Two-stage split reaction chambers and multi-stage series microchannel reactors

Abstract

This invention provides a two-stage diversion reaction chamber and a multi-stage series microchannel reactor, belonging to the field of microreactors. Specifically, it includes: a fixed wall forming a heart-shaped chamber space, with the inlet located in the concave center and the outlet in the convex center; an arc-shaped baffle positioned below the inlet; and two ivory-shaped diversion baffles symmetrically positioned below the arc-shaped baffle and above the outlet. The larger end of the ivory-shaped baffles is close to the arc-shaped baffle, while the tip points towards the outlet. The shortest distance between the upper surface of the ivory-shaped baffle and the lower arc surface of the arc-shaped baffle is greater than the shortest distance between the lower surface of the ivory-shaped baffle and the fixed wall. Through this solution, the secondary diversion structure within the channel eliminates the flow dead zone below the diversion baffles, improving both mixing and mass transfer efficiency and fluid mixing intensity within the channel.

Description

Technical Field

[0001] This application relates to the field of microreactors, and more particularly to a two-stage split reaction chamber and a multi-stage series microchannel reactor. Background Technology

[0002] Currently, the most widely used microchannel reactor structure on the market is Corning's heart-shaped structure. Its enhanced mass transfer principle is shear-splitting-binding-reshearing. Compared to other microchannel reactor structures, it features lower flow resistance within the channels, higher mass and heat transfer efficiency, lower backmixing probability, and better control over reaction temperature and residence time. Figure 2 As shown, its disadvantages are as follows: In the heart-shaped channel structure, due to the excessively large flow area below the arched baffle, the two-phase fluids decelerate before mixing after separation, causing fluid to accumulate in a large area below the arched baffle (the velocity vector distribution of the fluid below the baffle in the figure is dispersed). This results in a wide stagnant boundary layer, reducing mass transfer efficiency, creating a dead zone effect, and leading to poor local mixing. This effect is particularly pronounced at low flow rates.

[0003] CN117717983A discloses a micro-mixing and reaction structure and its reactor based on heart-shaped feature optimization. By adjusting the Corning heart-shaped structure, the problem of wide and large-area stagnant boundary layer distribution in the Corning heart-shaped microchannel reactor is effectively solved. However, the optimized structure increases the size and area of ​​the turbulence baffle. Although it improves the fluid mixing effect at low flow rates, it increases the pressure drop loss of the channel in high flow rate reaction systems, which is not conducive to industrial scale-up production and has low space utilization.

[0004] CN111001348A discloses a multi-unit mixer that can rapidly mix two or more reaction media in different states under high-throughput conditions, achieving good mixing results. Its drawback is that the reaction chambers in this series of microreactors are relatively complex, and "dead zones" are easily formed in some reaction chamber areas during low-throughput reactions, leading to poor mixing and mass transfer. Summary of the Invention

[0005] Therefore, in order to overcome the shortcomings of the prior art, the present invention provides a reaction chamber with secondary diversion through a secondary diversion structure in the channel, which can eliminate the flow dead zone below the diversion baffle, stabilize the flow of the reaction fluid in the microchannel, and improve the mixing and mass transfer efficiency while increasing the mixing intensity of the fluid in the channel, as well as a multi-stage series microchannel reactor.

[0006] To achieve the above objectives, the present invention provides a two-stage diversion reaction chamber, comprising: a fixed wall, wherein the cavity space formed by the fixed wall is heart-shaped, the cavity inlet of the reaction chamber is recessed in the middle of the heart shape, and the cavity outlet of the reaction chamber is protruding in the middle of the heart shape; an arc-shaped baffle disposed below the cavity inlet; and two ivory-shaped diversion baffles symmetrically disposed below the arc-shaped baffle and above the cavity outlet, wherein the larger end of the ivory-shaped diversion baffle is close to the arc-shaped baffle, the tip of the ivory-shaped diversion baffle points towards the cavity outlet, and the shortest distance between the upper surface of the ivory-shaped diversion baffle and the lower arc surface of the arc-shaped baffle is greater than the shortest distance between the lower surface of the ivory-shaped diversion baffle and the fixed wall.

[0007] In one embodiment, the two ends of the ivory-shaped diversion baffle are a spherical end and a conical end, respectively, and the two ends are smoothly connected by an arc.

[0008] In one embodiment, the upper and lower arc surfaces of the arc-shaped baffle are parallel, and the two ends of the baffle are smoothly connected by an arc.

[0009] In one embodiment, under low flow rate conditions, the ratio of the shortest distance d between the upper surface of the ivory-shaped diverting baffle and the lower arc surface of the arc-shaped baffle to the shortest distance e between the lower surface of the ivory-shaped diverting baffle and the fixed wall is 1.1 to 1.2.

[0010] Under high flow rate conditions, the ratio of the shortest distance d between the upper surface of the ivory-shaped diverting baffle and the lower arc surface of the arc-shaped baffle to the shortest distance e between the lower surface of the ivory-shaped diverting baffle and the fixed wall is between 1.2 and 1.4.

[0011] In one embodiment, the ratio of the furthest distance b at the head of the two symmetrical ivory-shaped diversion baffles to the length of the maximum width a inside the reaction chamber ranges from 0.4 to 0.6.

[0012] In one embodiment, the length ratio of the minimum distance c between the tail ends of the two symmetrical ivory-shaped diversion baffles to the minimum width k of the cavity outlet ranges from 1.8 to 2.2.

[0013] In one embodiment, the ratio of the length f of the ivory-shaped diversion baffle to the distance h from the apex of the lower arc surface of the arc-shaped baffle to the outlet of the cavity is in the range of 0.40 to 0.50.

[0014] A multi-stage series-connected microchannel reactor includes: a three-way inlet unit; N reaction chambers connected in series as described above for secondary flow splitting, where N is an integer greater than or equal to 1; and an outlet unit. The three-way inlet unit, the N series-connected reaction chambers for secondary flow splitting, and the outlet unit are connected sequentially. The inlet of the first reaction chamber for secondary flow splitting is connected to the outlet of the three-way inlet unit, and the outlet of the last reaction chamber for secondary flow splitting is connected to the inlet of the outlet unit. The interior of the microchannel reactor, except for the reaction chambers for secondary flow splitting, is a solid structure.

[0015] In one embodiment, the N secondary flow reaction chambers connected in series are arranged in multiple columns, and the two secondary flow reaction chambers connected between adjacent columns are connected by U-shaped tubes and arranged in opposite parallel directions.

[0016] In one embodiment, the three-phase inlet unit has a first inlet and a second inlet; the second inlet is connected to the first inlet through a second pipeline, the second pipeline is located around the first pipeline, and the end of the second pipeline is connected to the end of the first pipeline, and the two-phase fluids are squeezed, contacted and mixed with each other at the pipeline outlet.

[0017] Compared with the prior art, the advantages of this invention are: the secondary diversion structure, composed of an arc-shaped baffle and an ivory-shaped diversion baffle within the channel, improves the mixing intensity of the fluid within the channel. After diversion by the secondary ivory diversion structure, the fluid collides and contacts below the diversion baffle before flowing to the next stage reaction chamber, eliminating the flow dead zone below the diversion baffle, stabilizing the flow of the reaction fluid within the microchannel, and further improving the mixing and mass transfer efficiency.

[0018] Moreover, the secondary flow splitting structure causes the entire reaction channel in the reaction chamber to be distributed in an S-shape (snake-like) on the reaction plate, which reduces the volume occupied by the reaction chamber in the entire microreactor, increases the length of the reaction channel, improves the liquid holding capacity of the reaction chamber, and ensures good mixing and mass transfer between the reaction fluids.

[0019] In addition, the secondary flow splitting structure also forms multiple flow channels that narrow and then widen within the reaction chamber to accelerate the flow velocity and achieve a jet effect. This causes the reacting fluids to collide with the baffles at high speed, resulting in turbulence. This not only improves the mixing effect of the fluids and the magnitude of intermolecular diffusion, ensuring uniform mixing and improving mass transfer efficiency, but also increases space utilization. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the heart-shaped reaction chamber in the background art;

[0022] Figure 2 This is a vector velocity cloud diagram of the heart-shaped reaction chamber in the background technology;

[0023] Figure 3 This is a schematic diagram of the structure of a multi-stage series microchannel reactor in an embodiment of the present invention;

[0024] Figure 4 This is a schematic cross-sectional view of the inlet section of a multi-stage series microchannel reactor in an embodiment of the present invention;

[0025] Figure 5 This is another cross-sectional schematic diagram of the multi-stage series microchannel reactor in an embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of the structure of the two-stage flow-diverting reaction chamber in an embodiment of the present invention;

[0027] Figure 7 This is a vector velocity cloud diagram of the reaction chamber in the secondary flow splitting embodiment of the present invention;

[0028] Figure 8 This is a vector phase diagram of the reaction chamber with secondary flow splitting in an embodiment of the present invention;

[0029] Figure 9 This is a streamline velocity diagram of the secondary flow-diverting reaction chamber in an embodiment of the present invention;

[0030] Figure 10 This is a schematic cross-sectional view of the outlet section of the multi-stage series microchannel reactor in an embodiment of the present invention;

[0031] Figure 11 This is a schematic diagram showing the dimensions of the reaction chamber in the secondary flow splitting embodiment of the present invention. Detailed Implementation

[0032] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0033] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] It should be noted that the following description covers various aspects of embodiments within the scope of protection of this invention. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using other structures and / or functionalities besides one or more of the aspects set forth herein.

[0035] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0036] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0037] Commonly used channel structures on the market, such as Figure 1 As shown, due to the excessively large flow area below the arc-shaped baffle, the two-phase fluids decelerate before mixing in the area below the baffle after being separated. This structure... Figure 2 The vector velocity diagram shows that vortices are formed below the arc-shaped baffle. Therefore, during liquid-liquid, gas-liquid, or solid-liquid reactions, fluid accumulation or solid blockage will occur directly below the arc-shaped baffle. It is unavoidable that there is a large area of ​​stagnant boundary layer distribution below the arc-shaped baffle, which will form dead zones, reduce mixing and mass transfer efficiency, and may even cause channel blockage during solid-liquid reactions.

[0038] like Figure 3 As shown in the figure, this application provides a multi-stage series microchannel reactor M, which includes a three-way inlet unit, N secondary-way reaction chambers 2 connected in series, and an outlet unit, where N is an integer greater than or equal to 1. The interior of the microchannel reactor, except for the secondary-way reaction chambers 2, is a solid structure. The solid structure ensures that the fluid flows only through the designed channels, avoiding bypasses or stagnation zones; the absence of internal gaps improves overall stability. The three-way inlet unit, several secondary-way reaction chambers connected in series, and the outlet unit are connected along the axis and arranged symmetrically to the axis. Different states of the reaction fluid medium enter the reaction chamber from the three-way inlet unit, where the fluid collides and shears, resulting in interphase mixing, mass transfer, and diffusion.

[0039] like Figure 4 As shown, the three-phase inlet unit 1 has a first inlet 5 and a second inlet 7. The second inlet 7 is connected to the first inlet 5 through a second pipe 8. The second pipe 8 is located around the first pipe 6, and its end is connected to the end of the first pipe 6. The two-phase fluids are squeezed and mixed at the pipe outlet. Fluid A is introduced into the second pipe 8 (the outer main pipe), and fluid B is introduced into the first pipe 6, realizing sleeve-type premixing and avoiding sudden mixing that could cause local overheating / over-concentration. The outer fluid surrounds the central flow (similar to a coaxial injector), using the velocity gradient to enhance initial mixing. The two inlets independently control the flow rate to adapt to reactions with different stoichiometric ratios (e.g., A:B = 1:10 to 10:1).

[0040] The N secondary split-flow reaction chambers connected in series are arranged in multiple rows. For example... Figure 5 As shown, the two reaction chambers connected between adjacent columns are linked by U-shaped tubes 4 and arranged in reverse parallel. The U-shaped tubes 4 allow for a 180° turn, significantly reducing local resistance loss compared to right-angle bends; the reverse parallel arrangement reduces the equipment's size and footprint, making it suitable for space-constrained scenarios (such as micro-chemical plants). The inlet of the first reaction chamber is connected to the outlet of the three-way inlet unit, and the outlet of the last reaction chamber is connected to the inlet of the outlet unit.

[0041] like Figure 6 As shown, the secondary diversion reaction chamber 2 includes a fixed wall, an arc-shaped baffle 10, and two ivory-shaped diversion baffles 11.

[0042] The cavity formed by the fixed wall is heart-shaped, which maximizes the liquid holding capacity of the reaction cavity. The inlet of the reaction cavity is located in the concave center of the heart shape, and the outlet of the reaction cavity is located in the convex center of the heart shape.

[0043] The arc-shaped baffle 10 is a primary flow disruptor and is located below the feed inlet of the cavity.

[0044] Two ivory-shaped flow divider baffles 11 are secondary flow disturbance elements, symmetrically positioned below the arc-shaped baffle and above the cavity outlet. The larger end of the ivory-shaped flow divider baffles 11 is close to the arc-shaped baffle, while the tip of the ivory-shaped flow divider baffles 11 points towards the cavity outlet. The ivory-shaped flow divider baffles allow the fluid to flow along a predetermined flow path, similar in structure to a "vortex generator," thereby disrupting the stable boundary layer. The resulting vortices greatly enhance the mixing effect of the fluid, ensuring thorough mixing. CFD simulations using different sizes of the ivory-shaped flow divider baffles reveal a channel structure with excellent mixing performance and minimal flow resistance.

[0045] The shortest distance between the upper surface of the ivory-shaped diversion baffle and the lower arc surface of the arc-shaped baffle is greater than the shortest distance between the lower surface of the ivory-shaped diversion baffle and the fixed wall.

[0046] The arc-shaped baffle, the ivory-shaped diversion baffle, and the inner wall of the fixed wall form a mixing channel. The mixing channel includes a primary shearing diversion section 12, a deceleration section 13, a secondary collision diversion section 14, a collision and extrusion section 15, a buffer section 16, and a recombination and mixing section 17.

[0047] The upper arc surface of the arc-shaped baffle and the inner wall of the fixed wall form a primary shearing and diversion section 12. In the primary shearing and diversion section, at least two fluids converge and are compressed into a mixed fluid at the outlet through the three-way inlet unit. The mixed fluid forms a jet at the inlet of the cavity. The fluid impacts the arc-shaped baffle 10 at high speed, and the mixed fluid is accelerated and sheared by collision. The mixed fluid is divided into two and flows to the two side channels (deceleration section 13).

[0048] The lower arc surface of the arc-shaped baffle and the inner wall of the fixed wall constitute the deceleration section 13. In the deceleration section 13, the fluid flows through the waist area of ​​the channels on both sides, the channels widen, the flow velocity decreases, and the fluid mixes, recombines and accumulates in this area.

[0049] The upper part of the ivory-shaped diversion baffle and the lower arc surface of the arc-shaped baffle form a secondary collision diversion section 14. In the secondary collision diversion section 14, the mixed and recombined fluid collides with the front end of the ivory-shaped diversion baffle, improving the fluid mixing intensity and mass transfer efficiency. As the channel narrows, the fluid is squeezed and accelerated to flow towards the channels on both sides of the ivory-shaped diversion baffle, increasing the fluid velocity and forcing the fluids to contact and penetrate each other, further improving the mixing effect.

[0050] The lower arc surface directly below the arc-shaped baffle and the upper surface of the ivory-shaped diverting baffle constitute the collision and compression section 15. In the collision and compression section, the fluid flowing through the upper part of the ivory-shaped diverting baffle undergoes collision, compression, and mixing directly below the arc-shaped baffle, as shown in the streamline velocity diagram ( Figure 9 The velocities of the fluids are relatively close) and the vector velocity contour map ( Figure 7 (Dense distribution of medium velocity vectors), vector phase diagram ( Figure 8As can be seen from the dense distribution of the vectors of each phase, the fluid after being diverted by the arc-shaped baffle does not generate eddies below the baffle, and the mixed fluid does not stagnate in the collision and extrusion section 15. This can eliminate the dead zone phenomenon formed by the heart-shaped structure channel below the baffle, and keep the fluid after the collision and extrusion mixing on both sides moving towards the next stage of the reaction chamber.

[0051] The lower part of the ivory-shaped diverting baffle 11 and the inner wall of the fixed wall form a buffer section 16. In the buffer section 16, after secondary collision diversion, the fluid accelerates and flows into the reaction zone between the lower end of the ivory-shaped diverting baffle and the fixed wall, where the flow velocity decreases and the fluid is buffered and accumulated. Below the ivory-shaped diverting baffle 11 is a high-speed flow field, which effectively solves the problem that the stagnant boundary layer distributed on the fixed wall surface is difficult to diffuse, mix and transfer to the high-speed flow field.

[0052] The lower parts of the two ivory-shaped diversion baffles 11 and the inner wall of the fixed wall constitute the recombining and mixing section 17. In the recombining and mixing section 17, the fluid from between the two ivory-shaped diversion baffles 11 undergoes recombining, mixing, and compression contact with the two side walls of the lower fixed wall, further improving the contact mixing efficiency between the fluids and enhancing the mass transfer between the fluids. After recombining and mixing, the fluid flows out of the reaction chamber and enters the downstream reaction chamber.

[0053] like Figure 6 As shown, the mixing channel utilizes a variable diameter channel structure multiple times, thus forming a Venturi nozzle-like structure. This increases the flow velocity, enhances the mixing efficiency and mass transfer effect, promotes fluid flow along the walls, and minimizes the width of the stagnant boundary layer. Within the reaction chamber, the fluid undergoes multiple collisions and mixing processes through the arrangement of baffles, improving the mixing quality and effect. The ivory-shaped diverting baffles prevent the high-speed fluid from accumulating and forming eddies when it reaches the lower part of the reaction channel, while simultaneously increasing the intensity of interphase mixing and mass transfer, preventing the formation of a wide stagnant boundary layer at this location.

[0054] The shortest distance between the upper surface of the ivory-shaped diversion baffle and the lower arc surface of the curved baffle is greater than the shortest distance between the lower surface of the ivory-shaped diversion baffle and the fixed wall. Symmetrical ivory-shaped diversion baffles are installed below the curved baffle. After being squeezed, mixed, and diverted by the curved baffles, the fluid flows to the two side channels, widening the channels and reducing the fluid velocity. The fluid impacts the front end of the ivory-shaped diversion baffles, enhancing the secondary mixing intensity. Because the shortest distance between the upper surface of the ivory-shaped diversion baffle and the lower arc surface of the curved baffle is greater than the shortest distance between the lower surface of the ivory-shaped diversion baffle and the fixed wall, the fluid flows as much as possible to the upper part of the ivory-shaped diversion baffles. After being squeezed and mixed at the upper part of the symmetrical ivory-shaped diversion baffles, the fluid flows downwards, colliding and mixing with the fluid at the lower part of the ivory-shaped diversion baffles before flowing to the next stage reaction chamber. This prevents fluid accumulation and dead zone effects at this point.

[0055] The outlet of the last reaction chamber 2 is connected to the inlet of the outlet unit 3. For example... Figure 10 As shown, the outlet end 9 of the outlet unit 3 is used for material discharge.

[0056] The aforementioned multi-stage series microchannel reactor enhances fluid mixing intensity within the channels through a secondary diversion structure comprised of arc-shaped baffles and ivory-shaped diversion baffles. After diversion by the secondary ivory diversion structure, the fluid collides and contacts below the diversion baffles before flowing to the next stage reaction chamber, eliminating the flow dead zone below the diversion baffles. This stabilizes the flow of the reaction fluid within the microchannels, further improving mixing and mass transfer efficiency.

[0057] Moreover, the secondary flow splitting structure causes the entire reaction channel in the reaction chamber to be distributed in an S-shape (snake-like) on the reaction plate, which reduces the volume occupied by the reaction chamber in the entire microreactor, increases the length of the reaction channel, improves the liquid holding capacity of the reaction chamber, and ensures good mixing and mass transfer between the reaction fluids.

[0058] In addition, the secondary flow splitting structure also forms multiple flow channels that narrow and then widen within the reaction chamber to accelerate the flow velocity and achieve a jet effect. This causes the reacting fluids to collide with the baffles at high speed, resulting in turbulence. This not only improves the mixing effect of the fluids and the magnitude of intermolecular diffusion, ensuring uniform mixing and improving mass transfer efficiency, but also increases space utilization.

[0059] In one embodiment, such as Figure 6 As shown, the ivory-shaped flow divider has a spherical end and a conical end, connected by a smooth arc. The spherical end is larger than the conical end, forming the larger end of the ivory-shaped flow divider. The spherical end helps increase the collision area of ​​the fluid, improving the mixing intensity and mass transfer efficiency. The conical end reduces the volume occupied by the ivory-shaped flow divider within the cavity space, increasing the flow channel area in the middle and on both lower sides of the two ivory-shaped flow dividers. Therefore, during the reorganization, mixing, and compression contact of the liquid, the contact mixing efficiency between the fluids is further improved.

[0060] In one embodiment, such as Figure 6 As shown, the upper and lower arc surfaces of the arc-shaped baffle are parallel, and the two ends of the baffle are smoothly connected by an arc. The wall thickness of the entire arc-shaped baffle is constant, the stress is reasonably distributed, and the cross-sectional area of ​​the flow channel is also stable.

[0061] In one embodiment, such as Figure 11As shown, under low flow rate conditions, the ratio of the shortest distance *d* between the upper surface of the ivory-shaped diverter baffle and the lower arc surface of the curved baffle to the shortest distance *e* between the lower surface of the ivory-shaped diverter baffle and the fixed wall is 1.1 to 1.2. Flow rate flux refers to the flux level achieved by the system under different flow rate conditions; low flow rate flux refers to the liquid flux measured at a relatively low feed flow rate (e.g., 0-40 ml / min).

[0062] Under high flow rate conditions, the ratio of the shortest distance d between the upper surface of the ivory-shaped diverter baffle and the lower arc surface of the arc-shaped baffle to the shortest distance e between the lower surface of the ivory-shaped diverter baffle and the fixed wall is between 1.2 and 1.4. High flow rate refers to the liquid flux measured at a relatively high feed flow rate (e.g., 100-200 ml / min).

[0063] In one embodiment, such as Figure 11 As shown, the ratio of the furthest distance b at the head end of the two symmetrical ivory-shaped diversion baffles to the length of the maximum width a in the reaction chamber ranges from 0.4 to 0.6, and the ratio of b:a is preferably 0.5.

[0064] In one embodiment, the length ratio of the minimum distance c between the tail ends of the two symmetrical ivory-shaped diversion baffles to the minimum width k of the cavity outlet ranges from 1.8 to 2.2, and the c:k ratio is preferably 2.

[0065] In one embodiment, the ratio of the length f of the ivory-shaped diversion baffle to the distance h from the vertex of the lower arc surface of the arc-shaped baffle to the outlet of the cavity is in the range of 0.40 to 0.50, and the ratio of f:h is preferably 0.45.

[0066] Test Implementation Examples

[0067] Using the Villermaux-Dushman method, the microchannel reactor of this application was tested three times consecutively (referred to as Examples 1-3), and the mixing effect was compared with that of a conventional microchannel reactor (referred to as Comparative Example 1). The specific process is as follows:

[0068] Solution A is prepared by using deionized water and removing the oxygen with nitrogen gas. It is an aqueous solution of potassium iodide, potassium iodate, sodium hydroxide, and boric acid with molar concentrations of 0.032 mol / L, 0.006 mol / L, 0.09 mol / L, and 0.09 mol / L, respectively.

[0069] Solution B is prepared by using deionized water and nitrogen gas to remove the oxygen: it is a 98% sulfuric acid solution diluted to a 0.03 mol / L dilute sulfuric acid solution.

[0070] Using syringe pump one, solution A was pumped into the microreactor at a flow rate of 20 mL / min through the first inlet. After stabilization, solution B was pumped into the microreactor at a flow rate of 20 mL / min through the second inlet using syringe pump two. After the system stabilized, a sample was taken at the outlet and measured using a UV spectrophotometer at a wavelength of 353 nm. 3- Concentration, I 3- The concentration level indicates the degree of imperfection in the mixing.

[0071] To more accurately quantify the mixing effect, a mixing factor Xs (0 ≤ Xs ≤ 1) is defined as a standard to characterize the degree of ideality of the mixture.

[0072] Xs= Where Y represents the ratio of the number of protons consumed in the redox reaction to the total number of protons initially added to the reaction system:

[0073] Y=

[0074] Y ST The value of Y represents the infinitely slow mixing condition: Y ST =

[0075] When the mixing is perfectly ideal, Xs=0; when the mixing is infinitely slow, Xs=1. The table below records the parameter settings and Xs values ​​for the examples and comparative examples.

[0076]

[0077] Compared with Comparative Example 1, the three test results X of the embodiment were different. S The value is significantly smaller than that of the comparative example, which indicates that the effect of the embodiment is significantly better than that of the comparative example.

[0078] Therefore, this embodiment effectively solves the problem of a wide and large-area stagnant boundary layer below the arc-shaped baffle in the heart-shaped microchannel by arranging secondary flow dividers, further improving the fluid collision and compression mixing intensity. The secondary collision, flow division, and compression by the ivory-shaped flow dividers greatly improves mass transfer efficiency, making it more applicable under low-flow-rate reaction conditions, resulting in better mixing and reducing the likelihood of fluid residue accumulation and dead zones. High-speed flow fields exist on both sides of the ivory-shaped flow dividers, solving the problem of the stagnant boundary layer distributed on the wall surface being difficult to diffuse, mix, and transfer mass into the high-speed flow field.

[0079] This embodiment utilizes an inlet jet to continuously collide, shear, split, decelerate, recombine, break up, split, convect, compress, and recombine the fluid, increasing the solid-liquid contact area, enhancing the diffusion rate of molecules in each phase, and efficiently strengthening the fluid mixing efficiency, thereby achieving rapid mixing between the phases. By repeatedly employing the Venturi effect, the fluid flow velocity is increased, accelerating the mixing and contact efficiency between fluids.

[0080] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A two-stage flow-diverting reaction chamber, characterized in that, include: The fixed wall forms a heart-shaped cavity space. The inlet of the reaction cavity is located in the recessed part of the heart shape, and the outlet of the reaction cavity is located in the protruding part of the heart shape. An arc-shaped baffle is disposed below the feed inlet of the cavity; Two ivory-shaped diversion baffles are symmetrically arranged below the arc-shaped baffle and above the discharge port of the cavity. The larger end of the ivory-shaped diverting baffle is close to the arc-shaped baffle, and the tip of the ivory-shaped diverting baffle points towards the discharge port of the cavity. The shortest distance between the upper surface of the ivory-shaped diversion baffle and the lower arc surface of the arc-shaped baffle is greater than the shortest distance between the lower surface of the ivory-shaped diversion baffle and the fixed wall. Under low flow rate conditions, the ratio of the shortest distance d between the upper surface of the ivory-shaped diverting baffle and the lower arc surface of the arc-shaped baffle to the shortest distance e between the lower surface of the ivory-shaped diverting baffle and the fixed wall is 1.1 to 1.

2. Under high flow rate conditions, the ratio of the shortest distance d between the upper surface of the ivory-shaped diverting baffle and the lower arc surface of the arc-shaped baffle to the shortest distance e between the lower surface of the ivory-shaped diverting baffle and the fixed wall is between 1.2 and 1.

4.

2. The two-stage diversion reaction chamber according to claim 1, characterized in that, The ivory-shaped diversion baffle has a spherical end and a conical end at its two ends, which are connected by a smooth arc.

3. The two-stage diversion reaction chamber according to claim 1, characterized in that, The upper and lower arc surfaces of the arc-shaped baffle are parallel, and the two ends of the arc-shaped baffle are smoothly connected by an arc.

4. The two-stage diversion reaction chamber according to claim 1, characterized in that, The ratio of the furthest distance b at the head of the two symmetrical ivory-shaped diversion baffles to the length of the maximum width a inside the reaction chamber ranges from 0.4 to 0.

6.

5. The two-stage diversion reaction chamber according to claim 1, characterized in that, The ratio of the minimum distance c between the tail ends of the two symmetrical ivory-shaped diversion baffles to the length of the minimum width k of the cavity outlet ranges from 1.8 to 2.

2.

6. The two-stage diversion reaction chamber according to claim 1, characterized in that, The ratio of the length f of the ivory-shaped diversion baffle to the distance h from the vertex of the lower arc surface of the arc-shaped baffle to the outlet of the cavity is in the range of 0.40~0.

50.

7. A multi-stage series microchannel reactor, characterized in that, include: A three-way inlet unit; N secondary diversion reaction chambers as described in any one of claims 1 to 6, connected in series, wherein N is an integer greater than or equal to 1; One export unit; The three-stage inlet unit, the N series-connected secondary-stage reaction chambers, and the outlet unit are connected in sequence. The inlet of the first reaction chamber is connected to the outlet of the three-way inlet unit, and the outlet of the last secondary-way reaction chamber is connected to the inlet of the outlet unit. Except for the reaction chamber of the secondary diversion, the interior of the microchannel reactor is a solid structure.

8. The multi-stage series microchannel reactor according to claim 7, characterized in that, The N secondary flow reaction chambers connected in series are arranged in multiple rows. The two secondary flow reaction chambers connected to each other in adjacent rows are connected by U-shaped tubes and arranged in opposite parallel directions.

9. The multi-stage series microchannel reactor according to claim 7, characterized in that, The three-phase inlet unit has a first inlet and a second inlet; the second inlet is connected to the first inlet through a second pipeline, the second pipeline is located outside the first pipeline, and the end of the second pipeline is connected to the end of the first pipeline, and the two-phase fluids are squeezed, contacted and mixed with each other at the pipeline outlet.

Images