Piezoelectric self-driven microreactor device and applications

Abstract

The application belongs to the field of micro chemical technology, and particularly relates to a piezoelectric self-driven micro reactor device and application. The piezoelectric self-driven micro reactor device comprises a spiral flow channel layer, a Tesla valve layer, a pump cavity layer and a cover plate which are sequentially stacked from bottom to top and detachably connected. Two inlets are arranged through the pump cavity layer, and a liquid storage cavity is formed in the pump cavity layer. A buzzer sheet is arranged between the pump cavity layer and the cover plate. A through hole is formed in the center of the pump cavity layer and the Tesla valve layer, and the through holes are located in the same vertical direction. A spiral flow channel is arranged on the spiral flow channel layer, and one end of the spiral flow channel extends to the side wall of the spiral flow channel layer and serves as an outlet. The piezoelectric self-driven micro reactor device uses the Tesla valve flow channel as an inlet, so that the flow of the reaction liquid is large and the response is fast. Under the driving of the buzzer sheet, multiple reaction liquids can be simultaneously delivered. The delivery of the reaction liquid is realized under a small volume. The working frequency is low, the flow pulsation is small, and the delivery of the reaction liquid is stable.

Description

Technical Field

[0001] This invention belongs to the field of microchemical technology, specifically a piezoelectric self-driven microreactor device and its application. Background Technology

[0002] In the field of microchemical technology, traditional microreactors typically rely on external pumps to drive fluid flow, which suffers from bottlenecks such as large size, high energy consumption, low integration, and noise. For example, conventional micropumps require precision valve structures, which can easily lead to increased fluid resistance, clogging, and high maintenance costs.

[0003] Existing microreactors mainly use multiple external pumps for fluid drive, which are bulky and noisy. However, using valved piezoelectric micropumps has the following drawbacks: 1. Valved pumps require check valves, which are complex in structure; 2. Check valves have limited lifespan and are prone to wear and fatigue; 3. Check valves have complex structures and slow response speeds. Summary of the Invention

[0004] To address the shortcomings of the existing technology, this invention provides a piezoelectric self-driven microreactor device and its application. The piezoelectric self-driven microreactor device uses a Tesla valve channel as the inlet, enabling a larger flow rate and faster response of the transported reaction liquid; driven by a buzzer, it can simultaneously transport multiple reaction liquids; it is easy to manufacture and has low cost; and it operates within a 15cm... 3 The following total volume enables fluid transport and reaction; the operating frequency is high, typically twice or more than that of valved pumps, enabling continuous and stable unidirectional flow and avoiding flow fluctuations caused by frequent valve opening and closing in valved pumps.

[0005] Based on the above technical objectives, the present invention adopts the following technical solution: The present invention protects a piezoelectric self-driven microreactor device, comprising a spiral flow channel layer 7, a Tesla valve layer 6, a pump chamber layer 5 and a cover plate 2, which are stacked from bottom to top and detachably connected by bolts 1 and nuts 8. A liquid storage chamber 13 is provided on the pump chamber layer 5, and a buzzer 3 is provided between the pump chamber layer 5 and the cover plate 2.

[0006] The function of the spiral flow channel layer 7 is to generate Dean's secondary flow. Due to centrifugal force, Dean's secondary flow phenomenon occurs in the arc-shaped channel, enhancing mixing and preventing excessively high or low local concentrations during the reaction from affecting the growth of titanium dioxide nanoparticles and thus causing uneven particle size. It also ensures that the reactants spend the same amount of time in the piezoelectric self-driven microreactor, avoiding batch-to-batch variations in the product.

[0007] The function of the Tesla valve layer 6 is unidirectional shut-off. When the reservoir 13 expands, reactants are drawn in from the inlet 11. At this time, the fluid of the reactants flows forward in the Tesla valve and is not shut off. When the reservoir 13 contracts, the reactants are pumped out from the reservoir 13, forming a jet, and enter the spiral channel of the spiral channel layer 7. However, a small amount of fluid will flow back to the inlet 11. At this time, the fluid flows in reverse in the Tesla valve and is shut off, thereby reducing the backflow of reactants and increasing the flow rate of the piezoelectric self-driven microreactor device.

[0008] The function of the buzzer 3 is to generate continuous alternating deformation under the action of an alternating signal, thereby producing the effect of expanding and contracting the liquid storage chamber 13. The working principle of the pump chamber layer 5 is that after expanding and contracting the liquid storage chamber 13, the liquid storage chamber 13 draws in and pumps out fluid to form a jet.

[0009] The buzzer 3 is composed of a piezoelectric ceramic ring 9, a copper sheet 10, and an electrode layer. The copper sheet 10 is used to amplify the vibration of the piezoelectric ceramic ring 9. The piezoelectric ceramic ring 9 is attached to the copper sheet 10, and the electrode layer is attached to the piezoelectric ceramic ring 9. The wires are connected to the copper sheet 10 and the electrode layer respectively. The buzzer 3 was purchased.

[0010] Two inlets 11 are provided through the pump chamber layer 5, which can penetrate the cover plate 2 and deliver different reactants through the two inlets 11 respectively; the outer diameter of the copper sheet 10 corresponds to the size of the liquid storage chamber 13, and a sealing ring 4 is provided between the copper sheet 10 and the liquid storage chamber 13; the buzzer 3 will deform, and if the sealing ring is not used, the liquid storage chamber 13 will leak. A wire is connected to the buzzer 3, and the wire is electrically connected to the signal generator.

[0011] Both the pump chamber layer 5 and the Tesla valve layer 6 have through holes in the center, and the through holes are located in the same vertical direction, so that the reactants can be pumped into the spiral flow channel layer 7 through the through holes on the pump chamber layer 5 and the Tesla valve layer 6.

[0012] A spiral flow channel is provided on the spiral flow channel layer 7, with one end of the spiral flow channel located in the center of the spiral flow channel layer 7 and the other end extending to the side wall of the spiral flow channel layer 7 and serving as the outlet 12.

[0013] Preferably, the cover plate 2 has a through slot, the function of which is to energize the buzzer 3, that is, to provide the buzzer 3 with an AC signal. The AC signal is generated by a signal generator, but the signal generator only has a very low voltage, so it needs to be passed through a voltage amplifier before being connected to the buzzer 3. Alternatively, the signal generation and amplification can be integrated together by an integrated circuit board, with the through slot corresponding to the position of the liquid storage cavity 13.

[0014] Preferably, the Tesla valve layer 6 is a two-inlet Tesla valve layer to a ten-inlet Tesla valve layer, all of which can be applied to this invention.

[0015] Preferably, the liquid storage chamber is a blind hole opened on the pump chamber layer 5, and the through hole is opened in the center of the blind hole.

[0016] This invention also protects the application of a piezoelectric self-driven microreactor device in the preparation of titanium dioxide nanofluids.

[0017] Preferably, the titanium dioxide nanofluid is prepared according to the following steps: An alternating signal is provided to the piezoelectric ceramic ring 9 by a signal generator, and the piezoelectric ceramic ring 9 drives the liquid storage chamber 13 to expand or compress.

[0018] When the storage chamber 13 expands, the titanium source alcohol solution and the alkali solution enter from different inlets 11 and flow into the Tesla valve layer 6. The titanium source alcohol solution and the alkali solution meet through the Tesla valve channel on the Tesla valve layer 6, and then enter the storage chamber 13 through the through holes opened on the Tesla valve layer 6 and the pump chamber layer 5, and mix in the storage chamber 13 to obtain the reaction solution.

[0019] When the storage chamber 13 is squeezed, the reaction liquid is pumped out from the through hole of the storage chamber 13; a jet is formed in the through hole of the storage chamber 13, similar to water jetting out into the through hole in the middle of the Tesla valve layer 6, and then enters the innermost ring of the spiral flow channel layer 7. The reaction liquid pumped out from the inner ring to the outer ring and then to the outlet continues to react in the spiral flow channel of the spiral flow channel layer 7, and the obtained titanium dioxide nanofluid is discharged through the outlet 12. The buzzer provides a power source to the storage chamber 13 through vibration, realizing the entry and exit of the reaction liquid in the storage chamber 13, and the fluid flow is caused by the jet action.

[0020] Preferably, the titanium source is titanium tetrachloride, tetrabutyl titanate, metatitanic acid, titanium trichloride, tetraethyl titanate, or isopropyl titanate; in the titanium source alcohol solution, the mass percentage of the titanium source is 0.1wt% to 10wt%.

[0021] Preferably, the alkaline solution is composed of ammonia, water and ethanol, wherein the mass percentage of ammonia in the alkaline solution is 0.5wt% to 5wt% and the mass percentage of water is 0.5wt% to 3wt%.

[0022] Preferably, the molar ratio of titanium source to alkali is 1~6:1.

[0023] Preferably, in the prepared titanium dioxide nanofluid, the particle size of the titanium dioxide nanoparticles is <50nm.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention uses a Tesla valve as the inlet, which increases the flow rate of the reaction liquid and increases the response time (existing technologies with valves require the opening and closing of the valve, which takes time; while this invention is a valveless type, which does not have a valve plate and pumps the fluid through a special structure, and the liquid starts to be pumped out as soon as the signal is triggered).

[0025] Driven by a buzzer, this invention can simultaneously deliver multiple reaction liquids (currently, reaction liquids are typically delivered on a flat surface by multiple piezoelectric micropumps, and valve-type reaction liquids have limited lifespan; this invention further simplifies the size of the microreactor and reduces the failure rate (it was found during the experiment that the buzzer had a high failure rate)).

[0026] The piezoelectric self-driven microreactor device of the present invention has the advantages of easy processing and low cost.

[0027] The piezoelectric self-driven microreactor device of this invention is located at 15 cm. 3 The overall volume below enables fluid transport and reaction, reducing the size of the piezoelectric self-driven microreactor device. Furthermore, the powerful heat and mass transfer capabilities of the microchannels reduce the particle size of the product, accelerate the reaction rate, and enable continuous synthesis (the reaction liquid is continuously passed through and the product is collected at the outlet). The mass of reactants reacting at the same time is small, reducing the risk.

[0028] The piezoelectric self-driven microreactor device of this invention operates at a high frequency, typically twice or more than that of a valved pump, enabling continuous and stable unidirectional flow and avoiding flow fluctuations caused by frequent valve opening and closing in valved pumps.

[0029] The piezoelectric self-driven microreactor device of the present invention can also realize gas transportation (gas is a fluid just like liquid; when no liquid is added, this piezoelectric self-driven microreactor device will pump out gas and discharge the residual liquid inside by pumping in air), and remove the reaction liquid residue inside the reactor.

[0030] 2. Since the reaction liquid stays in the piezoelectric self-driven microreactor device for the same amount of time, the batch-to-batch quality of the product can be guaranteed to be stable. The product quality of traditional reaction devices is different between large-scale and small-scale tests, while the piezoelectric self-driven microreactor device of this invention has no scale-up effect. Only multiple reactors need to be connected in parallel to achieve mass production.

[0031] 3. The piezoelectric self-driven microreactor device of the present invention is a valveless piezoelectric micropump. It achieves fluid drive by relying on the inverse piezoelectric effect of piezoelectric materials and has the advantages of small size, fast response (millisecond level), low energy consumption and no moving parts. Attached Figure Description

[0032] Figure 1 This is an exploded view of the piezoelectric self-driven microreactor device of the present invention.

[0033] Figure 2 This is a cross-sectional view of the piezoelectric self-driven microreactor device of the present invention.

[0034] Figure 3 This is a schematic diagram of the internal fluid flow of the piezoelectric self-driven microreactor device of the present invention.

[0035] Figure 4 This is a top view of the pump chamber layer of the piezoelectric self-driven microreactor device of the present invention.

[0036] Figure 5 This is a top view of the spiral flow channel layer of the piezoelectric self-driven microreactor device of the present invention.

[0037] Figure 6 This is a top view of the two-inlet Tesla valve layer of the piezoelectric self-driven microreactor device of the present invention.

[0038] Figure 7 This is a top view of the four-inlet Tesla valve layer of the piezoelectric self-driven microreactor device of the present invention.

[0039] Figure 8 This is a scanning electron microscope image of titanium dioxide powder prepared using the piezoelectric self-driven microreactor device of the present invention.

[0040] Figure 9 The figure shows the simulation results of the suction and pumping of the piezoelectric self-driven microreactor device of the present invention using COMSOL software.

[0041] Figure 10 The cumulative flow diagrams of the inlet and outlet of the piezoelectric self-driven microreactor device of this invention are obtained by using existing technology COMSOL Multiphysics multiphysics coupling calculation.

[0042] Figure 11 This is a physical image of the piezoelectric self-driven microreactor device of the present invention.

[0043] Explanation of reference numerals in the attached figures: 1- Bolt; 2- Cover plate; 3- Piezoelectric ceramic sheet; 4- Sealing ring; 5- Pump chamber layer; 6- Two-inlet Tesla valve layer; 7- Spiral flow channel layer; 8- Nut; 9- Piezoelectric ceramic ring; 10- Copper sheet; 11- Inlet; 12- Outlet; 13- Liquid storage chamber. Detailed Implementation

[0044] The present invention will be specifically described below through embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above content.

[0045] Example 1 A piezoelectric self-driven microreactor device, such as Figures 1-7As shown, it includes a spiral flow channel layer 7, a Tesla valve layer 6, a pump chamber layer 5, and a cover plate 2, which are stacked and detachably connected from bottom to top. A liquid storage chamber 13 is opened on the pump chamber layer 5. A buzzer 3 is arranged between the pump chamber layer 5 and the cover plate 2. The Tesla valve layer 6, the pump chamber layer 5, the sealing ring 4, the buzzer 3, and the cover plate 2 together form a piezoelectric micropump, and the spiral flow channel layer 7 is a microreactor.

[0046] The piezoelectric self-driven microreactor device of the present invention has two inlets 11 and one outlet 12. The two inlets 11 are respectively connected in the pump chamber layer 5. A spiral flow channel is provided on the spiral flow channel layer 7, and one end of the spiral flow channel is located in the center of the spiral flow channel layer 7, and the other end extends to the side wall of the spiral flow channel layer 7 and serves as the outlet 12.

[0047] The outer diameter of the buzzer 3 corresponds to the size of the liquid storage cavity 13, and a sealing ring 4 is provided between the buzzer 3 and the liquid storage cavity 13; a wire is connected to the buzzer 3, and the wire is electrically connected to the signal generator; after being electrically connected to the signal generator, the signal generator provides an alternating signal to the piezoelectric ceramic ring 9 to drive the liquid storage cavity 13 to vibrate up and down, expanding or squeezing the liquid storage cavity 13.

[0048] Both the pump chamber layer 5 and the Tesla valve layer 6 have through holes in their centers, and the through holes are located in the same vertical direction.

[0049] When the storage chamber 13 is expanded, fluid A (titanium source alcohol solution) and fluid B (alkali solution) enter from the two inlets 12 located on the pump chamber layer 5, respectively. They then meet through the Tesla valve channel of the Tesla valve layer 6 and converge at the through hole on the Tesla valve layer 6. They then enter the storage chamber 13 through the through holes opened on the Tesla valve layer 6 and the pump chamber layer 5, and mix in the storage chamber 13 to obtain the reaction solution. At the same time, a very small amount of reaction solution that was originally located at the through hole of the Tesla valve layer 6 also enters the storage chamber 13.

[0050] When the storage chamber 13 is squeezed, the reaction liquid is pumped out from the through hole of the storage chamber 13 and forms a jet. It enters the innermost circle of the spiral flow channel layer 7 through the through hole on the Tesla valve layer 6. The pumped reaction liquid continues to react in the spiral flow channel of the spiral flow channel layer 7 and the obtained titanium dioxide nanofluid is discharged through the outlet 12. Due to the one-way shut-off function of the Tesla valve, the liquid is reduced from flowing out of the inlet in the opposite direction along the Tesla flow channel.

[0051] Because of its multiple Tesla valve structures, this invention can achieve chemical reactions with various reaction solutions and different reaction solution ratios by designing different combinations of the number of inlets 11. Figure 7 This is an example of a reaction with a reaction solution ratio of 1:1:1:1.

[0052] Under the action of a high-frequency (100Hz~5000Hz) alternating signal, the present invention can draw in air from two inlets 11 and pump the gas out from outlet 12, as described above. This action removes residual liquid in the piezoelectric self-driven microreactor device, preventing contamination, affecting subsequent reactions, and damaging the piezoelectric self-driven microreactor device.

[0053] The present invention provides a spiral flow channel layer 7 below the Tesla valve layer 6. The pumped reaction liquid continues to react in the spiral flow channel 7. The Dean secondary flow generated by the spiral flow channel can continuously mix the reactants. According to the nucleation theory, when the nucleation raw materials are mixed strongly, a large amount of reactants are consumed in the nucleation stage, and the growth of micro and nano particles is therefore limited, resulting in a small particle size distribution of the particle product.

[0054] Example: Using a piezoelectric self-driven microreactor, a titanium source (tetrabutyl titanate) was dispersed at 2.2 wt% in ethanol to obtain solution A; 0.5 wt% alkaline solution (ammonia), 2 wt% water, and ethanol were mixed to obtain solution B; the reaction yielded titanium dioxide nanofluids with a size below 50 nm, as shown in the SEM image. Figure 8 As shown. The actual output of this device at 200Vpp is 30mL / min, obtained using existing COMSOL Multiphysics technology and multiphysics coupling calculations. The cumulative flow rates at the inlet and outlet are as follows... Figure 10 As shown, Figure 10 The results show that the piezoelectric self-driven microreactor device of the present invention can achieve stable flow output.

[0055] Figure 9 The figure shows the simulation results of the suction and pumping of the piezoelectric self-driven microreactor device of the present invention using COMSOL software. Figure 11 The image shown is a physical diagram of the piezoelectric self-driven microreactor device of this invention, which has been comprehensively analyzed through simulation and practical application.

[0056] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A piezoelectric self-driven microreactor device, characterized in that, It includes a spiral flow channel layer (7), a Tesla valve layer (6), a pump chamber layer (5), and a cover plate (2) that are stacked and detachably connected from bottom to top; Two inlets (11) are provided through the pump chamber layer (5), and the two inlets (11) penetrate the cover plate (2). A liquid storage chamber (13) is provided on the pump chamber layer (5). A buzzer (3) is provided between the pump chamber layer (5) and the cover plate (2). The outer diameter of the buzzer (3) corresponds to the size of the liquid storage chamber (13). A sealing ring (4) is provided between the buzzer (3) and the liquid storage chamber (13). A wire is connected to the buzzer (3). The wire is electrically connected to the signal generator. Both the pump chamber layer (5) and the Tesla valve layer (6) have through holes in their centers, and the through holes are located in the same vertical direction. The spiral flow channel layer (7) is provided with a spiral flow channel, and one end of the spiral flow channel is located in the center of the spiral flow channel layer (7), and the other end extends to the side wall of the spiral flow channel layer (7) and serves as an outlet (12).

2. The piezoelectric self-driven microreactor device according to claim 1, characterized in that, The cover plate (2) is also provided with a through slot to facilitate the power supply of the buzzer.

3. The piezoelectric self-driven microreactor device according to claim 1, characterized in that, The Tesla valve layer (6) consists of a two-inlet Tesla valve layer and a ten-inlet Tesla valve layer.

4. The piezoelectric self-driven microreactor device according to claim 1, characterized in that, The liquid storage chamber is a blind hole opened on the pump chamber layer (5).

5. The application of the piezoelectric self-driven microreactor device according to claim 1 in the preparation of titanium dioxide nanofluids.

6. The application according to claim 5, characterized in that, Titanium dioxide nanofluids were prepared according to the following steps: The signal generator provides an alternating signal to the buzzer (3), and the buzzer (3) drives the liquid storage chamber (13) to expand or compress. When the storage chamber (13) expands, the titanium source alcohol solution and the alkaline solution enter from different inlets (11) and flow into the Tesla valve layer (6). The titanium source alcohol solution and the alkaline solution meet through the Tesla valve channel on the Tesla valve layer (6) and then enter the storage chamber (13) through the through holes opened on the Tesla valve layer (6) and the pump chamber layer (5), and mix in the storage chamber (13) to obtain a reaction solution. When the reservoir (13) is squeezed, the reaction liquid is pumped out from the through hole of the reservoir (13) and forms a jet. It enters the innermost ring of the spiral flow channel layer (7) through the through hole on the Tesla valve layer (6). The pumped reaction liquid continues to react in the spiral flow channel of the spiral flow channel layer (7) and the obtained titanium dioxide nanofluid is discharged through the outlet (12).

7. The application according to claim 6, characterized in that, The titanium source is titanium tetrachloride, tetrabutyl titanate, metatitanic acid, titanium trichloride, tetraethyl titanate, or isopropyl titanate; in the titanium source alcohol solution, the mass percentage of the titanium source is 0.1wt%~10wt%.

8. The application according to claim 6, characterized in that, The alkaline solution is composed of ammonia, water and ethanol, with the mass percentage of ammonia in the alkaline solution being 0.5wt%~5wt% and the mass percentage of water being 0.5wt%~3wt%.

9. The application according to claim 6, characterized in that, The molar ratio of titanium source to alkali is 1~6:

1.

10. The application according to claim 6, characterized in that, In the prepared titanium dioxide nanofluid, the particle size of the titanium dioxide nanoparticles is <50nm.

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