5 through micropores. In the mixing reaction tank 6, it undergoes high-speed collision with the dispersed phase fluid to complete the initial crushing and mixing to form a mixed reaction liquid. The mixed reaction liquid further diffuses and converges through the reaction liquid annular gap channel 15 to complete the secondary mixing of fully emulsified dispersion, and finally flows out from the reaction liquid outlet pipe 3. Figure 2 The green arrows represent reaction mixtures after the dispersed and continuous phases have been fully mixed.

[0043] Because the micropores and the mixing reaction tank 6 have different flow cross-sectional areas, a significant velocity difference can be formed between the two fluid streams, generating strong velocity shear at the micropore outlet. This velocity difference allows the continuous phase jet to collide with the dispersed phase upon entering the mixing reaction tank 6, tearing the dispersed phase into tiny droplets and significantly increasing the contact area between the two phases. When the flow velocity reaches a turbulent state, the micropore jet can further induce chaotic convection and turbulent kinetic energy dissipation, completing the uniform mixing of the two phases within milliseconds, exhibiting advantages such as high mixing efficiency and strong controllability.

[0044] The heat exchange type fluid distribution microporous collision mixing reactor of the present invention can synthesize organic compounds in a liquid-liquid system with a high volume flow rate. Because the mixing reaction tank 6 and the several micropores distributed thereon are uniformly distributed, and the diameter of the reaction liquid outlet pipe 3 is 30mm-50mm, it can be applied to high-throughput material mixing reactions at the pilot stage and above.

[0045] Example 5: Application of heat exchange type fluid distribution microporous collision microreactor.

[0046] The applicability of the microreactor of the present invention to a fast exothermic reaction system was verified by the diazotization reaction of 3,4-dichloroaniline. The operation was carried out using the method described above in this application. A 16.33% (w / w) solution of 3,4-dichloroaniline toluene and a 30.85% (w / w) hydrochloric acid were fed to a pre-cooling mixing unit for acidification and mixing. The temperature of the pre-cooling mixing unit was controlled at 0°C. The acidified material was then introduced into the microreactor of the present invention as the dispersed phase.

[0047] A 19.68% sodium nitrite aqueous solution was introduced as the continuous phase into the continuous phase inlet pipe 2, and the reaction temperature of the microreactor was controlled at 10℃ through internal and external heat exchange units. The dispersed phase and the continuous phase were mixed and reacted in parallel in several mixing reaction tanks by microporous jet impact. The molar ratio of 3,4-dichloroaniline, sodium nitrite and hydrochloric acid was 1:1.123:2.99; the residence time in the microreactor was 0.5s.

[0048] After continuous diazotization, the diazotization yield in this embodiment is approximately 99.5% based on the consumption of 3,4-dichloroaniline. Under the same conditions, the diazotization yield without using the microreactor of this application is approximately 90%. This demonstrates the adaptability of the microreactor of this invention to the mixing, heat exchange, and continuous operation of strongly exothermic diazotization systems.

[0049] This invention also has significant application value in the fields of exothermic reactions such as fine chemical synthesis and nanoparticle preparation. Its core advantage lies in the synergistic effect of high-precision temperature control and uniform material distribution: the design of inner and outer double-layer countercurrent heat exchange channels enables precise control of the reaction environment temperature and maintains environmental stability under extreme conditions (-40℃ to 200℃).

[0050] Example 6: The structure is the same as in Example 1, but the difference from Example 1 is that: The inner diameter of the dispersed phase inlet pipe 1 is 35 mm, and the flow rate is 0.065 m / s; the inner diameter of the continuous phase inlet pipe 2 is 15 mm, and the flow rate is 0.355 m / s; the inner diameter of the reaction liquid outlet pipe 3 is 30 mm.

[0051] The mixing effect of Example 1 in this invention was tested by numerical simulation. The numerical simulation test process is as follows: (1) Geometric modeling and mesh generation Geometric Construction: A 3D model of the reactor in Example 1 was created in COMSOL. The inner diameter of the dispersed phase inlet pipe 1 is 50 mm, the inner diameter of the continuous phase inlet pipe 2 is 20 mm, and the width of the mixing reaction tank 6 is 10 mm, the height is 5 mm, and there are 15 such tanks. The inner diameter of the micropores is 0.5 mm. There are 21 micropores on each mixing reaction tank 6, arranged in three rows. The distance between two rows of micropores on the same mixing reaction tank 6 is 4 mm, and the distance between two micropores in the same row is 1 mm.

[0052] The radial length of the continuously connected pipeline 5 is 10mm, the inner diameter of the reaction liquid outlet pipe 3 is 50mm, and the inner diameters of the internal countercurrent heat exchange pipeline inlet pipe 7, internal countercurrent heat exchange pipeline outlet pipe 8, internal countercurrent heat exchange pipeline 9, external heat exchange pipeline inlet pipe 10, and external heat exchange pipeline outlet pipe 12 are all 20mm.

[0053] Mesh generation: The overall model is discretized using a free tetrahedral mesh. Local mesh refinement and boundary layer meshing are applied to areas with strong turbulent disturbances, such as micropores, to accurately capture turbulent features such as jets and eddies, while ensuring computational convergence.

[0054] (2) Selection and setting of physical field interface Choosing a dual-physics coupling between turbulent flow and rarefied mass transport: Turbulent physics: Select a suitable turbulence model (k-ε) for microscale jets to describe the fluid turbulence velocity field, pressure field, turbulent kinetic energy, and dissipation rate distribution, and assume that the fluid is an incompressible Newtonian fluid.

[0055] The physical field for mass transfer of rare matter is the velocity field coupled with turbulent flow, which describes the evolution of the concentration field of solute under turbulent mixing and considers the enhancing effect of turbulent diffusion on mass transfer.

[0056] (3) Definition of boundary conditions and initial conditions Inlet boundary: Dispersed phase inlet pipe 1 is set with a turbulent inlet velocity. Ethanol solvent is added for easy observation; the concentration of the ethanol solvent is 0 mol / m³. 3The turbulence intensity and turbulence scale are specified; the flow rate of the continuous phase inlet pipe 2 is set, and the concentration of the ethanol solvent is 1 mol / m³. 3 The turbulence parameters are set synchronously, and the volumetric flow rate ratio of the dispersed phase fluid to the continuous phase fluid is 1:1.

[0057] Outlet boundary: The reaction liquid outlet pipe 3 is set as a pressure outlet with a gauge pressure of 0 Pa to ensure continuous fluid flow. At the same time, the outlet boundary conditions for turbulence variables are set.

[0058] Wall Boundaries: All flow channel walls are set as no-slip walls with wall functions (to adapt to turbulence models), and flux-free boundaries are set to avoid fluid leakage and solute diffusion.

[0059] Initial conditions: The fluid concentration in the flow channel is 0 at the initial moment, and the velocity field and turbulence variables are set to 0 or small disturbances. Start steady-state calculation.

[0060] (4) Solver configuration and steady-state calculation Research type: Select steady-state study to obtain the steady-state concentration field distribution of turbulent mixing after full development.

[0061] Solver settings: Use an iterative solver (such as FGMRES) combined with multigrid preprocessing, and set a relative tolerance (such as 10). -6 This enables strongly coupled computation of turbulence-dilute mass transfer, ensuring steady-state convergence.

[0062] Calculation execution: COMSOL iteratively solves the coupled equations of turbulent flow and mass transport until the residuals meet the convergence criteria, obtaining the steady-state flow field and concentration field, such as... Figure 7 As shown.

[0063] (5) Calculate the mixing uniformity MI (Mixing Index) The definition of mixing uniformity (MI) is: (1); In formula (1): σ: Standard deviation of fluid concentration obtained from simulation calculation; σmax: Standard deviation of the theoretical maximum concentration; When MI→1, σ is much smaller than σ max This indicates that the fluid is uniformly dispersed, close to the ideal mixing target, and the mixing is thorough; When MI→0, σ is approximately equal to σ max This indicates that the fluid stratification or clusters have not diffused, resulting in poor mixing.

[0064] The formula for calculating σ is: (2); In formula (2): ci The concentration of fluid monitored at a certain monitoring point; After being mixed in the mixing reaction tank 6, the liquid flows through the annular channel 15, is collected by the conical manifold 16, and finally flows out through the outlet pipe 3. The average concentration of the fluid in the outlet is as follows: N: Total number of monitoring points; The larger the σ, the greater the concentration difference at different locations (the less uniform the mixing, and the more obvious the concentration stratification / clustering). The smaller σ is, the closer the concentration is to the mean (the more uniform the mixing and the higher the consistency of the fluid distribution).

[0065] From such Figure 6 , Figure 7 It can be seen that the continuous phase fluid flowing out through the micropores and the dispersed phase fluid flowing into the front section of the mixing reaction tank 6 through the dispersed phase inlet pipe 1 collide with each other at the rear section of the mixing reaction tank 6. The mixing mode is dissipation under turbulent conditions, and the subsequent mixing mode relies on molecular diffusion.

[0066] In addition, the mixing uniformity was verified by changing the micropore diameter in this embodiment, and the results were as follows: Figure 8 The comparison chart shown here corresponds to different micropore diameters D, indicating the mixing uniformity. Figure 8 As can be seen, when the micropore inner diameter D is 0.2 mm, the mixing uniformity can reach above 0.98, and when the micropore inner diameter D is 0.3 mm, the mixing uniformity can reach above 0.96, close to 1. The fluid is uniformly dispersed within the micropore diameter range of 0.2 mm to 0.3 mm, approaching the ideal mixing target, indicating thorough mixing. However, when the micropore diameter is 0.4 mm, 0.5 mm, and 0.6 mm, the mixing uniformity gradually decreases, showing a poorer mixing effect compared to the micropore diameter range of 0.2 mm to 0.3 mm.

[0067] It is understood that the above specific description of the present invention is only for illustrating the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention to achieve the same technical effect; as long as the use needs are met, they are all within the protection scope of the present invention.

Claims

1. A heat-exchange type fluid distribution collision microreactor, characterized in that, Includes the main flow pipeline, microporous jet mixing unit, and heat exchange unit; The main flow pipeline includes a dispersed phase inlet pipe, a reaction liquid outlet pipe, and a continuous phase inlet pipe. A conical distributor, a first structure, a second structure, a third structure, and a conical manifold are sequentially connected within the main flow pipeline. The outer diameter of the second structure is larger than the outer diameter of the first structure. The conical distributor, the first structure, the second structure, the third structure, and the conical manifold are coaxial. The microporous jet mixing unit includes a continuous phase annular gap channel, micropores, continuously connected pipelines, and several mixing reaction tanks; the continuous phase annular gap channel is provided with micropores, which are connected to the mixing reaction tanks through continuously connected pipelines; the several mixing reaction tanks are evenly distributed circumferentially around the central axis of the second structure. A dispersed phase annular channel is provided between the main flow pipeline and the conical distributor and the first structure; a reaction liquid annular channel is provided between the main flow pipeline and the conical manifold and the third structure; the continuous phase inlet pipe is connected to several mixing reaction tanks through the continuous phase annular channel, and both ends of the mixing reaction tank are connected to the dispersed phase annular channel and the reaction liquid annular channel, respectively; the dispersed phase annular channel is connected to the dispersed phase inlet pipe, and the reaction liquid annular channel is connected to the reaction liquid outlet pipe; The small-diameter end of the conical splitter faces the dispersed phase inlet pipe, the large-diameter end of the conical splitter is fixedly connected to the first structure, the small-diameter end of the conical manifold faces the reaction liquid outlet pipe, and the large-diameter end of the conical manifold is fixedly connected to the third structure. The heat exchange unit includes an internal counter-current heat exchange device and an external heat exchange device.

2. The heat exchange type fluid distribution collision microreactor according to claim 1, characterized in that, The external heat exchange device is arranged around the outer wall of the continuous phase annular channel and the reaction liquid annular channel; the internal countercurrent heat exchange device is arranged inside several mixing reaction tanks.

3. The heat exchange type fluid distribution collision microreactor according to claim 1, characterized in that, The inner diameter of the dispersed phase inlet pipe is 35mm-50mm, the inner diameter of the continuous phase inlet pipe is 15mm-25mm, the inner diameter of the reaction liquid outlet pipe is 30mm-50mm, and the length of the continuously connected pipe is 5mm-10mm.

4. The heat exchange type fluid distribution collision microreactor according to claim 3, characterized in that, The number of mixing reaction tanks is 15-50.

5. The heat exchange type fluid distribution collision microreactor according to claim 1, characterized in that, The micropores are circular with a diameter of 0.2mm-0.5mm, and there are 4-21 micropores on each mixing reaction tank.

6. The heat exchange type fluid distribution collision microreactor according to claim 1, characterized in that, The cone angle of the cone-shaped splitter is 60°, and the cone angle of the cone-shaped combiner is 60°.

7. A method of using the heat exchange type fluid distribution collision microreactor according to any one of claims 1-6, characterized in that, Includes the following steps: S1: The dispersed phase fluid is introduced into the dispersed phase inlet pipe and evenly distributed to each mixing reaction tank through the conical distributor; S2: The continuous phase fluid is introduced into the continuous phase inlet pipe, and after entering the continuous phase annular gap channel, it is jetted out through micropores and continuously connected pipelines, and mixed with the dispersed phase fluid in the mixing reaction tank to form a reaction mixture. The volume flow ratio of the dispersed phase fluid to the continuous phase fluid is 1:1-1:

200. S3: The reaction mixture flows through each mixing reaction tank to the reaction liquid annular channel, and then is collected by the conical manifold and discharged through the reaction liquid outlet pipe; Steps S1 and S2 are performed simultaneously, followed by step S3, or step S1 is performed first, followed by steps S2 and S3. While steps S1 to S3 are being performed, heat exchange is carried out through an internal counter-current heat exchange device and an external heat exchange device, and the flow directions of the heat exchange medium in the internal counter-current heat exchange device and the external heat exchange device are opposite.

8. The application of the heat exchange type fluid distribution collision microreactor according to any one of claims 1-6 in nitration, diazotization or halogenation reactions.

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