A reaction chamber and multi-stage series microchannel reactor

Abstract

The present invention discloses a reaction chamber and a multi-stage serial microchannel reactor. The reaction chamber comprises a teardrop-shaped cavity shell and a built-in octopus-shaped diversion baffle, and a four-stage mixing flow channel is formed between the two: collision shear section: the fluid at the feed inlet impacts the baffle head at high speed to achieve forced diversion and primary shear; deceleration and reorganization section: the waist-expanding flow channel reduces the flow rate, promotes fluid reorganization and interface fusion; acceleration section: the narrow channel between the tentacles squeezes and accelerates the fluid, and enhances osmotic mixing; mixing section: the baffle tail is provided with a vortex-breaking sharp corner to eliminate vortexes and guide to the discharge port. The multi-stage reactor consists of a three-division inlet unit, N series-connected reaction chambers and outlet units, and is arranged in reverse parallel by a U-shaped tube. Except for the reaction chamber, the interior thereof is a solid structure, and the three-division inlet adopts a peripheral pipeline nested in a central pipeline design to achieve graded feeding control. This structure has both efficient microscopic forced mixing and low flow resistance characteristics.

Description

Technical Field

[0001] The present invention belongs to the technical field of microreactors, and in particular relates to a reaction chamber and a multi-stage series microchannel reactor. Background Art

[0002] A microreactor is a miniaturized chemical or biological reaction device whose core structure consists of micron- to millimeter-scale channels or chambers. Through its highly integrated design, microreactors enable efficient mixing of reactants, mass transfer, and heat transfer, significantly improving reaction efficiency and controllability. They are widely used in fields such as chemical synthesis, pharmaceuticals, materials science, and energy.

[0003] Microreactors differ from other reactors in that they control reactions within the smallest possible area, with characteristic dimensions typically ranging from micrometers to millimeters. After more than a decade of development, a wide variety of microreactor structures have emerged on the market.

[0004] The most widely used microreactor at present is the heart-shaped structure represented by Corning microreactor. Its principle of enhancing mass transfer is shear-diversion-combination-reshear. Compared with other microchannel structures, it has less resistance, more shear times and higher mass transfer efficiency when flowing through the same distance and diameter. Its disadvantages are: Figure 1 As shown in the figure, in a heart-shaped structure, the area below the arched baffle is too large, causing the fluid to decelerate significantly after diversion and before re-combining. The fluid accumulates in a large area below the arch, forming a wide stagnant boundary layer, reducing mass transfer efficiency and creating a dead zone effect, resulting in poor local mixing. This effect is particularly evident at low flow rates.

[0005] In multiphase and rapid chemical reactions, fast and efficient mixing is particularly important. Since most of the channel structures of microreactor chips are at the micron to millimeter level, the fluid in the channel is in a laminar state, which is not conducive to the rapid mixing of substances, especially at low flow rates. In order to enhance the mixing of the fluids in the chip channels, some complex mixing structures are usually set in the channels, such as baffles, pin fins with variable diameter cavities, and additional mixing units, in the hope that the fluid can be cut when passing through or local vortices can be generated to increase the mixing effect. However, these structures will increase the pressure drop of the fluid, and a large pressure drop is not conducive to scaled-up production, and also brings energy loss. Therefore, it is very necessary to design a high-speed mixing microreactor without increasing the pressure drop.

[0006] In the prior art, Chinese patent application CN117717983A discloses a micro-mixing and reaction structure and a reactor thereof based on the optimization of heart-shaped features. By adjusting the Corning heart-shaped structure, the problem of wide and large-area stagnant boundary layer distribution in the Corning heart-shaped structure microchannel reactor is effectively solved. However, this structure increases the size and area of ​​the baffle. Although it improves the mixing effect, it increases the pressure drop loss of the system and reduces the space utilization rate.

[0007] Chinese patent application CN201820003421.3 discloses a microchannel reactor with a channel structure that includes both linear and non-linear channels. The non-linear channels can be S-shaped, Z-shaped, or other irregularly shaped curved channels. While this improves mixing between the phases of fluid, it also increases pressure drop in the microchannels and the risk of channel blockage within the reaction chamber.

[0008] Chinese patent application CN111001348A discloses a multi-unit mixer consisting of a three-division inlet unit, a series of reaction chamber modules, and an outlet unit. This mixer enables rapid mixing of two or more fluids at high throughput, achieving excellent mixing results. However, its disadvantages are that the reaction chambers in the series of microreactors are complex and prone to forming "dead zones" within certain reaction chamber areas. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a reaction chamber and a multi-stage series microchannel reactor in response to the above-mentioned deficiencies in the prior art. The unique structural design of the reaction chamber can achieve high-speed mixing without increasing the pressure drop and avoid the formation of "dead zones" in some areas of the reaction chamber.

[0010] A first aspect of the present invention discloses a reaction chamber, comprising a chamber shell and an octopus-shaped diversion baffle inside the chamber shell; the chamber shell is in a water droplet shape, the chamber feed port of the chamber shell is located at the head of the water droplet, and the chamber discharge port of the chamber shell is located at the tail of the water droplet;

[0011] A mixing channel is formed between the octopus-shaped diversion baffle and the inner wall of the cavity shell, and the mixing channel includes a collision shear section, a deceleration and recombination section, an acceleration section and a mixing section;

[0012] The collision shear section is a flow channel between the inner wall of the cavity shell on both sides of the cavity feed inlet and the octopus head of the octopus-shaped diverter baffle. When the mixed fluid enters from the cavity feed inlet, the mixed fluid impacts the octopus head of the octopus-shaped diverter baffle at high speed in the collision shear section, and the mixed fluid is accelerated, collided and sheared, and the mixed fluid is divided into two and flows to the flow channels on both sides of the octopus head.

[0013] The deceleration and reorganization section is a flow channel between the waist of the inner wall on both sides of the cavity shell and the waist of both sides of the octopus-shaped diversion baffle. When the mixed fluid flows through the deceleration and reorganization section, the flow channel gradually widens and the flow rate decreases. The mixed fluid is mixed, reorganized and accumulated in this area.

[0014] The acceleration section is a flow channel between the lower waist of the inner wall on both sides of the cavity shell and the tentacles on both sides of the octopus tail of the octopus-shaped diversion baffle. When the mixed fluid flows through the acceleration section, the mixed fluid is squeezed and accelerated to pass through, the fluid flow rate increases, and the fluids are forced to contact and penetrate each other;

[0015] The mixing section is a flow channel between the inner wall of the cavity shell tail and the octopus tail of the octopus-shaped diverter baffle, and is connected to the cavity discharge port; the middle position of the octopus tail of the octopus-shaped diverter baffle has a vortex-breaking sharp corner, which is used to break the vortex formed after the fluid is accelerated by the acceleration section, so that the movement direction of the high-speed mixed fluid flowing out of the acceleration section is toward the cavity discharge port.

[0016] In the above-mentioned reaction chamber, the vortex breaking corner is an acute angle structure with the tip pointing toward the cavity discharge port.

[0017] The second aspect of the present invention discloses a multi-stage series microchannel reactor, comprising:

[0018] a three-way inlet unit;

[0019] N reaction chambers according to the first aspect are connected in series, wherein N is an integer greater than or equal to 1;

[0020] an export unit;

[0021] The three-division inlet unit, the N reaction chambers connected in series, and the outlet unit are connected in sequence;

[0022] The cavity feed port of the first reaction cavity is connected to the outlet end of the three-division inlet unit, and the cavity discharge port of the last reaction cavity is connected to the inlet end of the outlet unit.

[0023] The multi-stage series microchannel reactor has a solid structure inside except for the reaction cavity.

[0024] In the multi-stage serial microchannel reactor, N reaction chambers connected in series are arranged in multiple rows, and two reaction chambers connected between adjacent rows are connected by U-shaped tubes and arranged in reverse parallel.

[0025] In the above-mentioned multi-stage series microchannel reactor, the three-division inlet unit has a first feed port and a second feed port; the first feed port is connected to the cavity feed port of the first reaction cavity through a first pipeline; the second feed port is connected to the end of the first pipeline through a second pipeline, and the first pipeline is arranged on the periphery of the second pipeline.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] 1. The reaction chamber uses an octopus-like diversion baffle to achieve a mixing channel that narrows and then widens twice (the first narrowing at the octopus head and the second narrowing at the tentacles on both sides of the octopus tail). This accelerates the flow rate to achieve a jet effect, thereby improving the mixing effect of the fluid, ensuring uniform mixing of the fluid, increasing the magnitude of molecular diffusion, and improving mass transfer efficiency. At the same time, it also improves space utilization and increases the liquid holding capacity of the microchannel reaction chamber.

[0028] 2. Since most of the designs on the market are based on the design concept of imitating the heart-shaped channel structure, this design concept is to design the wall shell as a water droplet-like structure, the spoiler unit is an octopus-like spoiler structure, and the diversion baffle above the channel is arc-shaped. The high-speed fluid is divided into two by the top of the arc and flows into the wide channel on both sides. The flow rate slows down, resulting in primary mixing and improving space utilization; then the channels on both sides are narrowed, the flow rate increases, and the mixing effect of the fluid is enhanced.

[0029] 3. A spoiler tip is set at the bottom of the octopus-shaped diversion baffle. The vortex-breaking sharp corner can prevent the high-speed fluids on both sides from accumulating and forming vortices when flowing to the lower part of the reaction channel. The fluid will not form a widely distributed retention boundary layer here, thereby improving the mass transfer and mixing efficiency in the lower part of the reaction channel.

[0030] In summary, the present invention effectively solves the problem of wide and large-area stagnant boundary layer distribution in the heart-shaped structure microchannel reactor, greatly improves the mass transfer efficiency, is more applicable to working conditions with low flow rates of fluid media, and has a better mixing effect; it is not easy to produce fluid residual accumulation and dead zones, and there are high-speed flow fields on both sides of the diverter baffle, which solves the problem that the stagnant boundary layer distributed on the wall is difficult to diffuse and transfer mass to the high-speed flow field.

[0031] After the structure of the present invention is optimized, the retained boundary layer has a very narrow distribution and can easily diffuse and transfer mass to the surrounding high-speed flow field area, thereby greatly improving the mass transfer efficiency.

[0032] The present invention uses the inlet jet method to cause the fluid to continuously collide and split, mix and reorganize, and accelerate the fragmentation, thereby increasing the contact area, improving the magnitude of molecular diffusion, and effectively enhancing the mixing efficiency of the fluid, thereby achieving rapid mixing between phases.

[0033] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the structure of the heart-shaped reaction chamber.

[0035] Figure 2 Schematic diagram of the structure of the reaction chamber of the present invention.

[0036] Figure 3 This is a cloud diagram of the vector flow velocity in the reaction chamber of the present invention.

[0037] Figure 4 This is the vector phase diagram inside the reaction chamber of the present invention.

[0038] Figure 5 It is a structural schematic diagram of the multi-stage series microchannel reactor of the present invention.

[0039] Figure 6 It is a structural schematic diagram of the inlet section of the multi-stage series microchannel reactor of the present invention.

[0040] Figure 7 It is a structural schematic diagram of the outlet section of the multi-stage series microchannel reactor of the present invention.

[0041] Description of the accompanying drawings:

[0042] DETAILED DESCRIPTION

[0043] Example 1

[0044] like Figure 2 — Figure 4 As shown, the present invention discloses a reaction chamber 2, comprising a chamber shell and an octopus-shaped diversion baffle 10 inside the chamber shell; the chamber shell is in a water drop shape, the chamber feed port of the chamber shell is at the head of the water drop shape, and the chamber discharge port of the chamber shell is at the tail of the water drop shape;

[0045] A mixing channel is formed between the octopus-shaped diversion baffle 10 and the inner wall of the cavity shell, and the mixing channel includes a collision shear section 12, a deceleration and recombination section 13, an acceleration section 14 and a mixing section 15;

[0046] The collision shear section 12 is a flow channel between the inner wall of the cavity shell on both sides of the cavity feed port and the octopus head of the octopus-shaped diverter baffle 10. When the mixed fluid enters from the cavity feed port, the mixed fluid impacts the octopus head of the octopus-shaped diverter baffle 10 at high speed in the collision shear section 12, and the mixed fluid is accelerated, collided and sheared, and the mixed fluid is divided into two and flows to the flow channels on both sides of the octopus head;

[0047] The deceleration and recombining section 13 is a flow channel between the waist of the inner wall on both sides of the cavity shell and the waist of the octopus-shaped diversion baffle 10 on both sides. When the mixed fluid flows through the deceleration and recombining section 13, the flow channel gradually widens and the flow rate decreases. The mixed fluid is mixed, recombined and accumulated in this area;

[0048] The acceleration section 14 is a flow channel between the lower waist of the inner wall on both sides of the cavity shell and the tentacles on both sides of the octopus tail of the octopus-shaped diversion baffle 10. When the mixed fluid flows through the acceleration section 14, the mixed fluid is squeezed and accelerated to pass through, the fluid flow rate increases, and the fluids are forced to contact and penetrate each other;

[0049] The mixing section 15 is a flow channel between the inner wall of the cavity shell tail and the octopus tail of the octopus-like diverter baffle 10, and is connected to the cavity discharge port; the middle position of the octopus tail of the octopus-like diverter baffle 10 has a vortex-breaking sharp corner 11, which is used to break the vortex formed after the fluid is accelerated by the acceleration section 14, so that the movement direction of the high-speed mixed fluid flowing out of the acceleration section 14 is toward the cavity discharge port.

[0050] It should be noted that the vortex breaking corner 11 is an acute angle structure with the tip pointing toward the cavity discharge port.

[0051] It should be noted that, in the collision and shear section 12, in actual use, at least two fluids are squeezed together at the outlet through the three-division inlet unit 1 to form a mixed fluid, and the mixed fluid forms a jet through the inlet of the reaction chamber 2. The fluids impact the octopus-shaped diversion baffle 10 at high speed, and the mixed fluid is accelerated, collided and sheared, and the mixed fluid is split into two and flows into the channels on both sides;

[0052] Deceleration and reorganization section 13: The fluid flows through the waist area of ​​the channels on both sides, the channels become wider, the flow rate decreases, and the fluid is mixed, reorganized and accumulated in this area;

[0053] Acceleration section 14: The mixed and recombined fluids pass through a narrow channel, where they are squeezed and accelerated, the fluid flow rate increases, and the fluids are forced to contact and penetrate each other, further improving the mixing effect.

[0054] Mixing section 15: Since the commonly used heart-shaped channel on the market will form a dead zone below the baffle, the present invention designs a vortex breaking corner 11 below. Figure 3 and Figure 4 From the vector streamline diagram, it can be seen that the mixed fluid does not produce any retention phenomenon in the mixing section 15, breaking the vortex formed after the fluid is accelerated by the acceleration section 14, so that the high-speed fluids on both sides maintain their original motion and flow out of the reaction chamber 2 after mixing, and enter the downstream reaction chamber for mixing.

[0055] It should be noted that the teardrop-shaped cavity structure and smooth diversion baffle design can reduce inlet turbulence and pressure drop and reduce energy loss. The path from the feed port (head) to the discharge port (tail) conforms to the natural flow direction of the fluid and avoids backflow.

[0056] In the collision shear section 12, high-speed impact realizes molecular-level shearing, breaking up fluid agglomerates. The presence of the octopus-shaped diversion baffle 10 forces diversion (one into two) to eliminate the risk of biased flow. The presence of the deceleration and reorganization section 13 reduces the flow velocity, prolongs the fluid residence time, promotes molecular diffusion, and causes laminar interface fusion of different components in the low-speed area.

[0057] The presence of the acceleration section 14 (inter-tentacle squeezing) increases the shear rate through the narrow flow channel (Bernoulli effect).

[0058] The presence of the mixing section 15 allows the sharp corners to destroy the Karman vortex street and prevent energy dissipation at the outlet.

[0059] Example 2

[0060] like Figure 5 — Figure 7 As shown, the present invention discloses a multi-stage series microchannel reactor, comprising:

[0061] a three-dividing inlet unit 1;

[0062] N reaction chambers 2 as described in Example 1 are sequentially connected in series, wherein N is an integer greater than or equal to 1;

[0063] an outlet unit 3;

[0064] The three-division inlet unit 1, the N reaction chambers 2 connected in series, and the outlet unit 3 are connected in sequence;

[0065] The cavity feed port of the first reaction cavity 2 is connected to the outlet end of the three-division inlet unit 1, and the cavity discharge port of the last reaction cavity 2 is connected to the inlet end of the outlet unit 3. The outlet end 9 of the outlet unit 3 is used for discharging materials.

[0066] It should be noted that multiple chambers in series (N≥2) achieve industrial-grade throughput (linear growth in production capacity); maintain the same flow state in each unit (geometric similarity principle), avoiding the loss of transfer efficiency when traditional reactors are scaled up; the series structure realizes step-by-step reactions (such as: A+B→C, C+D→E), which is suitable for complex multi-step syntheses (such as continuous production of pharmaceutical APIs).

[0067] In this embodiment, the interior of the microchannel reactor is a solid structure except for the reaction cavity 2 .

[0068] It should be noted that the solid structure ensures that the fluid only passes through the designed flow channel, avoiding bypass or stagnation areas; there are no internal gaps, which improves overall stability.

[0069] In this embodiment, N reaction chambers 2 connected in series are arranged in multiple rows, and two reaction chambers 2 connected in adjacent rows are connected via a U-shaped tube 4 and are arranged in reverse parallel.

[0070] It should be noted that the U-shaped tube 4 achieves a 180° turn, which can significantly reduce local resistance loss compared to a right-angle elbow; the reverse parallel arrangement reduces the size of the equipment and is suitable for scenarios with limited space (such as micro-chemical plants).

[0071] In this embodiment, the three-way flow inlet unit 1 has a first feed port 5 and a second feed port 6; the first feed port 5 is connected to the cavity feed port of the first reaction chamber 2 through a first pipeline 7; the second feed port 6 is connected to the end of the first pipeline 7 through a second pipeline 8, and the first pipeline 7 is arranged on the periphery of the second pipeline 8.

[0072] It should be noted that fluid A is introduced into the first pipeline 7 (peripheral main pipeline) and fluid B is introduced into the second pipeline 8 to achieve sleeve-type premixing to avoid local overheating / overconcentration caused by sudden mixing; the peripheral fluid wraps the central flow (similar to a coaxial syringe), and the flow rate gradient is used to enhance the initial mixing; the dual feed ports independently control the flow rate to adapt to reactions with different stoichiometric ratios (such as A:B=1:1 to 1:10).

[0073] In summary, the present invention discloses a mixer formed by a three-division inlet unit 1, several reaction chambers 2 connected in series, and an outlet unit 3 connected in sequence, so as to solve the problem of quickly and efficiently completing uniform mixing of liquid and liquid, gas and liquid, or gas and gas at high throughput. The present invention is used for high-throughput rapid mixing of two or more fluids.

[0074] The present invention forms partial turbulent mixing under a high Reynolds index, improves the magnitude of molecular diffusion, and has extremely high mixing efficiency; when the inlet has a small flux, the mixing effect between the two-phase fluids is better.

[0075] Deionized water was fed into the microreactor through the first feed port 5 using a metering pump at flow rates of 50, 60, 70, 80, 90, and 100 ml / min, respectively. Deionized water was then fed into the microchannel reactor through the second feed port 6 using a metering pump at the same flow rate. After the fluid in the microchannel stabilized, the pressure at its inlet and outlet was measured, and the inlet and outlet pressure difference was calculated. A pressure drop test was also performed on a commercially available heart-shaped microchannel reactor, and the pressure drop results are compared as shown in the following table:

[0076] .

[0077] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A reaction chamber, characterized in that: The invention comprises a cavity shell and an octopus-shaped diversion baffle inside the cavity shell; the cavity shell is in a water drop shape, the cavity feed port of the cavity shell is at the head of the water drop shape, and the cavity discharge port of the cavity shell is at the tail of the water drop shape; A mixing channel is formed between the octopus-shaped diversion baffle and the inner wall of the cavity shell, and the mixing channel includes a collision shear section, a deceleration and recombination section, an acceleration section and a mixing section; The collision shear section is a flow channel between the inner wall of the cavity shell on both sides of the cavity feed inlet and the octopus head of the octopus-shaped diverter baffle. When the mixed fluid enters from the cavity feed inlet, the mixed fluid impacts the octopus head of the octopus-shaped diverter baffle at high speed in the collision shear section, and the mixed fluid is accelerated, collided and sheared, and the mixed fluid is divided into two and flows to the flow channels on both sides of the octopus head. The deceleration and reorganization section is a flow channel between the waist of the inner wall on both sides of the cavity shell and the waist of both sides of the octopus-shaped diversion baffle. When the mixed fluid flows through the deceleration and reorganization section, the flow channel gradually widens and the flow rate decreases. The mixed fluid is mixed, reorganized and accumulated in this area. The acceleration section is a flow channel between the lower waist of the inner wall on both sides of the cavity shell and the tentacles on both sides of the octopus tail of the octopus-shaped diversion baffle. When the mixed fluid flows through the acceleration section, the mixed fluid is squeezed and accelerated to pass through, the fluid flow rate increases, and the fluids are forced to contact and penetrate each other; The mixing section is a flow channel between the inner wall of the cavity shell tail and the octopus tail of the octopus-shaped diverter baffle, and is connected to the cavity discharge port; the middle position of the octopus tail of the octopus-shaped diverter baffle has a vortex-breaking sharp corner, which is used to break the vortex formed after the fluid is accelerated by the acceleration section, so that the movement direction of the high-speed mixed fluid flowing out of the acceleration section is toward the cavity discharge port.

2. The reaction chamber according to claim 1, characterized in that: The vortex breaking corner is an acute angle structure with the tip facing the cavity discharge port.

3. A multi-stage series microchannel reactor, characterized in that: include: a three-way inlet unit; N reaction chambers according to claim 1 or 2 connected in series, wherein N is an integer greater than or equal to 1; an export unit; The three-division inlet unit, the N reaction chambers connected in series, and the outlet unit are connected in sequence; The cavity feed port of the first reaction cavity is connected to the outlet end of the three-division inlet unit, and the cavity discharge port of the last reaction cavity is connected to the inlet end of the outlet unit.

4. The multi-stage serial microchannel reactor according to claim 3, characterized in that: The interior of the microchannel reactor is a solid structure except for the reaction cavity.

5. The multi-stage serial microchannel reactor according to claim 3, characterized in that: N reaction chambers connected in series are arranged in multiple rows, and two reaction chambers connected between adjacent rows are connected by U-shaped tubes and arranged in reverse parallel.

6. The multi-stage serial microchannel reactor according to claim 3, characterized in that: The three-division inlet unit has a first feed port and a second feed port; the first feed port is connected to the cavity feed port of the first reaction cavity through a first pipeline; the second feed port is connected to the end of the first pipeline through a second pipeline, and the first pipeline is arranged on the periphery of the second pipeline.

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