bubble generator

Abstract

This application discloses a bubble generator comprising a first chamber, a second chamber, and a third chamber. During operation, a liquid medium enters through the liquid inlet of the first chamber, and a gaseous medium enters through the gas inlet, where they initially mix to form a gas-liquid mixture. Subsequently, the gas-liquid mixture is injected at high speed through a jet nozzle into the turbulent dissipation chamber of the second chamber, creating a strong turbulent environment within the chamber. The bubbles in the mixture are initially broken up and dispersed under the influence of turbulence. The pre-treated gas-liquid mixture continues to enter the cavitation ejection chamber of the third chamber through a jet nozzle. The cavitation effect generated by the structure of this chamber further refines the bubbles, ultimately forming a stable stream of micro- and nano-bubbles that are discharged. The entire process relies on the sequential connection of the first, second, and third chambers, and the guiding and limiting effects of the jet nozzle and jet nozzle achieve gas-liquid mixing and progressive bubble breaking.

Description

Technical Field

[0001] This application relates to the field of micro / nano bubble generation technology, and more particularly to a bubble generator. Background Technology

[0002] Micro- and nanobubble technology, with its superior characteristics such as large specific surface area, high mass transfer efficiency, and long residence time, shows broad application prospects in fields such as wastewater treatment, water remediation, mineral flotation, and medical engineering. The generation methods of micro- and nanobubbles mainly include dissolved gas release, electrolysis, ultrasonic cavitation, and hydraulic cavitation. Among these, hydraulic cavitation based on Venturi tube and swirl coupling has attracted much attention due to its advantages such as simple structure, low energy consumption, and no moving parts.

[0003] However, existing hydraulic cavitation-type micro / nano bubble generators generally suffer from the following technical bottlenecks: First, the single breakup mechanism results in a large average bubble size and uneven distribution, making it difficult to meet the stringent requirements of narrow distribution in fine chemical and medical fields. Second, traditional multi-stage Venturi tube structures often employ simple geometric repetition, which can refine bubbles to some extent, but energy consumption increases linearly with the number of stages, and the later-stage bubbles are prone to secondary coalescence due to the lack of a stabilizing mechanism, resulting in limited practical effectiveness. Furthermore, the swirl vanes and microporous injection structure are susceptible to clogging by impurities in the water during long-term operation, leading to high maintenance costs. In addition, existing devices experience a sharp drop in breakup efficiency at low throughput (flow rate < 1 m³ / h) due to insufficient flow velocity, while at high throughput (flow rate > 5 m³ / h), excessive turbulence causes bubbles to break up and then coalesce, resulting in a narrow applicable operating range. Therefore, there is an urgent need for a novel micro / nano bubble generator capable of gradient breakup, cascaded energy utilization, anti-coalescence, and wide-range adaptive operation. Summary of the Invention

[0004] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This part of the invention is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0006] In view of this, embodiments of this application propose a bubble generator, comprising: The first cavity is provided with a gas phase inlet and a liquid phase inlet; The second cavity has a turbulent dissipation cavity, and the first cavity is connected to the turbulent dissipation cavity through a jet nozzle; The third cavity contains a cavitation ejector cavity, and the second cavity is connected to the cavitation ejector cavity through a jet nozzle.

[0007] In one feasible implementation, the liquid inlet is arranged tangentially along the first cavity to supply liquid medium tangentially to the first cavity.

[0008] In one feasible implementation, the ratio of the diameter of the first cavity to the diameter of the jet nozzle is 8 to 12.

[0009] In one feasible implementation, the end of the turbulent dissipation cavity near the jet nozzle is the first end, and the other end is the second end. The turbulent dissipation cavity is trapezoidally expanding with a diffusion angle of 50° to 60°. The ratio of the maximum diameter of the turbulent dissipation cavity to the diameter of the jet nozzle is 8 to 12.

[0010] In one feasible implementation, there are multiple jet nozzles, which are arranged in parallel, and the ratio of the center distance to the diameter of the multiple jet nozzles is 3 to 5.

[0011] In one feasible implementation, the cavitation ejector cavity has an inlet end near the second cavity and an outlet end at the other end. The ratio of the diameter of the output end to the diameter of the inlet end is 1.5 to 2.5, and the diffusion angle is 6° to 10°.

[0012] In one feasible implementation, the ratio of the total length of the bubble generator to the first cavity is 4 to 6.

[0013] In one feasible implementation, the ratio of the length of the first cavity to the length of the second cavity is 1.5 to 2; The ratio of the length of the second cavity to the length of the third cavity is 0.8 to 1.2.

[0014] In one feasible implementation, the inner walls of the first cavity, the second cavity, and the third cavity are all provided with an anti-cavitation coating, the thickness of which is 0.1 mm to 0.3 mm.

[0015] In one feasible implementation, the material used to prepare the anti-cavitation coating includes nano-ceramics and / or polytetrafluoroethylene composites.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: The bubble generator provided in this embodiment includes a first chamber, a second chamber, and a third chamber. During operation, a liquid medium enters through the liquid inlet of the first chamber, and a gaseous medium enters through the gas inlet, where they initially mix to form a gas-liquid mixture. Subsequently, the gas-liquid mixture is injected at high speed through a jet nozzle into the turbulent dissipation chamber of the second chamber, creating a strong turbulent environment within the chamber. The bubbles in the mixture are initially broken up and dispersed under the influence of turbulence. The pre-treated gas-liquid mixture continues to enter the cavitation ejection chamber of the third chamber through a jet nozzle. Under the influence of this chamber structure, a cavitation effect is generated, further refining the bubbles and ultimately forming a stable stream of micro- and nano-bubbles that are discharged. The entire process relies on the sequential connection of the first, second, and third chambers, and the guiding and limiting effects of the jet nozzle and jet nozzle achieve gas-liquid mixing and progressive bubble breakage.

[0017] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic structural diagram of a bubble generator according to an embodiment of this application; Figure 2 A schematic structural diagram of a bubble generator according to one embodiment of this application from another angle; Figure 3 A schematic diagram illustrating the particle size distribution trend in the usage state of a bubble generator according to an embodiment of this application; Figure 4 An image of bubbles in use of a bubble generator according to an embodiment of this application; Figure 5 A schematic structural diagram of a bubble generator according to another embodiment provided in this application; Figure 6 A schematic structural diagram of a bubble generator according to another embodiment of this application; Figure 7 A schematic structural diagram of a bubble generator according to another embodiment of this application; Figure 8A schematic structural diagram of a bubble generator according to another embodiment of this application from another angle.

[0019] in, Figures 1 to 8 The correspondence between the reference numerals and component names in the attached drawings is as follows: 111 First cavity, 112 Second cavity, 113 Third cavity; 1111 Gas phase inlet, 1112 Liquid phase inlet; 1121 Turbulent dissipation cavity, 1122 Jet nozzle; 1131 Cavitation ejector cavity, 1132 Jet nozzle; 120 Liquid supply pipe, 130 Branch pipe, 140 Gas supply main pipe, 150 Liquid phase guide cavity, 160 First flange, 170 Second flange, 180 First pressure gauge, 190 First regulating valve, 200 Second pressure gauge, 210 Third pressure gauge, 220 Second regulating valve. Detailed Implementation

[0020] The following description provides numerous specific details to offer a more thorough understanding of the technical solutions provided by this invention. However, it will be apparent to those skilled in the art that the technical solutions provided by this invention can be implemented without one or more of these details.

[0021] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0022] Exemplary embodiments according to the present invention will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of the invention is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art.

[0023] like Figures 1 to 4 As shown, where Figure 3The horizontal axis represents the bubble content, and the vertical axis represents the bubble size. This application proposes a bubble generator, including: a first cavity 111, on which a gas phase inlet 1111 and a liquid phase inlet 1112 are provided; a second cavity 112, in which a turbulent dissipation cavity 1121 is formed, and the first cavity 111 is connected to the turbulent dissipation cavity 1121 through a jet nozzle 1122; and a third cavity 113, in which a cavitation ejection cavity 1131 is formed, and the second cavity 112 is connected to the cavitation ejection cavity 1131 through a jet nozzle 1132.

[0024] The bubble generator provided in this embodiment includes a first chamber 111, a second chamber 112, and a third chamber 113. During operation, a liquid medium enters the first chamber 111 through the liquid inlet 1112, and a gaseous medium enters through the gas inlet 1111. The two are initially mixed in the first chamber 111 to form a gas-liquid mixture. Subsequently, the gas-liquid mixture is injected at high speed through a jet nozzle 1122 into the turbulent dissipation chamber 1121 of the second chamber 112, creating a strong turbulent environment inside the chamber. The bubbles in the mixture are initially broken and dispersed under the action of turbulence. The gas-liquid mixture that has completed the initial treatment continues to enter the cavitation ejection chamber 1131 of the third chamber 113 through a jet nozzle 1132. Under the action of the chamber structure, a cavitation effect is generated, and the bubbles are further refined, eventually forming a stable micro-nano bubble flow that is discharged. The entire process relies on the sequential connection of the first cavity 111, the second cavity 112, and the third cavity 113. Through the guiding and limiting effects of the jet nozzle 1122 and the jet orifice 1132, gas-liquid mixing and bubble breakage are achieved.

[0025] The bubble generator provided in this application embodiment utilizes a three-section cavity working synergistically. The well-designed gas-phase inlet 1111 and liquid-phase inlet 1112 ensure sufficient initial gas-liquid mixing, laying the foundation for subsequent bubble breakage. The guiding effect of the jet nozzle 1122 provides sufficient kinetic energy to the gas-liquid mixture. Upon entering the turbulent dissipation cavity 1121, the strong turbulent environment efficiently achieves initial bubble breakage and dispersion, improving bubble distribution uniformity. The cavitation ejection cavity 1131 further refines the bubbles using the cavitation effect, significantly reducing bubble size and increasing bubble specific surface area. The overall structure, through the precise connection between the jet nozzle 1122 and the jet orifice 1132, ensures smooth flow of the gas-liquid mixture between the cavities with minimal energy loss. This design effectively solves the problems of large bubble size and uneven distribution in traditional bubble generators. The generated micro-nano bubbles exhibit strong stability, meeting the demands for high-quality bubbles in water treatment, chemical reactions, and other scenarios. Furthermore, it features a simple structure, reliable operation, and wide applicability.

[0026] The bubble generator provided in this application addresses the technical challenges of existing micro / nano bubble generators, such as large and widely distributed bubble size, high energy consumption due to multi-stage structures, easy clogging, and severe secondary aggregation. It offers a compact, energy-efficient, high-quality, and easy-to-maintain three-stage gradient-coordinated micro / nano bubble generator. Through a gradient breaking mechanism of phase distribution control, turbulent dissipation, and cavitation ejection, it achieves progressive refinement and stable output of bubbles with a single energy input. The median average diameter of the micro / nano bubbles can be reduced to 180 nm, making it suitable for a wide flow rate range of 0.5-5 m³ / h. The system's energy efficiency is improved by more than 80% compared to traditional structures.

[0027] like Figures 1 to 4 As shown, in one feasible embodiment, the liquid inlet 1112 is arranged tangentially along the first cavity 111 to supply liquid medium tangentially into the first cavity 111. This arrangement, with the liquid inlet 1112 tangentially positioned within the first cavity 111, allows the liquid medium to be injected tangentially into the cavity, creating a strong swirling flow field. This swirling flow field forms a 90° counter-current impact shear with the axially introduced gaseous medium. Under the combined action of centrifugal force and turbulent shear, the gas and liquid phases achieve efficient premixing, causing bubbles to be stretched and broken, reducing the initial median bubble diameter by 40%-60%. Simultaneously, the swirling effect optimizes the gas-liquid phase distribution, laying a uniform mixing foundation for subsequent bubble breakage and effectively improving the overall bubble refinement and distribution uniformity.

[0028] like Figures 1 to 4 As shown, where Figure 1 In this context, D1 represents the diameter of the first cavity 111, and d1 represents the diameter of the jet nozzle 1122. In one feasible embodiment, the ratio of the diameter of the first cavity 111 to the diameter of the jet nozzle 1122 is 8 to 12. This configuration allows the first cavity 111 to form a suitable strong swirling flow field, providing an ideal flow field environment for thorough gas-liquid premixing and bubble pre-breakup. Combined with the 90° counter-current shear between the tangential liquid inlet 1112 and the axial gas inlet 1111, the initial median bubble diameter can be reduced by 40%-60%. Simultaneously, this ratio ensures that the gas-liquid mixture accelerates to a high speed of 8-12 m / s when flowing through the jet nozzle 1122, providing sufficient kinetic energy for the subsequent strong turbulent breakup in the second cavity 112, achieving cascaded energy utilization, avoiding energy waste, and adapting to wide flow conditions, ensuring bubble breakup efficiency and uniformity.

[0029] like Figures 1 to 4 As shown, in one feasible embodiment, the end of the turbulent dissipation cavity 1121 closest to the jet nozzle 1122 is the first end, and the other end is the second end. The turbulent dissipation cavity 1121 is trapezoidally expanding with a diffusion angle of 50° to 60°.

[0030] In this technical solution, the turbulent dissipation cavity 1121 adopts a trapezoidal gradually expanding design of 50° to 60°, which can efficiently guide the diffusion flow of the gas-liquid mixture injected at high speed through the jet nozzle 1122. This angle range allows the swirl attenuation coefficient α > 0.8, enabling rapid decay of swirling kinetic energy and effectively suppressing secondary bubble coalescence caused by swirling backmixing. Simultaneously, the gradually expanding structure induces strong flow separation, forming intense shear between the backflow zone and the main flow zone, resulting in a turbulent kinetic energy dissipation rate of 10. 5 -10 6 With a flow rate of m² / s³, it provides sufficient energy for bubble breakage, achieving secondary fine breakage. Its trapezoidal structure also optimizes the flow field distribution, avoiding excessive or insufficient local turbulence. Combined with the size ratio of the jet nozzle 1122, it ensures stable breakage efficiency under wide flow conditions. Connecting the front and rear chambers enables cascaded energy utilization, improving the overall bubble refinement effect and distribution uniformity.

[0031] like Figures 1 to 4 As shown, Figure 1 As shown, D2 is the maximum diameter of the turbulent dissipation cavity 1121, and d1 is the diameter of the jet nozzle 1122. In one feasible embodiment, the ratio of the maximum diameter of the turbulent dissipation cavity 1121 to the diameter of the jet nozzle 1122 is 8 to 12. This configuration allows for secondary bubble breakage through strong turbulent dissipation and suppresses swirling backmixing through flow separation. This ratio is compatible with the 50°-60° gradually expanding structure of the turbulent dissipation cavity 1121, providing sufficient diffusion space for the gas-liquid mixture of the high-speed jet, promoting the formation of a strong turbulent environment in the flow field, and achieving a turbulent kinetic energy dissipation rate of 10. 5 -10 6 The m² / s³ provides sufficient energy for secondary bubble breakage. Simultaneously, a suitable size ratio induces efficient flow separation, creating intense shear between the backflow and main flow zones, resulting in a swirl attenuation coefficient α > 0.8. This rapidly attenuates the swirling kinetic energy, effectively suppressing secondary bubble coalescence caused by swirling backmixing, and ensuring the continuity and stability of the bubble breakage effect.

[0032] like Figures 1 to 4 As shown, in one feasible embodiment, there are multiple jet nozzles 1132, arranged in parallel, with the center-to-diameter ratio of the multiple jet nozzles 1132 being 3 to 5. This arrangement allows the multiple jet nozzles 1132 to form a coherent vortex street, enhancing bubble breakage efficiency. Reasonable spacing avoids flow field interference between nozzles, ensuring that each nozzle jet generates a stable and strong shear force, achieving uniform bubble breakage. Simultaneously, it adapts to the flow field characteristics of the turbulent dissipation cavity 1121, enabling uniform distribution of the gas-liquid mixture, laying the foundation for cavitation refinement in the third cavity 113, reducing the risk of blockage, and improving the operational stability of the device.

[0033] like Figures 1 to 4 As shown, where Figure 1As shown, d2 is the diameter of the inlet end and D3 is the diameter of the output end. In one feasible embodiment, the end of the cavitation ejector cavity 1131 closest to the second cavity 112 is the inlet end and the other end is the output end; wherein, the ratio of the diameter of the output end to the diameter of the inlet end is 1.5 to 2.5, and the diffusion angle is 6° to 10°.

[0034] In this technical solution, the ratio of the output diameter to the inlet diameter is 1.5 to 2.5, and the diffusion angle is 6° to 10°, providing crucial guarantees for bubble refinement and stable output. The reasonable diameter ratio provides ample cavitation space, and combined with the small-angle gradually expanding structure, the flow field smoothly transitions to a laminar state, with a flow separation index β < 0.1. This not only further refines bubbles to below 200 nm through boundary layer shearing and microcavitation collapse of microjets, but also suppresses bubble collision and coalescence, with a coalescence rate of < 3%. Simultaneously, this structure optimizes fluid pressure distribution, achieving an outlet Weber number We3 of 1.5-2.5 and a total pressure drop controlled at 0.15-0.4 MPa, achieving energy-efficient utilization, adapting to a wide flow rate range of 0.5-5 m³ / h, ensuring stable output with a narrow bubble distribution, and meeting high-quality application requirements.

[0035] like Figures 1 to 4 As shown, Figure 1 As shown, L1, L2, and L3 are the lengths of the first cavity 111, the second cavity 112, and the third cavity 113, respectively. In one feasible embodiment, the ratio of the total length of the bubble generator to the first cavity 111 is 4 to 6. This configuration makes the device compact, with the ratio of the total length to the diameter of the first cavity 111 controlled at 4-6:1. It can directly replace existing pipeline-type equipment without requiring additional installation space or pumping energy consumption. At the same time, the reasonable allocation of the total length provides sufficient space for the three-section cavity to realize their functions, ensuring the orderly connection of each stage of swirling mixing, turbulent breaking, and cavitation stabilization, avoiding flow field turbulence and energy waste, and ensuring stable bubble generation under wide flow conditions.

[0036] like Figures 1 to 4 As shown, Figure 1As shown, L1, L2, and L3 are the lengths of the first cavity 111, the second cavity 112, and the third cavity 113, respectively. In one feasible embodiment, the ratio of the length of the first cavity 111 to the length of the second cavity 112 is 1.5 to 2; the ratio of the length of the second cavity 112 to the length of the third cavity 113 is 0.8 to 1.2. This configuration, with a ratio of 1.5-2:1, provides sufficient space for the first cavity 111 to ensure the formation of a stable, strong swirling flow field, achieving thorough gas-liquid premixing and bubble pre-breakup. The ratio of 0.8-1.2:1 allows the second cavity 112 to fully realize strong turbulent dissipation and secondary bubble breakup, while reserving space for the third cavity 113 to ensure the full utilization of laminarization and cavitation effects, suppressing bubble coalescence, ensuring smooth phase distribution control, turbulent dissipation, and cavitation ejection, and improving bubble quality and energy utilization.

[0037] In one feasible implementation, the inner walls of the first cavity 111, the second cavity 112, and the third cavity 113 are all provided with an anti-cavitation coating, the thickness of which is 0.1 mm to 0.3 mm. This design effectively resists the impact and erosion caused by cavitation during gas-liquid mixing, extending the service life of the cavities. The material properties reduce the coefficient of friction of the inner walls, decreasing flow resistance and energy loss, ensuring smooth fluid flow and stable operation of the gradient breaking mechanism. Simultaneously, the coating prevents corrosion and contamination of the gas-liquid mixture on the cavity walls, ensuring the purity of micro-nano bubbles, making it suitable for demanding operating conditions in wastewater treatment, medical applications, and other fields, and improving the reliability and ease of maintenance of the device.

[0038] In one feasible implementation, the material used to prepare the anti-cavitation coating includes nano-ceramics and / or polytetrafluoroethylene composites. This configuration allows the anti-cavitation coating to possess both excellent impact resistance and low friction characteristics. It can resist the impact erosion caused by cavitation effects, extending the service life of the cavity, while also reducing internal wall frictional resistance, minimizing energy loss, and ensuring the stable operation of the gradient crushing mechanism. Simultaneously, the material exhibits strong chemical stability, preventing cavity corrosion and contamination of the gas-liquid mixture, ensuring the purity of micro- and nano-bubbles, and adapting to harsh operating conditions in various fields.

[0039] The working principle of the bubble generator provided in this application embodiment is as follows: Liquid fluid enters tangentially from the side wall of the first cavity 111 at a certain pressure (0.2-0.4 MPa), forming a strong swirling flow field within the cylindrical cavity of the first cavity 111 with a diameter of 20 mm. Gas is injected from the axial inlet, forming a 90° counter-current shear with the swirling liquid. Under the combined action of centrifugal force and turbulent shear, the gas and liquid phases achieve initial mixing, and the bubbles are stretched and broken. The gas-liquid mixture is then accelerated to 8-12 m / s through a 2 mm constricted jet orifice at the top, and the jet enters the second cavity 112. In the second cavity 112, the mixture diffuses from the 2 mm inlet to the 20 mm outlet, and the 55° diffusion angle triggers strong flow separation, forming a backflow zone and a main flow zone with intense shear. The bubbles undergo secondary breakage in this region. The large angle effectively prevents the swirling energy from being transferred upstream, preventing bubble re-agglomeration. Finally, the bubbles enter the third cavity 113, gradually expanding from the 2 mm inlet to the 4 mm outlet at a small angle of 6°, achieving laminar flow. During this stage, the bubbles are further refined to 5-10 μm through boundary layer shearing and microcavitation collapse microjets. At the same time, the low turbulence environment inhibits bubble collision and coalescence, ensuring stable bubble output.

[0040] The bubble generator provided in this application optimizes the physical process of micro- and nano-bubble generation through a three-stage gradient synergistic structure: the first chamber 111 utilizes a strong swirling flow field coupled with jet cavitation to complete gas-liquid premixing and bubble pre-breakup, reducing the initial median bubble diameter to the micrometer level; the second chamber 112 effectively attenuates the swirling kinetic energy through large-angle diffusion, preventing bubble coalescence caused by swirling backmixing; the third chamber 113 uses small-angle diffusion to achieve bubble cavitation, further reducing the bubble size. The three chambers form a complete physical chain of phase distribution control, turbulent dissipation, and cavitation ejection. This embodiment maintains stable performance over a wide flow range (0.5-5 m³ / h), has no moving parts or microporous structures, strong anti-clogging capability, and extends the maintenance cycle to over 6 months. Its compact structure, with a total length L to diameter D1 ratio of only 4 to 6:1, allows it to directly replace existing pipeline bubble generators without requiring additional pumping energy.

[0041] Example 1 The bubble generator provided in this application includes: a first cavity 111, which serves as a swirling-jet coupled phase distribution control cavity. The first cavity 111 has a tangential liquid phase inlet 1112 on its sidewall, an axial gas phase inlet 1111 at its bottom, and a 2mm diameter necked jet orifice at its top. The first cavity 111 has a diameter of 20mm and forms a strong swirling flow field inside, used for gas-liquid premixing, bubble pre-breaking, and phase distribution control. A second cavity 112 serves as a turbulent dissipation cavity 1121. The second cavity 112 has a trapezoidal, gradually expanding structure, with its inlet end connected to the jet nozzle 1122 of the first cavity 111. The inlet diameter is 2mm. The outlet diameter is 20mm, the diffusion angle is 50-60° with the axial angle, and it is equipped with multiple parallel jet nozzles 1132 with a diameter of 2mm. The second cavity 112 is used to prevent swirling back mixing by dissipating strong turbulence and secondary breaking up of the jet array. The third cavity 113 serves as a cavitation ejector cavity 1131. The third cavity 113 has a small-angle trapezoidal gradually expanding structure. Its inlet end is connected to the parallel jet nozzles 1132 of the second cavity 112. The inlet diameter is 2mm, the outlet diameter is 4mm, and the diffusion angle is 6-10° with the axial angle. The third cavity 113 is used to stabilize the bubble interface through laminar flow control, suppress secondary coalescence, and output narrowly distributed micro-nano bubbles.

[0042] The three cavities are connected in series along the axial direction and their internal cavities are interconnected, forming a gradient crushing and energy cascade utilization system.

[0043] In some examples, the ratio of the diameter D1 of the first cavity 111 to the diameter d1 of the jet nozzle 1122 is 8 to 12:1, which is used to generate a strong swirling flow field to achieve gas-liquid premixing and bubble pre-breakup.

[0044] In some examples, the second cavity 112 has a trapezoidal gradually expanding structure, the inlet diameter of the jet nozzle 1122 is d1, the outlet diameter is D2, the ratio of D2 to d1 is 8-12:1, the diffusion angle θ1 is 50-60° with the axial angle, and the top wall is provided with multiple parallel jet nozzles 1132, the orifice diameter of the jet nozzles 1132 is d2=d1; the second cavity 112 is used to achieve secondary bubble breakage through strong turbulent dissipation and to suppress swirling backmixing through flow separation; In some examples, the third cavity 113 has a small-angle trapezoidal gradually expanding structure. The inlet diameter of the third cavity 113 is equal to d2, the outlet diameter is D3, the ratio of D3 to the inlet diameter d2 is 1.5 to 2.5:1, and the diffusion angle θ2 is 6-10° with the axial direction. The third cavity 113 is used to stabilize the bubble interface and suppress secondary coalescence through laminar flow control. In some examples, the three cavities are connected in series along the axial direction and their internal cavities are interconnected, forming a gradient crushing and energy cascade utilization system, achieving an average bubble Sauter diameter of less than 200 nm under a total pressure drop ΔP = 0.15-0.4 MPa.

[0045] In some examples, the tangential liquid inlet 1112 of the first cavity 111 forms an angle of 90° with the axial gas inlet 1111, resulting in countercurrent impact shearing and reducing the median diameter of the initial bubble by 40-60%.

[0046] In some examples, the number of parallel jet nozzles 1132 in the second cavity 112 is 4 to 8, and the ratio of the center distance of the nozzles to the diameter of the nozzles is 3-5:1, which can form a coherent vortex street to enhance the crushing efficiency.

[0047] In some examples, the diffusion angle θ1 of the second cavity 112 satisfies 50°≤θ1≤60°, making the swirl attenuation coefficient α>0.8 and the turbulent kinetic energy dissipation rate ε=10. 5 -10 6 m² / s³.

[0048] In some examples, the diffusion angle θ2 of the third cavity 113 satisfies 6°≤θ2≤10°, making the flow separation index β<0.1 and the outlet Weber number We3=1.5-2.5.

[0049] In some examples, the ratio of the total length L of the three cavities to the diameter D1 of the first cavity 111 is 4-6:1, and the length distribution of each cavity satisfies L1:L2:L3=1.5-2:1:0.8-1.2. Where L1 is the length of the first cavity 111, L2 is the length of the second cavity 112, and L3 is the length of the third cavity 113.

[0050] In some examples, the inner walls of each cavity are provided with an anti-cavitation coating with a thickness of 0.1-0.3 mm, and the material is nano-ceramic or polytetrafluoroethylene composite material.

[0051] The bubble generator provided in this application embodiment can be applied in the fields of sewage treatment, chemical reaction or medical disinfection. Under the conditions of liquid flow rate of 0.5 to 5 m³ / h and gas-liquid ratio of 0.05 to 0.2, the system energy utilization rate η = 0.35 to 0.45 and the bubble coalescence rate < 3%.

[0052] The bubble generator provided in this application includes a first chamber 111, a second chamber 112, and a third chamber 113 connected in series along the axial direction. The first chamber 111 forms a strong swirling flow field through a tangential liquid inlet 1112 and an axial gas inlet 1111, achieving gas-liquid premixing and bubble pre-breakup. The second chamber 112 adopts a large-angle trapezoidal gradually expanding structure and is equipped with a porous parallel jet array, achieving secondary bubble breakup and suppressing swirling backmixing through strong turbulent dissipation. The third chamber 113 adopts a small-angle trapezoidal gradually expanding structure to achieve flow field cavitation and interface stabilization, suppressing secondary coalescence. This invention generates high-quality micro- and nano-bubbles with a median particle size of less than 200 nm under a total pressure drop of 0.15-0.4 MPa through gradient breakup and energy cascading mechanisms. The device has no moving parts and microporous structure, has strong anti-clogging ability, and is applicable to a flow rate range of 0.5-5 m³ / h, showing significant advantages in fields such as wastewater treatment, chemical reactions, and medical disinfection.

[0053] Example 2 like Figures 1 to 8 As shown, the bubble generator provided in this embodiment includes: a first chamber 111, a second chamber 112, and a third chamber 113 connected in sequence. The first chamber 111 is provided with a gas phase inlet 1111 and a liquid phase inlet 1112. The second chamber 112 forms a turbulent dissipation chamber 1121. The first chamber 111 is connected to the turbulent dissipation chamber 1121 through a jet nozzle 1122. The third chamber 113 forms a cavitation ejection chamber 1131. The second chamber 112 is connected to the cavitation ejection chamber 1131 through a jet nozzle 1132. A liquid supply pipe 120; a branch pipe 130 connected to the liquid supply pipe 120; and a gas supply main pipe 140 connected to the bubble generator.

[0054] The bubble generator provided in this embodiment includes a liquid supply pipe 120, branch pipes 130, a bubble generator, and a gas supply main pipe 140. In the bubble generator, oxygen or air can be introduced through the gas phase inlet 1111, and adsorption tailings for in-situ leaching can be introduced through the liquid phase inlet 1112. The bubble generator is used to supply oxygen-containing bubbles to the formation to oxidize the minerals in the formation and improve the efficiency of in-situ leaching uranium mining. In specific operation, the liquid is diverted through the liquid supply pipe 120 to each branch pipe 130, and then enters the bubble generator through the liquid phase inlet 1112 of the first chamber 111. Simultaneously, the gas is transported through the gas supply main pipe 140 to the gas phase inlet 1111 of the first chamber 111, where it is initially mixed with the liquid to form a gas-liquid mixture. The mixture is then injected at high speed through the jet nozzle 1122 into the turbulent dissipation chamber 1121 of the second chamber 112. Under the action of turbulent disturbance, the bubbles are initially sheared and broken. Next, the gas-liquid mixture enters the cavitation ejector cavity 1131 of the third cavity 113 through the jet nozzle 1132. The cavitation effect further refines the bubbles, ultimately generating micro- and nano-bubbles that meet the requirements. These bubbles are then discharged along with the fluid and injected into the leaching layer, completing the efficient delivery and release of the oxidant. The entire process relies on the synergistic effect of each cavity and the interconnecting structure to achieve continuous gas-liquid mixing and bubble refinement.

[0055] The bubble generator provided in this embodiment of the application, through the diversion design of the liquid supply pipe 120 and the branch pipe 130, combined with the precise gas supply from the gas supply main pipe 140, ensures stable gas-liquid two-phase transport. The first chamber 111 provides a stable space for initial gas-liquid mixing. The turbulent dissipation chamber 1121 of the second chamber 112 achieves initial bubble breakage through turbulent disturbance. The cavitation ejection chamber 1131 of the third chamber 113 enhances the bubble refinement effect through cavitation. The three chambers are linked in sequence, significantly improving the bubble breakage efficiency and uniformity. The structural design of the jet nozzle 1122 and jet orifice 1132 ensures smooth fluid transport and energy concentration, facilitating precise control of bubble size. The overall structure, through the orderly cooperation of its components, effectively solves the problem of fixed bubble size in traditional devices, adapts to in-situ leaching layers with different permeability coefficients, improves oxidation reaction efficiency, and provides technical support for the stable and efficient operation of in-situ leaching uranium mining processes.

[0056] In one feasible embodiment, the bubble generator further includes: a liquid phase guiding cavity 150, which is sleeved on the first cavity 111 and is connected to the first cavity 111 through a liquid phase inlet 1112; a first flange 160, which is disposed on the liquid phase guiding cavity 150; and a second flange 170, which is disposed on the third cavity 113; wherein the bubble generator is disposed on the branch pipe 130 through the first flange 160 and the second flange 170.

[0057] In this technical solution, the bubble generator also includes a liquid phase guiding cavity 150, a first flange 160, and a second flange 170. During operation, liquid is diverted from the liquid supply pipe 120 to the branch pipe 130, guided by the liquid phase guiding cavity 150, and enters the first cavity 111 through the liquid phase inlet 1112. Gas is transported to the gas phase inlet 1111 of the first cavity 111 through the gas supply main pipe 140, where it mixes with the liquid. The mixture is injected through the jet nozzle 1122 into the turbulent dissipation cavity 1121 of the second cavity 112, where the bubbles are initially broken up by turbulence. Then, it enters the cavitation ejection cavity 1131 of the third cavity 113 through the jet nozzle 1132, where the bubbles are further refined by the cavitation effect. Finally, the gas-liquid mixture containing a high concentration of micro- and nano-bubbles is discharged and injected into the leaching layer. The oxidation efficiency is ensured throughout the process by the synergistic effect of each cavity.

[0058] In this technical solution, during the assembly of the bubble generator, the liquid phase guiding cavity 150 is first fitted and fixed to the outside of the first cavity 111, ensuring precise communication between the liquid phase guiding cavity 150 and the liquid phase inlet 1112. Then, the first flange 160 is installed at a preset position on the liquid phase guiding cavity 150, and the second flange 170 is fixed to the end of the third cavity 113. Next, the first cavity 111, the second cavity 112, and the third cavity 113 are connected sequentially to ensure unobstructed internal passages. Finally, the assembled bubble generator is aligned and tightened with the branch pipe 130 using the first flange 160 and the second flange 170, and the sealing at the connection is checked. Modular assembly can be completed without specialized tools, adapting to the needs of rapid on-site installation.

[0059] In this technical solution, the liquid phase guiding cavity 150 can stably guide the liquid flow, ensuring uniform gas-liquid mixing and improving the stability of bubble generation. The design of the first flange 160 and the second flange 170 enables rapid assembly and disassembly of the bubble generator and the branch pipe 130, significantly reducing maintenance difficulty and downtime. The modular assembly method allows the device to adapt to scenarios with multiple branch pipes 130 operating in parallel, enhancing its adaptability to various operating conditions. The overall structure is compact and well-sealed, effectively preventing fluid leakage. Combined with subsequent control mechanisms, it significantly improves the oxidation efficiency and production continuity in the in-situ leaching uranium mining process.

[0060] In one feasible implementation, there are at least two branch pipes 130, and each branch pipe 130 is provided with a bubble generator.

[0061] In this technical solution, at least two branch pipes 130 are configured, each equipped with a bubble generator, significantly improving the operational efficiency and adaptability of the device. The multi-branch parallel design allows for the simultaneous delivery of bubble-containing fluid to multiple injection wells, or multi-point coverage injection into the same area, meeting the operational needs of large-scale in-situ leaching of uranium. Each branch pipe 130 is independently equipped with a bubble generator, enabling precise control of bubble size based on the permeability coefficient of the corresponding ore layer, achieving differentiated adaptation for different areas and avoiding the problem of a single device being unable to handle complex geological conditions. Simultaneously, the multi-branch structure can distribute operational pressure, reducing the impact of single-path failures on overall production. Combined with quick-release connections and modular design, this further enhances equipment maintenance flexibility and production continuity, significantly optimizing the oxidation effect and operational stability of in-situ leaching of uranium.

[0062] In one feasible embodiment, the bubble generator further includes a gas branch pipe, one end of which is connected to the gas supply main pipe 140, and the other end of which passes through the liquid phase guide cavity 150 and is connected to the gas phase inlet 1111.

[0063] In this technical solution, the bubble generator may also include a gas branch pipe. The design of the gas branch pipe enables precise diversion and directional delivery of gas supply. One end is connected to the main gas supply pipe 140 to ensure a stable gas source, while the other end passes through the liquid phase guide cavity 150 and directly reaches the gas phase inlet 1111, shortening the gas transmission path, reducing the risk of leakage, and ensuring that the gas is efficiently integrated into the first cavity 111 and mixed with the liquid. This structure allows the gas supply and liquid guide to work together, avoiding gas loss or uneven mixing during transmission, and improving the gas-liquid mixing efficiency and bubble generation concentration. At the same time, the gas branch pipe can be adapted to the multi-branch pipe 130 and the bubble generator to achieve independent gas supply control for each bubble generator. With the help of the flow regulation component, it can accurately match the ore layer requirements corresponding to different branch pipes 130, further enhancing the adaptability of the device to complex geological conditions and ensuring the uniformity and stability of the oxidation reaction.

[0064] In one feasible embodiment, the bubble generator further includes: a first pressure gauge 180, which is disposed on the branch pipe 130 and located at the inlet end of the bubble generator; a first regulating valve 190, which is disposed on the branch pipe 130; a second pressure gauge 200, which is disposed on the branch pipe 130 and located at the outlet end of the bubble generator; a third pressure gauge 210 and a second regulating valve 220, which are disposed at the gas phase inlet 1111 end of the bubble generator.

[0065] In this technical solution, the bubble generator may further include a first pressure gauge 180, a second pressure gauge 200, a first regulating valve 190, a third pressure gauge 210, and a second regulating valve 220. Based on this, the first pressure gauge 180 and the second pressure gauge 200 monitor the liquid pressure at the inlet and outlet of the bubble generator in real time, respectively, while the third pressure gauge 210 accurately captures the gas pressure at the gas phase inlet 1111. The three gauges work together to achieve full-process visual monitoring of gas-liquid pressure, providing data support for operational condition judgment. This allows for timely detection of abnormal pressure fluctuations and avoids the risk of incomplete bubble breakage or equipment damage due to pressure imbalance. The first regulating valve 190 and the second regulating valve 220 correspond to the flow control of the liquid and gas circuits, respectively. Combined with the pressure gauge feedback data, they enable fine-tuning of the gas-liquid flow rate, precisely matching the optimal range of vortex number and cavitation number, ensuring that the bubble size stably reaches the target value, and adapting to the needs of mineral layers with different permeability coefficients. This configuration enables the device to control pressure and flow in tandem, which not only improves the uniformity of bubble generation and oxidation efficiency, but also enhances the stability and safety of equipment operation through real-time monitoring and precise adjustment, further reducing maintenance costs caused by imbalances in operating conditions.

[0066] In one feasible implementation, the liquid inlet 1112 is arranged tangentially along the first cavity 111 to supply liquid medium tangentially into the first cavity 111. This arrangement, with the liquid inlet 1112 tangentially positioned within the first cavity 111, allows the liquid medium to be injected tangentially into the cavity, creating a strong swirling flow field. This swirling flow field forms a 90° counter-current impact shear with the axially introduced gaseous medium. Under the combined action of centrifugal force and turbulent shear, the gas and liquid phases achieve efficient premixing, causing bubbles to be stretched and broken, reducing the initial median bubble diameter by 40%-60%. Simultaneously, the swirling effect optimizes the gas-liquid phase distribution, laying a foundation for uniform mixing and subsequent step-by-step bubble breakage, effectively improving the overall bubble refinement and distribution uniformity.

[0067] In one feasible implementation, the ratio of the diameter of the first cavity 111 to the diameter of the jet nozzle 1122 is 8 to 12. This configuration allows the first cavity 111 to form a suitable strong swirling flow field, providing an ideal flow environment for thorough gas-liquid premixing and bubble pre-breakup. Combined with the 90° counter-current shear between the tangential liquid inlet 1112 and the axial gas inlet 1111, the initial median bubble diameter can be reduced by 40%-60%. Simultaneously, this ratio ensures that the gas-liquid mixture accelerates to a high speed of 8-12 m / s when flowing through the jet nozzle 1122, transferring sufficient kinetic energy for the subsequent strong turbulent breakup in the second cavity 112, achieving cascaded energy utilization, avoiding energy waste, and adapting to wide flow conditions, ensuring bubble breakup efficiency and uniformity.

[0068] In one feasible implementation, the end of the turbulent dissipation cavity 1121 closest to the jet nozzle 1122 is the first end, and the other end is the second end. The turbulent dissipation cavity 1121 is trapezoidally expanding with a diffusion angle of 50° to 60°.

[0069] In this technical solution, the turbulent dissipation cavity 1121 adopts a trapezoidal gradually expanding design of 50° to 60°, which can efficiently guide the diffusion flow of the gas-liquid mixture injected at high speed through the jet nozzle 1122. This angle range allows the swirl attenuation coefficient α > 0.8, enabling rapid decay of swirling kinetic energy and effectively suppressing secondary bubble coalescence caused by swirling backmixing. Simultaneously, the gradually expanding structure induces strong flow separation, forming intense shear between the backflow zone and the main flow zone, resulting in a turbulent kinetic energy dissipation rate of 10. 5 -10 6 With a flow rate of m² / s³, it provides sufficient energy for bubble breakage, achieving secondary fine breakage. Its trapezoidal structure also optimizes the flow field distribution, avoiding excessive or insufficient local turbulence. Combined with the size ratio of the jet nozzle 1122, it ensures stable breakage efficiency under wide flow conditions. Connecting the front and rear chambers enables cascaded energy utilization, improving the overall bubble refinement effect and distribution uniformity.

[0070] In one feasible implementation, the ratio of the maximum diameter of the turbulent dissipation cavity 1121 to the diameter of the jet nozzle 1122 is 8 to 12. This configuration allows for secondary bubble breakage through strong turbulent dissipation and suppresses swirling backmixing through flow separation. This ratio is compatible with the 50°-60° gradually expanding structure of the turbulent dissipation cavity 1121, providing ample diffusion space for the gas-liquid mixture of the high-speed jet, promoting a strongly turbulent environment in the flow field, and achieving a turbulent kinetic energy dissipation rate of 10. 5 -10 6 The m² / s³ provides sufficient energy for secondary bubble breakage. Simultaneously, a suitable size ratio induces efficient flow separation, creating intense shear between the backflow and main flow zones, resulting in a swirl attenuation coefficient α > 0.8. This rapidly attenuates the swirling kinetic energy, effectively suppressing secondary bubble coalescence caused by swirling backmixing, and ensuring the continuity and stability of the bubble breakage effect.

[0071] In one feasible implementation, multiple jet nozzles 1132 are arranged in parallel, with the center-to-diameter ratio of the multiple nozzles 1132 being 3 to 5. This arrangement allows the multiple jet nozzles 1132 to form a coherent vortex street, enhancing bubble breakage efficiency. Reasonable spacing avoids flow field interference between nozzles, ensuring that each nozzle jet generates a stable and strong shear force, achieving uniform bubble breakage. Simultaneously, it adapts to the flow field characteristics of the turbulent dissipation cavity 1121, enabling uniform distribution of the gas-liquid mixture, laying the foundation for cavitation refinement in the third cavity 113, reducing the risk of blockage, and improving the operational stability of the device.

[0072] In one feasible implementation, the cavitation ejector cavity 1131 has an inlet end near the second cavity 112 and an outlet end at the other end; wherein the ratio of the diameter of the outlet end to the diameter of the inlet end is 1.5 to 2.5, and the diffusion angle is 6° to 10°.

[0073] In this technical solution, the ratio of the output diameter to the inlet diameter is 1.5 to 2.5, and the diffusion angle is 6° to 10°, providing crucial guarantees for bubble refinement and stable output. The reasonable diameter ratio provides ample cavitation space, and combined with the small-angle gradually expanding structure, the flow field smoothly transitions to a laminar state, with a flow separation index β < 0.1. This not only further refines bubbles to below 200 nm through boundary layer shearing and microcavitation collapse of microjets, but also suppresses bubble collision and coalescence, with a coalescence rate of < 3%. Simultaneously, this structure optimizes fluid pressure distribution, achieving an outlet Weber number We3 of 1.5-2.5 and a total pressure drop controlled at 0.15-0.4 MPa, achieving energy-efficient utilization, adapting to a wide flow rate range of 0.5-5 m³ / h, ensuring stable output with a narrow bubble distribution, and meeting high-quality application requirements.

[0074] In one feasible implementation, the ratio of the total length of the bubble generator to the diameter of the first cavity 111 is 4 to 6. This configuration makes the device compact, with the total length to the diameter of the first cavity 111 controlled at 4-6:1. It can directly replace existing pipeline-type equipment without requiring additional installation space or pumping energy consumption. At the same time, the reasonable allocation of the total length provides sufficient space for the three-section cavity to realize their functions, ensuring the orderly connection of each stage of swirling mixing, turbulent breaking, and cavitation stabilization, avoiding flow field turbulence and energy waste, and ensuring stable bubble generation under wide flow conditions.

[0075] In one feasible implementation, the length ratio of the first cavity 111 to the length of the second cavity 112 is 1.5 to 2; the length ratio of the second cavity 112 to the length of the third cavity 113 is 0.8 to 1.2. This configuration, with a ratio of 1.5-2:1, provides sufficient space for the first cavity 111 to ensure the formation of a stable, strong swirling flow field, achieving thorough gas-liquid premixing and bubble pre-breakup. The 0.8-1.2:1 ratio allows the second cavity 112 to fully realize strong turbulent dissipation and secondary bubble breakup, while reserving space for the third cavity 113 to ensure the full utilization of laminarization and cavitation effects, suppressing bubble coalescence, ensuring smooth phase distribution control, turbulent dissipation, and cavitation ejection, and improving bubble quality and energy utilization.

[0076] In one feasible implementation, the inner walls of the first cavity 111, the second cavity 112, and the third cavity 113 are all provided with an anti-cavitation coating, the thickness of which is 0.1 mm to 0.3 mm. This design effectively resists the impact and erosion caused by cavitation during gas-liquid mixing, extending the service life of the cavities. The material properties reduce the coefficient of friction of the inner walls, decreasing flow resistance and energy loss, ensuring smooth fluid flow and stable operation of the gradient breaking mechanism. Simultaneously, the coating prevents corrosion and contamination of the gas-liquid mixture on the cavity walls, ensuring the purity of micro-nano bubbles, making it suitable for demanding operating conditions in wastewater treatment, medical applications, and other fields, and improving the reliability and ease of maintenance of the device.

[0077] In one feasible implementation, the material used to prepare the anti-cavitation coating includes nano-ceramics and / or polytetrafluoroethylene composites. This configuration allows the anti-cavitation coating to possess both excellent impact resistance and low friction characteristics. It can resist the impact erosion caused by cavitation effects, extending the service life of the cavity, while also reducing internal wall frictional resistance, minimizing energy loss, and ensuring the stable operation of the gradient crushing mechanism. Simultaneously, the material exhibits strong chemical stability, preventing cavity corrosion and contamination of the gas-liquid mixture, ensuring the purity of micro- and nano-bubbles, and adapting to harsh operating conditions in various fields.

[0078] The working principle of the bubble generator provided in this application embodiment is as follows: Liquid fluid enters tangentially from the side wall of the first cavity 111 at a certain pressure (0.2-0.4 MPa), forming a strong swirling flow field within the cylindrical cavity of the first cavity 111 with a diameter of 20 mm. Gas is injected from the axial inlet, forming a 90° counter-current shear with the swirling liquid. Under the combined action of centrifugal force and turbulent shear, the gas and liquid phases achieve initial mixing, and the bubbles are stretched and broken. The gas-liquid mixture is then accelerated to 8-12 m / s through a 2 mm constricted jet orifice at the top, and the jet enters the second cavity 112. In the second cavity 112, the mixture diffuses from the 2 mm inlet to the 20 mm outlet, and the 55° diffusion angle triggers strong flow separation, forming a backflow zone and a main flow zone with intense shear. The bubbles undergo secondary breakage in this region. The large angle effectively prevents the swirling energy from being transferred upstream, preventing bubble re-agglomeration. Finally, the bubbles enter the third cavity 113, gradually expanding from the 2 mm inlet to the 4 mm outlet at a small angle of 6°, achieving laminar flow. During this stage, the bubbles are further refined to 5-10 μm through boundary layer shearing and microcavitation collapse microjets. At the same time, the low turbulence environment inhibits bubble collision and coalescence, ensuring stable bubble output.

[0079] The bubble generator provided in this application optimizes the physical process of micro- and nano-bubble generation through a three-stage gradient synergistic structure: the first chamber 111 utilizes a strong swirling flow field coupled with jet cavitation to complete gas-liquid premixing and bubble pre-breakup, reducing the initial median bubble diameter to the micrometer level; the second chamber 112 effectively attenuates the swirling kinetic energy through large-angle diffusion, preventing bubble coalescence caused by swirling backmixing; the third chamber 113 uses small-angle diffusion to achieve bubble cavitation, further reducing the bubble size. The three chambers form a complete physical chain of phase distribution control, turbulent dissipation, and cavitation ejection. This embodiment maintains stable performance over a wide flow range (0.5-5 m³ / h), has no moving parts or microporous structures, strong anti-clogging capability, and extends the maintenance cycle to over 6 months. Its compact structure, with a total length L to diameter D1 ratio of only 4 to 6:1, allows it to directly replace existing pipeline bubble generators without requiring additional pumping energy.

[0080] According to a second aspect of the embodiments of this application, a control method is provided, applied to a bubble generator as described in any of the above technical solutions, the control method comprising: Step 201: Determine the target bubble diameter based on the permeability coefficient of the in-situ leaching layer; Step 202: Collect the liquid flow rate, gas flow rate, and pressure difference across the bubble generator during operation; Step 203: Calculate and obtain the swirl number and cavitation number based on the liquid flow rate, gas flow rate, and pressure difference; Step 204: Adjust the liquid flow rate or gas flow rate based on one of the following: target bubble diameter, liquid flow rate, gas flow rate, pressure difference, swirl number, and cavitation number, to adjust the diameter of the bubbles output by the bubble generator.

[0081] The control method provided in this application embodiment is applied to the bubble generator of any of the above technical solutions, and therefore the control method has all the beneficial effects of the bubble generator of the above technical solutions, which will not be elaborated here.

[0082] The control method provided in this application significantly improves the adaptability and oxidation efficiency of in-situ leaching uranium mining processes. Step 201 determines the target bubble diameter based on the ore layer permeability coefficient, achieving precise matching between bubble size and geological conditions. This solves the problem of poor adaptability caused by fixed bubble size in traditional devices. In high-permeability zones, large bubbles of 10-50 μm can be output to ensure rapid diffusion, while in low-permeability zones, micro-nano bubbles of ≤10 μm can be generated to penetrate deep into pores, avoiding insufficient oxidation or gas blockage. Steps 202-203 collect key data such as gas-liquid flow rate and pressure difference, and calculate the swirl number and cavitation number using formulas, providing a quantitative basis for adjustment and replacing traditional experience-based operations, making the control more scientific. Step 204 dynamically adjusts the gas-liquid flow rate based on multi-dimensional parameters, which can correct bubble diameter deviations in real time, maintaining the swirl number and cavitation number within the optimal range, ensuring the uniformity and stability of bubble generation. The overall method achieves adaptive control of bubble size. Combined with the modular structure of the device, it further enhances the adaptability to operating conditions, significantly improves oxygen mass transfer efficiency and production continuity, and reduces operation and maintenance costs caused by changes in geological conditions.

[0083] In one feasible implementation, the step of adjusting the liquid flow rate or gas flow rate based on one of the target bubble diameter, liquid flow rate, gas flow rate, pressure difference, swirl number, and cavitation number to adjust the diameter of the bubbles output by the bubble generator includes: when the target bubble diameter is less than or equal to 10 μm, the gas-liquid ratio of the bubble generator is less than or equal to 0.08; when the target bubble diameter is greater than 10 μm and less than or equal to 50 μm, the gas-liquid ratio of the bubble generator is greater than or equal to 0.1.

[0084] In this technical solution, for low-permeability ore layers requiring ≤10μm micro / nano bubbles, controlling the gas-liquid ratio to ≤0.08 enhances the swirling shear and cavitation fragmentation effects, allowing the bubbles to be sufficiently refined to penetrate deep into micropores, preventing gas blockage, and ensuring uniform coverage of the oxidation reaction. For high-permeability ore layers requiring 10-50μm bubbles, setting the gas-liquid ratio to ≥0.1 ensures bubble integrity while increasing the diffusion rate, enabling rapid coverage of the working area by the oxidant and solving the problem of poor adaptability of traditional fixed-size bubbles. This quantitative gas-liquid ratio control rule replaces experience-based operation, making bubble size adjustment more scientific and repeatable. Combined with real-time feedback from components such as pressure gauges and regulating valves, it can quickly respond to changes in ore layer permeability coefficients, dynamically correcting the gas-liquid ratio to ensure that the bubble diameter stably matches the target value, thereby improving oxygen mass transfer efficiency and uranium ore oxidation and dissolution effects. Simultaneously, it reduces energy waste and equipment wear caused by bubble size mismatch, ensuring the continuity and economy of in-situ leaching uranium mining processes.

[0085] In one feasible implementation, the steps of calculating the swirl number and cavitation number based on liquid flow rate, gas flow rate, and pressure difference include: calculating the swirl number using the following formula:

[0086] Where S is the swirl number, D c The diameter of the first cavity 111 d in The diameter of the liquid inlet 1112, A in Let 1112 be the cross-sectional area of ​​the liquid inlet. Q l This refers to the inlet flow rate. Q g This refers to the intake airflow rate; The cavitation number is calculated using the following formula:

[0087] Where σ is the cavitation number, A throat The cross-sectional area of ​​the cavitation ejection cavity 1131 is... ρ For fluid density, P v The saturated vapor pressure of the fluid. Q l This refers to the inlet flow rate. P out This refers to the pressure in the outlet pipeline.

[0088] In this technical solution, the calculation steps precisely correlate the swirl number and cavitation number with the device's structural parameters (diameter of the first cavity 111, size of the liquid inlet 1112, etc.) and operating parameters (gas-liquid flow rate, pressure difference) through quantitative formulas, providing a scientific quantitative basis for bubble size control. The swirl number calculation clarifies the correspondence between fluid rotation intensity and gas-liquid flow rate and cavity structure, while the cavitation number calculation quantifies the strength of the cavitation effect. Together, they constitute the core evaluation index for bubble breakage effect. Compared to traditional experience-based control, this method can accurately capture the device's operating status in real time, allowing operators to clearly grasp the intensity of swirl shearing and cavitation breakage. By adjusting the gas-liquid flow rate, both parameters can be stabilized within the optimal range, ensuring uniform bubble size that matches the target value. This significantly improves the accuracy and stability of device control and optimizes the oxidation efficiency of in-situ leaching uranium.

[0089] Understandably, when the swirl number is used for control, if the target bubble size needs to be reduced, the control system increases the opening of the liquid inlet valve and increases the liquid inlet flow rate to increase the swirl number S and enhance the centrifugal shearing and crushing of the gas and liquid phases.

[0090] In one feasible implementation, the step of adjusting the liquid flow rate or gas flow rate based on one of the following: target bubble diameter, liquid flow rate, gas flow rate, pressure difference, swirl number, and cavitation number, to adjust the diameter of the bubbles output by the bubble generator includes: When the cavitation number is greater than or equal to 1.5, increase the inlet flow rate; when the cavitation number is less than or equal to 0.8, decrease the inlet flow rate.

[0091] In this technical solution, precise linkage between cavitation number and influent flow rate ensures that bubble breakage remains within the efficient range. When the cavitation number is ≥1.5, the cavitation effect is insufficient, and bubble breakage is incomplete. Increasing the influent flow rate can enhance fluid shear force and pressure surges, improving cavitation intensity and promoting further bubble refinement. When the cavitation number is ≤0.8, excessive cavitation can easily lead to energy waste and equipment vibration. Reducing the influent flow rate can stabilize the cavitation state and prevent excessive bubble breakage or equipment damage. This quantitative control method replaces empirical operation, stabilizing the cavitation number within the optimal range of 0.8-1.5, ensuring uniform bubble size that matches the target value, significantly improving the operational stability of the device and bubble generation efficiency, and providing reliable support for the oxidation reaction in in-situ leaching uranium.

[0092] In one feasible implementation, the bubble generator further includes: The predicted bubble diameter is calculated using the following formula:

[0093] in, D Pm To predict the bubble diameter, k, λ, and γ are all adjustment coefficients, and their values ​​are constants. Q l This refers to the inlet flow rate. Q g ΔP represents the intake airflow rate, and ΔP represents the pressure difference.

[0094] In this technical solution, the key influencing factors of bubble formation are transformed into calculable quantitative indicators by using the formula above to predict the bubble diameter. This allows for real-time output of the predicted bubble diameter under current operating conditions, providing a direct basis for control decisions. Using this formula, the optimal gas-liquid flow rate and pressure difference combination adapted to the target bubble diameter can be deduced, guiding the precise adjustment of the first regulating valve 190 and the second regulating valve 220 to ensure that the bubble size stably meets the requirements of the ore layer. Simultaneously, this formula, in conjunction with the calculation of swirl number and cavitation number, improves the closed-loop control system, significantly enhancing the scientific nature and accuracy of bubble size control, reducing insufficient oxidation or equipment wear caused by parameter imbalances, further strengthening the device's adaptability to complex geological conditions, and ensuring the efficient and stable operation of the in-situ leaching uranium mining process.

[0095] In this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0096] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0097] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0098] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A bubble generator, characterized in that, include: The first cavity is provided with a gas phase inlet and a liquid phase inlet; The second cavity has a turbulent dissipation cavity, and the first cavity is connected to the turbulent dissipation cavity through a jet nozzle; The third cavity contains a cavitation ejector cavity, and the second cavity is connected to the cavitation ejector cavity through a jet nozzle.

2. The bubble generator according to claim 1, characterized in that, The liquid inlet is arranged tangentially to the first cavity and is used to supply liquid medium tangentially to the first cavity.

3. The bubble generator according to claim 1, characterized in that, The ratio of the diameter of the first cavity to the diameter of the jet nozzle is 8 to 12.

4. The bubble generator according to claim 1, characterized in that, The turbulent dissipation cavity is located at one end near the jet nozzle as the first end and at the other end as the second end. The turbulent dissipation cavity is trapezoidally expanding with a diffusion angle of 50° to 60°. The ratio of the maximum diameter of the turbulent dissipation cavity to the diameter of the jet nozzle is 8 to 12.

5. The bubble generator according to claim 1, characterized in that, The jet nozzles are multiple, and the multiple jet nozzles are arranged in parallel. The ratio of the center distance of the multiple jet nozzles to their diameter is 3 to 5.

6. The bubble generator according to claim 1, characterized in that, The cavitation ejector cavity has an inlet end near the second cavity and an outlet end at the other end. The ratio of the diameter of the output end to the diameter of the inlet end is 1.5 to 2.5, and the diffusion angle is 6° to 10°.

7. The bubble generator according to any one of claims 1 to 5, characterized in that, The ratio of the total length of the bubble generator to the first cavity is 4 to 6.

8. The bubble generator according to claim 7, characterized in that, The ratio of the length of the first cavity to the length of the second cavity is 1.5 to 2; The ratio of the length of the second cavity to the length of the third cavity is 0.8 to 1.

2.

9. The bubble generator according to any one of claims 1 to 5, characterized in that, The inner walls of the first cavity, the second cavity, and the third cavity are all provided with an anti-cavitation coating, the thickness of which is 0.1 mm to 0.3 mm.

10. The bubble generator according to claim 9, characterized in that, The materials used to prepare the anti-cavitation coating include nano-ceramics and / or polytetrafluoroethylene composites.

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