A passive mixing flow channel structure

Abstract

This invention belongs to the field of hybrid structures, specifically relating to a passive hybrid flow channel structure, including a circular flow channel body; the inner wall of the circular flow channel body is provided with a first flow-disrupting element and a second flow-disrupting element, the first flow-disrupting element and the second flow-disrupting element are arranged opposite to each other and spaced apart to form a flow gap; the first flow-disrupting element and the second flow-disrupting element are both spirally inclined relative to the central axis of the circular flow channel body, so that when the fluid passes through the circular flow channel body, it is guided by the first flow-disrupting element and the second flow-disrupting element to form a composite vortex that combines axial propulsion and circumferential rotation.

Description

Technical Field

[0001] This invention belongs to the field of hybrid structures, specifically relating to a passive hybrid flow channel structure. Background Technology

[0002] The preparation of lipid nanoparticles typically requires the use of passive mixing devices to achieve efficient homogenization of different fluids. Currently, commonly used passive mixing structures include T-tube mixers, herringbone mixing structures, spiral channels, and mixing channels based on the Dean vortex effect. The Dean vortex effect refers to the phenomenon where, when a fluid flows inside a curved channel, the centrifugal force generates a pair of counter-rotating secondary vortices across the channel cross-section, effectively enhancing the mixing effect. Mixing channels designed based on the Dean vortex effect have been widely applied in lipid nanoparticle preparation due to their excellent mixing performance.

[0003] However, the various traditional mixing structures currently used in the industry all have obvious technical shortcomings and limitations in application. Among them, T-tube mixers have high operating pressure, a narrow range of suitable fluid flow rates, and poor adaptability to operating conditions; fishbone-type mixing structures can only achieve single-sided fluid disturbance, have a single mixing method, and are prone to material deposition problems inside the flow channel; the overall adaptability and mixing uniformity of various conventional mixing structures are difficult to meet the requirements of high-quality preparation.

[0004] Meanwhile, most existing mainstream micromixing channel designs are two-dimensional planar configurations. The mixing area of ​​such structures is very limited, resulting in weak overall fluid mixing intensity. To achieve the mixing effect required for lipid nanoparticle preparation, it is necessary to increase the overall length of the mixing channel and enlarge the structural size of individual mixing sub-units, leading to low equipment integration. Furthermore, these two-dimensional channels can only achieve effective and strong mixing in localized, narrow areas; the vast majority of the channel area merely serves as a fluid guide, resulting in insufficient fluid disturbance and poor overall mixing efficiency and uniformity. This makes them unsuitable for the high-precision, high-efficiency continuous preparation of lipid nanoparticles.

[0005] In summary, the passive mixing channels currently used in the preparation of lipid nanoparticles generally suffer from problems such as a single disturbance mode, insufficient mixing intensity, limited effective mixing area, poor adaptability to operating conditions, and easy deposition. There is an urgent need for a passive mixing channel structure that can enhance the fluid disturbance effect and improve the overall mixing performance. Summary of the Invention

[0006] The purpose of this invention is to provide a passive mixing channel structure to solve the above-mentioned problems.

[0007] To achieve the above objectives, the present invention provides a passive mixing channel structure, including a circular channel body; The inner wall of the circular flow channel body is provided with a first flow-disrupting element and a second flow-disrupting element. The first flow-disrupting element and the second flow-disrupting element are arranged opposite to each other and spaced apart to form a flow gap. Both the first and second turbulence elements are spirally inclined relative to the central axis of the circular flow channel body, so that when the fluid passes through the circular flow channel body, it is guided by the first and second turbulence elements to form a composite vortex that combines axial propulsion and circumferential rotation.

[0008] Furthermore, in the passive mixing channel structure, the angle between the length direction of the first baffle and the axial direction of the circular channel body is 30° to 60°; the angle between the length direction of the second baffle and the axial direction of the circular channel body is 30° to 60°.

[0009] Furthermore, in the passive mixing channel structure, the circular channel body includes a first semicircular channel and a second semicircular channel with identical structures; the first turbulence element is disposed on the inner wall of the first semicircular channel, and the second turbulence element is disposed on the inner wall of the second semicircular channel.

[0010] Furthermore, in the passive mixing channel structure, on the connecting surface of the first semicircular channel and the second semicircular channel, the projections of the first baffle and the second baffle intersect each other.

[0011] Furthermore, in the passive mixing channel structure, the first turbulence element and the second turbulence element have the same structure; the second turbulence element includes a second transition surface and a third transition surface connected in sequence, the second transition surface is a frontal turbulence surface facing the fluid flow direction, and the third transition surface is a back-flow guiding surface facing away from the fluid flow direction.

[0012] Furthermore, in the passive mixing channel structure, a first transition surface is formed at the connection between the second transition surface and the second semi-circular channel, a second transition surface is formed at the connection between the third transition surface and the second semi-circular channel, and a third transition surface is formed at the connection between the second transition surface and the third transition surface. The first transition surface, the second transition surface, and the third transition surface are all set to rounded corner transitions.

[0013] Furthermore, in the passive mixing channel structure, both the first and second baffles are crescent-shaped arc structures, with a shape that is high in the middle and low at both ends along their own length.

[0014] Furthermore, in the passive mixing channel structure, along the axial direction of the circular channel body, a plurality of first flow disruptors are arranged at intervals in sequence, and a plurality of second flow disruptors are arranged at intervals in sequence.

[0015] Furthermore, in the passive mixing channel structure, the first semi-circular channel is integrally formed with the first baffle, and the second semi-circular channel is integrally formed with the second baffle.

[0016] Furthermore, the passive mixing channel structure also includes a round-to-square transition channel section; the round-to-square transition channel section is coaxially connected to both ends of the circular channel body.

[0017] Compared with the prior art, the present invention has at least the following technical effects: This invention incorporates flow-disrupting elements on the inner wall of a circular flow channel. Both sets of elements extend spirally and obliquely relative to the central axis of the channel, cooperating to form a flow gap penetrating the central axis. This induces bidirectional mixing disturbances—axial propulsion and circumferential rotation—in the fluid flow, solving the problems of single-sided disturbance, limited mixing patterns, and easy deposition inherent in traditional mixing structures. Furthermore, it addresses the limitations of existing two-dimensional mixing channels, such as restricted mixing area, weak mixing intensity, and the need for lengthened channels and larger unit sizes to achieve uniform mixing. This invention effectively enhances the overall disturbance capability and mixing uniformity of the channel, simplifies structural dimensions, improves equipment integration, broadens the applicable flow rate range, and improves high-pressure adaptability. It significantly improves overall operational adaptability and fluid mixing efficiency, better meeting the demands of efficient, continuous, and high-quality lipid nanoparticle preparation. Attached Figure Description

[0018] Figure 1 This is a front view of a passive mixing channel structure according to an embodiment of the present invention; Figure 2 This is a front view of a labeled passive mixing channel structure according to an embodiment of the present invention; Figure 3 This is a side view of a labeled passive mixing channel structure according to an embodiment of the present invention; Figure 4 This is a top view of a labeled passive mixing channel structure according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the second semicircular flow channel in one embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the second baffle in one embodiment of the present invention; Figure 7 This is a side view of the second semicircular flow channel in one embodiment of the present invention; Figure 8 This is a simulation diagram of the mixing principle of two fluids in a passive mixing channel structure according to an embodiment of the present invention; Figure 9 This is a structural diagram of a passive mixing channel structure with a round-to-square transition channel section in one embodiment of the present invention.

[0019] Among them, 1. Circular flow channel body; 11. First semi-circular flow channel; 12. Second semi-circular flow channel; 2. First baffle; 3. Second baffle; 31. First curved surface; 32. Second curved surface; 41. First transition surface; 42. Second transition surface; 43. Third transition surface; 5. Circular to square transition flow channel section; 6. Flow gap. Detailed Implementation

[0020] The passive mixing channel structure of the present invention will now be described in more detail with reference to the schematic diagrams, which illustrate preferred embodiments of the invention. It should be understood that those skilled in the art can modify the invention described herein while still achieving its advantageous effects. Therefore, the following description should be understood as being of general knowledge to those skilled in the art and is not intended to limit the invention.

[0021] For clarity, not all features of the actual embodiments are described. In the following description, well-known functions and structures are not detailed in detail, as they would obscure the invention with unnecessary detail. It should be understood that in the development of any actual embodiment, numerous implementation details must be made to achieve the developer's specific objectives, such as changes from one embodiment to another according to limitations related to the system or business. Furthermore, it should be understood that such development work may be complex and time-consuming, but is merely routine work for those skilled in the art.

[0022] Based on the teachings of this specification, those skilled in the art can form new technical solutions through cross-combination of different implementation methods without creating technical contradictions. Such variations should all be considered to fall within the protection scope of this invention.

[0023] The invention is described more specifically by way of example in the following paragraphs with reference to the accompanying drawings. The advantages and features of the invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[0024] This embodiment discloses a passive mixing channel structure, mainly applied to the passive mixing of various fluids in lipid nanoparticle preparation systems. Mixing is achieved by relying on the fluid's own flow energy, eliminating the need for additional driving and agitation components. This embodiment addresses the common problems of passive mixing channels used in current lipid nanoparticle preparation, such as limited agitation methods, insufficient mixing intensity, limited effective mixing area, poor adaptability to operating conditions, and easy deposition.

[0025] Reference Figure 1-3 As shown, the passive mixing channel structure in this embodiment includes a circular channel body 1.

[0026] The inner wall of the circular flow channel body 1 is provided with a first flow-disrupting element 2 and a second flow-disrupting element 3. The first flow-disrupting element 2 and the second flow-disrupting element 3 are arranged opposite to each other and spaced apart to form a flow gap 6. The first flow-disrupting element 2 and the second flow-disrupting element 3 are both spirally inclined relative to the central axis of the circular flow channel body 1, so that when the fluid passes through the circular flow channel body 1, it is guided by the first flow-disrupting element 2 and the second flow-disrupting element 3 to form a composite vortex that combines axial propulsion and circumferential rotation.

[0027] Furthermore, both the first spoiler 2 and the second spoiler 3 are spirally inclined relative to the central axis. And as... Figure 4 As shown, the angle α between the length direction of the first baffle 2 and the axial direction of the circular flow channel body 1 is 30° to 60°; the angle α between the length direction of the second baffle 3 and the axial direction of the circular flow channel body 1 is 30° to 60°.

[0028] If the included angle α is less than 30°, the helical guiding effect is weak, and the fluid is unlikely to form an effective circumferential rotational disturbance. If the included angle α is greater than 60°, the resistance to axial flow of the fluid will increase sharply, the back pressure of the system will increase, and the suitable flow velocity range will narrow. Multiple experiments have verified that setting the included angle α within the range of 30 to 60 degrees yields the optimal overall performance. In this embodiment, the included angle α is preferably set to 45°, which can effectively control the flow channel pressure loss while ensuring good circumferential disturbance strength, and is suitable for a wider range of flow velocity conditions during the preparation of lipid nanoparticles.

[0029] In this embodiment, the circular flow channel body 1 includes a first semi-circular flow channel 11 and a second semi-circular flow channel 12 with identical structures. The first semi-circular flow channel 11 and the second semi-circular flow channel 12 are interlocked to form a complete circular fluid channel. The first flow-disrupting element 2 (blue structure in the figure) is disposed on the arc-shaped inner wall of the first semi-circular flow channel 11, and the second flow-disrupting element 3 (yellow structure in the figure) is disposed on the arc-shaped inner wall of the second semi-circular flow channel 12.

[0030] Furthermore, on the connecting surface of the first semicircular flow channel 11 and the second semicircular flow channel 12, the projections of the first baffle 2 and the second baffle 3 are intersected.

[0031] Reference Figure 2 and Figure 4 In this embodiment, the staggered arrangement of the structure avoids the obstruction of fluid flow caused by the first and second flow deflectors 2 and 3 being directly opposite each other, effectively preventing the flow gap 6 from being blocked or clogged, and ensuring normal fluid flow. This structure allows the fluid to continuously exchange and mix between the two flow deflectors, strengthening the cross-mixing of fluid in the upper and lower regions of the flow channel, and further improving the overall mixing uniformity.

[0032] Reference Figure 8 The red and green lines in the diagram correspond to the flow trajectories of two different fluids, which can intuitively demonstrate the mixing effect of the two fluids after passing through the passive mixing channel structure.

[0033] In this embodiment, both the first baffle 2 and the second baffle 3 are spirally inclined relative to the central axis of the circular flow channel body 1. When the fluid flows axially along the circular flow channel body 1, guided by the first baffle 2 and the second baffle 3, the fluid simultaneously generates axial propulsion motion and circumferential rotational motion, forming a composite vortex of axial propulsion and circumferential rotation, which greatly improves the mixing effect between the fluids.

[0034] Specifically, the first spoiler 2 and the second spoiler 3 have the same structure. This embodiment takes the structure of the second spoiler 3 as an example. Figure 5 and Figure 6 The second spoiler 3 includes a first curved surface 31 and a second curved surface 32.

[0035] Reference Figure 6 The first curved surface 31 is a flow-facing disturbance surface facing the direction of fluid flow. When the fluid impacts the flow-facing disturbance surface of the first curved surface 31, the flow direction will be deflected, actively guiding the fluid to generate vortex disturbance. The second curved surface 32 is a flow-directing surface facing away from the direction of fluid flow. It can smoothly guide the disturbed fluid, reduce large-area flow separation at the tail of the disturbance component, reduce fluid flow resistance, suppress material deposition caused by local vortex stagnation, and is suitable for lipid nanoparticle preparation conditions.

[0036] Furthermore, refer to Figure 6 A first transition surface 41 is formed at the connection between the first curved surface 31 and the second semi-circular flow channel 12, a second transition surface 42 is formed at the connection between the second curved surface 32 and the second semi-circular flow channel 12, and a third transition surface 43 is formed at the connection between the first curved surface 31 and the second curved surface 32. The first transition surface 41, the second transition surface 42 and the third transition surface 43 are all set to rounded corner transitions.

[0037] Among them, combined Figure 5 Both the first transition surface 41 and the second transition surface 42 are arc-shaped curves adapted to the arc-shaped inner wall of the second semi-circular flow channel 12, so that the bottom of the second turbulence element 3 can smoothly transition and fit with the inner wall of the second semi-circular flow channel 12 without obvious gaps, reducing material dead corners and lowering the risk of lipid nanoparticle adhesion and deposition. (Refer to...) Figure 3 and Figure 7The third transition surface 43 is configured as a curve that is concave inward toward the center of the circular flow channel body 1. The concave contour can change the flow direction of the fluid at the edge of the flow gap 6 and enhance the mixing effect.

[0038] Furthermore, both the first spoiler 2 and the second spoiler 3 have a crescent-shaped arc structure, with a shape that is high in the middle and low at both ends along their own length direction.

[0039] Specifically, when viewed radially along the circular flow channel body 1, refer to... Figure 3 and Figure 7 The vertex of the third transition surface 43 facing the center is lower than the splicing surface formed by the first semicircular flow channel 11 and the second semicircular flow channel 12. Since the first baffle 2 and the second baffle 3 are respectively set on the inner walls of the upper and lower semicircular flow channels, the splicing surface of the two semicircular flow channels is the dividing plane between them. Setting the highest point of the inner side of the third transition surface 43 to be lower than this splicing surface ensures that the inner ends of the baffles on both sides will not cross over or abut against the installation area of ​​the baffles on the opposite side, thus avoiding positional interference and mutual collision between the upper and lower sets of baffles from the structural gap. At the same time, this setting can accurately retain the flow gap 6 between the baffles on both sides, avoiding the situation where the baffles interfere with each other, causing gap compression deformation and sealing failure, so that the fluid exchange channel inside the flow channel is regular and unobstructed, ensuring the stable mixing effect of bidirectional disturbance and radial mixing, and preventing problems such as mixing blind zones and flow channel blockage due to structural interference.

[0040] Furthermore, in this embodiment, the first transition surface 41, the second transition surface 42, and the third transition surface 43 are all configured with rounded corners. Since sharp corner structures are prone to causing local fluid stagnation and lipid material adsorption and deposition, this embodiment adopts a rounded corner transition method, which can weaken local flow dead corners, reduce the probability of material adhesion, agglomeration and deposition during the preparation of lipid nanoparticles, and reduce local flow resistance.

[0041] Furthermore, along the axial direction of the circular flow channel body 1, a plurality of first flow disruptors 2 are arranged at intervals in sequence, and a plurality of second flow disruptors 3 are arranged at intervals in sequence.

[0042] Specifically, in this embodiment, the number of flow-disrupting components can be flexibly selected according to the actual mixing conditions. They can be set to one or more to adapt to the usage requirements of different fluid flow rates and mixing precision.

[0043] In a preferred embodiment, refer to Figure 2Five first flow disruptors 2 and five second flow disruptors 3 are evenly spaced on the first semicircular flow channel 11 and the second semicircular flow channel 12, respectively. Multiple flow disruptors on the same semicircular flow channel are arranged parallel to each other to ensure the uniformity and consistency of axial disturbance. The fluid flows sequentially along the flow channel axis through multiple sets of mutually matched flow disruptors, forming a continuous multi-stage disturbance effect.

[0044] Compared to structures with only a single set of turbulence units, the multi-stage turbulence units in this embodiment can continuously disrupt the laminar fluid interface, thereby progressively enhancing the mixing effect of the fluid in the radial and circumferential directions. While ensuring good mixing uniformity, it is not necessary to significantly increase the overall length of the flow channel, thus effectively reducing the overall size of the equipment and improving mixing efficiency.

[0045] Furthermore, in this embodiment, the first semi-circular flow channel 11 is integrally formed with the first baffle 2, and the second semi-circular flow channel 12 is integrally formed with the second baffle 3. The integrally formed structure eliminates assembly gaps, avoiding the problems of material retention and contamination or particle agglomeration caused by gaps. At the same time, it facilitates mass production using micro-machining, molding and other processes, reducing the assembly difficulty of processing.

[0046] Furthermore, the passive mixing channel structure also includes a round-to-square transition channel section 5, which is coaxially connected to both ends of the circular channel body 1. The upstream and downstream pipelines are often square microchannels or circular pipes, when facing situations such as... Figure 9 When the inlet and outlet are square flow channel areas, a round-to-square transition flow channel section 5 can be used to achieve a smooth transition connection between the outer square flow channel and the inner circular flow channel body, avoiding the problem of violent fluid eddies caused by abrupt changes in the flow channel cross section, as well as sudden changes in local pressure, reducing the risk of material deposition at the inlet and outlet, and facilitating the integration and assembly of the mixing flow channel and the entire lipid nanoparticle preparation pipeline system.

[0047] In this embodiment, the specific working principle of the passive mixing channel structure is as follows: Two or more fluids to be mixed flow from the upstream pipeline into the transition channel section 5, which transitions from a round to a square shape at one end. After a smooth transition in the cross-section, the fluids enter the interior of the circular channel body 1. As the fluids flow forward, they continuously come into contact with multiple sets of spirally inclined first and second flow-disrupting elements 2 and 3. The fluids are deflected by the upstream curved surface and generate circumferential rotational flow under the guidance of the spiral profile. At the same time, the fluids continue to be transported forward axially, forming a bidirectional mixing disturbance of axial propulsion and circumferential rotation.

[0048] The fluid continuously exchanges with each other on both sides of the flow channel through the flow gap 6 between the two side baffles, breaking the fluid stratification phenomenon. The fluid passes through multiple sets of staggered first baffles 2 and second baffles 3, continuously enhancing the interlayer mixing effect. After mixing, the fluid flows out through the rear round-to-square transition flow channel section 5 and enters the downstream process.

[0049] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the protection scope of the present invention.

Claims

1. A passive mixing channel structure, characterized in that, It includes a circular flow channel body (1); the inner wall of the circular flow channel body (1) is provided with a first flow-disrupting element (2) and a second flow-disrupting element (3), the first flow-disrupting element (2) and the second flow-disrupting element (3) are arranged opposite to each other and are spaced apart to form a flow gap (6). The first turbulence element (2) and the second turbulence element (3) are both spirally inclined relative to the central axis of the circular flow channel body (1) so that when the fluid passes through the circular flow channel body (1), it is guided by the first turbulence element (2) and the second turbulence element (3) to form a composite vortex that combines axial propulsion and circumferential rotation.

2. The passive mixing channel structure according to claim 1, characterized in that, The angle between the length direction of the first baffle (2) and the axial direction of the circular flow channel body (1) is 30° to 60°; the angle between the length direction of the second baffle (3) and the axial direction of the circular flow channel body (1) is 30° to 60°.

3. The passive mixing channel structure according to claim 1, characterized in that, The circular flow channel body (1) includes a first semi-circular flow channel (11) and a second semi-circular flow channel (12) with the same structure; the first turbulence member (2) is provided on the inner wall of the first semi-circular flow channel (11), and the second turbulence member (3) is provided on the inner wall of the second semi-circular flow channel (12).

4. The passive mixing channel structure according to claim 3, characterized in that, On the connecting surface of the first semicircular flow channel (11) and the second semicircular flow channel (12), the projections of the first baffle (2) and the second baffle (3) intersect each other.

5. The passive mixing channel structure according to claim 1, characterized in that, The first turbulence element (2) has the same structure as the second turbulence element (3); the second turbulence element (3) includes a first curved surface (31) and a second curved surface (32), the first curved surface (31) is a frontal turbulence surface facing the direction of fluid flow, and the second curved surface (32) is a back-flow guiding surface facing away from the direction of fluid flow.

6. The passive mixing channel structure according to claim 5, characterized in that, A first transition surface (41) is formed at the connection between the first curved surface (31) and the second semi-circular flow channel (12), a second transition surface (42) is formed at the connection between the second curved surface (32) and the second semi-circular flow channel (12), and a third transition surface (43) is formed at the connection between the first curved surface (31) and the second curved surface (32). The first transition surface (41), the second transition surface (42) and the third transition surface (43) are all set to rounded corner transitions.

7. The passive mixing channel structure according to claim 1, characterized in that, Both the first spoiler (2) and the second spoiler (3) have a crescent-shaped arc structure, with a high middle and low ends along their own length.

8. The passive mixing channel structure according to claim 1, characterized in that, Along the axial direction of the circular flow channel body (1), a plurality of first flow disturbances (2) are arranged at intervals in sequence, and a plurality of second flow disturbances (3) are arranged at intervals in sequence.

9. The passive mixing channel structure according to claim 3, characterized in that, The first semi-circular flow channel (11) is integrally formed with the first baffle (2), and the second semi-circular flow channel (12) is integrally formed with the second baffle (3).

10. The passive mixing channel structure according to claim 1, characterized in that, It also includes a round-to-square transition channel section (5); the round-to-square transition channel section (5) is coaxially connected to both ends of the circular channel body (1).

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