A mixing device for solution preparation

Abstract

The utility model discloses a kind of mixing device for solution preparation, it relates to solution preparation technical field, the mixing device for solution preparation, including reaction kettle, stirring mechanism and raw material dispersion mechanism, stirring mechanism is located inside reaction kettle, for the mixture of magnesium filings and organic solvent is mixed and dispersed, raw material dispersion mechanism is used to be evenly transported and dispersed to the different area in reaction kettle of magnesium filings, stirring mechanism includes stirring shaft, multistage paddle assembly and be set at multistage paddle tail end telescopic spoiler, telescopic spoiler is unfolded with the change of stirring speed in stirring process automatically, to adjust fluid disturbance range. The utility model is by integrating multistage paddle assembly, telescopic spoiler, ultrasonic transmitter, hollow stirring shaft inert gas injection system and magnetic coupling conical flow guide structure, realize that magnesium filings is in organic solvent High-efficient dispersion and uniform mixing, effectively improve the stability and reaction efficiency of grignard reagent preparation process.

Description

Technical Field

[0001] This utility model relates to the field of solution preparation technology, and in particular to a mixing device for solution preparation. Background Technology

[0002] In the synthesis of 4-isopropylpyridine, Grignard reagents are one of the key intermediates, and their preparation quality directly affects the efficiency of subsequent reactions and the purity of the final product.

[0003] However, traditional Grignard reagent preparation methods generally suffer from uneven dispersion of magnesium shavings in organic solvents (such as tetrahydrofuran or diethyl ether), and easy agglomeration and deposition at the bottom or side walls of the reaction vessel. This results in insufficient reaction contact area, leading to delayed start-up or incomplete reaction. At the same time, since the reaction is a violently exothermic process, insufficient local mixing can easily cause heat accumulation, leading to side reactions or even safety risks, seriously affecting the reproducibility of the reaction and product yield. Utility Model Content

[0004] This utility model provides a mixing device for solution preparation, including a reaction vessel, a stirring mechanism, and a raw material dispersion mechanism. The stirring mechanism is located inside the reaction vessel and is used to mix and disperse a mixture of magnesium shavings and organic solvent. The raw material dispersion mechanism is used to uniformly transport and disperse the magnesium shavings to different areas inside the reaction vessel. The stirring mechanism includes a stirring shaft, a multi-stage blade assembly, and a retractable baffle at the end of the multi-stage blades. The retractable baffle automatically expands during the stirring process as the stirring speed changes to adjust the range of fluid disturbance.

[0005] Preferably, the multi-stage impeller assembly includes a turbine-type impeller fixed on the upper layer of the stirring shaft and an anchor-type impeller on the lower layer. The turbine-type impeller is used to generate a strong shear flow to break up the agglomerated magnesium shavings, and the anchor-type impeller rotates close to the inner wall of the reactor to prevent magnesium shavings from depositing on the side wall.

[0006] Preferably, the retractable agitator is made of an elastic metal sheet with an arc-shaped structure, hinged to an opening at the end of the turbine blade. Limiting plates are provided on both sides of the opening. When the stirring speed exceeds a set threshold, it automatically expands outward under the action of centrifugal force and automatically retracts when the speed decreases.

[0007] Preferably, the outer circumferential side of the reactor is provided with multiple ultrasonic transmitters for synchronously emitting ultrasonic waves during the stirring process.

[0008] Preferably, the stirring shaft has a hollow structure with multiple radial injection holes on its sidewall. The upper end of the stirring shaft extends to the outside of the reactor and is connected to an external inert gas supply system for injecting tiny inert bubbles into the reactor during the stirring process to form a gas-liquid-solid three-phase mixed flow.

[0009] Preferably, the bottom of the reactor is provided with a conical hopper, and the cavity of the conical hopper is embedded with an array of permanent magnets, which forms a magnetic coupling with the magnetic anchor blades to help guide the fluid to flow upward and form a bottom-up circulating flow field.

[0010] Preferably, the raw material dispersion mechanism includes a dispersion plate fixed inside the reactor, a plurality of discharge holes are distributed in a ring on the dispersion plate, a stirring shaft passes through the center of the dispersion plate and is rotatably connected to the dispersion plate, and a push plate is fixedly connected to the upper part of the stirring shaft, with the lower side of the push plate abutting against the upper side of the dispersion plate.

[0011] Preferably, one end of the pusher plate is rotatably equipped with a ball bearing, which rolls within a groove opened on the inner wall of the reactor.

[0012] Preferably, a dispersion chamber is provided on the upper side of the reactor, and a radial discharge port is provided at the lower end of the dispersion chamber.

[0013] Preferably, a driven wheel is fixedly connected to the upper end of the stirring shaft, and a driving wheel is rotatably provided at the upper end of the reactor. The driving wheel and the driven wheel mesh with each other, and the driving wheel is driven by a motor.

[0014] This utility model provides a mixing device for solution preparation, which, compared with the prior art, has the following advantages:

[0015] 1. This utility model improves the uniformity of magnesium shavings dispersion and reaction start-up efficiency in organic solvents by setting up a stirring mechanism and a raw material dispersion mechanism in synergy. It adopts a multi-stage blade assembly. The upper turbine blade generates a strong shear flow to break up the agglomerated magnesium shavings, while the lower anchor blade rotates close to the inner wall of the reactor, effectively preventing magnesium shavings from depositing on the side walls and bottom. At the same time, a retractable baffle is set at the end of the blade. It automatically expands under the action of centrifugal force as the stirring speed increases, expanding the fluid disturbance range and enhancing the mixing intensity. When the speed decreases, it automatically retracts to reduce energy consumption and realize the dynamic adjustment of stirring performance. Furthermore, it combines an ultrasonic transmitter to perform acoustic-assisted dispersion of materials, effectively breaking up small agglomerates and improving the initial reaction activity, thereby improving the overall stability and reaction efficiency of the Grignard reagent preparation process.

[0016] 2. This invention introduces inert gas through radial injection holes on the hollow stirring shaft, forming microbubbles in the reaction system and constructing a gas-liquid-solid three-phase mixed flow. This not only enhances the suspension of magnesium chips but also plays a role in uniform mass transfer and heat dissipation, avoiding local overheating and side reactions. The conical hopper at the bottom of the reactor is embedded with a permanent magnet array, which forms a magnetic coupling with the magnetic anchor blades, guiding the fluid to form a circulating flow field from bottom to top, further suppressing solid sedimentation. The raw material dispersion mechanism achieves continuous and uniform feeding of magnesium chips through the cooperation of a rotating pusher plate and a dispersion plate with a discharge hole. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model;

[0019] Figure 2 This is a partial cross-sectional view of the reaction vessel according to an embodiment of the present invention;

[0020] Figure 3 This is a schematic cross-sectional view of the overall structure of the reactor according to an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the stirring mechanism structure according to an embodiment of the present invention;

[0022] Figure 5 This is an embodiment of the present utility model. Figure 4 A schematic diagram of the structure at point A;

[0023] Figure 6 This is a top view schematic diagram of the dispersion plate structure according to an embodiment of the present utility model;

[0024] Figure 7 This is a cross-sectional schematic diagram of the conical bucket structure according to an embodiment of the present utility model;

[0025] Figure 8 This is a schematic diagram of the ball groove structure according to an embodiment of the present invention.

[0026] Figure label:

[0027] 1. Reactor; 2. Stirring shaft; 3. Turbine blade; 4. Anchor blade; 5. Retractable agitator; 6. Opening; 7. Limiting plate; 8. Injection hole; 9. Push plate; 10. Ball bearing; 11. Driven wheel; 12. Driving wheel; 13. Dispersion plate; 14. Discharge hole; 15. Dispersion chamber; 16. Conical hopper; 17. Cavity; 18. Permanent magnet array; 19. Groove; 20. Ultrasonic transmitter. Detailed Implementation

[0028] The following detailed description, in conjunction with the accompanying drawings, outlines some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0029] Please refer to Figures 1-8This utility model provides a mixing device for solution preparation, including a reaction vessel 1, a stirring mechanism and a raw material dispersion mechanism. The various parts work together to achieve uniform feeding, efficient dispersion and stable reaction of magnesium chips.

[0030] Reactor 1 is a sealed pressure-resistant container with a feed inlet and observation window at the top and a discharge valve at the bottom. The vessel body is made of stainless steel and is polished to reduce material adhesion. During the reaction, nitrogen or argon is continuously introduced to maintain an inert atmosphere inside, preventing moisture and oxygen from entering and causing the Grignard reagent to decompose.

[0031] The stirring mechanism is located inside the reactor 1 and consists of a stirring shaft 2, a multi-stage blade assembly, and a retractable baffle 5.

[0032] The stirring shaft 2 is a vertically arranged hollow metal shaft. Its upper end extends out of the top cover of the reactor 1 and is connected to the drive system, while its lower end extends to a position close to the bottom of the reactor.

[0033] like Figure 4 As shown, the multi-stage impeller assembly includes a turbine impeller 3 fixed on the upper layer of the stirring shaft 2 and an anchor impeller 4 on the lower layer. The turbine impeller 3 has multiple radial blades and generates a strong shear flow when rotating at high speed, which can effectively break up the agglomerated magnesium shavings. The shape of the anchor impeller 4 matches the inner wall contour of the reactor 1 and runs close to the inner wall when rotating, preventing magnesium shavings from depositing on the side walls and bottom edges.

[0034] The retractable baffle 5 is made of an elastic metal sheet (such as spring steel or titanium alloy) and has an arc-shaped structure. It is installed in the opening 6 at the end of the turbine blade 3 by means of hinge. Parallel limiting plates 7 are provided on both sides of the opening 6 to limit the maximum deployment angle of the retractable baffle 5. When the stirring speed is low, the retractable baffle 5 relies on its own elasticity to maintain the contracted state, reducing flow resistance and energy consumption. When the speed increases to the set threshold, the centrifugal force overcomes the elastic restoring force and pushes the retractable baffle 5 to expand outward, significantly increasing the fluid disturbance area and enhancing the mixing intensity. It automatically retracts after the speed decreases, realizing the dynamic adjustment function.

[0035] The stirring shaft 2 adopts a hollow design, with multiple radial injection holes 8 distributed along the axial direction on its sidewall. The upper end of the shaft is connected to an external inert gas supply system (such as a high-purity nitrogen or argon source) through a rotary joint. During the stirring process, the inert gas is transported through the hollow shaft and released into the reaction system in the form of tiny bubbles from the injection holes 8, forming a gas-liquid-solid three-phase mixed flow. This design not only enhances the suspension of magnesium chips, but also promotes mass and heat transfer by driving fluid circulation through the rising bubbles, effectively alleviating the temperature accumulation caused by local heat release and avoiding side reactions. The injection holes 8 are bent downwards to prevent liquid from entering.

[0036] like Figure 7As shown, the bottom of the reactor 1 is provided with a conical bucket 16, which has a cavity 17 inside. The cavity 17 is embedded with a permanent magnet array 18. The magnetic poles are arranged in a specific direction to form a stable magnetic field. The anchor blade 4 is made of magnetic material (such as ferrite or neodymium iron boron composite material). When it rotates with the stirring shaft 2, it generates a magnetic coupling effect with the permanent magnet array 18 at the bottom, which further enhances the upward traction force of the fluid at the bottom. Combined with the guiding effect of the conical bucket 16, a spiral upward flow field is formed from bottom to top, which completely eliminates the dead corner at the bottom and prevents magnesium chips from settling.

[0037] Multiple ultrasonic transmitters 20 are evenly arranged around the outer wall of the reactor 1, with a working frequency of 20–40 kHz. They can be started synchronously with the stirring shaft 2. The ultrasonic waves penetrate the reactor wall and enter the reaction liquid phase, generating a cavitation effect, which further breaks up the tiny magnesium agglomerates, increases their specific surface area and reaction activity, and helps to quickly initiate the Grignard reaction, especially in the early stage of the reaction.

[0038] The raw material dispersion mechanism is used to achieve continuous and uniform addition of magnesium chips, avoiding excessive local concentration or blockage caused by one-time feeding. The raw material dispersion mechanism includes a dispersion chamber 15 set at the top of the reactor 1, a dispersion plate 13 located inside the reactor body, and a push plate 9 linked to the stirring shaft 2.

[0039] The dispersion bin 15 is used to store magnesium shavings to be added. It has radial discharge ports at the bottom to ensure that the material is initially evenly distributed.

[0040] The dispersion plate 13 is horizontally fixed inside the reactor 1. It has a through hole in the center for the stirring shaft 2 to pass through and is rotatably connected to it. Multiple discharge holes 14 are distributed in a ring on the dispersion plate 13 as channels for magnesium chips to enter the reaction zone.

[0041] The pusher plate 9 is fixed to the upper end of the stirring shaft 2, and its lower surface is in close contact with the upper surface of the dispersion plate 13. A ball bearing 10 is installed at one end of the pusher plate 9. The ball bearing 10 is embedded in the annular groove 19 opened in the inner wall of the reactor 1, so that the pusher plate 9 maintains a stable trajectory when rotating with the shaft. When the stirring shaft 2 rotates, the pusher plate 9 rotates synchronously, scraping and forcibly pushing the magnesium shavings falling from the dispersion chamber 15 to each discharge hole 14, so as to achieve uniform circumferential feeding.

[0042] The driven wheel 11 is fixedly connected to the upper end of the stirring shaft 2, and the top of the reactor 1 is provided with a rotatable driving wheel 12. The driving wheel 12 and the driven wheel 11 are driven by gear meshing. The driving wheel 12 is driven by an external motor.

[0043] In summary, firstly, magnesium shavings are stored in the dispersion chamber 15 and initially evenly distributed through the radial discharge ports. Then, the pusher plate 9, along with the rotating stirring shaft 2, scrapes them onto the discharge holes 14 on the dispersion plate 13, ensuring uniform circumferential feeding. The stirring shaft 2 drives a multi-stage impeller assembly. The upper turbine impeller 3 generates a strong shear flow to break up the agglomerated magnesium shavings, while the lower anchor impeller 4 adheres tightly to the inner wall to prevent deposition. At the same time, the retractable turbulence component 5 dynamically adjusts the mixing intensity according to the rotation speed. The hollow stirring shaft 2 releases inert gas through the injection holes 8 to form microbubbles, promoting mass and heat transfer. Combined with the magnetic coupling generated by the bottom conical bucket 16 and the permanent magnet array 18, the fluid is guided to circulate from bottom to top. The external ultrasonic transmitter 20 further assists in breaking up the magnesium shaving agglomerates and improving the reactivity.

[0044] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A mixing apparatus for solution preparation, characterized in that: The reactor includes a reaction vessel (1), a stirring mechanism, and a raw material dispersion mechanism. The stirring mechanism is located inside the reaction vessel (1) and is used to mix and disperse the mixture of magnesium chips and organic solvent. The raw material dispersion mechanism is used to uniformly transport and disperse the magnesium chips to different areas inside the reaction vessel (1). The stirring mechanism includes a stirring shaft (2), a multi-stage blade assembly, and a retractable baffle (5) located at the end of the multi-stage blades. The retractable baffle (5) automatically expands during the stirring process as the stirring speed changes, so as to adjust the range of fluid disturbance.

2. The solution-preparing mixing device according to claim 1, wherein: The multi-stage impeller assembly includes a turbine impeller (3) fixed on the upper layer of the stirring shaft (2) and an anchor impeller (4) on the lower layer. The turbine impeller (3) is used to generate a strong shear flow to break up the agglomerated magnesium chips, and the anchor impeller (4) rotates close to the inner wall of the reactor (1) to prevent magnesium chips from depositing on the side wall.

3. The mixing apparatus for solution preparation according to claim 2, characterized in that: The retractable turbulence component (5) is made of an elastic metal sheet and has an arc-shaped structure. It is hinged to the opening (6) at the end of the turbine blade (3). Limiting plates (7) are provided on both sides of the opening (6). When the stirring speed exceeds the set threshold, it automatically expands outward under the action of centrifugal force and automatically retracts when the speed decreases.

4. The solution-preparing mixing device according to claim 3, wherein: Multiple ultrasonic transmitters (20) are arranged circumferentially on the outer side of the reactor (1) for synchronously emitting ultrasonic waves during the stirring process.

5. The solution-preparing mixing device according to claim 4, wherein: The stirring shaft (2) has a hollow structure and multiple radial injection holes (8) on its side wall. The upper end of the stirring shaft (2) extends to the outside of the reactor (1) and is connected to an external inert gas supply system for injecting tiny inert bubbles into the reactor (1) during the stirring process to form a gas-liquid-solid three-phase mixed flow.

6. The mixing apparatus for solution preparation according to claim 5, characterized in that: The bottom of the reactor (1) is provided with a conical bucket (16), and the cavity (17) provided in the conical bucket (16) is embedded with a permanent magnet array (18), which forms a magnetic coupling with the magnetic anchor blade (4) to help guide the fluid to flow upward and form a circulating flow field from bottom to top.

7. The solution-preparing compounding device according to claim 1, wherein: The raw material dispersion mechanism includes a dispersion plate (13) fixed inside the reactor (1). Several discharge holes (14) are distributed in a ring on the dispersion plate (13). The stirring shaft (2) passes through the center of the dispersion plate (13) and is rotatably connected to the dispersion plate (13). A push plate (9) is fixedly connected to the upper part of the stirring shaft (2). The lower side of the push plate (9) is in contact with the upper side of the dispersion plate (13).

8. The mixing apparatus for solution preparation according to claim 7, characterized in that: One end of the pusher plate (9) is rotatably equipped with a ball bearing (10), which rolls in the groove (19) opened on the inner wall of the reactor (1).

9. The solution-preparing mixing device according to claim 8, wherein: The upper side of the reactor (1) is provided with a dispersion chamber (15), and the lower end of the dispersion chamber (15) is provided with a radioactive discharge port.

10. The solution-preparing compounding device according to claim 1, wherein: The upper end of the stirring shaft (2) is fixedly connected to a driven wheel (11), and the upper end of the reactor (1) is rotatably provided with a driving wheel (12). The driving wheel (12) and the driven wheel (11) mesh with each other, and the driving wheel (12) is driven by a motor.

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