A two-dimensional main-side mixing structure of microchannels

Abstract

The present invention discloses a two-dimensional main-bypass hybrid microchannel structure, which includes two microchannels, namely the main channel and the bypass channel. The main channel and the bypass channel converge at the mixing point. The angle between the direction of the main channel before entering the mixing point and the direction of the outlet after mixing at the mixing point, that is, the first mixing angle, is 0 degree. The angle between the direction of the bypass channel before entering the mixing point and the direction of the outlet after mixing, that is, the second mixing angle, is not equal to 0 degree and not greater than 90 degrees. After necessary direction adjustment, the mixed microchannel enters the splitting point and splits into two paths after the splitting point. The outlet directions of the two paths after leaving the splitting point respectively form a certain angle with the inlet direction, that is, the first splitting angle and the second splitting angle. The first splitting angle and the second splitting angle are equal in size, both not equal to 0 degree and less than 90 degrees. The present invention overcomes the disadvantages of poor mixing performance and long reaction time of the heart-shaped structure, and at the same time solves the disadvantages of large pressure difference between the inlet and the outlet, poor fluidity and the existence of easy-to-block areas of the Tesla structure. Therefore, it is more suitable for continuous flow synthesis.

Description

Technical Field

[0001] The present invention relates to the technical field of two-dimensional microchannel technology, and particularly relates to a two-dimensional microchannel main-side mixing structure. Background Art

[0002] As Figure 1 shown, a two-dimensional microchannel reaction structure or reactor is commonly used in the continuous flow synthesis of chemical substances. It usually has two inlets for injecting two reaction liquids respectively, and one outlet for outputting the mixed liquid of intermediate reactants or reaction products. Such a microchannel is usually processed in the form of a connected two-dimensional groove on a transparent high-borosilicate or quartz glass plate. If the reaction liquid flowing through the microchannel on a glass plate does not reach the time required for complete reaction, multiple plates can be connected in series to form a longer reaction channel. To better mix two liquid flows in a limited microchannel to shorten the reaction time, this connected two-dimensional groove is always formed by repeatedly connecting a certain specific shape of microstructures in series.

[0003] As Figure 2 shown, in each microstructure, there must be a mixing point, represented by a dot, to mix two liquid flows; and there must also be a splitting point, represented by a square dot, to split the mixed liquid flow into two paths to prepare for entering the next microstructure.

[0004] Obviously, from the perspective of the role played by the microstructure in continuous flow synthesis, although the cross-sectional shape and bending shape of each channel will have an impact, the key role is still played by the structural characteristics at the mixing point and the splitting point.

[0005] Among various existing two-dimensional microchannel reaction structures or reactors, there are two most representative structures.

[0006] The first is the heart-shaped structure, as Figure 3 shown. The structures at the mixing point and the splitting point of this structure are both symmetric and there is no distinction between the main and the side. As Figure 4 shown, at the mixing point, the first mixing angle 3a and the second mixing angle 3b are equal in size and both are less than 90 degrees. As Figure 5 shown, at the splitting point, the first splitting angle 4a and the second splitting angle 4b are also equal in size and both are not greater than 90 degrees. Numerical simulation shows that this structure has a small pressure difference between the inlet and the outlet, good fluidity, and no easy-to-block area; but the mixing performance is poor, and it takes a longer time when used in microchannel chemical reactions.

[0007] The second is the Tesla structure, as Figure 6As shown. Tesla's original intention in inventing this structure was to design a one-way valve, hoping to prevent the flow in the main path (shown by the thick solid line). This prevention is achieved by introducing reverse momentum through the liquid flow from the bypass path (shown by the thick dashed line) at an obtuse angle to the main path direction. When the Tesla structure is used as a microchannel for chemical reactions, each such confluence point becomes a well-mixed mixing point because there is a component of counterflow between the two inlet flows. As Figure 7 shown, at the mixing point, the direction of inlet 1 is the same as the outlet direction, or in other words, the first mixing angle 3a is 0 degrees; the angle between the direction of inlet 2 and the outlet direction, that is, the second mixing angle 3b, is always greater than 90 degrees. At the same time, the two paths split from each splitting point are not symmetrical. One path has an unchanged direction, shown by the dashed line, and has better fluidity; the other path, shown by the solid line, has reduced fluidity due to the change in direction and may cause blockage in this section when used in microchannel chemical reactions. As Figure 8 shown, at the splitting point, the inlet direction is the same as the outlet 1 direction, or in other words, the first splitting angle 4a is 0 degrees; the deflection angle from the inlet direction to the outlet 2 direction, which is the second splitting angle 4b, is always greater than 0 degrees. Numerical simulations show that although this structure has good mixing performance, it has a large pressure difference between the inlet and outlet, poor fluidity, and there are areas prone to blockage, so it is not suitable for microchannel chemical reactions. In fact, Tesla's original intention in inventing this structure was not for this application. Summary of the Invention

[0008] In order to overcome the defects of the above prior art, the purpose of the present invention is to provide a two-dimensional microchannel main-bypass mixing structure, which overcomes the disadvantages of poor mixing performance and long reaction time of the heart-shaped structure, and at the same time solves the problems of large pressure difference between the inlet and outlet, poor fluidity and areas prone to blockage of the Tesla structure, so it is more suitable for continuous flow synthesis.

[0009] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0010] A two-dimensional microchannel main-bypass mixing structure includes two microchannels, one of which is the main path 5 and the other is the bypass path 6. The main path 5 and the bypass path 6 meet at a point to form a mixed path, and the meeting point is the mixing point 1. Along the flow direction, at the mixing point 1, the angle between the main path 5 and the mixed path is the first mixing angle 3a, and the angle between the bypass path 6 and the mixed path is the second mixing angle 3b. The first mixing angle 3a is 0 degrees, that is, the outlet direction of the mixed path is the same as the direction of the main path 5; the second mixing angle 3b is not equal to 0 degrees and not greater than 90 degrees;

[0011] After necessary direction adjustment of the microchannel formed by the mixed mixing path, it enters the splitting point 2. After the splitting point 2, two paths are formed. The directions of the two outlets after leaving the splitting point 2 form a certain included angle with the direction of the microchannel formed by the mixing path. The included angles are the first splitting angle 4a and the second splitting angle 4b. The magnitudes of the first splitting angle 4a and the second splitting angle 4b are equal, neither equal to 0 degree and less than 90 degrees.

[0012] After necessary direction adjustment of the two split microchannels, they enter the next mixing point. The mixing method is similar to that when entering the mixing point 1 for the first time. There is a distinction between the main path 5 and the bypass 6 for the subsequent mixing. From the direction of the main path 5 before splitting, it is swapped left and right compared to the previous mixing.

[0013] As needed, the above - mentioned mixing, splitting, and then mixing method can be repeated multiple times.

[0014] As needed, the fluidity is improved by reducing the second mixing angle 3b and / or the two equal first splitting angles 4a and second splitting angles 4b.

[0015] The starting - point mixing point of the two microchannels is divided into three inlets or two inlets;

[0016] When the starting point is three inlets, the middle inlet is used to inject the first reaction liquid, and the two side inlets inject the second reaction liquid in equal amounts;

[0017] When the starting point is two inlets, the two inlets respectively inject one reaction liquid.

[0018] Advantages of the present invention:

[0019] At the mixing point, the present invention abandons the symmetry of the heart - shaped structure and adjusts the asymmetry of the Tesla structure. Compared with the Tesla structure, the first mixing angle also remains zero, but the second mixing angle changes from an obtuse angle to a right angle or an acute angle. The first mixing angle remaining zero better retains the mixing effect of the Tesla structure; the second mixing angle changing from an obtuse angle to a right angle or an acute angle eliminates the recoil momentum introduced by the Tesla structure for flow resistance, and is more suitable for continuous - flow synthesis.

[0020] At the splitting point, the present invention abandons the asymmetry of the Tesla structure and draws on the symmetry of the heart - shaped structure. Because one of the two paths split by the Tesla structure has poor fluidity, it is prone to cause blockage of reactants in a section before entering the next mixing point, while the latter does not have this problem.

[0021] Therefore, the microchannel structure of the present invention has good mixing uniformity, no easily blocked areas, and is more suitable for continuous - flow synthesis. Brief Description of the Drawings

[0022] Figure 1It is the overall layout diagram of the microchannel for continuous flow synthesis in the prior art.

[0023] Figure 2 It is the flow schematic diagram of the microchannel for continuous flow synthesis in the prior art.

[0024] Figure 3 It is the schematic diagram of the heart-shaped structure in the prior art.

[0025] Figure 4 It is the schematic diagram of the mixing point of the heart-shaped structure in the prior art.

[0026] Figure 5 It is the schematic diagram of the splitting point of the heart-shaped structure in the prior art.

[0027] Figure 6 It is the schematic diagram of the Tesla structure in the prior art.

[0028] Figure 7 It is the schematic diagram of the mixing point of the Tesla structure in the prior art.

[0029] Figure 8 It is the schematic diagram of the splitting point of the Tesla structure in the prior art.

[0030] Figure 9 The schematic diagram of the structure of the present invention.

[0031] Figure 10 The schematic diagram of the mixing point of the present invention.

[0032] Figure 11 The schematic diagram of the splitting point of the present invention.

[0033] Figure 12 The schematic diagram of the deformed structure of the present invention.

[0034] Figure 13 The schematic diagram of the first specific embodiment of the present invention.

[0035] Figure 14 The schematic diagram of the second specific embodiment of the present invention.

[0036] Figure 15 The schematic diagram of the third specific embodiment of the present invention.

[0037] Figure 16 It is the comparison schematic diagram of the mixing effects of various structures after passing through three mixing points.

[0038] Among them: 1 mixing point, 2 splitting point, 3a first mixing angle, 3b second mixing angle, 4a first splitting angle, 4b second splitting angle, 5 main path, 6 bypass path. Detailed implementation manners

[0039] The present invention will be further described in detail below with reference to the embodiments.

[0040] As shown in Figure 9 Figure Figure 9 : A two-dimensional microchannel main-bypass mixing structure includes two microchannels. One is the main channel 5, and the other is the bypass channel 6. The main channel 5 and the bypass channel 6 converge at a point to form a combined channel, and the convergence point is the mixing point 1. Along the flow direction, at the mixing point 1, the angle between the main channel 5 and the combined channel is the first mixing angle 3a, and the angle between the bypass channel 6 and the combined channel is the second mixing angle 3b. The first mixing angle 3a is 0 degrees, that is, the outlet direction of the combined channel is the same as the direction of the main channel 5; the second mixing angle 3b is not equal to 0 degrees and not greater than 90 degrees; (as shown in Figure 10 Figure Figure 10 )

[0041] After the necessary direction adjustment of the microchannel formed by the combined channel after mixing, it enters the splitting point 2. After the splitting point 2, it is divided into two paths. The outlet directions of the two paths after leaving the splitting point 2 form a certain angle with the direction of the microchannel formed by the combined channel, and the angles are the first splitting angle 4a and the second splitting angle 4b. The first splitting angle 4a and the second splitting angle 4b are equal in magnitude, both not equal to 0 degrees and less than 90 degrees. (as shown in Figure 11 Figure Figure 11 )

[0042] After the necessary direction adjustment of the two split microchannels, they enter the next mixing point. The mixing method is similar to that when entering the mixing point 1 for the first time. Regarding the division of the main channel 5 and the bypass channel 6 in the subsequent mixing, when viewed from the direction of the main channel 5 before splitting, it is reversed left and right compared with the previous mixing.

[0043] As shown in Figure 12 Figure Figure 12 : As needed, the above mixing, splitting, and then mixing methods can be repeated multiple times.

[0044] As needed, the fluidity is improved by reducing the second mixing angle 3b and / or the two equal first splitting angle 4a and second splitting angle 4b.

[0045] Example 1:

[0046] As shown in Figure 13 Figure Figure 13 , this scheme has three inlets. Taking the direction shown in the attached drawing as the standard, on the left side of the figure, the first mixing point is a mixing point with three inlets and two outlets. When in use, the first reaction liquid is injected through the middle inlet, and the second reaction liquid is injected equally through the two side inlets. The structure of the mixing point in this scheme is complex, but the mixing effect is very good. As the first mixing point of the microchannel, it can accelerate the synthesis process.

[0047] Example 2:

[0048] As shown in Figure 14 Figure Figure 14 , this scheme has two inlets. Taking the direction shown in the attached drawing as the standard, on the left side of the figure. A reaction liquid is injected separately from the two inlets. The first mixing point of this scheme is the same as other mixing points, and there is only a normal mixing effect at the inlet.

[0049] Example 3:

[0050] As shown Figure 15 in the figure, there are two microchannels. One is the first main path 51, and the other is the first bypass path 61. The first main path 51 and the first bypass path 61 meet at a point to form a first mixing point 11. Along the flow direction, at the first mixing point 11, the microchannel formed by the mixed path after mixing undergoes necessary direction adjustment and then enters the first splitting point 21. After the first splitting point 21, two paths are formed, which are divided into the second main path 52 and the second bypass path 62. From the direction of the first main path 51 before splitting, the second main path 52, the second bypass path 62, the first main path 51, and the first bypass path 61 have their left and right directions of the main path and the bypass swapped compared with the previous mixing.

[0051] After necessary direction adjustment, the two split microchannels enter the next mixing point, and the mixing method is similar to that of entering the mixing point 1 last time.

[0052] Figure 16 From left to right are the heart-shaped structure of the prior art, the Tesla structure of the prior art, the structure of the present invention, and the deformed structure of the present invention. Under the same input conditions, after passing through three mixing points respectively, numerical simulations of the mixing effects are carried out, and the simulation results are compared as shown in the following table. The results show that in the third and fourth drawings of the present invention, although the overall fluidity is slightly worse and the mixing separation degree is medium, it has the best mixing uniformity and no easy-to-block areas, and is more suitable for continuous flow synthesis than the heart-shaped structure and the Tesla structure.

[0053]

[0054]

[0055] From the line of the second drawing in the Figure 16 appendix, it can be seen that for the Tesla structure of the prior art, the mixing separation degree is the smallest, the inlet and outlet pressure difference is the largest, and there is an easy-to-block area in the overall channel;

[0056] From the line of the first drawing in the Figure 16 appendix, it can be seen that for the heart-shaped structure of the prior art, the mixing uniformity is the worst and the mixing separation degree is the largest.

Claims

1. A two-dimensional main-side mixing structure of a microchannel, characterized in that, It includes two microchannels, one of which is the main channel (5) and the other is the bypass channel (6). The main channel (5) and the bypass channel (6) converge at a point to form a mixed channel, and the convergence point is the mixing point (1). Along the flow direction, at the mixing point (1), the angle between the main channel (5) and the mixed channel is the first mixing angle (3a), and the angle between the bypass channel (6) and the mixed channel is the second mixing angle (3b). The first mixing angle (3a) is 0 degree, that is, the outlet direction of the mixed channel is the same as the direction of the main channel (5); the second mixing angle (3b) is not equal to 0 degree and not greater than 90 degrees. After necessary direction adjustment, the microchannel formed by the mixed channel after mixing enters the splitting point (2). After the splitting point (2), it forms two paths. The outlet directions of the two paths after leaving the splitting point (2) form certain angles with the direction of the microchannel formed by the mixed channel, and the angles are the first splitting angle (4a) and the second splitting angle (4b). The first splitting angle (4a) and the second splitting angle (4b) are equal in magnitude, both not equal to 0 degree and less than 90 degrees.

2. The two-dimensional microchannel main-side mixing structure according to claim 1, wherein After necessary direction adjustment, the two split microchannels enter the next mixing point, and the mixing method is similar to the previous one. Regarding the distinction between the main channel (5) and the bypass channel (6) in the subsequent mixing, from the direction of the main channel (5) before splitting, it is swapped left and right compared with the previous mixing.

3. The two-dimensional microchannel main-side mixing structure according to claim 1, characterized in that The above mixing, splitting and then mixing methods can be repeated multiple times.

4. A two-dimensional microchannel main-side mixing structure according to claim 1, characterized in that The fluidity is improved by reducing the second mixing angle (3b) and / or the two equal first splitting angle (4a) and second splitting angle (4b).

5. A two-dimensional microchannel main-side mixing structure according to claim 1, characterized in that The starting point mixing point of the two microchannels is divided into three inlets or two inlets; When the starting point has three inlets, the middle inlet is used to inject the first reaction liquid, and the two side inlets inject the second reaction liquid in equal amounts; When the starting point has two inlets, the two inlets respectively inject a reaction liquid.

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