Micro-reaction generator with vortex structure

Abstract

The invention discloses a micro-reaction generator with a vortex structure, which relates to the technical field of chemical engineering, and comprises a main channel pipe, the whole main channel pipe body is of a zigzag-like structure, and the main channel pipe body is provided with an inlet end and an outlet end. The main channel pipe comprises a plurality of bent structures and three-dimensional polygonal channels, and the three-dimensional polygonal channels are located at the corners of the zigzag structures. According to the invention, the Bezier curve composition cavity is arranged to induce stretching and folding of the fluid to enhance mixing, a strong vortex is formed, the capability of components on two sides passing through a mixing contact surface is obviously enhanced, and the vortex efficiency is improved, so that the mixing efficiency is improved. Fluid flows into the three-dimensional polygonal channels to form vortex perpendicular to the flow direction and rotates between the two kinds of fluid, contact lines are stretched and lengthened through the vortex, mass transfer driving force is greatly increased, and the mixing performance is improved. Fluid flows through the bent structures and the three-dimensional polygonal channels for multiple times, mixing is promoted through the secondary flow effect, and the mixing efficiency is gradually improved along with increase of the Reynolds number.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical engineering, and particularly relates to a micro reaction generator with a vortex structure. Background Art

[0002] The core working mechanism of a microfluidic concentration gradient generator lies in constructing a stable concentration distribution difference by means of fluid mixing and molecular diffusion processes in a microchannel. Solutions with different initial concentrations are injected into the same flow channel. When these fluids meet and mix in a restricted space, the solute molecules in the solution will spontaneously migrate to the low-concentration region due to the characteristics of thermal motion. Under the coordinated regulation of the laminar flow characteristics and diffusion effect of the fluid, a continuous concentration gradient distribution is formed at specific spatial positions in the microchannel. This artificially constructed concentration gradient field can highly restore the complex chemical microenvironment characteristics in organisms and provide precisely controllable physicochemical conditions for experimental research in fields such as cell biology and drug screening.

[0003] Existing Christmas tree-shaped microfluidic concentration gradient generators (MCGGs) and other geometric shapes also rely on molecular diffusion to achieve concentration gradients. This condition limits the low rate in the case of a continuous low-gradient generator in order to achieve complete mixing in the branches before reaching the next bifurcation. Based on the fact that the mixing efficiency of a square-wave mixer is very low when the Reynolds number is 2 - 20, this makes the Christmas tree-shaped concentration gradient chip can only be used at low Reynolds numbers. The above-mentioned MCGGs only work well at low Reynolds numbers (Re) and cannot achieve efficient mixing at high Reynolds numbers. Therefore, a new technology needs to be designed to improve this phenomenon. Summary of the Invention

[0004] Aiming at the problems in the above-mentioned prior art, the present invention provides a micro reaction generator with a vortex structure. By setting a cavity composed of Bessel curves to induce stretching and folding of the fluid to enhance mixing, a strong vortex is formed, significantly enhancing the ability of the two-side components to pass through the mixing contact surface, improving the efficiency of the vortex and thus the mixing efficiency. The fluid flows into a three-dimensional polygonal channel to form a vortex perpendicular to the flow direction, and is stretched and extruded in a curved pipe with a vortex structure, enhancing the contact area between fluids and promoting mixing. Utilize the influence of the vortex to stretch and extend the contact line, greatly increasing the mass transfer driving force, thereby improving the mixing performance. After flowing through the curved structure and the three-dimensional polygonal channel multiple times, the mixing is continuously promoted by the secondary flow effect, and the higher the Reynolds number, the higher the mixing efficiency can be achieved.

[0005] The present invention is implemented through the following technical solutions: A micro-reaction generator with an eddy current structure, including a main channel tube, the overall body of the main channel tube is in a serrated-like structure, one end of the main channel tube is provided with an inlet end, the inlet end is provided with at least two bifurcated inlets, the other end of the main channel tube is provided with an outlet end, the main channel tube and the inlet end form a T-shaped bifurcation, and the main channel tube, the inlet end and the outlet end are arranged horizontally.

[0006] The main channel tube includes a plurality of bending structures and a three-dimensional polygonal channel. The three-dimensional polygonal channel is located at the corner of the serrated structure, and the inner cavities of two adjacent bending structures are communicated through the inner cavity of the three-dimensional polygonal channel.

[0007] The bending structure includes at least two combined Bezier curve channels, and the combined Bezier curve channels include a convex part and a concave part.

[0008] The three-dimensional polygonal channel is in a longitudinally symmetric protruding form, the longitudinal cross-sectional profile of the three-dimensional polygonal channel is a symmetric hexagon, and the vertex A and vertex D of the hexagon are on the axis of symmetry and the apex angle A is a right angle.

[0009] Further, the positions of two adjacent bending structures are perpendicular to each other.

[0010] Further, the shape of each Bezier curve is determined by three points that can form an isosceles triangle.

[0011] Further, the outer contours of the convex part and the concave part are two symmetric Bezier curves.

[0012] Further, the two Bezier curves forming the outer contours of the convex part and the concave part share an axis of symmetry.

[0013] Further, two adjacent combined Bezier curve channels are in opposite directions and are connected end to end through a straight connection channel.

[0014] Further, the inner wall layer of the micro-reaction generator is provided with a hydrophilic coating or a glass-PDMS composite structure.

[0015] Advantages: By providing a main channel pipe and a three-dimensional polygonal channel, the present invention enhances mixing by inducing stretching and folding of the fluid as it flows through the cavity formed by the Bezier curves of the first bending structure. The middle of the fluid contact line is squeezed, and one side of the contact line is pulled to one side of the curve by a sudden centrifugal force, causing a secondary flow of the fluid and forming a strong eddy parallel to the flow direction. With the assistance of the eddy, the ability of the two components on both sides to pass through the mixing contact surface is significantly enhanced, the efficiency of the eddy is improved, and it is beneficial to improve the mixing efficiency. When the fluid flows into the three-dimensional polygonal channel, the sudden expansion of the channel space generates a centrifugal force. The middle of the fluid contact line is squeezed towards the center of the channel, and both sides of the contact line are stretched to both sides of the channel. The fluid forms an eddy rotating between the two fluids perpendicular to the flow direction, increasing the mass transfer area between the fluids while shortening the mass transfer distance, enhancing the contact area between the fluids and promoting mixing. Utilizing the influence of the eddy, the contact line is stretched and extended, greatly increasing the mass transfer driving force, thereby improving the mixing performance. The fluid flows through the bending structure and the three-dimensional polygonal channel multiple times to form eddies, and the mixing is promoted by the secondary flow effect. As the Reynolds number increases, the mixing efficiency gradually becomes higher. Description of the Drawings

[0016] Figure 1 Is a three-dimensional structure diagram of an embodiment of the present invention; Figure 2 Is a front view of an embodiment of the present invention; Figure 3 Is a detailed diagram of the eddy structure of an embodiment of the present invention; Figure 4 Is a partial detailed diagram of an embodiment of the present invention; Figure 5 Is a Bezier curve parameter - mixing efficiency diagram of an embodiment of the present invention; Figure 6 Is a cross-sectional contour diagram of the three-dimensional polygonal channel of an embodiment of the present invention; Figure 7 Is a streamline comparison diagram of the three-dimensional polygonal channel of an embodiment of the present invention with respect to parameter a; Figure 8 Is a streamline comparison diagram of the three-dimensional polygonal channel of an embodiment of the present invention with respect to parameter b; Figure 9 Is a polygonal cavity parameter - mixing efficiency diagram of an embodiment of the present invention; Figure 10 Is a fluid flow direction diagram of an embodiment of the present invention; Figure 11 Is a fluid simulation streamline diagram of an embodiment of the present invention; Figure 12 Is a fluid simulation surface concentration diagram of an embodiment of the present invention; Figure 13 Is a longitudinal cross-section of the fluid simulation eddy structure of an embodiment of the present inventionFigure Ⅰ ; Figure 14 Cross-section of the fluid simulation eddy current structure according to an embodiment of the present invention Figure Ⅱ .

[0017] In the figure: 1 - main channel pipe; 2 - inlet end; 3 - bending structure; 4 - Bessel curve combined channel; 4a - convex part; 4b - concave part; 5 - three-dimensional polygon channel; 6 - straight connection channel; 7 - outlet end. Detailed implementation manners

[0018] The present invention will be further described in detail below with reference to the accompanying drawings of the specification and the embodiments.

[0019] As Figures 1 to 14 shown, a micro-reaction generator with an eddy current structure includes a main channel pipe 1. The overall body of the main channel pipe 1 has a serrated-like structure. One end of the main channel pipe 1 is provided with an inlet end 2, and the inlet end 2 is provided with at least two bifurcated inlets. The other end of the main channel pipe 1 is provided with an outlet end 7. The main channel pipe 1 and the inlet end 2 form a T-shaped bifurcation, and the main channel pipe 1, the inlet end 2 and the outlet end 7 are arranged horizontally. The above settings can ensure that two fluids enter the micro-reaction generator through the provided inlet end 2 and are mixed along the inner cavity of the main channel pipe 1. The zigzag main channel pipe 1 is beneficial to the generation of collisions during fluid mixing, enhancing the mixing effect.

[0020] In this embodiment, Figure 5 (a) in is the change diagram of MI and COP values with the change of the abscissa parameter c1 in this embodiment; Figure 5 (b) in is the change diagram of MI and COP values with the change of the abscissa parameter d1 in this embodiment; Figure 5 (c) in is the change diagram of MI and COP values with the change of the abscissa parameter d2 in this embodiment; Figure 5 (d) in is the schematic diagram of the Bessel curve structure parameters; among them, c1, d1, and d2 are all Figure 5 the distance parameters of the corresponding symbols in (d) in; MI is the cross-section mixing efficiency; COP is the ratio of the cross-section mixing efficiency to the pressure drop; In this embodiment, Figure 9 (a) in is the change diagram of MI and COP values with the change of the abscissa parameter a in this embodiment; Figure 9 (b) is the change diagram of MI and COP values with the change of the abscissa parameter b; among them, the parameter a and the parameter b are all Figure 6 the distance parameters of the corresponding symbols in.

[0021] The main channel tube 1 includes a plurality of bending structures and a three-dimensional polygonal channel. The three-dimensional polygonal channel 5 is located at the corner of the serrated structure, and the inner cavities of two adjacent bending structures 3 are connected through the inner cavity of the three-dimensional polygonal channel 5.

[0022] The bending structure 3 includes at least two combined Bezier curve channels 4, and the combined Bezier curve channels 4 include a convex portion 4a and a concave portion 4b.

[0023] The three-dimensional polygonal channel 5 is longitudinally symmetrically convex. The longitudinal section profile of the three-dimensional polygonal channel 5 is a symmetric hexagon, and the vertices A and D of the hexagon are on the symmetry axis and the apex angle A is a right angle.

[0024] According to the comparison of multiple groups of data for determining the shape parameters of the three-dimensional polygonal channel 5, when the perpendicular line segment a = 0.225 mm and the line segment b = 0.275 mm from the midpoint g of the diagonal AD of the hexagon in the longitudinal section of the three-dimensional polygonal channel 5 to the side BC, and the floating values are both ±0.001 mm, the eddy current formed when the fluid passes through the three-dimensional polygonal channel 5 is the strongest and the mixing efficiency is the best. The above settings cause the channel space to suddenly expand when the fluid flows into the three-dimensional polygonal channel 5, generating a centrifugal force, and the fluid forms an eddy current perpendicular to the flow direction. Utilizing the influence of the eddy current, the contact line is stretched and extended, and the mass transfer driving force is greatly increased, thereby improving the mixing efficiency. The lengths of a and b determine the shape of the three-dimensional polygonal combined channel. As a and b increase, the eddy current effect perpendicular to the flow direction of the fluid is further enhanced, improving the mixing performance.

[0025] In the present invention, by providing the main channel tube 1 and the three-dimensional polygonal channel 5, when the fluid flows through the Bezier curve combined channel 4 of the bending structure 3, at a relatively low Reynolds number, this will induce the stretching and folding of the fluid and change the flow direction of the fluid to enhance mixing; when the Reynolds number increases to Re = 10 or higher, when the two fluids flow through the Bezier curve combined channel 4, the middle of the contact line is squeezed, and one side of the contact line is suddenly pulled to one side of the curve by the centrifugal force, and the fluid generates a secondary flow and forms a strong vortex parallel to the flow direction. With the assistance of the vortex, the ability of the two components on both sides to pass through the mixing contact surface is significantly enhanced, the efficiency of the vortex is improved, and it is beneficial to improve the mixing efficiency. When the fluid flows into the three-dimensional polygonal channel 5, the sudden expansion of the channel space generates a centrifugal force, the middle of the fluid contact line is squeezed to the center of the channel, and both sides of the contact line are stretched to both sides of the channel. The fluid forms a vortex perpendicular to the flow direction and rotates between the two fluids, increasing the mass transfer area between the fluids while shortening the mass transfer distance, enhancing the contact area between the fluids and promoting mixing. Utilizing the influence of the vortex, the contact line is stretched and extended, and the mass transfer driving force is greatly increased, thereby improving the mixing performance. The fluid flows through the bending structure 3 and the three-dimensional polygonal channel 5 multiple times, and the mixing is promoted by the secondary flow effect. As the Reynolds number increases, the mixing efficiency gradually becomes higher.

[0026] In this embodiment, the adjacent two bending structures are in a vertical positional relationship. The above setting changes the flow direction of the fluid, and the sudden change in the fluid direction increases the contact area between the two fluids, further enhancing the mixing efficiency of the fluid.

[0027] In this embodiment, the shape of each Bessel curve is determined by three points that can form an isosceles triangle. Combining the symmetry of the Bessel curve and the special shape of the isosceles triangle formed by the three points, the midline of the isosceles triangle in the two Bessel curves of the convex portion 4a and the concave portion 4b can be made to coincide. According to the comparison of multiple sets of data of the isosceles triangles formed by the three points that determine the shape of the Bessel curve: when the width of the main channel is 0.3 mm, the three points of the curve of the convex portion 4a form an isosceles triangle with a base length of 2*c2 of 0.5 mm and a height c1 of 1 mm; the three points of the concave portion 4b form an isosceles triangle with a base length of 2*d2 of 1.1 mm and a height d1 of 0.4 mm. The floating values of the above parameters are all ±0.001 mm. At these parameters, the mixing efficiency of the Bessel curve combined channel 4 is the best. This parameter feature is that the shape of the Bessel curve is used to determine the morphological structure of the Bessel curve combined channel 4. The best parameters were tested and analyzed for the mixing efficiency by adjusting the shape of the Bessel curve. According to the fluid mixing simulation, the optimal parameters of the Bessel curve were determined at the highest mixing efficiency point. When the fluid passes through this channel and is squeezed by the curve, the suddenly generated centrifugal force induces the fluid to generate a second flow. The connection line between the maximum point of the concave portion 4b and the maximum point of the convex portion 4a is perpendicular to the flow direction of the fluid, so that the fluid can generate a secondary flow when passing through this area, improving the mixing efficiency. At the same time, the energy power of the fluid reaches the maximum at this ratio.

[0028] In this embodiment, the outer contours of the convex portion and the concave portion are two symmetric Bessel curves.

[0029] Preferably, the two Bessel curves that make up the outer contours of the convex portion and the concave portion share a symmetry axis.

[0030] In this embodiment, two adjacent Bessel curve combined channels 4 are in opposite directions and are connected end to end through a straight connection channel 6. The above setting can make the fluid, when passing through this curved structure 3, be completely squeezed into the convex portion 4a by the inner wall of the concave portion 4b and then be pushed into the next Bessel curve combined channel 4 by the impact. The fluid is continuously promoted by this structure twice, improving the mixing efficiency of the fluid.

[0031] In this embodiment, the inner wall layer of the microreactor is provided with a hydrophilic coating (such as PEG modification) or a glass-PDMS composite structure. The above setting can reduce the friction between the fluid and the inner wall of the channel tube and reduce the adsorption of drugs in the microreactor.

[0032] The working principle of this embodiment is as follows: S1: The operator places the generator in this embodiment properly and prepares the relevant drugs. In this embodiment, 0.9% normal saline is added to one inlet end of the micro-reactor, and cephalosporin antibiotics or other antibiotic drugs are added to the other inlet end. As Figure 10 shown, first, the fluids are respectively input into the inner cavity of the main channel tube 1 from the bifurcated inlets. The fluid flows into the inlet end 2 of the main channel tube 1, first passes through the straight connection channel, and then passes through a 45° corner. As Figures 11 to 12 shown, the fluid continues to flow through the inner cavity of the Bezier curve combination channel 4 of the first bending structure 3. When the Reynolds number is low, this will induce the stretching and folding of the fluid and change the flow direction of the fluid to enhance mixing; when the Reynolds number increases to Re = 10 or higher, the middle of the contact line of the two fluids is squeezed when flowing through the Bezier curve combination channel 4, and one side of the contact line is suddenly pulled to one side of the curve by the centrifugal force, and the fluid generates a secondary flow and forms a strong vortex parallel to the flow direction. With the assistance of the vortex, the ability of the two components on both sides to pass through the mixing contact surface is significantly enhanced, the efficiency of the vortex is improved, and thus the mixing efficiency is improved.

[0033] S2: As Figures 11 to 12 shown, immediately afterwards, the fluid flows into the three-dimensional polygonal channel 5 at the corner. The sudden expansion of the channel space generates a centrifugal force, the middle of the fluid contact line is squeezed to the center of the channel, and both sides of the contact line are stretched to both sides of the channel. The fluid forms a vortex perpendicular to the flow direction. These vortices rotate between the two fluids. Therefore, the mass transfer area between the fluids increases, the mass transfer distance shortens, the contact area between the fluids is enhanced, and mixing is promoted. Utilizing the influence of the vortex, the contact line is stretched and extended, and the mass transfer driving force is greatly increased, thereby improving the mixing performance.

[0034] S3: The mixed fluid after passing through the three-dimensional polygonal channel 5 enters the second bending structure 3. The same Bezier curve combination channel 4 will induce the stretching and folding of the fluid to enhance mixing. The fluid forms a strong vortex perpendicular to the flow direction again, significantly enhancing the ability to pass through the mixing contact surface, improving the efficiency of the vortex, and thus improving the mixing efficiency.

[0035] S4: The fluid after being mixed by the above structure then continues to enter the next bending structure 3. As Figures 11 to 14 shown, the fluid is promoted to mix again by the secondary flow effect. The fluid flowing through the bending structure and the three-dimensional polygonal channel repeatedly is continuously strengthened in mixing until it completely passes through the micro-channel of the serrated-like structure. As the Reynolds number increases, the mixing efficiency also gradually becomes higher. Finally, the fluid flows out through the channel outlet end 7.

[0036] S5: After completing the mixing of the fluid, the device is closed.

[0037] The present invention has been specifically described above in connection with the embodiments. Without departing from the core scope of the present invention, various improvements can still be made, and components therein can be replaced with equivalents. As long as there is no structural conflict, the features in the embodiments disclosed in the present invention can be combined with each other in any way. The exhaustive description of these combination cases is not given in this specification, which is only for the consideration of saving space and resources. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed herein, but covers all technical solutions falling within the scope of the claims.

Claims

1. A microreactor with a vortex structure, comprising a main channel tube, characterized in that : The main channel pipe body as a whole has a serrated-like structure. One end of the main channel pipe is provided with an inlet end, and the inlet end is provided with at least two bifurcated inlets. The other end of the main channel pipe is provided with an outlet end. The main channel pipe and the inlet end form a T-shaped bifurcation, and the main channel pipe, the inlet end and the outlet end are horizontally arranged; The main channel pipe includes a plurality of bending structures and a three-dimensional polygonal channel. The three-dimensional polygonal channel is located at the corner of the serrated structure, and the inner cavities of two adjacent bending structures are communicated through the inner cavity of the three-dimensional polygonal channel; The bending structure includes at least two combined Bezier curve channels, and the combined Bezier curve channels include a convex part and a concave part; The three-dimensional polygonal channel has a longitudinally symmetric convex shape. The longitudinal cross-sectional profile of the three-dimensional polygonal channel is a symmetric hexagon. The vertex A and vertex D of the hexagon are on the axis of symmetry and the apex angle A is a right angle.

2. The micro-reaction generator with a vortex structure according to claim 1, wherein: The position relationship between two adjacent bending structures is perpendicular.

3. The micro-reaction generator with a vortex structure according to claim 1, characterized in that: The shape of each Bezier curve is determined by three points that can form an isosceles triangle.

4. The micro-reaction generator with an eddy current structure according to claim 1, characterized in that: The outer contours of the convex part and the concave part are two symmetric Bezier curves.

5. The micro-reaction generator with an eddy current structure according to claim 1, characterized in that: The two Bezier curves that make up the outer contours of the convex part and the concave part share one axis of symmetry.

6. The micro-reaction generator with an eddy current structure according to claim 1, characterized in that: Two adjacent combined Bezier curve channels are in opposite directions and are connected end to end through a straight connecting channel.

7. The micro-reaction generator with a vortex structure according to claim 1, characterized in that: The inner wall layer of the micro-reactor is provided with a hydrophilic coating or a glass-PDMS composite structure.

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