A continuous flow microchannel reactor

Abstract

The application discloses a continuous flow microchannel reactor and relates to the technical field of microreactors.The application comprises a first reaction plate, the outer side of the first reaction plate is fixedly connected with a first heat exchange plate, the inner side of the first reaction plate is fixedly connected with a partition plate, one side of the partition plate is fixedly connected with a second reaction plate, the bottom side of the second reaction plate is fixedly connected with a second heat exchange plate; one side of the first reaction plate is provided with a first microchannel, the side edge of the first heat exchange plate is provided with a first feeding port, a second feeding port and a sample port, the first feeding port, the second feeding port and the sample port are all in communication with the first microchannel, the second reaction plate is provided with a second microchannel, the second microchannel is in communication with the first microchannel, and the first microchannel and the second microchannel are uniformly arranged with a plurality of buffer reaction units. The double-layer reaction plate provided with the partition plate is arranged, the buffer reaction units are matched with the reaction speed and the mixing of reactants, and therefore the quality of reaction products is improved.

Description

Technical Field

[0001] This invention relates to the field of microreactor technology, and more specifically to a continuous flow microchannel reactor. Background Technology

[0002] A continuous microfluidic reactor is a miniature device used for chemical reactions. It consists of microchannels, typically composed of channels at the micrometer level, which possess high specific surface area and high heat and mass transfer efficiency. In a continuous microfluidic reactor, reactants pass continuously through the microchannels, contacting catalysts or other reactants to carry out a chemical reaction.

[0003] The patent specification with publication number CN112973596A discloses a microchannel continuous flow reactor. The reactor includes a lower plate, a catalyst carrier, an upper plate, and a catalyst support plug. A first channel groove is formed on the upper surface of the lower plate, and the catalyst carrier is installed in the first channel groove. A second channel groove corresponding to the first channel groove is formed on the lower surface of the upper plate. The lower plate and the upper plate are clamped together by a tooling fixture. The first channel groove and the second channel groove form a microchannel. The upper plate has several threaded holes that extend from the upper surface of the upper plate to the second channel groove. The sealing thread of the catalyst support plug is screwed into the threaded hole to press the catalyst carrier to the bottom of the first channel groove.

[0004] The shortcomings of this technical solution are as follows: First, the reactants in this microfluidic reactor are added at the inlet, and the catalyst is added in segments along the microchannel path through which the reactor flows. This is because the microchannel is in the form of a single-layer straight tube, resulting in a short reaction time. The reaction time is compensated for by adding the catalyst segment by segment. However, this reaction method is still limited by the length of the single-layer straight tube, and there is a possibility of incomplete reaction. In addition, because the catalyst is added segment by segment, the reaction process is essentially a segmented reaction. Segmented reaction leads to uneven reaction at different points, resulting in unstable quality of the finished product. Finally, the reactor generates a large amount of heat during the reaction. The reactor is clamped by two plates for the microchannel. As the reaction progresses, the residual heat from the reaction of the catalyst and reactants in the microchannel reacts back into the reaction process. Temperature change is a very important factor affecting the reaction process. The upper and lower plates of this reactor are both flat and cannot provide heat dissipation channels. In actual use, heat dissipation cannot be effectively carried out, affecting the normal progress of the reaction and reducing the yield of the finished product. Summary of the Invention

[0005] The purpose of this invention is to provide a continuous flow microchannel reactor. The technical problem to be solved is as follows: In order to adapt to the short straight tube single-layer channel, the existing microflow reactor adopts a reaction method of adding catalyst in stages during the reaction. However, it cannot effectively dissipate heat during the reaction, resulting in insufficient reaction and low yield and unstable quality of the final product.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A continuous flow microchannel reactor includes a first reaction plate, a first heat exchange plate fixedly connected to the outer side of the first reaction plate, a partition fixedly connected to the inner side of the first reaction plate, a second reaction plate fixedly connected to one side of the partition plate, and a second heat exchange plate fixedly connected to the bottom side of the second reaction plate. A first microchannel is provided on one side of the first reaction plate, and a first inlet, a second inlet, and a sample inlet are provided on the side of the first heat exchange plate. The first inlet, the second inlet, and the sample inlet are all connected to the first microchannel. The sample inlet is used to detect the reaction state and calibrate the reaction solution ratio. A second microchannel is provided on the second reaction plate and is connected to the first microchannel. A plurality of buffer reaction units are evenly arranged in the first microchannel and the second microchannel. The buffer reaction units are used to improve the reaction saturation.

[0008] As a further aspect of the present invention: the first feed inlet and the sample inlet are disposed on one side of the first heat exchange plate, the second feed inlet is disposed on the adjacent side of the first feed inlet, the first reaction plate is adapted to have three injection holes for the first feed inlet, the second feed inlet and the sample inlet, one end of the first microchannel is provided with a feed channel, the feed channel is provided with two sub-channels, and the two injection holes connected to the first feed inlet and the second feed inlet are respectively connected to the two sub-channels.

[0009] As a further aspect of the present invention: a sample channel is provided on one side of the middle section of the first microchannel, the end of the sample channel is connected to the injection hole, and the injection hole is connected to the sample port, and the diameter of the first microchannel port is 600 micrometers to 2 millimeters.

[0010] As a further aspect of the present invention: both the first microchannel and the second microchannel are continuous reciprocating bent pipes, and the buffer reaction unit includes a partition block, with liquid distribution channels provided on both sides of the partition block.

[0011] As a further aspect of the present invention: the partition block is crescent-shaped, the liquid distribution channel is arranged in an arc around both sides of the partition block, and the concave side of the partition block is close to the inflow end of the reaction liquid.

[0012] As a further aspect of the present invention: a flow exchange channel is provided at the end of the first microchannel, a flow exchange hole is provided on the partition plate, the flow exchange channel is connected to the flow exchange hole, a receiving channel is provided on one side of the second microchannel, the receiving channel is connected to the bottom end of the flow exchange hole, a liquid outlet channel is provided at the end of the second microchannel, a liquid outlet hole is provided at the end of the liquid outlet channel, and a liquid outlet is provided on the second heat exchange plate adapted to the liquid outlet hole.

[0013] As a further aspect of the present invention: the first heat exchange plate, the first reaction plate, the partition plate, the second reaction plate and the second heat exchange plate are provided with support holes through the coaxial center line on both sides, and a support tube is installed in the support hole, and airflow is provided in the support tube.

[0014] As a further aspect of the present invention: the first heat exchange plate and the second heat exchange plate are provided with heat dissipation cavities on the side near the partition, both of the support holes penetrate the heat dissipation cavities, and the two ends of the support tube are adapted to the heat dissipation cavities on adjacent sides and are provided with heat dissipation hole groups.

[0015] As a further aspect of the present invention: both the first reaction plate and the second reaction plate are made of silicon carbide.

[0016] The beneficial effects of this invention are:

[0017] 1. In this invention, a first reaction plate is fixedly connected to one side of the first heat exchange plate, a partition is fixedly connected to one side of the first reaction plate, and a second reaction plate and a second heat exchange plate are sequentially connected to the other side of the partition. Reactants and catalysts are injected into the first microchannel in the first reaction plate through the first feed port and the second feed port. After the reaction occurs, the reactants flow into the second microchannel of the second reaction plate, realizing a double-channel reaction in the reactor, extending the reaction channel, and making the reaction more complete.

[0018] 2. In this invention, both the first and second microchannels are continuous reciprocating curved channels, and uniformly distributed buffer reaction units are set in the path of the microchannels. By setting crescent-shaped partition blocks and liquid distribution channels that split along both sides of the partition blocks in the buffer reaction units, the reaction mixture is continuously mixed along the arc-shaped liquid distribution channels after being decelerated, thereby prolonging the reaction time and increasing the contact rate between the reactants and the catalyst, and further improving the reaction saturation.

[0019] 3. In this invention, a sample inlet is provided at the first heat exchange plate and is connected to the middle section of the first microchannel. During the overall reaction process, the reactants and catalyst are injected synchronously through the first and second feed inlets, and then a continuous and uninterrupted double-layer reaction is carried out. During this period, the reaction status is monitored and the ratio of the reaction mixture is adjusted through the sample inlet in the early stage of the reaction. This not only maintains the continuity of the reaction and ensures the stability of the quality of the reaction product, but also provides detection and calibration functions for the reaction.

[0020] 4. In this invention, support holes are vertically provided on both sides of the reactor, and support pipes with heat dissipation hole groups are installed in the support holes. The first heat exchange plate and the second heat exchange plate are provided with heat dissipation chambers, and the heat dissipation chambers and heat dissipation hole groups are connected. By introducing air into the support pipe, the heat generated by the reaction in the reactor is continuously discharged. Combined with the high thermal conductivity of silicon carbide and the isolation of the double reaction layer by the partition, the reaction process is more stable. Attached Figure Description

[0021] The invention will now be further described with reference to the accompanying drawings.

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 This is a partial exploded view of the first heat exchange plate and the first reaction plate of the present invention;

[0024] Figure 3 This is a schematic diagram of the partition structure of the present invention;

[0025] Figure 4 This is a partial exploded view of the second reaction plate and the second heat exchange plate of the present invention;

[0026] Figure 5 This is the present invention. Figure 4 Enlarged detail view of point A in the middle;

[0027] Figure 6 This is a partial cross-sectional view of the mounting support tube of the present invention;

[0028] Figure 7 This is the present invention. Figure 6 A magnified view of the details at point B in the middle.

[0029] In the diagram: 1. First heat exchange plate; 2. First feed inlet; 3. Second feed inlet; 4. Sample inlet; 5. First reaction plate; 6. First microchannel; 7. Feed channel; 8. Sample channel; 9. Flow exchange channel; 10. Baffle plate; 11. Flow exchange hole; 12. Second reaction plate; 13. Second microchannel; 14. Flow receiving channel; 15. Liquid outlet channel; 16. Second heat exchange plate; 17. Liquid outlet; 18. Buffer reaction unit; 181. Partition block; 182. Liquid distribution channel; 19. Heat dissipation cavity; 20. Support hole; 21. Support tube; 22. Heat dissipation hole group. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] like Figures 1 to 7 As shown, a continuous flow microchannel reactor includes a first heat exchange plate 1. The first heat exchange plate 1 has a first feed inlet 2 and a second feed inlet 3 respectively set on the two sides of one corner. The first feed inlet 2 and the second feed inlet 3 are reactant addition port and catalyst addition port respectively. The reactant and catalyst are both fluids. A sample port 4 is set at the middle position on the same side of the first feed inlet 2.

[0032] like Figure 1 and Figure 2 As shown, a first reaction plate 5 is fixedly connected to the bottom surface of the first heat exchange plate 1. The top of the first reaction plate 5 is a flat plate structure. A first microchannel 6 is set in the middle of the bottom surface away from the first heat exchange plate 1. The first microchannel 6 has an inlet channel 7 adapted to be opened below the first inlet 2 and the second inlet 3. The inlet channel 7 is opened at the beginning of the first microchannel 6. The inlet channel 7 is provided with two sub-channels. The first reaction plate 5 is adapted to have two inlets above the two ports of the inlet channel 7, and injection holes are opened respectively, so that reactants and catalysts can be injected from the first inlet 2 and the second inlet 3 and converge in the inlet channel 7. The ends of the inlet channels 7 away from the inlet position converge with each other, and the reactants and catalysts are injected into the first microchannel 6 for reaction.

[0033] It should be noted that the first inlet 2, the second inlet 3, and the sample inlet 4 all penetrate the first heat exchange plate 1, and their diameters are the same as those of the connected first microchannel 6, ranging from 800 micrometers to 1.5 millimeters. The smaller diameter of the microchannel is beneficial for achieving a reaction environment with high specific surface area and high heat and mass transfer efficiency. Therefore, the diameter of the pipes for adding reactants and catalysts is also smaller, which can provide a higher reaction rate and better mixing effect. Since the sample inlet 4 is located in the middle of the first half of the reaction process, it allows for the extraction of the reaction liquid that has reacted by 1 / 4 for testing. The test port is used to determine whether the reaction is proceeding normally, so as to stop the reaction in time and achieve the purpose of preventing losses. On the other hand, since the addition of the first feed port 2 and the second feed port 3 is continuous and uninterrupted, the reaction liquid can be tested at the test port 4 to determine whether additional reactants or catalysts are needed to maintain the normal progress of the reaction. This serves as an adjustment window to improve the accuracy of the reaction and maintain the quality of the reaction product. That is, the test port 4 can be used as a test port for the reaction progress and as a calibration position for adjusting the balance of the reaction liquid, thereby providing a test function for timely loss prevention and a calibration function for generating a more stable product.

[0034] An injection port 4 is provided on one side of the top of the first reaction plate 5, and this injection port is connected to the bottom of the sample port 4. A sample channel 8 is provided on one side of the middle of the first microchannel 6. The bottom of the injection port of the sample port 4 is connected to the outer end of the sample channel 8. Therefore, the staff can extract the reaction liquid that has traveled to the middle section of the first microchannel 6 through the sample port 4, or add reactants or catalysts to the first microchannel 6, so as to realize the aforementioned testing and calibration function of the sample port 4. A flow exchange channel 9 is provided on the side of the first microchannel 6 away from the feed channel 7.

[0035] like Figure 3 and Figure 4 As shown, a partition plate 10 is fixedly connected to the bottom surface of the first reaction plate 5. A flow exchange hole 11 is opened at the end of the flow exchange channel 9 adapted to the partition plate 10. A second reaction plate 12 is fixedly connected to the bottom surface of the partition plate 10. A second microchannel 13 is opened on the side of the second reaction plate 12 near the partition plate 10. A receiving channel 14 is provided at one end of the second microchannel 13. One end of the receiving channel 14 is connected to the bottom surface of the flow exchange hole 11 and is used to receive the reaction liquid in the first microchannel 6 for continuous reaction. A liquid outlet channel 15 is provided at the end of the second microchannel 13. A liquid outlet hole is provided at the end of the liquid outlet channel 15. A second heat exchange plate 16 is fixedly connected to the bottom surface of the second reaction plate 12. A liquid outlet 17 is provided on one side of the second heat exchange plate 16 and is connected to the liquid outlet hole and is used to discharge the reaction liquid after the reaction is completed. It should be noted that since the overall structure of the reactor is a double-layer reaction channel, the reaction on both sides is isolated by the partition plate 10 to increase the distance between the reaction layers and prevent the reaction from being concentrated and overheated, which would affect the stability of the reaction process.

[0036] like Figure 2 , Figure 4 and Figure 5 As shown, the first microchannel 6 and the second microchannel 13 have the same overall structure, both consisting of continuous reciprocating bends within a flat surface. Buffer reaction units 18 are evenly arranged within the channels. A partition block 181 is positioned at the center of each buffer reaction unit 18, and liquid distribution channels 182 are symmetrically arranged on both sides of the partition block 181. It should be noted that the partition block 181 is crescent-shaped; the concave side of the partition block 181 is the inlet end of the catalyst and reactant mixture, while the convex side is the outlet end. Simultaneously, the buffer... The liquid distribution channels 182 on both sides of the reaction unit 18 split the liquid from one side of the inlet end until they merge at the outlet end. When the mixed liquid enters the concave side of the partition block 181, the flow rate is slowed down. Then it enters the liquid distribution channels 182 on both sides. After being slowed down, the mixed liquid enters the liquid distribution channel 182 set along the outside of the partition block 181 and undergoes continuous mixing in different directions. Thus, through slowing down and thorough mixing, the reactants and catalysts are fully mixed, thereby improving the contact rate of reactants and catalysts in the reaction liquid.

[0037] like Figure 2 and Figure 4 As shown, heat dissipation cavities 19 are opened on the side of the first heat exchange plate 1 and the second heat exchange plate 16 near the partition plate 10. The heat dissipation cavity 19 has a square structure. Since the heat exchange plates are attached to the adjacent reaction plates, and since the reaction plates and heat exchange plates are made of silicon carbide with high thermal conductivity, the heat generated during the reaction inside the reaction plate will be conducted to the heat dissipation cavity 19 through the silicon carbide plate, which is convenient for subsequent discharge.

[0038] like Figure 1 , Figure 6 and Figure 7As shown, each layer of the reactor has coaxial support holes 20 of the same diameter on both vertical sides. It should be noted that the support holes 20 are located inside the heat dissipation cavity 19. A support tube 21 is installed inside the support hole 20, which is used to fix the reactor in place. The support tube 21 is hollow and filled with circulating air by an air pump. At both ends of the support tube 21, at the same horizontal plane as the heat dissipation cavity 19, heat dissipation hole groups 22 are formed. These heat dissipation hole groups 22 are evenly arranged along the annular direction of the support tube 21. Because the support holes 20 are located inside the heat dissipation cavity 19, the support holes 20 are located within the heat dissipation cavity 19. The support tube 21 is connected to the heat dissipation cavity 19 at its location. Therefore, when air is injected into the support tube 21, it will carry away the heat in the connected heat dissipation cavity 19, thereby achieving continuous heat dissipation of the reactor. Preferably, the heat dissipation holes are arranged obliquely to reduce the entry of external impurities into the pipe and extend the service life of the pipe. It should be noted that since the side of the reaction plate containing microchannels is in contact with the partition plate 10, and the heat dissipation surface is not connected to the microchannels where the reaction is taking place, the heat dissipation is achieved by the high thermal conductivity of silicon carbide and the continuous ventilation of the heat dissipation cavity 19, which ensures heat dissipation efficiency and avoids interference with the reaction process.

[0039] Working principle: During the reaction, reactants and catalyst are injected into the first inlet 2 and the second inlet 3 of the reactor, respectively. The reactants and catalyst enter the two sub-channels in the feed channel 7 and converge into the first microchannel 6. By pressurizing, the mixture of reactants and catalyst in the first microchannel 6 travels along the pipeline. During this travel, it is buffered and mixed by the buffer reaction unit 18, ensuring that the reaction proceeds fully. The reaction continues until the end of the first microchannel 6, and then passes through the exchange hole 11, the baffle 10, and the second reaction plate 12. It then enters the second microchannel 13 through the receiving channel 14, where a second layer of further reaction takes place until it is discharged from the outlet 17. During this process, the operator can use the sample port 4 to detect the reaction liquid when it reaches 1 / 4 of the reaction progress, thereby judging the reaction progress. Whether the reaction is proceeding normally or requires replenishment of catalyst and reactants, the reactor continuously dissipates heat through the internal ventilation support pipe 21 to ensure stable reaction. It should be noted that the reactor adopts a double-layer uninterrupted reaction mode, and the reaction mixture is variable-speed and thoroughly mixed through the buffer reaction unit 18, which extends the reaction path length and increases the contact rate of reactants, thereby making the reaction more thorough and the product quality higher. At the same time, by setting heat dissipation chambers 19 inside the two heat exchange plates and connecting the heat dissipation chambers 19 to the support pipe 21, and by continuously ventilating the support pipe 21, the heat generated during the reaction is continuously discharged. Combined with the high thermal conductivity of silicon carbide and the barrier of the double reaction layer by the partition 10, the reaction quality is improved while maintaining the stability of the reaction.

[0040] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A continuous flow microchannel reactor comprising a first reaction plate (5), characterized in that, A first heat exchange plate (1) is fixedly connected to the outer side of the first reaction plate (5), and a partition plate (10) is fixedly connected to the inner side of the first reaction plate (5). A second reaction plate (12) is fixedly connected to one side of the partition plate (10), and a second heat exchange plate (16) is fixedly connected to the bottom side of the second reaction plate (12). A first microchannel (6) is provided on one side of the first reaction plate (5), and a first feed inlet (2), a second feed inlet (3), and a sample inlet (4) are provided on the side of the first heat exchange plate (1). The inlet (2), the second inlet (3), and the sample inlet (4) are all connected to the first microchannel (6). The sample inlet (4) is used to detect the reaction state and calibrate the reaction solution ratio. The second reaction plate (12) is provided with a second microchannel (13), which is connected to the first microchannel (6). The first microchannel (6) and the second microchannel (13) are evenly arranged with a number of buffer reaction units (18). The buffer reaction units (18) are used to improve the reaction saturation. The first feed inlet (2) and the sample inlet (4) are located on one side of the first heat exchange plate (1), and the second feed inlet (3) is located on the adjacent side of the first feed inlet (2). The first reaction plate (5) is adapted to have three injection holes for the first feed inlet (2), the second feed inlet (3) and the sample inlet (4). One end of the first microchannel (6) is provided with a feed channel (7). The feed channel (7) is provided with two sub-channels, and the two injection holes connected by the first feed inlet (2) and the second feed inlet (3) are respectively connected to the two sub-channels. A sample channel (8) is provided on one side of the middle section of the first microchannel (6). The end of the sample channel (8) is connected to the injection hole, and the injection hole is connected to the sample port (4). The diameter of the opening of the first microchannel (6) is 600 micrometers to 2 millimeters. The first microchannel (6) and the second microchannel (13) are both continuous reciprocating bent pipes. The buffer reaction unit (18) includes a partition block (181), and liquid distribution channels (182) are provided on both sides of the partition block (181). The partition block (181) is crescent-shaped, and the liquid distribution channel (182) is arranged in an arc around both sides of the partition block (181). The concave side of the partition block (181) is close to the inflow end of the reaction liquid. The first microchannel (6) is provided with a flow exchange channel (9) at its end, and the partition plate (10) is provided with a flow exchange hole (11). The flow exchange channel (9) is connected to the flow exchange hole (11). The second microchannel (13) is provided with a flow receiving channel (14) on one side. The flow receiving channel (14) is connected to the bottom end of the flow exchange hole (11). The second microchannel (13) is provided with a liquid outlet channel (15) at its end. The liquid outlet channel (15) is provided with a liquid outlet hole at its end. The second heat exchange plate (16) is adapted to the liquid outlet hole and is provided with a liquid outlet (17). The first heat exchange plate (1), the first reaction plate (5), the partition plate (10), the second reaction plate (12) and the second heat exchange plate (16) are provided with support holes (20) on both sides at the coaxial center line. A support tube (21) is installed in the support hole (20) and an airflow is provided in the support tube (21). The first heat exchange plate (1) and the second heat exchange plate (16) are provided with heat dissipation cavity (19) on the side near the partition (10), and the two support holes (20) penetrate the heat dissipation cavity (19). The two ends of the support tube (21) are adapted to the heat dissipation cavity (19) on the adjacent side and are provided with heat dissipation hole group (22).

2. A continuous flow microchannel reactor according to claim 1, wherein, Both the first reaction plate (5) and the second reaction plate (12) are made of silicon carbide.

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