Microbubble generation method and generation device

Abstract

The present invention relates to a method and device for generating microbubbles. The method for generating microbubbles includes the following steps: Step S1: A gas passes through a microporous material, and microbubbles are formed at the interface between the microporous material and the liquid. Due to the capillary effect of the microporous material, the bubbles are adsorbed on the surface of the microporous material; Step S2: Through the relative movement between the microporous material and the liquid, a cutting force is generated to impact the microbubbles adsorbed on the microporous material, so that the microbubbles are detached from the microporous material and enter the liquid. The present invention solves the technical problems of high energy consumption and great difficulty in the process of generating microbubbles, and poor microbubble generation effect.

Description

Technical Field

[0001] The present invention relates to the technical field of gas-liquid two-phase interface interaction, and particularly to a method and device for generating microbubbles. Background Art

[0002] Microbubbles are a special gas state existing at the interface between gas and liquid. Microbubbles are microbubbles with a diameter of less than one hundred micrometers generated during bubble generation. Microbubbles have characteristics such as self-boosting dissolution, increasing the gas-liquid interface area, carrying a negative surface charge, and reducing the friction and resistance of the liquid. They are widely used in many fields such as agriculture, environmental protection, chemical industry, energy, and ship speed increase. Other characteristics and applications of microbubbles are also constantly being discovered.

[0003] At present, there are various methods for generating microbubbles, such as the ultrasonic method, the pressure-release dissolved air method, the Venturi jet method, and the rotary cutting method, etc. However, due to the limited amount of bubbles generated by the ultrasonic method, and the complex equipment structure and large implementation difficulty required by the pressure-release dissolved air method, etc., the currently commonly used microbubble generation methods are the Venturi jet method and the rotary cutting method. Among them, the principle essence of the rotary cutting method is the same as that of the pressure-release method, both of which pressurize and dissolve gas through a high-speed rotating liquid and release pressure at the outlet to generate microbubbles. Compared with the pressure-release method, the rotary cutting method reduces the implementation difficulty and eliminates the complex pressurization equipment. Compared with the Venturi jet method, the water flow rotates forward, the water-gas fusion process is longer, and the bubble diameter formed at the outlet is finer. However, both the Venturi jet method and the rotary cutting method require the use of large water pumps or dissolved air pumps at the front end (requiring a head of 20m to 40m and a water pressure of 0.2MPa to 0.5MPa). These two methods cannot generate microbubbles at low speed and low pressure; limited by the water pump itself, the water-gas ratio currently cannot exceed 10:1 (that is, to generate 1 volume of microbubbles, 10 volumes of high-speed water flow are required); in addition, both the Venturi tube and the rotary cutter for generating microbubbles accelerate the water flow by shrinking the pipe diameter and finally perform high-speed jet at the outlet. Therefore, both the Venturi tube and the rotary cutter for generating microbubbles require huge energy consumption, and the rotation and friction of water during extrusion to generate heat are also an important factor in high energy consumption. When using the Venturi jet method and the rotary cutting method, large vehicles (such as forklifts or cranes, etc.) are required to transport the large water pumps or dissolved air pumps, and the construction difficulty is large. The above-mentioned various problems greatly restrict the popularization and application of microbubbles in actual production.

[0004] In view of the problems of high energy consumption, great difficulty, and poor microbubble generation effect in the process of generating microbubbles in the related art, no effective solution has been given yet.

[0005] Accordingly, based on years of experience and practice in the relevant industry, the present inventor proposes a microbubble generation method and a generation device to overcome the defects of the prior art. Summary of the Invention

[0006] An object of the present invention is to provide a microbubble generation method and a generation device. By applying pressure to a gas to make it pass through a microporous material and form microbubbles at the interface between the microporous material and a liquid, and then through the relative movement between the microporous material and the liquid, cutting the microbubbles before the bubbles themselves grow larger and merge with adjacent microbubbles to grow rapidly, so that they are peeled off the surface of the microporous material and enter the liquid in the form of microbubbles (with a diameter less than 100 μm), thereby achieving the purpose of generating microbubbles. Since this process does not require high-speed movement of the liquid and frictional heat generation under high pressure, it greatly reduces production energy consumption and saves costs. Moreover, the device has a simple structure and is easy to operate, with great economic benefits and is suitable for popularization and use.

[0007] The present invention can be realized by the following technical solutions:

[0008] The present invention provides a microbubble generation method, and the microbubble generation method includes the following steps:

[0009] Step S1: A gas passes through a microporous material and forms microbubbles at the interface between the microporous material and a liquid;

[0010] Step S2: Through the relative movement between the microporous material and the liquid, impact the microbubbles adsorbed on the microporous material so that the microbubbles are separated from the microporous material and enter the liquid.

[0011] In a preferred embodiment of the present invention, in step S2, the shear force of the liquid on the microbubbles is greater than the adsorption force of the capillary effect of the microporous material on the microbubbles.

[0012] The present invention provides a microbubble generation device, which includes an air-containing chamber disposed below the liquid level and a gas transmission pipeline for delivering gas into the air-containing chamber. A microporous material layer through which the gas in the air-containing chamber can pass is annularly provided around the air-containing chamber. One end of the gas transmission pipeline is located above the liquid level and is connected to a gas source, and the other end of the gas transmission pipeline extends into the air-containing chamber to make the gas in the air-containing chamber pass through the microporous material layer through air pressure and form microbubbles on the outer surface of the microporous material layer;

[0013] The microporous material layer moves and / or the liquid located outside the microporous material layer moves to cut the microbubbles so that the microbubbles enter the liquid.

[0014] In a preferred embodiment of the present invention, an air pump, a primary filter, and a secondary filter are sequentially arranged on the gas transmission pipeline along the gas flow direction, and the pore diameter of the filter element on the secondary filter is smaller than the pore diameter of the filter element on the primary filter and the pore diameter of the microporous material layer.

[0015] In a preferred embodiment of the present invention, a flow meter and a pressure gauge are arranged on the gas transmission pipeline, and an adjustment knob for controlling the gas flow rate is arranged on the flow meter.

[0016] In a preferred embodiment of the present invention, the thickness of the microporous material layer gradually increases from bottom to top.

[0017] In a preferred embodiment of the present invention, the microbubble generating device further includes an outer rotor motor for driving the circumferential rotation of the air storage chamber. The outer rotor motor is arranged inside the air storage chamber, and the outer rotor of the outer rotor motor is hermetically and fixedly connected to the lower inner wall of the microporous material layer.

[0018] In a preferred embodiment of the present invention, the microbubble generating device further includes a first fixing base. The microporous material layer is a vertically arranged cylindrical structure with a sealed top and an open bottom. A sealing cover made of microporous material and integrally formed with the microporous material layer is arranged at the top of the microporous material layer. The sealing cover has an upwardly convex hollow hemispherical structure, and the bottom of the outer rotor motor is hermetically and fixedly connected to the top of the first fixing base.

[0019] In a preferred embodiment of the present invention, the gas transmission pipeline includes a first main gas transmission pipe. One end of the first main gas transmission pipe is above the liquid level, and the other end of the first main gas transmission pipe sequentially passes through the first fixing base and the outer rotor motor and extends into the air storage chamber. A first plugging block is hermetically sealed inside the first main gas transmission pipe. The first main gas transmission pipe passes through the central hole of the outer rotor motor and is hermetically and fixedly connected to the outer rotor motor. A plurality of first gas transmission branch pipes are connected to the first main gas transmission pipe inside the air storage chamber, and each of the first gas transmission branch pipes is evenly distributed along the circumferential direction of the first main gas transmission pipe;

[0020] The first gas transmission branch pipe includes a horizontal pipe section and a vertical pipe section. One end of the horizontal pipe section is connected to the first main gas transmission pipe, the other end of the horizontal pipe section extends horizontally to a position close to the microporous material layer and is connected to the top end of the vertical pipe section, and the bottom end of the vertical pipe section extends vertically downward.

[0021] In a preferred embodiment of the present invention, the microbubble generating device further includes an inner rotor motor that drives the air-containing chamber to rotate circumferentially. The air delivery pipeline includes a second main air delivery pipe and a hollow shaft. The hollow shaft is the output shaft of the inner rotor motor, and a second plugging block is sealed inside the hollow shaft. The hollow shaft passes through the air-containing chamber, and the hollow shaft is in non-contact communication with one end of the second main air delivery pipe through a straight pipe. The other end of the second main air delivery pipe is located above the liquid level. A plurality of second air delivery branch pipes are connected to the second main air delivery pipe located in the air-containing chamber, and each of the second air delivery branch pipes is evenly distributed along the circumferential direction of the second main air delivery pipe;

[0022] The second air delivery branch pipe includes a horizontal pipe section and a vertical pipe section. One end of the horizontal pipe section is connected to the second main air delivery pipe, the other end of the horizontal pipe section extends horizontally to a position close to the microporous material layer and is connected to the top end of the vertical pipe section, and the bottom end of the vertical pipe section extends vertically downward.

[0023] In a preferred embodiment of the present invention, the microbubble generating device further includes a first upper cover and a first lower cover. The microporous material layer is a vertically arranged cylindrical structure with openings at both ends. The first upper cover and the first lower cover are respectively sealed at the top opening and the bottom opening of the microporous material layer. The hollow shaft sequentially passes through the first lower cover, the air-containing chamber, and the first upper cover from bottom to top, and the hollow shaft is respectively sealed and fixedly connected to the first lower cover and the first upper cover through flange couplings.

[0024] In a preferred embodiment of the present invention, the microbubble generating device further includes a bearing seat fixing plate and a second fixing base. The bearing seat fixing plate is located above the second fixing base, and the bearing seat fixing plate is connected to the second fixing base through a plurality of connecting columns. The air-containing chamber and the inner rotor motor are both arranged between the bearing seat fixing plate and the second fixing base. The inner rotor motor is located below the air-containing chamber and is fixed to the second fixing base. The hollow shaft passes through the bearing seat fixing plate and extends out;

[0025] A bearing and a sealing ring are sequentially sleeved on the hollow shaft located above the bearing seat fixing plate from top to bottom, and both the bearing and the sealing ring are arranged in the bearing seat.

[0026] In a preferred embodiment of the present invention, the microbubble generating device further includes a microbubble generating chamber and a brushless motor that drives the liquid outside the microporous material layer to rotate and flow circumferentially along the air-containing chamber. The microbubble generating chamber is a vertically arranged cylindrical structure with an open top and a sealed bottom. The brushless motor is located below the air-containing chamber. The output shaft of the brushless motor is arranged vertically upward. An impeller is provided on the output shaft of the brushless motor. The impeller is a sealed cylindrical hollow cavity. The output shaft of the brushless motor passes through the impeller and the impeller is fixed to the motor output shaft through a coupling. A plurality of spiral blades for providing an upward thrust to the liquid are provided on the outer wall of the impeller. The impeller is close to the bottom of the air-containing chamber, and both the air-containing chamber and the impeller are arranged inside the microbubble generating chamber. A cutting water channel is formed between the microporous material layer and the inner wall of the microbubble generating chamber;

[0027] A first liquid inlet and a plurality of first liquid outlets are respectively provided at the bottom and top of the microbubble generating chamber. A liquid circulation tank is provided at the bottom of the microbubble generating chamber. A plurality of second liquid inlets and second liquid outlets are provided on the liquid circulation tank. Each of the second liquid outlets is communicated with a corresponding first liquid inlet, and the first liquid inlet is communicated with external liquid. Each of the first liquid outlets is respectively communicated with a corresponding second liquid inlet through a liquid circulation pipeline. Each of the second liquid inlets extends tangentially along the inner wall of the liquid circulation tank to form a rotating water flow in the liquid circulation tank in the same direction as the rotation direction of the impeller.

[0028] In a preferred embodiment of the present invention, a flow regulating valve is provided on the liquid circulation pipeline.

[0029] In a preferred embodiment of the present invention, the cross-sectional area of the cutting water channel is smaller than the cross-sectional area of the first liquid inlet.

[0030] In a preferred embodiment of the present invention, the gas transmission pipeline includes a third main gas transmission pipe. One end of the third main gas transmission pipe is above the liquid level. The other end of the third main gas transmission pipe extends into the air-containing chamber and a third plugging block is sealed inside the third main gas transmission pipe. A plurality of third gas transmission branch pipes are connected to the third main gas transmission pipe located in the air-containing chamber. Each of the third gas transmission branch pipes is evenly distributed along the circumference of the third main gas transmission pipe;

[0031] The third gas transmission branch pipe includes a horizontal pipe section and a vertical pipe section. One end of the horizontal pipe section is connected to the third main gas transmission pipe. The other end of the horizontal pipe section extends horizontally to a position close to the microporous material layer and is connected to the top end of the vertical pipe section. The bottom end of the vertical pipe section extends vertically downward.

[0032] In a preferred embodiment of the present invention, the microbubble generating device further includes a second upper cover and a second lower cover. The microporous material layer is a vertically arranged cylindrical structure with openings at both ends. The second upper cover and the second lower cover are respectively sealed at the top opening and the bottom opening of the microporous material layer. The third gas supply branch pipe passes through the second upper cover from top to bottom and extends into the air storage chamber.

[0033] In a preferred embodiment of the present invention, the microbubble generating device further includes a third fixed base. The third fixed base is located below the microbubble generating box, and the brushless motor is fixed to the top of the third fixed base.

[0034] As described above, the characteristics and advantages of the microbubble generating method and device in the present invention are as follows: Under the action of a certain pressure, gas passes through the microporous material, and microbubbles are formed at the interface between the microporous material and the liquid. Before the microbubbles grow by themselves and quickly form large bubbles by fusing with adjacent microbubbles, through the relative movement between the microporous material and the liquid, the microbubbles adsorbed on the microporous material are impacted, so as to cut the microbubbles, making them break away from the microporous material and enter the liquid, achieving the purpose of generating microbubbles. This process does not require high-speed water flow, and at the same time avoids the problem of heat generation and energy consumption due to rotational friction under high pressure. It can effectively reduce production energy consumption and save production costs, and can quickly generate a large number of microbubbles with uniform particle sizes, having great economic benefits and being suitable for popularization and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The following drawings are only intended to illustrate and explain the present invention schematically and do not limit the scope of the present invention.

[0036] Wherein:

[0037] Figure 1 : is a flowchart of the microbubble generating method of the present invention.

[0038] Figure 2 : is one of the structural schematic diagrams of the microbubble generating device of the present invention.

[0039] Figure 3 : is Figure 2 The structural schematic diagram of the part below the liquid level in

[0040] Figure 4 : is another structural schematic diagram of the microbubble generating device of the present invention.

[0041] Figure 5 : is Figure 4 The structural schematic diagram of the part below the liquid level in

[0042] Figure 6: This is the third schematic structural diagram of the microbubble generating device of the present invention.

[0043] Figure 7 : It is Figure 6 the schematic structural diagram of the part below the liquid level in

[0044] The reference numerals in the present invention are:

[0045] 1. Air storage chamber; 2. Microporous material layer;

[0046] 3. Gas transmission pipeline; 301. First main gas transmission pipe;

[0047] 302. First branch gas transmission pipe; 303. Second main gas transmission pipe;

[0048] 304. Second branch gas transmission pipe; 305. Quick-connect gas pipe joint;

[0049] 306. Hollow shaft; 307. Second plugging block;

[0050] 308. Straight pipe; 309. Third main gas transmission pipe;

[0051] 310. Third branch gas transmission pipe; 311. Third plugging block;

[0052] 4. Shearing head; 5. Air pump;

[0053] 6. Primary filter; 7. Secondary filter;

[0054] 8. Flowmeter; 9. Adjusting knob;

[0055] 10. Pressure gauge; 11. Sealing cover;

[0056] 12. First fixed base; 13. Outer rotor motor;

[0057] 14. First plugging block; 15. Inner rotor motor;

[0058] 16. First upper cover; 17. First lower cover;

[0059] 18. Flange coupling; 19. Second fixed base;

[0060] 20. Bearing seat fixing plate; 21. Connecting column;

[0061] 22. Bearing seat; 23. Sealing ring;

[0062] 24. Bearing; 25. Liquid circulation pipeline;

[0063] 26. Second upper cover; 27. Second lower cover;

[0064] 28. Brushless motor; 29. Third fixed base

[0065] 30. Microbubble generation chamber; 3001. First liquid inlet

[0066] 3002. First liquid outlet; 31. Impeller

[0067] 32. Flow regulating valve; 33. Liquid circulation tank

[0068] 3301. Second liquid inlet; 3302. Second liquid outlet

[0069] 34. Cutting water channel Detailed implementation mode

[0070] For a clearer understanding of the technical features, objectives, and effects of the present invention, the specific implementation mode of the present invention will now be described with reference to the accompanying drawings.

[0071] Embodiment 1

[0072] As Figure 1 shown, the present invention provides a method for generating microbubbles, which includes the following steps:

[0073] Step S1: Gas passes through the microporous material and forms microbubbles at the interface between the microporous material and the liquid;

[0074] Specifically, step S1 includes:

[0075] Step S101: A microporous material layer 2 is circumferentially arranged around the outer periphery of the gas-containing chamber 1, and the gas-containing chamber 1 is placed below the liquid level;

[0076] Step S102: One end of the gas transmission pipeline 3 is located above the liquid level and is connected to a gas source, and the other end of the gas transmission pipeline 3 is connected to the gas-containing chamber 1. Gas is filled into the gas-containing chamber 1 through the gas transmission pipeline 3 to form a certain air pressure in the gas-containing chamber 1;

[0077] Step S103: Under the action of the air pressure in the gas-containing chamber 1, the gas in the gas-containing chamber 1 passes through the microporous material layer 2 and forms microbubbles on the outer surface of the microporous material layer 2.

[0078] Step S2: Through the relative movement of the microporous material and the liquid, the microbubbles adsorbed on the microporous material are impacted, so that the microbubbles can be detached from the microporous material and enter the liquid before growing to 100 μm.

[0079] Specifically, the microporous material layer 2 is driven to rotate along its circumferential direction and / or the liquid located outside the microporous material layer 2 is driven to flow along the circumferential direction of the microporous material layer 2, so as to cut the microbubbles through the relative movement between the microporous material layer 2 and the liquid, enabling the microbubbles to get rid of the adsorption force of the microporous material layer 2 and enter the liquid, thereby generating a large number of microbubbles.

[0080] Further, in step S2, the shear force of the liquid on the microbubbles is greater than the adsorption force of the capillary effect of the microporous material on the microbubbles, so that the bubbles can be impacted and separated from the microporous material and enter the liquid in the form of microbubbles.

[0081] Further, the time from the formation of the microbubbles to being cut and separated from the microporous material is less than the time required for the microbubbles to grow larger by themselves and quickly grow larger after fusing with adjacent microbubbles to form large bubbles (with a diameter of 100 μm as the boundary). Without the interference of external force (i.e., the shear force of the liquid on the microbubbles), the bubbles generated on the surface of the microporous material with a small pore diameter will gradually grow larger under the action of the capillary adsorption force of the microporous material and fuse with adjacent bubbles to form larger bubbles until the buoyancy of the bubbles can overcome the capillary adsorption force and then break away from the surface of the microporous material and enter the liquid in the form of large bubbles (with a diameter of more than 200 μm). Therefore, it is necessary to quickly cut the microbubbles formed at the interface between the microporous material and the liquid to ensure that they enter the liquid before the diameter of the bubbles increases to 100 μm.

[0082] The characteristics and advantages of the microbubble generation method of the present invention are:

[0083] The method for generating microbubbles causes gas to pass through a microporous material under a certain pressure, and forms microbubbles at the interface between the microporous material and the liquid. Before the microbubbles grow and merge with adjacent microbubbles to form larger bubbles, through the relative movement between the microporous material and the liquid (the movement of the microporous material can drive the movement of the microbubbles, which is equivalent to the microporous material constituting a cutting head that can drive the movement of the gas, so that relative movement is generated between the microbubbles and the liquid to achieve the effect of cutting the microbubbles; of course, conversely, the movement of the liquid can be used to impact the microbubbles on the microporous material), the microbubbles adsorbed on the microporous material are impacted, thereby cutting the microbubbles, causing them to detach from the microporous material and enter the liquid, achieving the purpose of generating microbubbles. Among them, since the method of driving the movement of the gas inside the microporous material by driving the movement of the microporous material consumes much less energy than the method of driving the movement of the surrounding liquid, therefore, the method of cutting microbubbles by the movement of the microporous material can greatly reduce energy consumption and is the best implementation method. However, compared with the existing rotary cutting method, neither of the above two methods for impacting microbubbles requires high-speed water flow during the entire implementation process, thus avoiding the problem of heat generation and energy consumption caused by high-pressure rotary friction, being able to effectively reduce production energy consumption and save production costs. Moreover, the present invention can quickly generate a large number of microbubbles with uniform particle sizes, having great economic benefits and being suitable for popularization and use.

[0084] Embodiment 2

[0085] As Figures 2 to 7 shown, the present invention provides a microbubble generating device, which includes an air-containing chamber 1 and a gas delivery pipe 3. The gas delivery pipe 3 is used to deliver gas into the air-containing chamber 1 to form a certain air pressure in the air-containing chamber 1. A microporous material layer 2 through which the gas in the air-containing chamber 1 can pass is annularly provided along the circumference of the air-containing chamber 1 on the periphery of the air-containing chamber 1. The air-containing chamber 1 is arranged below the liquid level. One end of the gas delivery pipe 3 is located above the liquid level and is connected to a gas source, and the other end of the gas delivery pipe 3 extends into the air-containing chamber 1, so that the gas in the air-containing chamber 1 passes through the gaps of the microporous material layer 2 under the air pressure and forms microbubbles on the outer surface of the microporous material layer 2; the microporous material layer 2 is driven to rotate circumferentially and / or the liquid located outside the microporous material layer 2 is driven to flow circumferentially along the microporous material layer 2, and the microbubbles on the outer surface of the microporous material layer 2 are cut through the relative movement between the liquid and the microporous material layer 2, so that the microbubbles enter the liquid. Of course, the microporous material layer 2 is not limited to circumferential rotation, and the liquid is not limited to flowing circumferentially along the microporous material layer 2. Various movement forms (such as left and right swinging, etc.) can be adopted as long as the liquid can quickly cut the microbubbles on the outer surface of the microporous material layer 2.

[0086] Further, as shown in Figure 2 , Figure 4 , Figure 6 , an air pump 5, a primary filter 6, and a secondary filter 7 are arranged on the gas transmission pipeline 3 in the order of the gas flow direction. The air pump 5, the primary filter 6, and the secondary filter 7 are all located above the liquid level. The pore diameter of the filter element on the secondary filter 7 is smaller than the pore diameter of the filter element on the primary filter 6 and the pore diameter of the microporous material layer 2. The dust in the gas is filtered by the primary filter 6 and the secondary filter 7. The primary filter 6 is used to filter large-particle dust in the gas, and the secondary filter 7 is used to filter small-particle dust in the gas, ensuring that the microporous material layer 2 will not be blocked by dust under long-term working conditions and extending the service life of the device. In addition, the filter elements on the primary filter 6 and the secondary filter 7 are consumables that are easy to replace and can be replaced regularly. The gas in the air storage chamber 1 can pass through the microporous material layer 2 by the centrifugal force generated by the rotation of the air storage chamber 1 and form a negative pressure in the air storage chamber 1, so that the gas from the gas source can enter the air storage chamber 1 for replenishment; however, the smaller the pores on the microporous material layer 2, the greater the gas resistance. When the centrifugal force generated by the gas rotation is not enough to pass through the microporous material layer 2, the gas can be pumped into the air storage chamber 1 by the air pump 5 to increase the air pressure in the air storage chamber 1, thereby increasing the penetration force of the gas in the air storage chamber 1 and ensuring that the gas smoothly passes through the microporous material layer 2. In addition, the gas can also be made to penetrate more easily by increasing the centrifugal force by increasing the rotation speed of the air storage chamber 1, but this method requires greater energy consumption compared with adding the air pump 5.

[0087] Further, as shown in Figure 2 , Figure 4 , Figure 6 , a flow meter 8 is arranged on the gas transmission pipeline 3 upstream of the air pump 5, and a pressure gauge 10 is arranged on the gas transmission pipeline 3 downstream of the secondary filter 7. An adjustment knob 9 for controlling the gas flow is arranged on the flow meter 8. The flow rate of the gas can be monitored in real time through the flow meter 8, and the adjustment knob 9 on the flow meter 8 can be adjusted according to the actual situation, so as to control the flow rate of the gas per unit time and adjust the particle size of the microbubbles. Among them, the flow meter 8 can be, but is not limited to, a glass rotor flow meter.

[0088] Furthermore, the thickness of the microporous material layer 2 gradually increases from bottom to top to balance the problem of uneven gas outlet caused by the water pressure difference between the upper and lower parts in the air storage chamber 1, thereby ensuring the consistency of the bubble diameter. The thickness at each position of the microporous material layer 2 can be adjusted according to the air resistance performance of the actually used microporous material. During actual use, the thickness of the microporous material layer 2 only needs to ensure that it has sufficient strength to support the movement of the air storage chamber 1. The thinner the microporous material layer 2, the smaller the air resistance and the better the gas permeability of the microporous material layer 2; there is no limit to the size specification of the air storage chamber 1. The larger the volume of the air storage chamber 1, the larger the surface area of the microporous material layer 2 and the larger the ventilation volume, but the corresponding frictional resistance during rotation will also be greater.

[0089] In an alternative embodiment of the present invention, as Figure 2 , Figure 3 shown, the microbubble generating device further includes an outer rotor motor 13 that drives the air storage chamber 1 to rotate circumferentially. The outer rotor motor 13 is arranged inside the air storage chamber 1. The rotor of the outer rotor motor 13 and the lower inner wall of the microporous material layer 2 are hermetically fixed and connected by sealant. The microporous material layer 2 can be driven to rotate by the rotor of the outer rotor motor 13. In this embodiment, a shear head 4 that can perform rotational motion below the liquid is formed by combining the outer rotor motor 13 and the microporous material layer 2. This embodiment can be understood as the movement of the microporous material driving the movement of the gas penetrating into the microporous material to generate microbubbles by rotating and cutting the liquid. Compared with the existing rotary cutting method that makes the liquid rotate at high speed, the energy consumption gap is huge. The theoretical energy consumption for the gas and the liquid to reach the same movement speed is more than two orders of magnitude different. Among them, the outer rotor motor 13 is an outer rotor brushless motor for underwater work.

[0090] Furthermore, as Figure 2 , Figure 3 shown, the microbubble generating device further includes a first fixed base 12. The microporous material layer 2 is a vertically arranged cylindrical structure with a sealed top and an open bottom. A sealing cover 11 made of microporous material and integrally formed with the microporous material layer 2 is provided at the top of the microporous material layer 2. The sealing cover 11 is a hollow hemispherical structure protruding upward. The bottom of the outer rotor motor 13 is hermetically and fixedly connected to the top of the first fixed base 12. The first fixed base 12 plays a supporting role for the microporous material layer 2 to ensure the stable working state of the device.

[0091] Specifically, as Figure 2 , Figure 3As shown in the figure, the gas transmission pipeline 3 includes a first main gas transmission pipe 301. One end of the first main gas transmission pipe 301 is above the liquid level. The other end of the first main gas transmission pipe 301 sequentially passes through the first fixed base 12 and the outer rotor motor 13 and extends into the air-containing chamber 1. A first plugging block 14 is sealed inside the first main gas transmission pipe 301. The first main gas transmission pipe 301 passes through the central hole of the outer rotor motor 13 and is sealed and connected to the outer rotor motor 13 by sealant. Four first gas transmission branch pipes 302 are connected to the first main gas transmission pipe 301 located in the air-containing chamber 1. Each first gas transmission branch pipe 302 is evenly distributed along the circumferential direction of the first main gas transmission pipe 301. The first gas transmission branch pipe 302 includes a horizontal pipe section and a vertical pipe section. One end of the horizontal pipe section is connected to the first main gas transmission pipe 301. The other end of the horizontal pipe section extends horizontally to a position close to the microporous material layer 2 and is connected to the top end of the vertical pipe section. The bottom end of the vertical pipe section extends vertically downward. Through the first main gas transmission pipe 301 and each first gas transmission branch pipe 302, the gas from the gas source is transported into the air-containing chamber 1, and the gas can be evenly distributed on the inner wall of the microporous material layer 2 as much as possible.

[0092] In another alternative embodiment of the present invention, as Figure 4 , Figure 5 shown, the microbubble generating device further includes an inner rotor motor 15. The inner rotor motor 15 is used to drive the air-containing chamber 1 to rotate circumferentially. The gas transmission pipeline 3 includes a second main gas transmission pipe 303 and a hollow shaft 306. The hollow shaft 306 is the output shaft of the inner rotor motor 15, and a second plugging block 307 is sealed inside the hollow shaft 306. The hollow shaft 306 passes through the air-containing chamber 1 and is connected to one end of the second main gas transmission pipe 303. The other end of the second main gas transmission pipe 303 is above the liquid level. Four second gas transmission branch pipes 304 are connected to the second main gas transmission pipe 303 located in the air-containing chamber 1. Each second gas transmission branch pipe 304 is evenly distributed along the circumferential direction of the second main gas transmission pipe 303. The second gas transmission branch pipe 304 includes a horizontal pipe section and a vertical pipe section. One end of the horizontal pipe section is connected to the second main gas transmission pipe 303. The other end of the horizontal pipe section extends horizontally to a position close to the microporous material layer 2 and is connected to the top end of the vertical pipe section. The bottom end of the vertical pipe section extends vertically downward. Through the second main gas transmission pipe 303 and each second gas transmission branch pipe 304, the gas from the gas source is transported into the air-containing chamber 1, and the gas can be evenly distributed on the inner wall of the microporous material layer 2 as much as possible. The hollow shaft 306 is both the output shaft of the inner rotor motor 15 and used for gas transmission. Among them, the inner rotor motor 15 is an inner rotor underwater brushless motor.

[0093] Furthermore, as Figure 4 , Figure 5As shown, the microbubble generating device further includes a first upper cover 16 and a first lower cover 17. The microporous material layer 2 is a vertically arranged cylindrical structure with openings at both ends. The first upper cover 16 is hermetically arranged at the top opening of the microporous material layer 2, and the first lower cover 17 is hermetically arranged at the bottom opening of the microporous material layer 2. The hollow shaft 306 passes through the first lower cover 17, the air-containing chamber 1, and the first upper cover 16 from bottom to top, and the hollow shaft 306 is hermetically and fixedly connected to the first lower cover 17 and the first upper cover 16 respectively through a flange coupling 18. Among them, the first upper cover 16 and the microporous material layer 2, as well as the first lower cover 17 and the microporous material layer 2, can be hermetically fixed through connection methods such as sealant. In this embodiment, the inner rotor motor 15, the microporous material layer 2, the first upper cover 16, and the first lower cover 17 are combined to form a shear head 4 that can rotate below the liquid.

[0094] Further, as Figure 4 , Figure 5 shown, a straight pipe 308 is connected between the hollow shaft 306 and the second main gas supply pipe 303, and the straight pipe 308 is connected to the second main gas supply pipe 303 through a quick-connect gas pipe joint 305, so that the hollow shaft is non-contact connected to the second main gas supply pipe.

[0095] Further, as Figure 4 , Figure 5 shown, the microbubble generating device further includes a bearing seat fixing plate 20 and a second fixing base 19. The bearing seat fixing plate 20 is located above the second fixing base 19. The bearing seat fixing plate 20 and the second fixing base 19 are connected by a plurality of connecting columns 21. The air-containing chamber 1 and the inner rotor motor 15 are both arranged between the bearing seat fixing plate 20 and the second fixing base 19. The inner rotor motor 15 is located below the air-containing chamber 1, and the inner rotor motor 15 is fixed on the second fixing base 19. The hollow shaft 306 passes through the bearing seat fixing plate 20 and extends out; the hollow shaft 306 located above the bearing seat fixing plate 20 is sleeved with a bearing 24 and a sealing ring 23 from top to bottom in sequence. The bearing 24 and the sealing ring 23 are both arranged in the bearing seat 22. The bottom of the straight pipe 308 is adhesively bonded to the top of the bearing 24 through sealant. Through the above structure, the overall stability of the device can be improved, and the inner rotor motor 15 can be prevented from jittering under the action of external forces during operation.

[0096] In another alternative embodiment of the present invention, as Figure 6 , Figure 7As shown in the figure, the microbubble generating device further includes a microbubble generating chamber 30 and a brushless motor 28. The brushless motor 28 is used to drive the liquid outside the microporous material layer 2 to rotate and flow circumferentially along the air-containing chamber 1. The microbubble generating chamber 30 is a vertically arranged cylindrical structure with an open top and a sealed bottom. The brushless motor 28 is located below the air-containing chamber 1, and the output shaft of the brushless motor 28 is arranged vertically upward. An impeller 31 is provided on the output shaft of the brushless motor 28. A plurality of helical blades for providing an upward thrust to the liquid are provided on the outer wall of the impeller 31. The impeller 31 is close to the bottom of the air-containing chamber 1, and both the air-containing chamber 1 and the impeller 31 are arranged inside the microbubble generating chamber 30. A cutting water channel 34 is formed between the microporous material layer 2 and the inner wall of the microbubble generating chamber 30. A circular first liquid inlet 3001 is provided at the bottom of the microbubble generating chamber 30 along the circumferential direction of the microbubble generating chamber 30. A plurality of first liquid outlets 3002 are provided at the top of the microbubble generating chamber 30. A liquid circulation tank 33 is provided at the bottom of the microbubble generating chamber 30. The liquid circulation tank 33 is a circular structure arranged horizontally. A plurality of second liquid inlets 3301 and second liquid outlets 3302 are provided on the liquid circulation tank 33. The second liquid outlet 3302 is a circular opening provided along the circumferential direction of the liquid circulation tank 33. The second liquid outlet 3302 is communicated with the first liquid inlet 3001, and the first liquid inlet 3001 is also communicated with the external liquid. Each first liquid outlet 3002 is respectively communicated with the corresponding second liquid inlet 3301 through a liquid circulation pipeline 25. Each second liquid inlet 3302 extends tangentially along the inner wall of the liquid circulation tank 33 to form a rotating water flow in the same direction as the rotation direction of the impeller 31 in the liquid circulation tank 33. During the working process, the impeller 31 rotates and forms a negative pressure in the microbubble generating chamber 30. The liquid is sucked into the microbubble generating chamber 30 through the circular first liquid inlet 3001 and flows upward. While flowing upward, the liquid rotates and flows circumferentially on the outer side of the microporous material layer 2, so as to cut the microbubbles on the outer surface of the microporous material layer 2. Then, a part of the liquid directly flows out through the top opening of the microbubble generating chamber 30, and the other part of the liquid flows into the corresponding liquid circulation tank 33 through the liquid circulation pipelines 25 on the microbubble generating chamber 30, and then circulates back into the microbubble generating chamber 30 through the second liquid outlets 3302 on the liquid circulation tank 33 and the first liquid inlet 3001 on the microbubble generating chamber 30 communicated therewith for recycling. The circulating back water flow has a certain kinetic energy, which can reduce the energy consumption of the impeller 31. Among them, the brushless motor 28 is an inner-rotor underwater working brushless motor.

[0097] Further, the impeller 31 is a cylindrical hollow cavity with a sealed top and a sealed bottom. The output shaft of the brushless motor 28 passes through the center of the impeller 31, and the impeller 31 is fixed on the output shaft of the brushless motor 28 through a coupling. The spiral blade is arranged on the outer wall of the impeller 31. During use, the thrust of the impeller 31 for the upward flow of the liquid is controlled to be less than the thrust of the impeller 31 for the circumferential rotation of the liquid. Therefore, it is necessary to adjust the spiral blade to have as small an inclination angle as possible, so that the water flow can rotate as many circles as possible during the process of flowing through the microporous material layer 2, so as to make full use of the liquid that consumes energy to move. In addition, by increasing the height of the air storage chamber 1, the above purpose can also be achieved, and it can be adjusted according to the actual situation during the working process.

[0098] Further, as Figure 6 shown, a flow regulating valve 32 is arranged on the liquid circulation pipeline 25, and the flow rate of the liquid passing through the liquid circulation pipeline 25 can be adjusted through the flow regulating valve 32.

[0099] Further, the cross-sectional area of the cutting water channel 34 should be slightly smaller than the cross-sectional area of the first liquid inlet 3001, so as to ensure that the water flow outside the air storage chamber 1 can closely adhere to the outer surface of the microporous material layer 2 to cut the microbubbles (the cross-sectional area of the cutting water channel 34 only needs to be slightly smaller than the cross-sectional area of the first liquid inlet 3001, otherwise it will cause air outlet obstruction and the air pressure of the air pump 5 needs to be increased); the water flow on the side away from the outer surface of the microporous material layer 2 is substantially ineffective water flow (it cannot cut the microbubbles on the outer surface of the microporous material layer 2). Therefore, the smaller the cross-sectional area of the cutting water channel 34, the better the effect. Only through the water flow in the cutting water channel 34 can it closely adhere to the outer surface of the microporous material layer 2, so as to improve the cutting efficiency of the microbubbles on the microporous material layer 2.

[0100] Specifically, as Figure 6 、 Figure 7 shown, the gas transmission pipeline 3 includes a third main gas transmission pipe 309. One end of the third main gas transmission pipe 309 is above the liquid level, and the other end of the third main gas transmission pipe 309 extends into the air storage chamber 1 and a third blocking block 311 is sealed inside the third main gas transmission pipe 309. Four third gas transmission branch pipes 310 are connected to the third main gas transmission pipe 309 located in the air storage chamber 1, and each third gas transmission branch pipe 310 is evenly distributed along the circumference of the third main gas transmission pipe 309; the third gas transmission branch pipe 310 includes a horizontal pipe section and a vertical pipe section. One end of the horizontal pipe section is connected to the third main gas transmission pipe 309, the other end of the horizontal pipe section extends horizontally to a position close to the microporous material layer 2 and is connected to the top end of the vertical pipe section, and the bottom end of the vertical pipe section extends vertically downward. The gas from the gas source is transported into the air storage chamber 1 through the third main gas transmission pipe 309 and each third gas transmission branch pipe 310, and the gas can be distributed as evenly as possible on the inner wall of the microporous material layer 2.

[0101] Further, as Figure 6 、 Figure 7 shown, the microbubble generating device further includes a second upper cover 26 and a second lower cover 27. The microporous material layer 2 is a vertically arranged cylindrical structure with openings at both ends. The second upper cover 26 is hermetically arranged at the top opening of the microporous material layer 2, and the second lower cover 27 is hermetically arranged at the bottom opening of the microporous material layer 2. The third gas delivery branch pipe 310 passes through the second upper cover 26 from top to bottom and extends into the air storage chamber 1. Among them, the second upper cover 26 and the microporous material layer 2, as well as the second lower cover 27 and the microporous material layer 2, can be hermetically fixed through connection methods such as sealant. In this embodiment, the shear head 4 that is below the liquid and along which the liquid can rotate circumferentially is formed by combining the microporous material layer 2, the second upper cover 26, and the second lower cover 27.

[0102] Further, as Figure 6 shown, the microbubble generating device further includes a third fixing base 29. The third fixing base 29 is located below the microbubble generating box 30, and the brushless motor 28 is fixed on the top of the third fixing base 29. The stability of the brushless motor 28 is improved through the third fixing base 29, preventing the brushless motor 28 from jittering under the action of external forces during operation.

[0103] The particle size of the microbubbles generated by the present invention can be adjusted according to actual needs. There are four factors in the present invention that can determine the particle size of the microbubbles: The first is the pore diameter and air permeability of the microporous material layer 2. The pore diameters and air permeabilities of different material parameters are different, and for the same material, its parameters also have certain fluctuations according to the actual use environment; the second is the rotational speed during the cutting of the microbubbles. The higher the rotational speed, the smaller the particle size of the cut microbubbles, but it is also affected by the air permeability of the material. If the pore diameter of the microporous material layer 2 is large, the wall is thin, and the air permeability is good, because the rotational speed increases, the centrifugal force of the gas rotation also increases, and the increase in the gas output volume instead leads to a larger particle size; the third is the air pressure in the air storage chamber 1, which can be regulated by the air pump 5. The greater the air pressure, the greater the gas output volume, and the larger the particle size of the microbubbles, and vice versa; the fourth is the adjustment knob 9 on the flowmeter 8. By changing the air resistance of the system, the gas output volume is adjusted, and thus the particle size of the microbubbles is adjusted.

[0104] The energy consumption of the present invention is described below through specific data:

[0105] The first equipment selection: The power of the motor (outer rotor motor 13 or inner rotor motor 15) is 600 W; the pore size of the microporous material layer 2 is 1 μm, the outer diameter of the microporous material layer 2 is 80 mm, and the vertical height of the microporous material layer 2 is selected as 66 mm, 134 mm, and 200 mm respectively; the filtration accuracy of the primary filter 6 (i.e., the pore size of the filter element) is 10 μm; the filtration accuracy of the secondary filter 7 is 0.1 μm; the air pump 5 uses a micro air pump, the rated power of the air pump 5 is 12 W, the rated air flow is 15 L, and the power consumption per liter is 15 / 12 = 0.8 W. During actual use, when the rotational speed of the brushless motor 28 is 770 revolutions per minute, the pressure in the air storage chamber 1 is 0.5 atmospheres, and it is obvious that there are fine air bubbles in the dispersed water.

[0106]

[0107] Table 1

[0108] It can be deduced from the data in Table 1:

[0109] After productization, the outer diameter of the microporous material layer 2 increases to 240 mm and the height increases to 1000 mm. It is necessary to calculate the energy consumption per liter in this case. Since the energy consumption is 12 W when the height of the microporous material layer 2 is 200 mm and 7.5 W when the height is 66 mm, and the energy consumption increases by 4.5 W after the surface area of the microporous material layer 2 increases by two times, the basic energy consumption can be calculated as 5.25 W, and the energy consumption brought by the frictional resistance during the rotation of the microporous material layer 2 with a height of 66 mm is 2.25 W; when the outer diameter of the microporous material layer 2 increases to 240 mm and the height increases to 1000 mm, that is, after the surface area of the microporous material layer 2 increases by 45 times, the frictional resistance energy consumption at this time is 2.25×45 = 101.3 W. Adding the basic energy consumption of 5.25 W, the total energy consumption is 106.5 W. Assuming that the air flow increases by the same multiple to 1.2×45 = 54, the energy consumption per liter of gas is 106.5 / 54 = 1.97, and adding the air pump energy consumption of 0.8 W, the total energy consumption required to transport one liter of gas flow is 2.77 W.

[0110] Second device selection: The power of the motor (brushless motor 28) is 1500 W; the pore diameter of the microporous material layer 2 is 1 μm, the outer diameter of the microporous material layer 2 is 80 mm, and the height of the microporous material layer 2 in the vertical direction is selected to be 200 mm; the height of the impeller 31 is 30 mm, the diameter is 70 mm, the number of spiral blades is 4, the width of the spiral blade is 5 mm, the inclination of the spiral blade (i.e., the angle with the horizontal direction of the spiral blade) is 10°, the width of the first liquid inlet 3001 is 2 mm, and the width of the cutting water channel 34 is 1.5 mm. When the motor speed is 1000 revolutions per minute, the voltage of the motor is 30 V, the current of the motor is 10 A, the air pressure in the air storage chamber 1 is 0.5 atmospheres, the air flow rate is 3.9 L / M, the energy consumption required for the motor to transport each liter of gas is 30×10 / 3.9 = 76.9 W, the energy consumption required for the air pump 5 to transport each liter of gas is 0.8 W, and the total energy consumption required to transport each liter of gas flow is 77.7 W.

[0111] For the existing rotary cutting method, the energy consumption per liter of intake air flow is 275 W (public data of existing manufacturers). When the first device is selected (i.e., driving the microporous material layer 2 to rotate), the total energy consumption of the device is reduced by 68.07 times (275 / 4.04 = 68.07). After productization, it is estimated that the total energy consumption of the device is reduced by 99.28 times (275 / 2.77 = 99.28); when the second device is selected (i.e., driving the liquid outside the microporous material layer 2 to flow circumferentially along the microporous material layer 2), the total energy consumption of the device is reduced by 3.54 times (275 / 77.7 = 3.54).

[0112] The characteristics and advantages of the microbubble generating device of the present invention are:

[0113] 1. The microbubble generating device forms a certain pressure in the air-containing chamber 1 by introducing gas into it. Under the action of air pressure, the gas in the air-containing chamber 1 passes through the microporous material layer 2 and forms microbubbles at the interface between the outer surface of the microporous material layer 2 and the liquid. By driving the relative movement between the microporous material layer 2 and the liquid, the microbubbles adsorbed on the microporous material layer 2 are impacted by the liquid, so that the microbubbles break away from the microporous material layer 2 and enter the liquid, achieving the purpose of generating microbubbles. The main energy consumption in the working process of the present invention is not the energy consumption for the gas to move, but the energy consumption to overcome the frictional resistance suffered by the air-containing chamber 1 during its rotational movement in the liquid. However, the present invention only requires that the rotational speed of the air-containing chamber 1 or the rotational flow rate of the liquid along the air-containing chamber 1 is greater than the speed at which the gas passes through the microporous material layer 2. The gas flow rate is usually at the centimeter level per second. At the same time, a microporous material with a relatively small surface friction coefficient is preferably used as the microporous material layer 2, and the liquid flow rate driven can be completely controlled below one meter per second. Therefore, the required rotational speed during the working process is relatively low. Moreover, the conditions required for generating microbubbles in the present invention have no limitation on the water-gas ratio, and this process does not require high-speed water flow, avoiding the problem of energy consumption due to frictional heat generation. Therefore, it can effectively reduce production energy consumption, save production costs, and can quickly generate a large number of microbubbles with uniform particle sizes, having great economic benefits.

[0114] 2. The weight and volume of the microbubble generating device are significantly reduced compared with the existing microbubble generating devices. The power equipment adopted in the present invention is a motor. The body weight of a 1KW motor is less than 0.5 kg, and most of the specifications of this device require a power of less than 1KW. The microporous material is also a lightweight material. The weight of the present invention mainly lies in the supporting equipment such as the fixed base. Therefore, the weight of the overall device can be controlled within 10 kg, and the volume of the entire device can be made within a diameter of 30 cm and a height of 120 cm. During actual use, it can be installed manually.

[0115] 3. The microbubble generating device adjusts its volume according to actual needs, and then regulates the generation amount of microbubbles. The entire device can be miniaturized. The power equipment adopts a low-power micro motor, and other parts can also be correspondingly reduced, thus greatly expanding the application fields of microbubbles. For example, it can enter the household and civilian fields. People can make and drink high-oxygen water and high-hydrogen water immediately to ensure good health. In addition, it can also be used to make ozone water for the preservation of vegetables, fruits, and meats and the removal of pesticide residues.

[0116] IV. The microbubble generating device has a simple structure and is easy to operate. All raw materials are industrial finished products, suitable for large-scale production. In addition, the present invention has low energy consumption and low power. The device only needs about 30 watts of power to generate microbubbles and can be powered by solar panels, enabling the production of microbubbles in fields, rivers and lakes. Microbubbles have been proven to have a significant effect on increasing crop yields and treating river sewage, making full use of sunlight, air and water, which is impossible to achieve with the existing rotary cutting method.

[0117] V. The particle size distribution of the microbubbles generated by the microbubble generating device is highly consistent. The particle size distribution of the microbubbles generated by the existing microbubble generating devices will exist from the nanometer scale to the micrometer scale (1 nanometer to 200 micrometers). However, the consistency of the particle size of the microbubbles in the invention depends on the consistency of the pore size distribution of the microporous material. Now the microporous material has good quality, so the particle size range of the generated microbubbles has good consistency.

[0118] The above are only the schematic specific embodiments of the present invention and are not intended to limit the scope of the present invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A microbubble generating device, characterized in that, The microbubble generating device includes an air storage chamber disposed below the liquid level and a gas delivery pipeline for delivering gas into the air storage chamber. A microporous material layer through which the gas in the air storage chamber can pass is annularly provided around the periphery of the air storage chamber. One end of the gas delivery pipeline is located above the liquid level and is connected to a gas source, and the other end of the gas delivery pipeline extends into the air storage chamber so that the gas in the air storage chamber can pass through the microporous material layer under air pressure and form microbubbles on the outer surface of the microporous material layer; The microporous material layer moves and / or the liquid located outside the microporous material layer moves to cut the microbubbles so that the microbubbles enter the liquid; The microbubble generating device further includes a microbubble generating box and a brushless motor for driving the liquid outside the microporous material layer to rotate and flow circumferentially along the air storage chamber. The microbubble generating box is a vertically arranged cylindrical structure with an open top and a sealed bottom. The brushless motor is located below the air storage chamber, and the output shaft of the brushless motor is arranged vertically upward. An impeller is provided on the output shaft of the brushless motor. The impeller is a sealed cylindrical hollow cavity. The output shaft of the brushless motor passes through the impeller and the impeller is fixed to the motor output shaft through a coupling. A plurality of spiral blades for providing an upward thrust to the liquid are provided on the outer wall of the impeller. The impeller is close to the bottom of the air storage chamber, and both the air storage chamber and the impeller are arranged inside the microbubble generating box. A cutting water channel is formed between the microporous material layer and the inner wall of the microbubble generating box; A first liquid inlet and a plurality of first liquid outlets are respectively provided at the bottom and the top of the microbubble generating box. A liquid circulation box is provided at the bottom of the microbubble generating box. A plurality of second liquid inlets and second liquid outlets are provided on the liquid circulation box. Each of the second liquid outlets is communicated with a corresponding first liquid inlet, and the first liquid inlet is communicated with external liquid. Each of the first liquid outlets is respectively connected to a corresponding second liquid inlet through a liquid circulation pipeline. Each of the second liquid inlets extends tangentially along the inner wall of the liquid circulation box to form a rotating water flow in the liquid circulation box in the same direction as the rotation direction of the impeller.

2. The microbubble generating device according to claim 1, characterized in that, A flow regulating valve is provided on the liquid circulation pipeline.

3. The microbubble generating device according to claim 1, characterized in that, The cross-sectional area of the cutting water channel is smaller than the cross-sectional area of the first liquid inlet.

4. The microbubble generating device according to claim 1, characterized in that, The gas delivery pipeline includes a third main gas delivery pipe. One end of the third main gas delivery pipe is located above the liquid level, and the other end of the third main gas delivery pipe extends into the air storage chamber and a third plugging block is sealed inside the third main gas delivery pipe. A plurality of third gas delivery branch pipes are connected to the third main gas delivery pipe located in the air storage chamber. Each of the third gas delivery branch pipes is evenly distributed circumferentially along the third main gas delivery pipe; The third gas delivery branch pipe includes a horizontal pipe section and a vertical pipe section. One end of the horizontal pipe section is connected to the third main gas delivery pipe, the other end of the horizontal pipe section extends horizontally to a position close to the microporous material layer and is connected to the top end of the vertical pipe section, and the bottom end of the vertical pipe section extends vertically downward.

5. The microbubble generating device according to claim 4, characterized in that, The microbubble generating device further includes a second upper cover and a second lower cover. The microporous material layer is a vertically arranged cylindrical structure with openings at both ends. The second upper cover and the second lower cover are respectively and sealingly arranged at the top opening and the bottom opening of the microporous material layer. The third gas delivery branch pipe passes through the second upper cover from top to bottom and extends into the air storage chamber.

6. The microbubble generating device according to claim 1, characterized in that, The microbubble generating device further includes a third fixed base. The third fixed base is located below the microbubble generating box, and the brushless motor is fixed to the top of the third fixed base.

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