A reverse collision micro-reaction channel

Abstract

The present invention discloses a reverse collision micro-reaction channel; the reverse collision micro-reaction channel is provided with an inlet channel connected in sequence, a reverse collision mixing unit connected in series, and an outlet; the reverse collision mixing unit is composed of a circular wall, an arc-shaped baffle, and a turbulent cylinder; the reverse collision micro-reaction channel provided by the present invention solves the problem of poor mixing effect of ordinary micro-reaction channels. The design of a circular wall plus an arc-shaped baffle allows the fluid to rotate around the flow cylinder in the reverse collision mixing unit, thereby enhancing the turbulence of the fluid in the unit, causing the fluid streamlines to rotate and intersect, and effectively improving the mixing efficiency; on the other hand, the smooth wall design reduces the fluid energy loss caused by sharp corners, reduces the flow dead zone, and reduces the flow resistance and has a large liquid holding capacity.

Description

Technical Field

[0001] The invention relates to the field of microreactor and microfluid mixing, in particular to a reverse collision microreaction channel. Background Art

[0002] Microreactors are devices that offer rapid heat and mass transfer, precise control of reaction parameters, inherent safety, and efficient production capacity. These characteristics have led to significant application and development potential in fields such as fine chemicals, biomedicine, functional material preparation, the food industry, and environmental protection. Passive microreactors, in particular, leverage the inertia, shear forces, and diffusion of fluids within microchannels to achieve efficient mixing of reactants without requiring additional energy consumption. Consequently, they play a crucial role in both academic research and industrial production.

[0003] Convective mass transfer refers to the mass transport of solutes between different regions caused by fluid flow. It is usually driven by pressure or temperature gradients and has a significant impact on reactions. In microreactors, molecular diffusion is dominant, and molecular diffusion and convective mass transfer work synergistically. Currently, common microreactor designs disrupt laminar flow by bending flow channels, installing baffles, and installing reflux devices, causing the fluid layer to segment, elongate, fold, and rupture, thereby increasing the fluid contact area and shortening the mass transfer distance to enhance the mixing process.

[0004] However, the overall mixing efficiency of existing micro-reaction channel designs is low, especially when the channels are enlarged to the millimeter level, the mixing effect needs to be improved. At the same time, it is easy to produce local flow dead zones, which is not conducive to the reaction, the flow resistance is large, and the operating costs are increased. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of low mixing efficiency of existing ordinary micro-reaction channel mixing when the channel size is at the millimeter level. The present invention designs a circular reverse collision micro-mixing channel and structurally designs the channel to maintain a small flow dead zone and a small flow resistance while having high mixing efficiency.

[0006] The present invention first provides a reverse collision micro-mixing channel, comprising at least two liquid inlets, an inlet channel connected to the liquid inlets, an outlet channel for mixed fluid to flow out, and a micro-mixing flow channel for connecting the inlet channel and the outlet channel;

[0007] The micro-mixing flow channel includes a plurality of reverse collision mixing units arranged in a staggered manner, and the reverse collision mixing unit includes an arc-shaped wall surface, a spoiler cylinder and an arc-shaped baffle; the arc-shaped wall surface and the arc-shaped baffle are enclosed to form an arc structure with a shape between a semicircle and a circle, and the arc opening of the arc structure faces the inside of the micro-mixing flow channel; the arc-shaped baffle is arranged on a side of the arc-shaped wall surface close to the outlet channel, and the spoiler cylinder is arranged at the center of the arc structure;

[0008] The arc structure on one side of the micro-mixing channel and the arc-shaped baffle on the other side form a fluid mixing channel for fluid circulation. The inlet of the first fluid mixing channel is connected to the inlet channel, the outlet of the last fluid mixing channel is connected to the outlet channel, and the outlet of the previous fluid mixing channel is connected to the inlet of the next fluid mixing channel.

[0009] As a preferred solution of the present invention, the arc baffle is arranged at the connection of the arc-shaped walls of the two reverse collision mixing units on the same side, and the center of the arc baffle coincides with the center of the connected arc-shaped wall near the inlet channel.

[0010] As a preferred embodiment of the present invention, one side of the inlet channel is connected to the arc-shaped wall of the first reverse collision mixing unit, and the other side of the inlet channel is provided with an arc-shaped baffle, the arc-shaped opening of the arc-shaped baffle faces the inside of the inlet channel.

[0011] The present invention also provides a fluid mixing method in the reverse collision micro-mixing channel, comprising the following steps:

[0012] 1) Various fluids to be mixed are respectively inputted from various liquid inlets of the reverse collision micro-mixing channel, and the various fluids intersect in the inlet channel;

[0013] 2) After the fluids merge into the fluid mixing channel, they flow along the arc structure and rotate around the turbulent cylinder in the fluid mixing channel due to the centrifugal force.

[0014] 3) After the fluid flows through the arc structure on one side, it hits the arc baffle on the other side. A part of the fluid continues to rotate and flow in the fluid mixing channel after the collision, and impacts and mixes with the fluid that subsequently enters this fluid mixing channel. The other part of the fluid flows from the outlet of this fluid mixing channel to the next fluid mixing channel;

[0015] 4) The fluid mixed through several throttle fluid mixing channels flows out from the outlet channel.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] On the one hand, the design of arc-shaped wall and arc-shaped baffle enables the fluid to rotate around the flow cylinder in the reverse collision mixing unit, which enhances the turbulence of the fluid in the unit, causes the fluid streamlines to rotate and intersect, and effectively improves the mixing efficiency; on the other hand, the smooth wall design reduces the fluid energy loss caused by sharp edges, reduces the flow dead zone, and reduces the flow resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of a circular reverse collision micro-mixing channel;

[0019] Figure 2 This is a simulated concentration cloud diagram of a circular reverse collision micro-mixing channel;

[0020] Figure 3 This is a simulated velocity cloud diagram of a circular reverse collision micro-mixing channel;

[0021] Figure 4 This is a vector diagram of the simulated flow field of a circular reverse collision micro-mixing channel;

[0022] Figure 5 This is a schematic diagram of the traditional Tesla mild hybrid channel;

[0023] Figure 6 This is a graph showing the relationship between mixing efficiency and Reynolds number in the simulation.

[0024] In the figure: 1. First fluid inlet; 2. Second fluid inlet; 3. Reverse collision mixing unit; 4. Turbine cylinder; 5. Arc-shaped wall; 6. Arc-shaped baffle; 7. Outlet channel. DETAILED DESCRIPTION

[0025] The present invention will be further described and illustrated below in conjunction with specific embodiments. The embodiments are merely illustrative of the present disclosure and do not limit its scope. The technical features of the various embodiments of the present invention may be combined accordingly, provided that there is no conflict between them.

[0026] As attached Figure 1 As shown, a specific embodiment of a circular reverse collision micro-reaction channel provided by the present invention includes a T-shaped inlet mixing channel, a reverse collision mixing unit and an outlet channel 7 connected in sequence;

[0027] The T-shaped inlet mixing channel includes a first fluid inlet 1, a second fluid inlet 2, and an inlet channel. The first fluid inlet 1 and the second fluid inlet 2 are respectively located at two ends of the inlet channel. The width of the first fluid inlet and the second fluid inlet are both 0.2mm-3mm. The T-shaped inlet mixing channel is followed by a reverse collision mixing unit 3 connected in series. The outlet channel is provided at the end of the reverse collision mixing units 3 connected in series.

[0028] Multiple reverse collision mixing units 3 are arranged in a staggered manner; the reverse collision mixing unit 3 includes an arc-shaped wall surface 5, a flow-disturbing cylinder 4, and an arc-shaped baffle 6. The diameter of the arc-shaped wall surface 5 is 0.5mm-8mm. The arc-shaped wall surface and the arc-shaped baffle 6 enclose an arc structure with a shape between a semicircle and a circle. The arc-shaped baffle is arranged at the edge of the circular wall surface to change the flow direction of the fluid. The arc-shaped baffle 6 is arranged at the connection of the arc-shaped wall surfaces 5 of the two reverse collision mixing units 3 on the same side. The center of the arc-shaped baffle 6 coincides with the center of the connected arc-shaped wall surface near the inlet channel. The flow-disturbing cylinder 4 is located in the center of the reverse collision mixing unit and is concentric with the arc-shaped wall surface. It divides the fluid and increases the collision frequency. One side of the inlet channel is connected to the arc-shaped wall surface of the first reverse collision mixing unit, and an arc-shaped baffle is provided on the other side of the inlet channel. The arc structure on one side of the micro-mixing channel and the arc-shaped baffle on the other side form a fluid mixing channel for fluid circulation. The inlet of the first fluid mixing channel is connected to the inlet channel, the outlet of the last fluid mixing channel is connected to the outlet channel, and the outlet of the previous fluid mixing channel is connected to the inlet of the next fluid mixing channel.

[0029] The reverse collision micro-mixing channel can flexibly select the number of reverse collision mixing units according to the actual mixing efficiency and reaction time requirements.

[0030] The present invention also provides a method for operating the reverse collision micro-mixing channel, comprising the following steps:

[0031] 1) Various fluids to be mixed are respectively inputted from various liquid inlets of the reverse collision micro-mixing channel, and the various fluids intersect in the inlet channel;

[0032] 2) After the fluids merge into the fluid mixing channel, they flow along the arc structure and rotate around the turbulent cylinder in the fluid mixing channel due to the centrifugal force.

[0033] 3) After the fluid flows through the arc structure on one side, it hits the arc baffle on the other side. A part of the fluid continues to rotate and flow in the fluid mixing channel after the collision, and impacts and mixes with the fluid that subsequently enters this fluid mixing channel. The other part of the fluid flows from the outlet of this fluid mixing channel to the next fluid mixing channel;

[0034] 4) The fluid mixed through several throttle fluid mixing channels flows out from the outlet channel.

[0035] Example 1: Reverse collision micro-mixing channel

[0036] Fluent 2021R2 software was used to simulate fluid mixing to test the mixing performance of the reverse collision micro-mixing channel. The fluid material was water with a density of 1000 kg / m 3 , the dynamic viscosity is 0.001 Pa·s, and the solute diffusion coefficient is 10 -9 m 2 / s. The calculation model uses a component transport model to couple the flow and mass transfer processes. The fluid inlet velocity is adjusted to simulate the mixing process under Reynolds numbers Re of 0.1, 1, and 10. The standard deviation of the solute concentration at the outlet cross section can be used to evaluate the mixing efficiency of the micro-reaction channel. The calculation formula is as follows:

[0037]

[0038] in is the mixing efficiency, for point The mass fraction of the tracer at The concentration is when completely mixed.

[0039] The results show that, as shown in the Figure 2 As shown in the figure, after multiple reverse collisions, the fluid can achieve a better mixing effect after passing through about six fluid mixing channels. The velocity cloud diagram is shown in the attached figure. Figure 3 As shown in the figure, there is no obvious dead zone in the fluid mixing channel, and the flow velocity near the outer arc wall is greater than that at the inner wall. The flow vector diagram is shown in the attached figure. Figure 4 As shown, it can be found that the fluid rotates around the flow cylinder in the fluid mixing channel. When flowing through the arc baffle, part of the fluid collides in the opposite direction and continues to rotate, while the other part of the fluid flows into the next mixing unit. After multiple collisions, the fluid effectively enhances the turbulence level and improves the mass transfer effect.

[0040] Comparative Example 2: Traditional Tesla Micro-Hybrid Channel

[0041] Fluent 2021R2 software was used to simulate fluid mixing to test the following Figure 5 Mixing performance of a conventional Tesla microreactor channel, shown in Figure 2, where the fluid material is water with a density of 1000 kg / m 3 , the dynamic viscosity is 0.001 Pa·s, and the solute diffusion coefficient is 10 -9 m 2 The calculation model uses a component transport model to couple the flow and mass transfer processes. The fluid inlet velocity is adjusted to simulate the mixing process of the fluid under Reynolds numbers Re of 0.1, 1, and 10.

[0042] like Figure 6As shown, by comparing Example 1 with Comparative Example 2, it can be found that when the Reynolds number is 0.1 to 10, the mixing effect of the reverse collision micro-reaction channel proposed by the present invention is better than that of the traditional Tesla micro-reaction channel.

[0043] The above-described embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. Persons skilled in the art will readily appreciate that variations and modifications may be made without departing from the scope of the present invention, all of which fall within the scope of protection of the present invention.

Claims

1. A reverse collision micro-mixing channel, characterized in that: The device comprises at least two liquid inlets, an inlet channel connected to the liquid inlets, an outlet channel for the mixed fluid to flow out, and a micro-mixing channel connecting the inlet channel and the outlet channel; The micro-mixing flow channel includes a plurality of reverse collision mixing units arranged in a staggered manner, and the reverse collision mixing unit includes an arc-shaped wall surface, a spoiler cylinder and an arc-shaped baffle; the arc-shaped wall surface and the arc-shaped baffle are enclosed to form an arc structure with a shape between a semicircle and a circle, and the arc opening of the arc structure faces the inside of the micro-mixing flow channel; the arc-shaped baffle is arranged on a side of the arc-shaped wall surface close to the outlet channel, and the spoiler cylinder is arranged at the center of the arc structure; The arc-shaped baffle is arranged at the connection of the arc-shaped walls of the two reverse collision mixing units on the same side, and the center of the arc-shaped baffle coincides with the center of the connected arc-shaped wall near the inlet channel; one side of the inlet channel is connected to the arc-shaped wall of the first reverse collision mixing unit, and an arc-shaped baffle is arranged on the other side of the inlet channel, and the arc-shaped opening of the arc-shaped baffle faces the inside of the inlet channel; The arc structure on one side of the micro-mixing channel and the arc-shaped baffle on the other side form a fluid channel for fluid circulation. The inlet of the first fluid channel is connected to the inlet channel, the outlet of the last fluid mixing channel is connected to the outlet channel, and the outlet of the previous fluid mixing channel is connected to the inlet of the next fluid mixing channel.

2. The reverse collision micro-mixing channel according to claim 1, characterized in that: The diameter of the circle where the arc-shaped wall surface is located is 0.5mm-8mm.

3. The reverse collision micro-mixing channel according to claim 1, characterized in that: The widths of the various liquid inlets are equal, ranging from 0.2 mm to 3 mm.

4. The reverse collision micro-mixing channel according to claim 1, characterized in that: The reverse collision micro-mixing channel flexibly selects the number of reverse collision mixing units according to the actual mixing efficiency and reaction time requirements.

5. A fluid mixing method in a reverse collision micro-mixing channel as claimed in claim 1, characterized in that: The following steps are involved: 1) Various fluids to be mixed are respectively inputted from various liquid inlets of the reverse collision micro-mixing channel, and the various fluids intersect in the inlet channel; 2) After the fluids merge into the fluid mixing channel, they flow along the arc structure and rotate around the turbulent cylinder in the fluid mixing channel due to the centrifugal force. 3) After the fluid flows through the arc structure on one side, it hits the arc baffle on the other side. A part of the fluid continues to rotate and flow in the fluid mixing channel after the collision, and impacts and mixes with the fluid that subsequently enters this fluid mixing channel. The other part of the fluid flows from the outlet of this fluid mixing channel to the next fluid mixing channel; 4) The fluid mixed through several throttle fluid mixing channels flows out from the outlet channel.

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