Method and equipment for generating micro-nano bubbles with built-in air chamber

Abstract

The invention relates to the technical field of micro-nano bubbles, and discloses a method and equipment for generating micro-nano bubbles with a built-in air chamber. 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 mixing gas and water by adopting rotary cutting and inner side 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, various mature fluid dynamics principles of cavitation effect, Venturi effect, shearing and crushing, impinging stream mixing and static mixing are combined, the design of a plurality of air chambers and two fluid flow deflectors is added, and especially the arrangement of a cavitation cavity, an annular air chamber and a built-in air chamber is adopted, so that the fluid mixing effect is greatly improved; the gas self-absorption is realized, and the generation efficiency and uniformity of the micro-nano bubbles are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-nano bubble technology, and particularly to a method and device for generating micro-nano bubbles with an internal air chamber. Background Art

[0002] Micro-nano bubbles refer to tiny bubbles with a radius between 0.1 and 50 μm. Micro-nano bubbles have special properties beyond ordinary bubbles, such as a large specific surface area, a slow rising speed of bubbles, a high interfacial potential, a high internal pressure, the ability to generate a large number of free radicals, a high mass transfer efficiency, and a high gas dissolution rate, which are unique properties different from ordinary large bubbles. In recent years, it has attracted wide attention and began to be applied in fields such as chemical engineering, materials, environmental engineering, biology, and pharmaceutical delivery.

[0003] Currently, the main methods for generating micro-nano bubbles are as follows: ultrasonic bubble generation method, dispersed air method, electrolytic bubble precipitation method, chemical reaction method, and microchannel method, etc. Although much progress has been made in the technology of micro-nano bubbles, there are still some challenges: one is the problem of bubble stability. Micro-nano bubbles are prone to coalescence and rupture, especially in a dynamic environment, and the life cycle of bubbles is short, resulting in the failure of bubbles during application. The second is the problem of controlling the bubble size. Although existing methods can generate micro-nano scale bubbles, the bubble size distribution is uneven, and it is difficult to precisely control the single size of bubbles, which limits the effectiveness of its specific applications. The third is the low generation efficiency. The bubble generation efficiency of many existing generation methods is low, especially in large-scale production, where the operation is complex and the cost is high. The fourth is the limited application fields. Although there have been breakthroughs in water treatment, drug delivery, etc., it still needs to be further verified and optimized in actual industrial applications. Summary of the Invention

[0004] To solve the technical problems existing in the prior art, the present invention provides a method and device for generating micro-nano bubbles with an internal air chamber.

[0005] The present invention is implemented by the following technical solutions: A micro-nano bubble generating device with an internal air chamber includes a water injection unit for generating a high-speed atomized water flow, an air-water pre-mixing unit for pre-mixing air and water by air-water swirling and cutting, an air-water mixing unit for mixing air and water by combining swirling and inner shearing, and a uniform stability unit for stabilizing and discharging micro-nano bubbles, and the water injection unit, the air-water pre-mixing unit, the air-water mixing unit, and the uniform stability unit are connected in series and arranged in sequence along the axis.

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

[0007] Further, the gas-water pre-mixing unit is annular, and it includes a gas-water pre-mixing chamber, a first gas chamber with an annular structure arranged on the outer periphery of the gas-water pre-mixing chamber, a gas guiding air path for supplying gas to the first gas chamber, and an air path for providing a swirling cutting air flow to the gas-water pre-mixing chamber. The air path is communicated with the first gas chamber.

[0008] Further, the gas guiding air path enters tangentially along the outer wall of the first gas chamber. The air path is a plurality of uniformly distributed pores with a diameter of 0.5 mm - 2.0 mm, and the air path enters the gas-water pre-mixing chamber tangentially along the inner wall of the first gas chamber.

[0009] Further, the gas-water mixing unit includes a contraction tube, a throat tube, and a diffuser tube arranged in sequence. The throat tube is provided with a second gas chamber with an annular structure coaxially arranged therewith. A second air path for providing a swirling cutting air flow to the inner cavity of the throat tube is formed between the second gas chamber and the inner side wall of the throat tube. An internal gas chamber for providing an inner shear air flow is arranged on the inner circle of the throat tube. The internal gas chamber is communicated with the second gas chamber through a first air tube. The internal gas chamber is provided with a jet air path for providing inner shear to the throat tube. The second gas chamber is provided with an inlet pipe for air intake.

[0010] Further, the second air path is a slit arranged on the throat tube. The slit is less than 0.2 mm. The second air path is arranged tangentially and rotationally along the axis of the throat tube or perpendicular or inclined to the axis of the throat tube. The inlet pipe enters the second gas chamber tangentially along the outer wall of the second gas chamber.

[0011] Further, the diameter ratio of the contraction tube, the throat tube, and the diffuser 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 diffuser tube is 6° - 12°.

[0012] Further, the cavity of the internal gas chamber is any one of a water droplet shape, a spindle shape, and a barrel shape with pointed ends at both ends. The water-facing surface of the internal gas chamber is a forwardly convex curved surface structure.

[0013] Further, the uniform and stable unit includes a straight pipe, a two-fluid guiding vane arranged inside the straight pipe, and a static mixing member arranged at the end of the two-fluid guiding vane; the static mixing member includes a first internal thread and a guiding column.

[0014] A method for generating micro-nano bubbles with an internal gas chamber includes the following steps:

[0015] Step S1, forming a high-speed atomized water flow by using a water injection unit;

[0016] Step S2, performing gas-water pre-mixing on the high-speed atomized water flow in a swirling cutting manner by using a gas-water pre-mixing unit;

[0017] Step S3, performing gas-water mixing in a manner combining swirling cutting and inner shear by using a gas-water mixing unit;

[0018] Step S4: Stabilize and discharge the mixed gas and water using a uniform and stable unit.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] 1. The high-speed atomized water flow generated by the nozzle of the present invention can achieve self-suction of gas and guide the formation of bubbles through the form of a Venturi tube. Different types of feed nozzles can be selected according to the working operation requirements to meet the micro-nano bubble generation needs under different conditions, which is flexible and variable, and improves the adaptability range of micro-nano bubble generation equipment.

[0021] 2. The present invention adopts a variety of gas chamber settings to further increase the formation quantity and distribution uniformity of micro-nano bubbles and the flexibility of operation.

[0022] 3. The present invention adopts a rotary cutting and mixing design, which is beneficial to shearing the fluid and forming strong turbulence, promoting gas-liquid mixing. Moreover, the rotation entry method has a self-cleaning effect, reducing sediment attachment and improving the anti-blocking performance.

[0023] 4. The present invention uses the built-in gas chamber to introduce additional turbulence when the air flow passes through in the way of middle-diffusion jet shearing and mixing, increasing the interfacial contact area, further shearing the bubbles, improving the mass transfer effect, and enhancing the distribution uniformity of the bubbles.

[0024] 5. The design of the uniform and stable unit of the present invention can keep the micro-nano bubbles from coalescing 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 micro-nano bubbles. Description of the Drawings

[0025] Figure 1 It is a schematic structural diagram of a micro-nano bubble generation device with a built-in gas chamber provided by the present invention;

[0026] Figure 2 It is a schematic structural diagram of the gas-water pre-mixing unit provided by the present invention;

[0027] Figure 3 It is a schematic structural diagram of the gas-water mixing unit provided by the present invention;

[0028] Figure 4 It is a schematic structural diagram of the second gas path provided by the present invention;

[0029] Figure 5 It is a schematic structural diagram of the uniform and stable unit provided by the present invention;

[0030] Figure 6 It is a schematic structural diagram of the power wave nozzle provided by the present invention;

[0031] Figure 7Schematic structural diagram of the Helmholtz nozzle provided by the present invention;

[0032] Figure 8 Schematic structural diagram of the conical nozzle provided by the present invention;

[0033] Figure 9 Schematic structural diagram of the combined nozzle of the power wave nozzle and the Helmholtz nozzle provided by the present invention;

[0034] Figure 10 Schematic structural diagram of the combined nozzle of the conical nozzle and the Helmholtz nozzle provided by the present invention;

[0035] Figure 11 Schematic structural diagram of the built-in air chamber with a water droplet-shaped structure provided by the present invention;

[0036] Figure 12 Schematic structural diagram of the built-in air chamber with a spindle-shaped structure provided by the present invention;

[0037] Figure 13 Schematic structural diagram of the built-in air chamber with a barrel-shaped structure with pointed ends provided by the present invention;

[0038] Figure 14 Schematic structural diagram of the first deflector provided by the present invention;

[0039] Figure 15 Cross-sectional view of the air-water mixing unit provided by the present invention.

[0040] Main symbol description:

[0041] 1. Water injection unit; 2. Air-water premixing unit; 3. Air-water mixing unit; 4. Uniform and stable unit; 1-1. Power wave nozzle; 1-2. Helmholtz nozzle; 1-3. Conical nozzle; 1-4. Combined nozzle of power wave nozzle and Helmholtz nozzle; 1-5. Combined nozzle of conical nozzle and Helmholtz nozzle; 12. Nozzle; 13. Power wave mixing cavity; 14. First deflector; 111. Resonant cavity; 112. Upper nozzle; 113. Reflection cone; 114. Lower nozzle; 115. Air inlet; 116. Partition; 117. Gas distribution cavity; 118. Suction hole; 119. Channel 1; 121. Nozzle 1; 131. Contraction cavity; 21. Air path 1; 22. Air-water premixing chamber; 23. Air chamber 1; 24. Air guiding air path; 31. Contraction pipe; 32. Throat pipe; 33. Diffusion pipe; 34. Air chamber 2; 35. Air path 2; 36. Inlet pipe; 37. Built-in air chamber; 38. Air pipe 1; 39. Injection air path; 41. Straight pipe; 42. Two-fluid deflector; 43. Static mixing member; 44. First internal thread; 45. Guide column. Detailed implementation manners

[0042] Next, in combination with the accompanying drawings and specific embodiments, the present invention will be further described. It should be noted that, on the premise of no conflict, any combination of the following-described embodiments or technical features can form a new embodiment.

[0043] Embodiment 1:

[0044] Please refer to Figures 1-5 , a micro-nano bubble generating device with an internal air chamber in this embodiment includes a water injection unit 1 for generating high-speed atomized water flow, a gas-water pre-mixing unit 2 for pre-mixing gas and water by means of gas-water swirl cutting, a gas-water mixing unit 3 for mixing gas and water by means of swirl cutting combined with inner shear, and a uniform stabilization unit 4 for stabilizing and discharging micro-nano bubbles. The water injection unit 1, the gas-water pre-mixing unit 2, the gas-water mixing unit 3, and the uniform stabilization unit 4 are connected in series and arranged in sequence along the axis.

[0045] The water flow 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 pre-mixed in the gas-water pre-mixing unit 2 by means of air flow swirl cutting, and then is mixed in the gas-water mixing unit 3 by means of secondary air flow swirl cutting and inner shear. The water flow and gas adopt the "jet mixing" method to achieve high-speed shearing of the water flow, realize gas-liquid mixing and fragmentation, and stably form micro-nano scale bubbles, which can effectively improve the generation efficiency and uniformity of bubbles.

[0046] Embodiment 2:

[0047] As shown in Figure 6 and Figure 14 , the water injection unit 1 adopts a power wave nozzle 1-1. Among them, the power wave nozzle 1-1 includes a first guide vane 14, a power wave mixing chamber 13, and a nozzle 12. The first guide vane 14 adopts a petal-shaped guide vane, and the blade inclination angle γ of the petal-shaped guide vane is 5°-30°. The power wave nozzle 1-1 can eject a fast jet of water flow, which can make the size of the bubbles more uniform and improve the efficiency of the bubble generator.

[0048] Embodiment 3:

[0049] As shown in Figure 8 , the water injection unit 1 adopts a conical nozzle 1-3. Among them, the conical nozzle 1-3 includes a contraction chamber 131 and a first nozzle 121.

[0050] Embodiment 4:

[0051] As shown in Figure 7As shown in the figure, the water injection unit 1 adopts a Helmholtz nozzle 1-2. Among them, the Helmholtz nozzle 1-2 includes a resonant cavity 111 with an annular hollow structure, a reflection cone 113 arranged on the inner side wall at the rear end of the resonant cavity 111, an upper nozzle 112 arranged at the front end of the resonant cavity 111, a lower nozzle 114 arranged at the rear end of the resonant cavity 111, and an air inlet 115 arranged on the resonant cavity 111 for providing air flow. A channel 119 coaxial with it penetrates through the reflection cone 113, and the channel 119 is communicated with the lower nozzle 114. The resonant cavity 111 is provided with a partition 116 with an annular structure. An annular gas distribution cavity 117 is formed outside the partition 116. The partition 116 is penetrated with air suction holes 118;

[0052] The diameter ratio of the upper nozzle 112 to the lower nozzle 114 is 1:1 - 1.6, and the ratio of the cavity length to the cavity diameter of the inner cavity of the resonant cavity 111 is 1:0.4 - 0.7; the taper δ of the reflection cone 113 is 110° - 130°;

[0053] The Helmholtz nozzle 1-2 uses the resonant cavity 111 to generate pressure fluctuations. The water flow and gas are subjected to the cavitation effect of self-excited oscillation pulsed jet, triggering local cavitation of the liquid, thereby forming tiny bubbles or cavities, which can further strengthen the jet action of the Venturi tube and improve the generation efficiency of micro-nano bubbles.

[0054] Example 5:

[0055] As Figure 9 shown in the figure, the water injection unit 1 adopts a combined nozzle 1-4 of a power wave nozzle and a Helmholtz nozzle. Among them, the combined 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. 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; by exciting the resonant cavity with power waves, the cavitation efficiency is improved and the dependence on the flow rate change is reduced, and the formation quantity, distribution uniformity and operation flexibility of micro-nano bubbles are further improved through various air chamber settings. The setting of the combined 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 changes in flow rate and pressure.

[0056] Example 6:

[0057] As Figure 10As shown, the water injection unit 1 adopts a combined nozzle of a conical nozzle and a Helmholtz nozzle 1-5. Among them, the combined nozzle of the conical nozzle and the Helmholtz nozzle 1-5 is the combination of the conical nozzle 1-3 shown in Embodiment 3 and the Helmholtz nozzle 1-2 shown in Embodiment 4. The nozzle 121 of the conical nozzle 1-3 shown in Embodiment 3 serves as the upper nozzle 112 of the Helmholtz nozzle 1-2 shown in Embodiment 4. By adopting the combination of the conical nozzle and the Helmholtz nozzle, through the resonance cavity, the cavitation efficiency is improved and the dependence on the flow rate change is reduced, and the formation quantity, distribution uniformity of micro-nano bubbles and the operation flexibility are further improved through various air chamber settings.

[0058] Embodiment 7:

[0059] As Figure 2 shown, the gas-water premixing unit 2 is annular, and it includes a gas-water premixing chamber 22, an air chamber 23 with an annular structure arranged on the outer periphery of the gas-water premixing chamber 22, a gas guiding air path 24 for supplying gas to the air chamber 23, and an air path 21 for providing a swirling and shearing air flow to the gas-water premixing chamber 22, and the air path 21 is communicated with the air chamber 23.

[0060] The gas guiding air path 24 enters tangentially along the outer wall of the air chamber 23. The air path 21 is a plurality of uniformly distributed air holes with a diameter of 0.5 mm - 2.0 mm, and the air path 21 enters the gas-water premixing chamber 22 tangentially along the inner wall of the air chamber 23;

[0061] When the gas-water premixing unit 2 performs premixing, the gas enters the air chamber 23 along the gas guiding air path 24 and then is premixed with the gas and water inside the gas-water premixing chamber 22 in a spiral jet shearing manner under the guidance of the air path 21. The spiral jet shearing mixing is beneficial to shearing the fluid and forming strong turbulence, promoting gas-liquid mixing, and the rotating entry method helps the self-cleaning effect, reduces the attachment of sediments, and improves the anti-blocking performance.

[0062] Embodiment 8:

[0063] As Figures 3-4 and Figures 11-13 and Figure 15 shown, the gas-water mixing unit 3 includes a contraction tube 31, a throat tube 32 and a diffuser tube 33 arranged in sequence. The throat tube 32 is provided with an air chamber 34 with an annular structure coaxially arranged therewith. An air path 35 for providing a swirling and shearing air flow to the inner cavity of the throat tube 32 is opened between the air chamber 34 and the inner side wall of the throat tube 32. An internal air chamber 37 for providing an inner shearing air flow is arranged on the inner circle of the throat tube 32. The internal air chamber 37 is communicated with the air chamber 34 through an air tube 38. The internal air chamber 37 is provided with an injection air path 39 for providing inner shearing to the throat tube 32. The air chamber 34 is provided with an air inlet pipe 36.

[0064] The second gas path 35 uses a slit provided on the throat tube 32, the slit being less than 0.2 mm. The second gas path 35 is arranged tangentially and rotationally along the axis of the throat tube 32 or arranged perpendicular or obliquely to the axis of the throat tube 32. The intake pipe 36 enters the second gas chamber 34 tangentially along the outer wall of the second gas chamber 34.

[0065] The diameter ratio of the contraction tube 31 to the throat tube 32 and the diffuser 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 diffuser tube 33 is 6° - 12°.

[0066] As Figure 11 shown, the built-in gas chamber 37 has a water droplet-shaped structure. In 11A, the injection gas path 39 is arranged perpendicular to the built-in gas chamber 37; in 11B, the injection gas path 39 is arranged obliquely to the built-in gas chamber 37;

[0067] As Figure 12 shown, the built-in gas chamber 37 has a spindle-shaped structure. In 12A, the injection gas path 39 is arranged perpendicular to the built-in gas chamber 37; in 12B, the injection gas path 39 is arranged obliquely to the built-in gas chamber 37;

[0068] As Figure 13 shown, the built-in gas chamber 37 has a barrel-shaped structure with pointed ends. In 13A, the injection gas path 39 is arranged perpendicular to the built-in gas chamber 37; in 13B, the injection gas path 39 is arranged obliquely to the built-in gas chamber 37;

[0069] The cavity of the built-in gas chamber 37 is any one of a water droplet shape, a spindle shape, and a barrel shape with pointed ends. The water-facing surface of the built-in gas chamber 37 has a convex curved surface structure. The ratio of the cross-sectional area of the built-in gas chamber 37 along the axis of the throat tube 32 to the cross-sectional area of the diameter of the throat tube 32 is 1:1 - 4. The angles at the pointed ends of both ends of the built-in gas chamber 37 are 30 - 60°

[0070] The injection gas path 39 is provided on the side of the built-in gas chamber 37 facing the water flow. The injection gas path 39 is a pore or a slit. The angles at both ends of the built-in gas chamber 37 are 30 - 60°;

[0071] In the gas-water mixing unit 3, pre-mixing is carried out in the same way as in the gas-water pre-mixing unit 2 by means of spiral jet shearing, and the built-in gas chamber 37 is used for diffusion-type jet shearing mixing from the middle. The built-in gas chamber 37 introduces additional turbulence when the gas flow passes through. Based on the action of the "gas-liquid interface" phenomenon, the interface contact area is increased, the bubbles are further sheared, gas self-aspiration is achieved, and the mass transfer effect and the uniformity of the bubble distribution are improved.

[0072] Example 9:

[0073] As Figure 5As shown in the figure, the uniform and stable unit 4 includes a straight pipe 41, a two-fluid guide vane 42 arranged inside the straight pipe 41, and a static mixing member 43 arranged at the end of the two-fluid guide vane 42.

[0074] The static mixing member 43 includes an internal thread one 44 arranged on the straight pipe 41 and a guide column 45 connected to the straight pipe 41;

[0075] The uniform and stable unit 4 can keep the micro-nano bubbles from coalescing during the diffusion process, reduce the countercurrent separation phenomenon, improve the ejection effect and dispersibility of the bubbles, and further optimize the formation and stability of the micro-nano bubbles.

[0076] Example 10:

[0077] A method for generating micro-nano bubbles with an internal air chamber includes the following steps:

[0078] Step S1, forming a high-speed atomized water flow by using the water injection unit 1;

[0079] Step S2, performing gas-water premixing on the high-speed atomized water flow in a rotary cutting manner by using the gas-water premixing unit 2;

[0080] Step S3, performing gas-water mixing in a rotary cutting combined with inner shearing manner by using the gas-water mixing unit 3;

[0081] Step S4, stabilizing and discharging the mixed gas and water by using the uniform and stable unit 4.

[0082] The high-speed atomized water flow generated by the nozzle of the present invention can realize self-suction of gas and guide the formation of bubbles through the form of a Venturi tube, can select different types of feed nozzles according to the working operation needs to meet the micro-nano bubble generation requirements under different conditions, is flexible and changeable, and improves the adaptation range of the micro-nano bubble generation equipment; adopting a variety of air chamber settings further improves the formation quantity, distribution uniformity and operation flexibility of the micro-nano bubbles. Adopting a rotary cutting mixing design is beneficial to shearing the fluid and forming strong turbulence, promoting gas-liquid mixing, and the rotary entry method has a self-cleaning effect, reducing sediment attachment and improving the anti-blocking performance; using the set internal air chamber to jet and shear mix in a middle diffusion manner introduces additional turbulence when the air flow passes through, increases the interfacial contact area, further shears the bubbles, improves the mass transfer effect and the distribution uniformity of the bubbles; can keep the micro-nano bubbles from coalescing during the diffusion process, reduce the countercurrent separation phenomenon, improve the ejection effect and dispersibility of the bubbles, and further optimize the formation and stability of the micro-nano bubbles;

[0083] The present invention is based on the phenomena of "self-excited oscillation", "jet mixing" and "gas-liquid interface" in fluid dynamics, and combines a variety of mature cavitation effects, Venturi effects, shear fragmentation, impinging stream mixing, and static mixing fluid dynamics principles. Additionally, the design of multiple air chambers and two-fluid guide vanes is incorporated, especially the settings of the cavitation chamber, annular air chamber, and built-in air chamber, enabling self-aspiration of gas and effectively improving the generation efficiency and uniformity of micro-nano bubbles.

[0084] The present invention can select different types of feed nozzles according to the working operation requirements to meet the micro-nano bubble generation needs under different conditions, being flexible and variable, and improving the adaptation range of micro-nano bubble generation equipment. The two-stage spiral jet shearing method is adopted for mixing, which is beneficial for shearing the fluid and forming strong turbulence, promoting gas-liquid mixing. Moreover, the rotational entry method helps with the self-cleaning effect, reducing sediment attachment and improving the anti-blocking performance. By using the built-in air chamber to jet and shear mix in a middle diffusion manner, additional turbulence is introduced when the air flow passes through, increasing the interface contact area, further shearing the bubbles, improving the mass transfer effect, and enhancing the uniformity of bubble distribution. It can keep the micro-nano bubbles from coalescing during the diffusion process, reduce the countercurrent separation phenomenon, improve the ejection effect and dispersibility of the bubbles, and further optimize the formation and stability of micro-nano bubbles.

[0085] The above embodiments are only the 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 substitutions made by those skilled in the art based on the present invention fall within the scope of protection required by the present invention.

Claims

1. A micro-nano bubble generating device with an internal air chamber, characterized in that, It includes a water injection unit (1) for generating high-speed atomized water flow, a gas-water pre-mixing unit (2) for pre-mixing gas and water by means of gas-water swirling and shearing, a gas-water mixing unit (3) for mixing gas and water by means of swirling and inner-shear combination, and a uniform stability unit (4) for stabilizing and discharging micro-nano bubbles. The water injection unit (1), the gas-water pre-mixing unit (2), the gas-water mixing unit (3) and the uniform stability unit (4) are connected in series and arranged in sequence along the axis.

2. The micro-nano bubble generating device with an internal air chamber according to claim 1, characterized in that, The water injection 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. The micro-nano bubble generating device with an internal air chamber according to claim 1, characterized in that, The gas-water pre-mixing unit (2) is annular and includes a gas-water pre-mixing chamber (22), a first gas chamber (23) with an annular structure arranged on the outer periphery of the gas-water pre-mixing chamber (22), a gas guiding air path (24) for supplying gas to the first gas chamber (23), and an air path one (21) for providing swirling air flow to the gas-water pre-mixing chamber (22). The air path one (21) is communicated with the first gas chamber (23).

4. A micro-nano bubble generating device with an internal air chamber as described in claim 3, characterized in that, The gas guiding air path (24) enters tangentially along the outer wall of the first gas chamber (23). The air path one (21) is a plurality of uniformly distributed air holes with a diameter of 0.5 mm - 2.0 mm, and the air path one (21) enters the gas-water pre-mixing chamber (22) tangentially along the inner wall of the first gas chamber (23).

5. A micro-nano bubble generating device with an internal air chamber as described in claim 1, characterized in that, The gas-water mixing unit (3) includes a contraction tube (31), a throat tube (32) and a diffuser tube (33) arranged in sequence. The throat tube (32) is provided with a second gas chamber (34) with an annular structure coaxially arranged therewith. An air path two (35) for providing swirling air flow to the inner cavity of the throat tube (32) is arranged between the second gas chamber (34) and the inner side wall of the throat tube (32). An internal gas chamber (37) for providing inner-shear air flow is arranged on the inner ring of the throat tube (32). The internal gas chamber (37) is communicated with the second gas chamber (34) through an air tube one (38). The internal gas chamber (37) is provided with an injection air path (39) for providing inner-shear to the throat tube (32). The second gas chamber (34) is provided with an inlet pipe (36) for air intake.

6. The micro-nano bubble generating device with an internal air chamber according to claim 5, characterized in that, The air path two (35) adopts a slit arranged on the throat tube (32). The slit is less than 0.2 mm. The air path two (35) is arranged tangentially and rotationally along the axis of the throat tube (32) or perpendicularly or obliquely along the axis of the throat tube (32). The inlet pipe (36) enters the second gas chamber (34) tangentially along the outer wall of the second gas chamber (34).

7. A micro-nano bubble generating device with an internal air chamber as described in claim 5, characterized in that, The diameter ratio of the contraction tube (31) to the throat tube (32) and the diffuser 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 diffuser tube (33) is 6° - 12°.

8. A micro-nano bubble generating device with an internal air chamber as described in claim 5, characterized in that, The cavity of the internal gas chamber (37) is any one of a water droplet shape, a spindle shape, and a barrel shape with pointed ends at both ends. The water-facing surface of the internal gas chamber (37) is a forwardly convex curved surface structure.

9. A micro-nano bubble generating device with an internal air chamber as described in claim 1, characterized in that, The uniform and stable unit (4) includes a straight pipe (41), a two-fluid guide vane (42) arranged inside the straight pipe (41), and a static mixing member (43) arranged at the end of the two-fluid guide vane (42); the static mixing member (43) includes a first internal thread (44) and a guide column (45).

10. A method for generating micro-nano bubbles with an internal air chamber, which uses the generating device described in claim 1, characterized in that, It includes the following steps: Step S1: Form a high-speed atomized water flow by using the water injection unit (1); Step S2: Perform gas-water premixing on the high-speed atomized water flow in a rotary cutting manner by using the gas-water premixing unit (2); Step S3: Perform gas-water mixing in a rotary cutting combined with inner side shearing manner by using the gas-water mixing unit (3); Step S4: Stabilize and discharge the mixed gas and water by using the uniform and stable unit (4).

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