Micro-nano bubble generation device based on ceramic membrane surface flow state optimization and generation method thereof

Abstract

The invention discloses a micro-nano bubble generation device based on ceramic membrane surface flow regime optimization and a generation method thereof.The micro-nano bubble generation device comprises a porous ceramic membrane and a power driving device, the power driving device is connected with a flow rate pressurizing device through a flow rate pressurizing pipeline, and the porous ceramic membrane is connected with the flow rate pressurizing device; the porous ceramic membrane is connected with a gas supply device through a gas conveying pipeline; the flow velocity supercharging device is used for providing flow velocity gradient and shear force on the surface of the porous ceramic membrane; and the power driving device and the gas supply device are connected with the monitoring control system. The generation method comprises the following steps: introducing gas into the porous ceramic membrane; continuous high-flow-speed liquid is applied through the power driving device, the flow speed pressurizing pipeline and the flow speed pressurizing device; running parameters of the gas supply device and the power driving device are monitored in real time, and dense vaporific micro-nano bubble water is generated on the surface of the porous ceramic membrane through dynamic adjustment. The sizes of the generated micro-nano bubbles are obviously reduced, and the micro-nano bubbles are uniformly distributed.

Description

Technical Field

[0001] The present invention belongs to aeration devices and methods, and specifically relates to a micro-nano bubble generation device based on the optimization of the surface flow state of a ceramic membrane and a method for generating the same. Background Art

[0002] Due to their extremely small volume, micro-nano bubbles have a higher number of bubbles under the same aeration volume, thus significantly increasing the gas-liquid specific surface area. In addition, due to the relatively high internal pressure of micro-nano bubbles, their residence time is relatively long. The higher internal pressure can resist the turbulent flow and buoyancy effects in the liquid, thereby prolonging the gas-liquid contact time. This long contact time significantly enhances the gas-liquid mass transfer efficiency and helps to achieve more efficient gas dissolution or pollutant oxidation during the water treatment process. However, existing micro-nano bubble generation methods mostly adopt mechanical cutting, Venturi injection, pressure release, ultrasonic, electrolysis and other methods. However, these technologies have some obvious deficiencies in application. For example, the pressure dissolution and gas release method requires a relatively high pressure (about 0.4 MPa) to be applied to the liquid, resulting in a significant increase in energy consumption; methods such as Venturi injection and mechanical cutting need to overcome the water flow resistance or pressurize the water, and the generated bubble size is relatively large; methods such as ultrasonic and electrolysis have relatively high energy consumption, and the generation concentration of micro-nano bubbles is limited.

[0003] Ceramic membranes have the advantages of strong chemical stability, high mechanical strength and good uniformity of micropore distribution, and are excellent micro-nano bubble diffusers. In a conventional ceramic membrane aeration system, the desorption of bubbles is mainly determined by the balance between buoyancy and the adhesion force on the surface of the ceramic membrane. When the buoyancy of the bubble is greater than the adhesion force between it and the surface of the ceramic membrane, the bubble will desorb. However, the buoyancy of micro-nano bubbles is relatively small, and being restricted by this desorption mechanism, they cannot desorb quickly, resulting in relatively large and widely distributed generated bubble diameters, which cannot meet the requirements of efficient gas-liquid mass transfer.

[0004] Generally speaking, existing ceramic membrane aeration devices and methods have disadvantages such as relatively large bubble sizes, low desorption efficiency and poor mass transfer performance. Summary of the Invention

[0005] Object of the Invention: In order to overcome the deficiencies existing in the prior art, the object of the present invention is to provide a micro-nano bubble generation device based on the optimization of the surface flow state of a ceramic membrane that can optimize the surface flow velocity conditions, has a high bubble generation efficiency and good gas mass transfer performance. Another object of the present invention is to provide a method for generating micro-nano bubbles based on the optimization of the surface flow state of a ceramic membrane with uniform bubble distribution.

[0006] Technical solution: A micro-nano bubble generating device based on the optimization of the surface flow state of a ceramic membrane according to the present invention includes a porous ceramic membrane and a power driving device. The power driving device is connected to a flow velocity boosting device through a flow velocity boosting pipeline, the porous ceramic membrane is connected to the flow velocity boosting device, and the porous ceramic membrane is connected to a gas supply device through a gas delivery pipeline; the flow velocity boosting device is used to provide a flow velocity gradient and shear force on the surface of the porous ceramic membrane; the power driving device, the gas supply device are connected to a monitoring and control system.

[0007] Further, the pore diameter of the porous ceramic membrane is 0.1 - 2 μm, the aeration pressure is 0.08 Mpa - 0.16 Mpa, and it has the characteristics of high mechanical strength, strong chemical stability and uniform pore size, and is suitable for efficient gas-liquid separation and micro-nano bubble generation.

[0008] Further, the power driving device is connected to the treated water.

[0009] Further, the flow velocity boosting device is a U-shaped cavity with an opening facing the porous ceramic membrane, and the straight outlet channel forms an angle of 0.5 - 5° with the surface of the ceramic membrane. The long side of the flow velocity boosting device is 8 - 9 cm, and the short side is 0.5 - 1.5 mm, so as to reduce the cross-sectional area and achieve the purpose of increasing the flow velocity.

[0010] Further, the gas supply device includes a gas generator, a gas flow controller, and a gas distributor. The gas distributor is used to supply gas evenly, and the gas flow controller is used to optimize the size and quantity of bubbles generated by aeration of the ceramic membrane.

[0011] Further, the monitoring and control system includes a gas flow sensor, a liquid flow sensor and a PLC control system. The gas flow sensor is arranged in the gas flow controller in the gas supply device, the liquid flow sensor is arranged at the power driving device, and the PLC control system is used to monitor the parameters of the gas flow sensor and the liquid flow sensor in real time and dynamically adjust the aeration pressure and aeration flow of the gas supply device, and the outlet flow of the power driving device.

[0012] The micro-nano bubble generating method according to the present invention includes the following steps:

[0013] Step 1, introducing gas into the porous ceramic membrane;

[0014] Step 2, applying a continuously high-flow liquid through the power driving device, the flow velocity boosting pipeline and the flow velocity boosting device;

[0015] Step 3, monitoring the distribution of micro-bubbles on the surface of the porous ceramic membrane in real time, dynamically adjusting the aeration pressure and aeration flow of the gas supply device and the outlet flow of the power driving device, so as to generate a dense fog-like micro-nano bubble water on the surface of the porous ceramic membrane, realizing precise control of the bubble size and concentration, and ensuring that the device is in the best operating state.

[0016] Furthermore, the aeration pressure of the gas supply device is 0.08 - 0.16 Mpa, and the aeration flow rate per unit area is 1.04×10 -3 ~2.08×10 -3 L / (cm 2 ·min). The outlet flow rate of the flow rate booster device is 0.5 - 2 m / s or more. The gas supply device is used to ensure that gas enters the ceramic membrane pores evenly, improve the gas-liquid mixing effect, and optimize the bubble generation conditions.

[0017] Furthermore, in step one, the gas is air, pure oxygen, ozone, or the gas to be purified.

[0018] Working principle: The liquid is accelerated to a high flow rate state by the surface flow pattern optimization device. When the liquid passes through the flow rate booster device, a high-speed liquid flow is formed due to the rapid reduction of the cross-section, thereby providing a significant flow rate gradient and shear force on the surface of the ceramic membrane. The strong shear force provided can effectively weaken the adhesion between the bubbles and the ceramic membrane surface, enabling them to detach earlier when they are smaller in size. At the same time, the high-speed fluid can further disperse the bubbles after they detach, making them evenly distributed in the liquid phase. The micro-nano bubbles generated by this device have smaller diameters and higher uniformity. In addition, the micro-nano bubbles prepared in this way have smaller diameters and higher internal pressures, and thus have a longer residence time. After stopping aeration, the milky white color in the liquid persists for a long time, which helps to significantly improve the gas-liquid mass transfer efficiency.

[0019] Beneficial effects: Compared with the prior art, the present invention has the following significant features:

[0020] 1. The size of the generated microbubbles is significantly reduced. The average diameter of the micron size is concentrated below 200 μm and is evenly distributed; the average diameter of the nano size is concentrated at 300 nm and is evenly distributed;

[0021] 2. The bubble detachment efficiency is significantly improved, the number of bubbles is significantly increased, and the gas-liquid mass transfer performance is significantly enhanced;

[0022] 3. The microbubbles have a longer residence time and remain dispersed within 3 - 5 minutes after stopping aeration, further improving the mass transfer effect;

[0023] 4. The device is flexible in operation and can adapt to different industrial requirements by adjusting the flow rate parameters;

[0024] 5. It consists only of a ceramic membrane and a surface flow pattern optimization device, is small in size, compact in structure, simple to operate and easy to maintain;

[0025] 6. The system has low energy consumption, the aeration pressure only needs 0.08 - 0.16 Mpa, and at the same time the gas utilization efficiency is significantly improved, making it suitable for large-scale industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 are schematic structural diagrams of Embodiment 1 and Embodiment 2 of the present invention;

[0027] Figure 2 is a perspective view of the flow velocity boosting device 4 of the present invention;

[0028] Figure 3 is a left view of the flow velocity boosting device 4 of the present invention;

[0029] Figure 4 is a size distribution diagram of the nano - bubbles of the present invention;

[0030] Figure 5 is a size distribution diagram of the micro - bubbles of the present invention;

[0031] Figure 6 is an aeration effect diagram without surface flow state optimization;

[0032] Figure 7 is a schematic structural diagram of Embodiment 3 of the present invention;

[0033] Figure 8 is a schematic structural diagram of Embodiment 4 of the present invention;

[0034] Figure 9 is a schematic structure of Embodiment 5 of the present invention;

[0035] Figure 10 is an in - tube micro - nano - bubble effect diagram of Embodiment 1 of the present invention;

[0036] Figure 11 is a direct outflow effect diagram of micro - nano - bubbles of Embodiment 5 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0037] Embodiment 1

[0038] As Figures 1 to 3, the power drive device 2 based on the surface flow regime optimization of the ceramic membrane is connected to the flow velocity boosting device 4 through the flow velocity boosting pipeline 3. The porous ceramic membrane 1 is an Al2O3 membrane with a porosity of 38% and a pore size range of 0.1 - 2 μm, and both the upper and lower ends are fixed with chucks. The upper chuck of the porous ceramic membrane 1 is embedded in the inner cavity of the flow velocity boosting device 4. The flow velocity boosting device 4 is a U-shaped cavity with an opening facing the porous ceramic membrane 1, and its outlet channel forms a small angle of less than 10° with the surface of the ceramic membrane. The front view of the porous ceramic membrane 1 is square, with a long side of 9 cm and a short side of 8 cm. The porous ceramic membrane 1 is connected to the gas supply device 5 through the gas delivery pipeline 6. The gas supply device 5 includes a gas generator, a gas flow controller, and a gas distributor. The gas distributor is used to supply gas evenly, and the gas flow controller is used to optimize the bubble size and quantity generated by aeration of the ceramic membrane. The flow velocity boosting device 4 is used to provide a flow velocity gradient and shear force on the surface of the porous ceramic membrane 1. The power drive device 2, the gas supply device 5 are connected to the monitoring and control system. The monitoring and control system includes a gas flow sensor, a liquid flow sensor, and a PLC control system. The gas flow sensor is set in the gas flow controller in the gas supply device 5, the liquid flow sensor is set at the power drive device 2, and the PLC control system is used to monitor the parameters of the gas flow sensor and the liquid flow sensor in real time and dynamically adjust the aeration pressure and aeration flow of the gas supply device 5, and the outlet flow velocity of the flow velocity boosting device 4. The power drive device 2, the flow velocity boosting pipeline 3, and the flow velocity boosting device 4 are collectively referred to as the surface flow regime optimization component.

[0039] During use, first place the porous ceramic membrane 1 in the upper middle part of the container containing the treated water 7, and adjust the aeration pressure and aeration flow of the gas supply device 5 so that the gas reaches the porous ceramic membrane 1 through the gas delivery pipeline 6 and reaches the optimal aeration state. The gas is air, pure oxygen, ozone, or the gas to be purified. Then adjust the power drive unit 2 so that the treated water reaches the flow velocity boosting device 4 through the flow velocity boosting pipeline 3 and reaches the set flow velocity at the outlet of the flow velocity boosting device 4, applying a continuous high-flow liquid to the porous ceramic membrane 1. Monitor the microbubble distribution on the surface of the porous ceramic membrane 1 in real time, and dynamically adjust the aeration pressure (0.08 - 0.16 Mpa) and aeration flow (0.15 - 0.3 L / min) of the gas supply device 5, and the outlet flow velocity (0.5 - 2 m / s or more) of the flow velocity boosting device 4. The gas released by the ceramic membrane unit 1 is cut by the high flow velocity of the flow velocity boosting device 4 to generate Figure 10 the dense fog-like micro-nano bubble water as shown.

[0040] As Figures 4 to 5 , in this embodiment, the size of the generated microbubbles is significantly reduced, the average diameter of the micron size is concentrated below 200 μm, and the distribution is uniform; the average diameter of the nano size is concentrated at 300 nm, and the distribution is uniform.

[0041] Comparative Example 1

[0042] The remaining structure of this comparative example is the same as that of Example 1, and the only difference is that: the surface flow state optimization component is removed. As Figure 6 , the effect diagram of normal aeration without surface flow state optimization shows the effect of aeration under the traditional method, with large bubble size, low desorption efficiency and poor mass transfer performance.

[0043] Example 2

[0044] As Figure 1 Arrange the porous ceramic membrane 1 in the upper-middle part of the container containing the treated water 7, adjust the aeration pressure and aeration flow rate of the gas supply device 5, so that the gas reaches the porous ceramic membrane 1 through the gas delivery pipeline 6 and reaches the optimal aeration state. Then adjust the power drive unit 2, so that the treated water reaches the flow rate booster device 4 through the flow rate booster pipeline 3 and reaches the set flow rate at the outlet of the flow rate booster device 4, and apply a continuous high-flow liquid to the porous ceramic membrane 1. The treated water 7 circulates in the container through the power drive unit.

[0045] Under laboratory conditions, the device of Example 1 was used to treat 9 L of an aqueous solution containing 300 ng / L of sulfamethoxazole, the water temperature was 13 °C, the aeration pressure of the porous ceramic membrane 1 was 0.12 Mpa, the ozone mass fraction was 1%, the aeration flow rate was 0.2 L / min, and the outlet surface flow rate of the surface flow state optimization component was 1 m / s. Aeration was carried out using the ceramic membrane with optimized surface flow state to degrade sulfamethoxazole. After aeration with the ceramic membrane with optimized surface flow state for 50 s, the ozone dosage reached 0.68 mg / L, and the degradation rate of sulfamethoxazole reached 100%.

[0046] Comparative Example 2

[0047] The remaining structure and process parameters of this comparative example are the same as those of Example 2, and the only differences are that: the surface flow state optimization component is removed, the porous ceramic membrane 1 is arranged at the bottom of the reactor, and the porous ceramic membrane 1 is replaced with a common titanium plate, and the titanium plate is arranged at the bottom of the reactor. Aeration was carried out using the titanium plate and the ceramic membrane without optimized surface flow state to degrade sulfamethoxazole. The results showed that after aeration with the titanium plate for 150 s, the ozone dosage reached 2.3 mg / L, and the degradation rate of sulfamethoxazole reached 100%. After aeration with the ceramic membrane without optimized surface flow state for 90 s, the ozone dosage reached 1.15 mg / L, and the degradation rate of sulfamethoxazole reached 100%. Degrading sulfamethoxazole using the ceramic membrane with optimized surface flow state can shorten the degradation time by 66.67% and 44.44% respectively compared with the titanium plate and the ceramic membrane without optimized surface flow state.

[0048] Example 3

[0049] As Figure 7, apply the structure of Example 1 to the water treatment of medium-sized devices. Place three sets of well-connected porous ceramic membranes 1 and flow rate boosting devices 4 in the middle of three containers that are about to receive treated water 7 and are connected in sequence. The treated water 7 flows through the three containers from top to bottom in sequence through the conveying module 8 and is discharged from the bottom of the third container. The power driving device 2 injects a small amount of treated water 7 into the center of the top of the flow rate boosting device 4 through the flow rate boosting pipeline 3. The gas supply device 5 is connected to the porous ceramic membrane 1 through the gas conveying pipeline 6.

[0050] Under pilot-scale conditions, operate in the form of three-stage series aeration to treat 1 m 3 / h of water volume. The residence time for each stage is 2 min. The water temperature is 13.5 °C. The size of the porous ceramic membrane 1 is 15 cm × 10 cm, the aeration pressure is 0.12 Mpa, the ozone mass fraction is greater than 6%, the aeration volume is 0.3 L / min, and the outlet surface flow velocity of the surface flow state optimization component is 1.5 m / s. Samples are taken at the outlet of each stage of the reactor to measure the liquid-phase ozone concentration.

[0051] Comparative Example 3

[0052] The rest of the structure and process parameters of this comparative example are the same as those of Example 3, and the only differences are: remove the surface flow state optimization component, arrange the pore ceramic membrane 1 at a depth of 1 / 4 of the water from the bottom of each stage of the reactor, and replace the porous ceramic membrane 1 with a common titanium plate, and the titanium plate is arranged at the bottom of each stage of the reactor. Compare the liquid-phase ozone concentration under aeration of the surface flow state optimized porous ceramic membrane 1 in Example 3 with the common titanium plate aeration in Comparative Example 3 and the non-surface flow state optimized porous ceramic membrane 1 in Comparative Example 3. The liquid-phase ozone concentrations at the outlet of each stage of the reactor using titanium plate aeration are 0.045 mg / L, 0.079 mg / L, and 0.132 mg / L. The liquid-phase ozone concentrations at the outlet of each stage of the reactor under aeration of the non-surface flow state optimized porous ceramic membrane 1 are 0.105 mg / L, 0.162 mg / L, and 0.251 mg / L. The liquid-phase ozone concentrations at the outlet of each stage of the reactor under aeration of the surface flow state optimized porous ceramic membrane 1 are 0.210 mg / L, 0.275 mg / L, and 0.360 mg / L. Using the non-surface flow state optimized ceramic membrane for aeration can increase the ozone dissolution amount by about 100% compared with titanium plate aeration. Using the ceramic membrane optimized by the surface flow state optimization technology can increase the ozone dissolution amount by about 200% - 400% due to the enhanced generation of micro-nano bubbles compared with titanium plate aeration.

[0053] Operating parameters and cost calculation:

[0054] For treating 10,000 m 3 / d, with an ozone dosage of 2 g / m 2Take the following as an example. When the ozone generator is at its rated output, the ozone concentration is 8 - 12 wt%. Set the number of 1 piece of porous ceramic membranes to 45 pieces, the size of a single membrane is 0.5 m × 0.14 m, with double-sided aeration. The aeration rate range per unit area of the porous ceramic membrane 1 is 0.36 - 0.6 m 3 / h·m 2 . Then, the aeration rate can be controlled by PLC to be 2.27 - 3.78 m 3 / h. To ensure the effect of optimized surface flow regime and no excessive energy consumption, the optimized surface flow velocity range is 1 - 1.5 m / s, and the water flow rate range is regulated by the PLC program to be 81 - 121.5 m 3 / h. Then, the selected pump power is approximately 4 - 8 kW.

[0055] If calculated at 0.5 yuan per degree of electricity, for treating 10,000 m 3 / d of water, the treatment cost of this method increases by approximately 0.5 - 1 cent per ton of water. Compared with titanium plate aeration, at the same ozone mass fraction and aeration rate, to reach the same ozone dissolution amount, the time can be shortened by 66.67%, that is, the efficiency is increased by more than 3 times. 2 / 3 of the ozone dosage can be saved. If pure oxygen is used as the oxygen source for the ozone generator, 3.8 - 6.4 L of pure oxygen can be saved per ton of water treated. Assuming the unit price of industrial pure oxygen is 1 yuan / m 3 , then 0.38 - 0.64 cents of cost can be saved per ton of water. At the same time, the power consumption of the ozone generator decreases by more than 66.67%. If calculated at 0.05 - 0.2 kW·h of electricity consumption per ton of water, then 0.8 - 3.3 cents of electricity cost can be saved per ton of water treated. The total cost per ton of water treated is reduced by approximately 0.68 - 2.94 cents.

[0056] Example 4

[0057] Such as Figure 8 , apply the structure of Example 1 to medium and small-sized devices. Place the well-connected porous ceramic membrane 1 and the flow velocity booster device 4 in the middle of the reaction vessel filled with treated water 7. The gas supply device 5 is connected to the top left side of the porous ceramic membrane 1 through the gas transmission pipeline 6, and the power drive device 2 injects the treated water 7 into the center of the top of the flow velocity booster device 4 through the flow velocity booster pipeline 3. The reaction vessel filled with treated water 7 is connected to another reaction vessel filled with treated water 7 through the chemical addition pipeline 9.

[0058] Generate a high-concentration ozone aqueous solution under extracorporeal circulation. Among them, the aeration pressure of the porous ceramic membrane 1 is 0.12 Mpa, and the aeration rate is 0.2 L / min. The ozone mass fraction is 6.2%. Samples are taken at 2, 4, 6, 8, 10, 20, 30, and 40 minutes to measure the liquid-phase ozone concentration. The liquid-phase ozone concentrations during aeration with the surface flow state optimized for the ceramic membrane are 1.244, 1.656, 2.047, 2.245, 2.391, 2.587, 2.643, and 2.689 mg / L respectively, and the apparent mass transfer coefficient is 0.229 min -1 Mix the prepared high-concentration ozone water into the remaining treated water 7 through the dosing pipeline 9 in a certain proportion to achieve the effects of disinfection and pollutant oxidation.

[0059] Comparative Example 4

[0060] The remaining structures and process parameters of this comparative example are the same as those of Example 4, and the only differences are: removing the surface flow state optimization component and replacing the porous ceramic membrane 1 with a titanium plate. The liquid-phase ozone concentrations during aeration without surface flow state optimization for the ceramic membrane are 0.910, 1.387, 1.652, 1.860, 2.012, 2.308, 2.448, and 2.557 mg / L respectively, and the apparent mass transfer coefficient is 0.162 min -1 The aeration pressure of the titanium plate is 0.02 Mpa, and the aeration rate is 0.2 L / min. Samples are taken at 2, 4, 6, 8, 10, 20, 30, and 40 minutes to measure the liquid-phase ozone concentration. The liquid-phase ozone concentrations during aeration with the titanium plate are 0.620, 1.005, 1.309, 1.468, 1.627, 2.052, 2.339, and 2.521 mg / L respectively, and the apparent mass transfer coefficient is 0.114 min -1 It can be seen that using the surface flow state optimization technology for the ceramic membrane to strengthen the generation of micro-nano bubbles can additionally promote more ozone to dissolve in water, and the mass transfer rate is increased by 48% additionally compared with the case without surface flow velocity, and is increased by 100% compared with titanium plate aeration.

[0061] Example 5

[0062] As Figure 9 , apply the structure of Example 1 to the laboratory device. Place the well-connected porous ceramic membrane 1 and the flow velocity boosting device 4 into the first empty reaction vessel. The gas supply device 5 is connected to the top left side of the porous ceramic membrane 1 through the gas delivery pipeline 6. The flow velocity boosting pipeline 3 is inserted into the reaction vessel of the treated water 7, and the treated water 7 is injected into the center of the top of the flow velocity boosting device 4 through the power driving device 2. The directly flowing bubble water is as Figure 11 .

[0063] Aerate at different ozone mass fractions and directly discharge the effluent. When the ozone mass fraction is 1.6%, the liquid-phase ozone concentration of the directly discharged effluent is 0.193 mg / L. When the ozone mass fraction is 4.3%, the liquid-phase ozone concentration of the directly discharged effluent is 0.445 mg / L. When the ozone generator output is set to 1.84 g / h and the ozone mass fraction is 6.2%, the liquid-phase ozone concentration of the directly discharged effluent is 0.670 mg / L.

Claims

1. A micro-nano bubble generating device based on ceramic membrane surface flow state optimization, characterized in that: The invention comprises a porous ceramic membrane (1) and a power drive device (2), wherein the power drive device (2) is connected to the flow velocity boosting device (4) via a flow velocity boosting pipeline (3), the porous ceramic membrane (1) is connected to the flow velocity boosting device (4), and the porous ceramic membrane (1) is connected to a gas supply device (5) via a gas delivery pipeline (6); the flow velocity boosting device (4) is used to provide a flow velocity gradient and shear force on the surface of the porous ceramic membrane (1); the power drive device (2) and the gas supply device (5) are connected to a monitoring and control system.

2. The micro-nano bubble generating device based on ceramic membrane surface flow state optimization according to claim 1 is characterized in that: The pore size of the porous ceramic membrane (1) is 0.1-2 μm, and the aeration pressure is 0.08 Mpa-0.16 Mpa.

3. The micro-nano bubble generating device based on ceramic membrane surface flow state optimization according to claim 1 is characterized in that: The power drive device (2) is connected to the treated water (7).

4. The micro-nano bubble generating device based on ceramic membrane surface flow state optimization according to claim 1 is characterized in that: The flow rate boosting device (4) is a U-shaped cavity with its opening facing the porous ceramic membrane (1), and its outlet channel forms an angle of less than 10° with the surface of the ceramic membrane (1).

5. The micro-nano bubble generating device based on surface flow optimization according to claim 4, characterized in that: The outlet of the flow rate booster device (4) has a long side of 8 to 9 cm and a short side of 0.5 to 1.5 mm.

6. The micro-nano bubble generating device based on ceramic membrane surface flow state optimization according to claim 1, characterized in that: The gas supply device (5) comprises a gas generator, a gas flow controller, and a gas distributor. The gas distributor is used to uniformly supply gas, and the gas flow controller is used to optimize the size and number of bubbles generated by aeration of the ceramic membrane (1).

7. The micro-nano bubble generating device based on ceramic membrane surface flow state optimization according to claim 1, characterized in that: The monitoring and control system comprises a gas flow sensor, a liquid flow sensor and a PLC control system. The gas flow sensor is arranged in a gas flow controller in the gas supply device (5). The liquid flow sensor is arranged at the power drive device (2) and calculates and displays the boost flow rate according to the outlet cross-sectional area of ​​the boost device (4). The PLC control system is used to monitor the parameters of the gas flow sensor and the liquid flow sensor in real time and dynamically adjust the aeration pressure and aeration flow of the gas supply device (5) and the outlet flow of the power drive device (2).

8. A method for generating micro-nano bubbles based on the micro-nano bubble generating device of ceramic membrane surface flow state optimization according to claim 1, characterized in that: The following steps are involved: Step 1, introducing gas into the porous ceramic membrane (1); Step 2, applying a continuous high-flow rate liquid through the power driving device (2), the flow rate boosting pipeline (3), and the flow rate boosting device (4); Step three, real-time monitoring of the microbubble distribution on the surface of the porous ceramic membrane (1), dynamically adjusting the aeration pressure and aeration flow of the gas supply device (5) and the outlet flow of the power drive device (2), so that dense mist of micro-nano bubble water is generated on the surface of the porous ceramic membrane (1).

9. The micro-nano bubble generation method according to claim 8, characterized in that: The aeration pressure of the gas supply device (5) is 0.08-0.16 MPa, and the aeration flow rate per unit area is 1.04×10 -3 ~2.08×10 -3 L / (cm 2 ·min), and the outlet flow rate of the flow rate boosting device (4) is above 0.5 to 2 m / s.

10. The method for generating micro-nano bubbles according to claim 8, characterized in that: In the step 1, the gas is air, pure oxygen, ozone or a gas to be purified.

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