Gas-water double-shearing micro-nano bubble generation method and equipment

Abstract

The invention relates to the technical field of micro-nano bubbles, discloses a gas-water double-shearing micro-nano bubble generation method and equipment, and comprises the gas-water double-shearing micro-nano bubble generation equipment. Comprising a water spraying unit for generating high-speed atomized water flow, a gas-water premixing unit for premixing gas and water by adopting gas-water rotary cutting, a gas-water mixing unit for adopting rotary cutting, a gas-water double-shearing mixing unit for gas-water double shearing and a uniform stabilizing unit for stabilizing and discharging micro-nano bubbles. Based on the phenomena of self-excited oscillation, jet mixing and gas-liquid interface in fluid dynamics, by combining various mature fluid dynamics principles of cavitation effect, Venturi effect, shear breaking, impinging stream mixing and static mixing, the design of multiple gas chambers is added, especially the cavitation cavity, the annular gas chamber and the double-shear configuration, gas self-absorption is achieved, and the gas self-absorption effect is achieved. And the generation efficiency and uniformity of the bubbles are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-nano bubbles, and in particular to a method and equipment for generating micro-nano bubbles by gas-water double shearing. Background Art

[0002] Micro-nano bubbles are tiny bubbles with a radius between 0.1 and 50 μm. They possess unique properties that surpass those of ordinary bubbles, such as large surface area, slow bubble rise, high interfacial potential, high internal pressure, the ability to generate large amounts of free radicals, high mass transfer efficiency, and high gas solubility. These unique properties distinguish them from larger bubbles. In recent years, they have attracted widespread attention and are being applied in fields such as chemical engineering, materials engineering, environmental engineering, biology, and pharmaceutical delivery.

[0003] Currently, the main methods for generating micro-nano bubbles are as follows: ultrasonic bubble generation, dispersed air, electrolytic bubble precipitation, chemical reaction, and microchannel methods. Although micro-nano bubble technology has made many advances, it still faces some challenges: First, the problem of bubble stability. Micro-nano bubbles are prone to merging and bursting, especially in dynamic environments. The bubble life cycle is short, resulting in bubble failure during application. Second, the problem of controlling bubble size. Although existing methods can produce micro-nano bubbles, the bubble size distribution is uneven, and it is difficult to precisely control the single size of the bubble, which limits its effectiveness in specific applications. Third, the generation efficiency is low. Many existing generation methods have low bubble generation efficiency, especially in large-scale production, and the operation is complex and costly. Fourth, the application areas are limited. Although there have been breakthroughs in water treatment, drug delivery, and other areas, further verification and optimization are still needed in actual industrial applications. Summary of the Invention

[0004] In order to solve the technical problems existing in the prior art, the present invention provides a gas-water double shear micro-nano bubble generation method and equipment.

[0005] The present invention is implemented by the following technical solution: a micro-nano bubble generating device with air-water double shearing, comprising a water injection unit for generating a high-speed atomized water flow, an air-water premixing unit for premixing air and water by air-water rotary shearing, an air-water mixing unit by rotary shearing, an air-water double shear mixing unit for air-water double shearing, and a uniform stabilization unit for stabilizing and discharging micro-nano bubbles, and the water injection unit, the air-water premixing unit, the air-water mixing unit, the air-water double shear mixing unit, and the uniform stabilization unit are connected front to back and are arranged in sequence along an axis.

[0006] Furthermore, the water spraying unit adopts any one of a power wave nozzle, a Helmholtz nozzle, a conical nozzle, a combination nozzle of a power wave nozzle and a Helmholtz nozzle, and a combination nozzle of a conical nozzle and a Helmholtz nozzle.

[0007] Furthermore, the air-water premixing unit is annular, and includes an air-water premixing chamber, an air chamber 1 of an annular structure arranged outside the air-water premixing chamber, an air guide air path for supplying air to air chamber 1, and an air path 1 for providing a rotary shear airflow to the air-water premixing chamber, and air path 1 is connected to air chamber 1.

[0008] Furthermore, the air-guiding air path enters tangentially along an outer wall of the air chamber, the air path is a plurality of evenly distributed air holes with a diameter of 0.5 mm to 2.0 mm, and the air path enters tangentially along an inner wall of the air chamber into the air-water premixing chamber.

[0009] Furthermore, the air-water mixing unit includes a contraction tube, a throat tube and a diffusion tube (33) arranged in sequence, the throat tube is provided with an air chamber 2 of an annular structure arranged coaxially therewith, an air path 2 for providing a rotary shear airflow to the inner cavity of the throat tube is opened between the air chamber 2 and the inner wall of the throat tube, and the air chamber 2 is provided with an air intake pipe for air intake.

[0010] Furthermore, the second air path adopts a gap set on the throat pipe, the gap is less than 0.2 mm, the second air path is set tangentially along the axis of the throat pipe or vertically or obliquely along the axis of the throat pipe, and the air inlet pipe enters the second air chamber tangentially along the outer wall of the second air chamber.

[0011] Furthermore, the diameter ratio of the contraction tube to the throat tube and the diffusion tube is 0.8-1.2:1:2.0-3.0, the angle α of the contraction tube is 40°-70°, and the angle β of the diffusion tube is 6°-12°.

[0012] Furthermore, the gas-water double shear mixing unit includes a straight tube with an internal thread at the front end, a venturi-like tube arranged in the straight tube, and a diversion annular gap that gradually shrinks and is arranged on the outside of the front end of the venturi-like tube, followed by a mixing chamber. The venturi-like tube includes a contraction tube, a throat tube and a diffusion tube arranged in sequence. A rotary cutting air path is opened between the mixing chamber and the inner circle of the throat tube. The gas and water ejected from the rotary cutting air path are sheared and mixed for the second time in the tangential direction of the throat tube, and are diffused and ejected along the diffusion tube, and finally enter the uniform and stable unit. The straight tube is provided with an air pipe for supplying air to the mixing chamber.

[0013] Furthermore, the uniform and stable unit includes a second straight pipe, two fluid guide plates arranged inside the second straight pipe, and a static mixing component arranged at the end of the two fluid guide plates; the static mixing component includes an internal thread 1 and a guide column.

[0014] A method for generating micro-nano bubbles by air-water double shearing, comprising the following steps:

[0015] Step S1, using a water spray unit to form a high-speed atomized water flow;

[0016] Step S2: using an air-water premixing unit to premix the high-speed atomized water flow with air and water by rotary cutting;

[0017] Step S3: using the gas-water mixing unit to mix the gas and water by rotary cutting combined with inner shearing;

[0018] Step S4: using an air-water double shear mixing unit to mix air and water in an air-water double shear manner.

[0019] Step S5: stabilizing and discharging the mixed gas and water using a uniform stabilization unit.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The high-speed atomized water flow generated by the nozzle of the present invention can achieve self-priming gas and guide bubble formation through the form of a Venturi tube. Different types of feed nozzles can be selected according to work operation needs to meet the micro-nano bubble generation requirements under different conditions. It is flexible and changeable, and the adaptability of the micro-nano bubble generation equipment is improved.

[0022] 2. The present invention adopts multiple air chamber settings to further improve the formation quantity and distribution uniformity of micro-nano bubbles and the flexibility of operation.

[0023] 3. The present invention adopts a rotary mixing design, which is conducive to shearing the fluid and forming strong turbulence, promoting gas-liquid mixing, and the rotary entry method has a self-cleaning effect, reduces sediment adhesion, and improves anti-blocking performance.

[0024] 4. The present invention adopts an air-water double shear design, the internal thread realizes the rotation of air and water, realizes the redistribution of air and water, and the air-water double shear mixing unit performs air-water double shear mixing, enhances the air-water shear strength, improves the bubble ejection effect and dispersion, optimizes the formation and stability of micro-nano bubbles, increases the interface contact area and contact time, further shears the bubbles, improves the mass transfer effect, and improves the uniformity of bubble distribution.

[0025] 5. The design of the uniform and stable unit of the present invention can prevent the micro-nano bubbles from agglomerating during the diffusion process, reduce the countercurrent separation phenomenon, improve the ejection effect and dispersion of the bubbles, and further optimize the formation and stability of the micro-nano bubbles. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic structural diagram of a gas-water double shear micro-nano bubble generating device provided by the present invention;

[0027] Figure 2 A schematic structural diagram of the gas-water premixing unit provided by the present invention;

[0028] Figure 3 A schematic structural diagram of the gas-water mixing unit provided by the present invention;

[0029] Figure 4A schematic diagram of the structure of the gas circuit 2 provided by the present invention;

[0030] Figure 5 This is a schematic structural diagram of the air-water double shear mixing unit provided by the present invention;

[0031] Figure 6 A schematic structural diagram of a uniform and stable unit provided by the present invention;

[0032] Figure 7 A schematic diagram of the structure of the power wave nozzle provided by the present invention;

[0033] Figure 8 A schematic structural diagram of the Helmholtz nozzle provided by the present invention;

[0034] Figure 9 A schematic structural diagram of a conical nozzle provided by the present invention;

[0035] Figure 10 A schematic diagram of the structure of a combined nozzle of a power wave nozzle and a Helmholtz nozzle provided by the present invention;

[0036] Figure 11 A schematic diagram of the structure of a combined conical nozzle and Helmholtz nozzle provided by the present invention;

[0037] Figure 12 A cross-sectional view of the air-water double shear mixing unit provided by the present invention;

[0038] Figure 13 A schematic diagram of the structure of the rotary cutting gas circuit provided by the present invention;

[0039] Figure 14 A schematic structural diagram of a guide plate 1 provided by the present invention;

[0040] Figure 15 This is a cross-sectional view of the gas-water mixing unit provided by the present invention.

[0041] Description of main symbols:

[0042] 1. Water injection unit; 2. Air-water premixing unit; 3. Air-water mixing unit; 4. Air-water double shear mixing unit; 5. Uniform stabilization unit; 1-1. Power wave nozzle; 1-2. Helmholtz nozzle; 1-3. Conical nozzle; 1-4. Combination nozzle of power wave nozzle and Helmholtz nozzle; 1-5. Combination nozzle of conical nozzle and Helmholtz nozzle; 12. Nozzle; 13. Power wave mixing cavity; 14. Guide vane 1; 111. Resonant cavity; 112. Upper nozzle; 113. Reflection cone; 114. Lower nozzle; 115. Air inlet; 116. Partition; 117. Gas distribution cavity; 118. Suction hole; 11 9. Channel 1; 121. Nozzle 1; 131. Contraction chamber; 21. Air path 1; 22. Air-water pre-mixing chamber; 23. Air chamber 1; 24. Air guide path; 31. Contraction tube; 32. Throat; 33. Diffuser; 34. Air chamber 2; 35. Air path 2; 36. Inlet pipe; 41. Straight pipe 1; 42. Internal thread; 43. Venturi-like tube; 44. Diverter annulus; 45. Mixing chamber; 46. Rotary cut air path; 47. Air pipe; 411. Contraction tube 1; 412. Throat 1; 413. Diffuser 1; 51. Straight pipe 2; 52. Two-fluid guide vane; 53. Static mixing component; 54. Internal thread 1; 55. Guide column. DETAILED DESCRIPTION

[0043] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0044] Example 1:

[0045] Please combine Figure 1 The present embodiment provides a micro-nano bubble generating device with air-water double shearing, comprising a water injection unit 1 for generating a high-speed atomized water flow, an air-water premixing unit 2 for premixing air and water by air-water rotary cutting, an air-water mixing unit 3 by rotary cutting, an air-water double shearing mixing unit 4 for air-water double shearing, and a uniform stabilizing unit 5 for stabilizing and discharging micro-nano bubbles, and the water injection unit 1, the air-water premixing unit 2, the air-water mixing unit 3, the air-water double shearing mixing unit 4, and the uniform stabilizing unit 5 are connected front to back and are arranged in sequence along the axis.

[0046] Water is pumped into the water injection unit 1 through a pump and a water pipe, and then a high-speed atomized water flow is ejected from the water injection unit 1. The high-speed atomized water flow is mixed in the gas-water pre-mixing unit 2 by adopting an airflow rotary cutting method, subjected to secondary airflow rotary cutting in the gas-water mixing unit 3, subjected to gas-water double shear mixing in the gas-water double shear mixing unit 4, and finally discharged from the uniform stabilization unit 5. The water flow and gas adopt a "jet mixing" method to achieve high-speed shearing of the water flow, gas-liquid mixing and crushing, and stably form micro-nano-scale bubbles, which can effectively improve the bubble generation efficiency and uniformity.

[0047] Example 2:

[0048] like Figure 7 and Figure 14 As shown, the water injection unit 1 adopts a dynamic wave nozzle 1-1, wherein the dynamic wave nozzle 1-1 includes a guide plate 14, a dynamic wave mixing chamber 13 and a nozzle 12. The guide plate 14 adopts a petal-shaped guide plate, and the blade inclination angle γ of the petal-shaped guide plate is 5°-30°. The dynamic wave nozzle 1-1 can spray out a rapid jet of water, which can make the size of the bubbles more uniform and improve the efficiency of the bubble generator.

[0049] Example 3:

[0050] like Figure 9 As shown, the water spraying unit 1 adopts a conical nozzle 1-3, wherein the conical nozzle 1-3 includes a contraction chamber 131 and a nozzle 121.

[0051] Example 4:

[0052] like Figure 8 As shown, the water injection unit 1 adopts a Helmholtz nozzle 1-2, wherein the Helmholtz nozzle 1-2 includes a resonant cavity 111 with an annular hollow structure, a reflective cone 113 provided on the inner side wall of the rear end of the resonant cavity 111, an upper nozzle 112 provided at the front end of the resonant cavity 111, a lower nozzle 114 provided at the rear end of the resonant cavity 111, and an air inlet 115 provided on the resonant cavity 111 for providing airflow. The reflective cone 113 is penetrated by a channel 119 coaxially arranged therewith, and the channel 119 is connected to the lower nozzle 114. The resonant cavity 111 is provided with a baffle 116 with an annular structure. The outer ring of the baffle 116 forms a gas distribution cavity 117 with an annular structure. The baffle 116 is penetrated by an air intake hole 118.

[0053] The diameter ratio of the upper nozzle 112 to the lower nozzle 114 is 1:1-1.6, the length-to-diameter ratio of the resonant cavity 111 is 1:0.4-0.7; the taper angle δ of the reflection cone 113 is 110°-130°;

[0054] The Helmholtz nozzle 1-2 uses a resonant cavity 111 to generate pressure fluctuations. The water flow and gas are subjected to the cavitation effect of the self-excited oscillating pulse jet, which triggers local cavitation of the liquid, thereby forming tiny bubbles or cavitations, which can further enhance the jet effect of the Venturi tube and improve the efficiency of micro-nano bubble generation.

[0055] Example 5:

[0056] like Figure 10 As shown, the water injection unit 1 adopts a combination nozzle 1-4 of a power wave nozzle and a Helmholtz nozzle, wherein the combination nozzle 1-4 of the power wave nozzle and the Helmholtz nozzle is a combination of the power wave nozzle 1-1 shown in Example 2 and the Helmholtz nozzle 1-2 shown in Example 4, and the nozzle 12 of the power wave nozzle 1-1 shown in Example 2 serves as the upper nozzle 112 of the Helmholtz nozzle 1-2 shown in Example 4; the resonant cavity is excited by the power wave, the cavitation efficiency is improved and the dependence on the flow rate change is reduced, and the formation quantity and distribution uniformity of micro-nano bubbles and the flexibility of operation are further improved through the setting of multiple air chambers. The setting of the combination nozzle 1-4 of the power wave nozzle and the Helmholtz nozzle does not rely on a fixed resonant cavity and is suitable for working conditions with large flow and pressure changes.

[0057] Example 6:

[0058] like Figure 11 As shown, the water jet unit 1 uses a combination of a conical nozzle and a Helmholtz nozzle 1-5, wherein the combination of the conical nozzle and Helmholtz nozzle 1-5 is similar to the combination of the conical nozzle 1-3 shown in Example 3 and the Helmholtz nozzle 1-2 shown in Example 4, and the nozzle 121 of the conical nozzle 1-3 shown in Example 3 serves as the upper nozzle 112 of the Helmholtz nozzle 1-2 shown in Example 4. The combination of the conical nozzle and the Helmholtz nozzle improves cavitation efficiency and reduces dependence on flow rate changes through the resonant cavity, and further improves the number and distribution uniformity of micro-nano bubbles formed and operational flexibility through the configuration of multiple air chambers.

[0059] Example 7:

[0060] like Figure 2 As shown, the air-water premixing unit 2 is annular, and includes an air-water premixing chamber 22, an air chamber 23 of an annular structure arranged on the periphery of the air-water premixing chamber 22, an air guide air path 24 for supplying air to the air chamber 23, and an air path 21 for providing a rotary shear airflow to the air-water premixing chamber 22, and the air path 21 is connected to the air chamber 23.

[0061] The air guide path 24 enters tangentially along the outer wall of the air chamber 1 23. The air path 1 21 is a plurality of evenly distributed air holes with a diameter of 0.5 mm to 2.0 mm. The air path 1 21 enters the air-water pre-mixing chamber 22 tangentially along the inner wall of the air chamber 1 23.

[0062] When the gas-water premixing unit 2 is premixing, the gas enters the gas chamber 23 along the air guide path 24 and then is premixed with the gas-water premixing chamber 22 by a spiral jet shearing method under the guidance of the gas path 21. The spiral jet shearing mixing is conducive to shearing the fluid and forming strong turbulence, promoting gas-liquid mixing, and the rotating entry method is conducive to the self-cleaning effect, reducing sediment adhesion, and improving the anti-blocking performance.

[0063] Example 8:

[0064] like Figure 3 、 Figure 4 and Figure 15 As shown, the air-water mixing unit 3 includes a contraction tube 31, a throat tube 32, and a diffusion tube 33 arranged in sequence. The throat tube 32 is provided with a second air chamber 34 of an annular structure arranged coaxially therewith. A second air path 35 for providing a rotary shearing airflow to the inner cavity of the throat tube 32 is provided between the second air chamber 34 and the inner side wall of the throat tube 32. The second air chamber 34 is provided with an air intake pipe 36 for air intake.

[0065] The second air path 35 adopts a gap set on the throat 32, the gap is less than 0.2 mm, the second air path 35 is set tangentially along the axis of the throat 32 or vertically or obliquely along the axis of the throat 32, and the air inlet pipe 36 enters the second air chamber 34 tangentially along the outer wall of the second air chamber 34.

[0066] The diameter ratio of the contraction tube 31 to the throat tube 32 and the diffuser 33 is 0.8-1.2:1:2.0-3.0, the angle α of the contraction tube 31 is 40°-70°, and the angle β of the diffuser 33 is 6°-12°;

[0067] The gas-water mixing unit 3 adopts a rotating jet shearing method for mixing. Based on the effect of the "gas-liquid interface" phenomenon, it increases the interface contact area, further shears the bubbles, realizes gas self-absorption, and improves the mass transfer effect and the uniformity of bubble distribution.

[0068] Example 9:

[0069] like Figure 5 and Figure 12-13 As shown, the air-water double shear mixing unit 4 includes a straight tube 41 with an internal thread 42 at the front end, a venturi-like tube 43 arranged in the straight tube 41, and a diverter annulus 44 arranged on the outside of the front end of the venturi-like tube 43 and gradually contracting, followed by a mixing chamber 45. The venturi-like tube 43 includes a contraction tube 411, a throat 412, and a diffuser 413 arranged in sequence. A rotary cutting air path 46 is opened between the mixing chamber 45 and the inner circle of the throat 412. The air and water ejected from the rotary cutting air path 46 are tangentially sheared and mixed for the second time in the throat 412, and diffused and ejected along the diffuser 413, and finally enter the uniform stabilization unit 5. The straight tube 41 is provided with an air pipe 47 for supplying air to the mixing chamber 45.

[0070] Among them, Figure 13 As shown in A, the rotary cutting gas path 46 adopts a gap, and the rotary cutting gas path 46 is tangential along the axis of the venturi-like tube 43;

[0071] like Figure 13 As shown in B, the rotary cut air path 46 has air holes, and the rotary cut air path 46 is arranged perpendicular to the axis of the venturi-like tube 43;

[0072] like Figure 13 As shown in C, the rotary cut air path 46 has air holes, and the rotary cut air path 46 and the axis of the venturi-like tube 43 are arranged obliquely.

[0073] Example 10:

[0074] like Figure 6 As shown, the uniform and stable unit 5 includes a second straight pipe 51 , a second fluid guide plate 52 arranged inside the second straight pipe 51 , and a static mixing component 53 arranged at the end of the second fluid guide plate 52 .

[0075] The static mixing component 53 includes an internal thread 1 54 provided on the straight pipe 2 51 and a guide column 55 connected to the straight pipe 2 51;

[0076] The uniform stabilization unit 5 can prevent the micro-nano bubbles from agglomerating during the diffusion process, reduce the countercurrent separation phenomenon, improve the ejection effect and dispersion of the bubbles, and further optimize the formation and stability of the micro-nano bubbles.

[0077] Example 11:

[0078] A method for generating micro-nano bubbles by air-water double shearing, comprising the following steps:

[0079] Step S1, using the water spray unit 1 to form a high-speed atomized water flow;

[0080] Step S2: using the gas-water premixing unit 2 to premix the high-speed atomized water flow with gas and water by rotary cutting;

[0081] Step S3, using the gas-water mixing unit 3 to mix the gas and water by rotary cutting combined with inner shearing;

[0082] Step S4, using the air-water double shear mixing unit 4 to mix air and water in an air-water double shear manner, the air-water double shear mixing unit 4 uses a straight tube 41 with an internal thread 42, a venturi tube 43, a diversion annulus 44, a mixing chamber 45 and a rotary cutting air path 46, and uses the air-water double shear manner to mix air and water, enhance the air-water shear strength, improve the bubble injection effect and dispersion, and optimize the formation and stability of micro-nano bubbles.

[0083] Step S5: Utilize the uniform stabilization unit 5 to stabilize and discharge the mixed gas and water.

[0084] The high-speed atomized water flow generated by the nozzle of the present invention can guide the formation of bubbles through the form of the Venturi tube. Different types of feed nozzles can be selected according to the working operation needs to meet the micro-nano bubble generation needs under different conditions. It is flexible and changeable, and the adaptability of the micro-nano bubble generation equipment is improved; a variety of air chamber settings are adopted to further improve the number of micro-nano bubbles formed and the uniformity of distribution and the flexibility of operation; the rotary cutting mixing design is adopted, which is conducive to shearing the fluid and forming strong turbulence, promoting gas-liquid mixing, and the rotary entry method has a self-cleaning effect, reduces sediment adhesion, and improves the anti-blocking performance; the internal thread rotary diversion is utilized, similar to the Venturi tube and gas-water double shear, and additional turbulence is introduced when the airflow passes through, thereby increasing the interface contact area, further shearing the bubbles, and utilizing the impact flow to enhance the shear strength, improve the bubble ejection effect and dispersibility, and optimize the formation of micro-nano bubbles; it can keep the micro-nano bubbles from agglomerating during the diffusion process, reduce the countercurrent separation phenomenon, improve the bubble ejection effect and dispersibility, and further optimize the formation and stability of micro-nano bubbles;

[0085] The present invention is based on the "self-excited oscillation", "jet mixing" and "gas-liquid interface" phenomena in fluid dynamics, and combines a variety of mature cavitation effects, Venturi effects, shear fragmentation, static mixing fluid dynamics principles, and adds multiple air chamber designs, especially the double shear configuration of cavitation cavity, annular air chamber and impinging flow, which realizes gas self-absorption and can effectively improve the efficiency and uniformity of bubble generation.

[0086] The present invention can select different types of feed nozzles according to work operation needs, meet the micro-nano bubble generation requirements under different conditions, is flexible and changeable, and improves the adaptability of the micro-nano bubble generation equipment; adopts a two-rotation jet shearing method for mixing, which is conducive to shearing the fluid and forming strong turbulence, promoting gas-liquid mixing, and the rotary entry method has a self-cleaning effect, reduces sediment adhesion, and improves anti-clogging performance; utilizes internal thread rotary diversion, Venturi tube-like and impact flow air-water double shearing, introduces additional turbulence when the airflow passes, increases the interface contact area, further shears the bubbles, improves the bubble ejection effect and dispersibility, and optimizes the formation of micro-nano bubbles; can keep the micro-nano bubbles from agglomerating during the diffusion process, reduce the countercurrent separation phenomenon, improve the bubble ejection effect and dispersibility, and further optimize the formation and stability of the micro-nano bubbles.

[0087] The above embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. A micro-nano bubble generating device with air-water double shearing, characterized in that: The invention comprises a water injection unit (1) for generating a high-speed atomized water flow, an air-water premixing unit (2) for premixing air and water by air-water rotary shearing, an air-water mixing unit (3) for rotary shearing, an air-water double shear mixing unit (4) for double shearing of air and water, and a uniform stabilization unit (5) for stabilizing and discharging micro-nano bubbles. The water injection unit (1), the air-water premixing unit (2), the air-water mixing unit (3), the air-water double shear mixing unit (4), and the uniform stabilization unit (5) are connected front to back and are arranged in sequence along an axis.

2. A micro-nano bubble generating device with air-water double shearing as claimed in claim 1, characterized in that: The water jet unit (1) adopts any one of a power wave nozzle (1-1), a Helmholtz nozzle (1-2), a conical nozzle (1-3), a combined nozzle of a power wave nozzle and a Helmholtz nozzle (1-4), and a combined nozzle of a conical nozzle and a Helmholtz nozzle (1-5).

3. A micro-nano bubble generating device with air-water double shearing as claimed in claim 1, characterized in that, The air-water premixing unit (2) is annular and comprises an air-water premixing chamber (22), an air chamber (23) of an annular structure arranged on the periphery of the air-water premixing chamber (22), an air guide air path (24) for supplying air to the air chamber (23), and an air path (21) for providing a rotary shearing air flow to the air-water premixing chamber (22), wherein the air path (21) is in communication with the air chamber (23).

4. A gas-water double shear micro-nano bubble generating device as claimed in claim 3, characterized in that: The air-guiding air path (24) enters tangentially along the outer wall of the air chamber (23), the air path (21) is a plurality of evenly distributed air holes with a diameter of 0.5 mm to 2.0 mm, and the air path (21) enters tangentially along the inner wall of the air chamber (23) into the air-water premixing chamber (22).

5. The micro-nano bubble generating device of air-water double shearing as claimed in claim 1, characterized in that: The air-water mixing unit (3) comprises a contraction tube (31), a throat tube (32) and a diffusion tube (33) which are arranged in sequence. The throat tube (32) is provided with a second air chamber (34) of an annular structure which is coaxially arranged therewith. A second air path (35) for providing a rotary shearing airflow to the inner cavity of the throat tube (32) is provided between the second air chamber (34) and the inner side wall of the throat tube (32). The second air chamber (34) is provided with an air intake pipe (36) for air intake.

6. The micro-nano bubble generating device of air-water double shearing as claimed in claim 5, characterized in that: The second air path (35) is provided with a slit on the throat (32), the slit being less than 0.2 mm. The second air path (35) is provided in a tangential rotational direction along the axis of the throat (32) or is provided vertically or obliquely along the axis of the throat (32). The air inlet pipe (36) enters the second air chamber (34) tangentially along the outer wall of the second air chamber (34).

7. The air-water double shear micro-nano bubble generating device according to claim 5, characterized in that: The diameter ratio of the contraction tube (31), the throat tube (32) and the diffusion tube (33) is 0.8-1.2:1:2.0-3.0, the angle α of the contraction tube (31) is 40°-70°, and the angle β of the diffusion tube (33) is 6°-12°.

8. The air-water double shear micro-nano bubble generating device according to claim 1, characterized in that: The air-water double shear mixing unit (4) comprises a straight tube (41) with an internal thread (42) at the front end, a venturi-like tube (43) arranged in the straight tube (41), and a diversion annular gap (44) arranged on the outside of the front end of the venturi-like tube (43) and gradually contracting, followed by a mixing chamber (45). The venturi-like tube (43) comprises a contraction tube (411), a throat tube (412), and a diffusion tube (413) arranged in sequence. A rotary cutting air path (46) is provided between the mixing chamber (45) and the inner circle of the throat tube (412). The air and water ejected from the rotary cutting air path (46) are subjected to secondary shear mixing in the throat tube (412) in a tangential direction, and are diffused and ejected along the diffusion tube (413) and finally enter the uniform and stable unit (5). The straight tube (41) is provided with an air pipe (47) for supplying air to the mixing chamber (45).

9. The micro-nano bubble generating device of air-water double shearing as claimed in claim 1, characterized in that: The uniform stabilizing unit (5) comprises a second straight pipe (51), a second fluid guide plate (52) arranged inside the second straight pipe (51), and a static mixing component (53) arranged at the end of the second fluid guide plate (52); the static mixing component (53) comprises an internal thread (54) and a guide column (55).

10. A method for generating micro-nano bubbles by air-water double shearing, which uses the generating device according to claim 1, characterized in that: The following steps are involved: Step S1, using the water spray unit (1) to form a high-speed atomized water flow; Step S2, using the gas-water premixing unit (2) to premix the high-speed atomized water flow with gas and water by rotary cutting; Step S3, using the gas-water mixing unit (3) to mix the gas and water by rotary cutting combined with inner shearing; Step S4: using the air-water double shear mixing unit (4) to perform air-water mixing in an air-water double shear manner. Step S5: Utilize the uniform stabilization unit (5) to stabilize and discharge the mixed gas and water.

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