Fluidic oscillator and aeration device

Abstract

The present application relates to the field of oscillator, and provides a fluid oscillator and an aeration device. The fluid oscillator comprises an inlet flow channel for accelerating fluid at the inlet to form a jet flow; two outlet flow channels in fluid communication with the inlet flow channel through a diverging flow channel; a feedback pipe in communication with the two outlet flow channels; and a pulsation source pipe downstream of the feedback pipe and in communication with the two outlet flow channels for generating pressure pulsation to promote switching of the jet flow between the two outlet flow channels. The fluid oscillator can realize high-frequency oscillation of the jet flow at a long distance without increasing the supply pressure and flow rate (i.e. without increasing energy consumption) by shortening the length of the feedback pipe; and the overall structure is more simple and compact.

Description

Technical Field

[0001] This invention relates to the field of oscillators, and provides a fluid oscillator and an aeration device. Background Technology

[0002] Microporous bubbling aeration technology is widely used in numerous fields such as water treatment, bio-fermentation, chemical reactions, and aquaculture due to its highly efficient gas-liquid mass transfer performance. Its basic principle is to dissolve gas in a liquid using an aeration device with micron- or millimeter-sized pores, forming a large number of bubbles. These bubbles release active ingredients as they rise, greatly improving mass transfer efficiency, playing a crucial role, especially in wastewater treatment and aquaculture.

[0003] However, in traditional steady-state aeration modes, the generated bubbles are generally too large, which limits further improvements in mass transfer efficiency and energy efficiency. For example, the bubble diameter is typically on the order of millimeters, several times or even tens of times larger than the pore size. Excessively large bubble size leads to a reduced specific surface area, decreasing the effective contact area between the gas and liquid; simultaneously, the rapid rise of large bubbles increases the destructiveness of turbulence, damaging the structure of microbial communities or particulate matter. Summary of the Invention

[0004] This invention provides a fluid oscillator to address the shortcomings of low mass transfer efficiency and low energy efficiency in related technologies.

[0005] This invention also provides an aeration device.

[0006] A first aspect of the present invention provides a fluid oscillator, comprising: Inlet channel, used to accelerate the inlet fluid to form a jet; Two outflow channels are in fluid communication with the inflow channel through a gradually expanding channel; Feedback tube, the feedback tube being connected to the two outflow channels; A pulsation source tube, located downstream of the feedback tube and connected to the two outflow channels, is used to generate pressure pulsations to cause the jet to switch between the two outflow channels.

[0007] According to one embodiment of the present invention, a turbulent fluid is provided in the outflow channel at a position corresponding to the feedback tube. The turbulent fluid is located between the feedback tube and the pulsation source tube and is used to generate a turbulent sound source upstream of the pulsation source tube.

[0008] According to one embodiment of the present invention, the ratio of the diameter of the turbulent fluid to the width of the outflow channel ranges from 1 / 10 to 1 / 5; The distance between the intersection of the outflow channels and the starting end of the gradually expanding channel is L1, and the ratio of L1 to the width of the outflow channel ranges from 8 to 12.

[0009] According to one embodiment of the present invention, the inlet channel includes a fluid inlet section with an inlet width of W1 and a contraction acceleration section with an outlet width of W2, wherein W2 / W1≦1 / 3, and the length of the fluid inlet section is L2, and L2 / W1≥6.

[0010] According to one embodiment of the present invention, the angle α between the central axis of the outflow channel and the central axis of the inflow channel ranges from 10 to 15 degrees.

[0011] According to one embodiment of the present invention, the ratio of the width of the feedback tube to the width of the outflow channel ranges from 1 / 6 to 1 / 3. Along the length of the outflow channel, the distance between the starting end of the gradually expanding channel and the feedback tube is L3, and the ratio of L3 to the width of the outflow channel ranges from 2 to 4. Along the length of the outflow channel, the distance between the feedback pipe and the end of the outflow channel is L4, and the ratio of L4 to the width of the outflow channel ranges from 3 to 7.

[0012] According to one embodiment of the present invention, the ratio of the diameter of the pulsation source tube to the width of the outflow channel ranges from 0.4 to 0.7.

[0013] According to one embodiment of the present invention, a pressurization section is provided at the end of each of the two outflow channels, and each pressurization section includes a gradually expanding section and a guiding section, wherein the gradually expanding section is connected between the guiding section and the outflow channel.

[0014] According to one embodiment of the present invention, the ratio of the width of the expanding section to the width of the outflow channel ranges from 1.5 to 2; The ratio of the length to the width of the guide section ranges from 2 to 4.

[0015] A second aspect of the present invention provides an aeration device, including the fluid oscillator as described above.

[0016] According to the fluid oscillator provided in the first aspect of the present invention, the jet possesses sufficient kinetic energy through efficient acceleration of the inlet channel; the synergistic effect of the feedback tube and the pulse source tube activates vortex resonance, generating stable and sufficiently strong pressure pulsations, which can quickly facilitate the switching of the jet between the two outlet channels, realizing the efficient conversion of continuous airflow into high-frequency pulsed airflow. The generated pulsed airflow has a stable frequency, uniform pulsation intensity, significantly reduced bubble size, and a greatly increased specific surface area, providing favorable conditions for gas-liquid mass transfer and effectively improving the efficiency of applications such as aeration. The contraction acceleration design of the inlet channel realizes the efficient conversion of pressure potential energy into kinetic energy, and the size optimization of the feedback tube and the pulse source tube reduces airflow resistance and energy loss, enabling the energy of the input airflow to be efficiently converted into pulsed kinetic energy. No additional power is required to drive pulse generation, and energy consumption is significantly reduced compared to traditional mechanical valve-type pulse devices. The pressure feedback effect of the feedback tube and the vortex resonance effect of the pulse source tube form a good coupling, ensuring regular and continuous jet switching and avoiding pulse interruption or disorder. The symmetrical design of the two outflow channels ensures consistent airflow characteristics on both sides, further guaranteeing the uniformity and stability of the pulsed airflow and improving the consistency of downstream application performance.

[0017] According to the aeration device provided in the second aspect of the present invention, the high-frequency pulsed airflow generated by the fluid oscillator can effectively break up bubbles, significantly reducing bubble size and increasing specific surface area, while extending the residence time of bubbles in the water, thus greatly improving gas-liquid mass transfer efficiency. Compared with traditional steady-state aeration devices, this aeration device significantly accelerates oxygen dissolution, rapidly increasing the dissolved oxygen level in the water and meeting the high-efficiency requirements of maintaining aerobic microbial activity and oxygenation in aquaculture. The oscillator achieves pulse modulation through vortex resonance, requiring no additional power drive, significantly reducing energy loss compared to traditional mechanical valve-type pulse aeration devices; simultaneously, the high mass transfer efficiency of microbubbles significantly reduces energy consumption per unit of dissolved oxygen, effectively saving operating energy consumption of the air supply unit while achieving the same aeration effect, and significantly reducing operating costs in the long term. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic perspective view of the fluid oscillator provided by the present invention.

[0020] Figure 2 This is a schematic top view of the fluid oscillator provided by the present invention.

[0021] Figure 3 This is a schematic enlarged view of the contraction acceleration section and the outflow channel provided by the present invention.

[0022] Figure 4 This is a schematic side view of the turbulent fluid and pulsation source pipe provided by the present invention.

[0023] Figure 5 This is a schematic view of the turbulence near the turbulent fluid provided by the present invention.

[0024] Figure 6 This is a schematic diagram simulating the vortex acoustic mechanism provided by the present invention.

[0025] Figure 7 This is a schematic waveform diagram of the pressure sensor signal at the outlet of the booster section provided by the present invention.

[0026] Figure 8 This is a schematic curve showing the comparison of oxygenation rates provided by the present invention.

[0027] Figure 9 This is a schematic perspective view of the aeration device provided by the present invention.

[0028] Figure label: 100. Inlet channel; 102. Outlet channel; 103. Diverging channel; 104. Feedback pipe; 106. Pulsation source pipe; 108. Turbulent fluid; 110. Fluid inlet section; 112. Contraction acceleration section; 114. Pressurization section; 116. Diverging section; 118. Guide section. Detailed Implementation

[0029] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0030] like Figures 1 to 8 As shown, a first aspect of the present invention provides a fluid oscillator, comprising: The inlet channel 100 is used to accelerate the inlet fluid to form a jet; Two outflow channels 102 are connected to the inflow channel 100 via a gradually expanding channel 103; Feedback tube 104 connects to two outflow channels 102; The pulsation source tube 106 is located downstream of the feedback tube 104 and is connected to two outflow channels 102. It is used to generate pressure pulsations to cause the jet to switch between the two outflow channels 102.

[0031] According to the fluid oscillator provided in the first aspect of the present invention, the jet possesses sufficient kinetic energy through the efficient acceleration of the inlet channel 100; the synergistic effect of the feedback pipe 104 and the pulse source pipe 106 activates vortex resonance, generating stable and sufficiently strong pressure pulsations, which can quickly cause the jet to switch between the two outlet channels 102, realizing the efficient conversion of continuous airflow into high-frequency pulsed airflow. The generated pulsed airflow has a stable frequency, uniform pulsation intensity, significantly reduced bubble size, and a significantly increased specific surface area, providing favorable conditions for gas-liquid mass transfer and effectively improving the efficiency of applications such as aeration. The contraction acceleration design of the inlet channel 100 realizes the efficient conversion of pressure potential energy into kinetic energy, and the size optimization of the feedback pipe 104 and the pulse source pipe 106 reduces airflow resistance and energy loss, enabling the energy of the input airflow to be efficiently converted into pulsed kinetic energy. No additional power is required to drive pulse generation, and energy consumption is significantly reduced compared to traditional mechanical valve-type pulse devices. The pressure feedback effect of the feedback tube 104 and the vortex resonance effect of the pulse source tube 106 are well coupled, ensuring regular and continuous jet switching and avoiding pulse interruption or turbulence. The symmetrical design of the two outflow channels 102 makes the flow characteristics of the airflow on both sides consistent, further ensuring the uniformity and stability of the pulsed airflow and improving the consistency of downstream application effects.

[0032] Please continue reading Figures 1 to 7 The fluid oscillator provided in the first aspect of the present invention achieves efficient modulation of continuous airflow into pulsed airflow through the coordinated design of the inflow channel 100, the dual outflow channels 102, the feedback tube 104 and the pulsation source tube 106.

[0033] The inlet channel 100 is an integrated structure, comprising a fluid inlet section 110 and a contraction-acceleration section 112. It is constructed entirely of corrosion-resistant, high-strength materials to ensure structural stability during airflow transport. The fluid inlet section 110 is a straight pipe structure, designed to effectively stabilize the inlet airflow, eliminating initial airflow disturbances and allowing the airflow to enter the contraction-acceleration section 112 with a uniform velocity profile. The cross-section of the contraction-acceleration section 112 is abruptly narrowed, converting the airflow pressure potential energy into kinetic energy through the Venturi effect, achieving rapid airflow acceleration and ultimately forming a high-speed jet. This provides sufficient kinetic energy for subsequent jet adhesion, deflection, and switching. The inner wall of the inlet channel 100 is smooth and burr-free, with smooth transitions at the joints between sections, reducing airflow resistance and eddy current generation, and ensuring energy conversion efficiency.

[0034] Two outflow channels 102 are symmetrically distributed on both sides of the inflow channel 100, and are fluidly connected to the end of the gradually expanding channel 103 at the end of the inflow channel 100, forming a bifurcated channel structure. The inner wall of the outflow channel 102 is smooth and flat, and its extension direction forms a reasonable angle with the central axis of the inflow channel 100, ensuring that the high-speed jet ejected from the inflow channel 100 can smoothly enter either outflow channel 102 and flow stably against the wall. The two outflow channels 102 have completely identical structural dimensions, ensuring that the flow characteristics of the airflow in the two channels are the same, providing a structural basis for the symmetrical switching of the jet. The length of the outflow channel 102 is designed to adapt to the installation position of the feedback pipe 104 and the pulsation source pipe 106, ensuring the effectiveness of pressure feedback and pulsation transmission.

[0035] The feedback pipe 104 is a tubular structure connecting two outflow channels 102. It is installed in the upstream region of each outflow channel 102, with both ends sealed to the sidewalls of the two outflow channels 102, forming a pressure feedback channel between the two channels. The inner wall of the feedback pipe 104 is smooth, and its flow cross-sectional area is adapted to the size of the outflow channels 102, enabling rapid exchange of pressure and airflow between the two outflow channels 102. When the airflow pressure in one outflow channel 102 changes, this pressure change can be quickly transmitted to the other outflow channel 102 through the feedback pipe 104, forming dynamic pressure feedback. This provides the triggering condition for the initial deflection of the jet and enhances the coupling effect between the channels.

[0036] The pulsation source pipe 106 is located downstream of the feedback pipe 104 and also connects to the two outflow channels 102. It is a cylindrical tubular structure with a smooth inner wall and optimized dimensions. The core function of the pulsation source pipe 106 is to generate pressure pulsations, which relies on the vortex resonance mechanism: when the airflow passes through the connection between the pulsation source pipe 106 and the outflow channel 102, an unstable shear layer is formed. The vortex generated by the separation of the shear layer drifts downstream and impacts the inner wall of the pipe, exciting pressure waves (sound waves). These pressure waves propagate and reflect rapidly within the pipe, forming continuous pressure pulsations. The intensity of this pressure pulsation is sufficient to cause the jet originally attached to one side of the outflow channel 102 to switch to the other side. Combined with the pressure feedback from the feedback pipe 104, the jet periodically alternates between the two outflow channels 102, ultimately modulating the continuous airflow into a pulsed airflow.

[0037] According to one embodiment of the present invention, a turbulent fluid 108 is provided in the outflow channel 102 at a position corresponding to the feedback pipe 104. The turbulent fluid 108 is located between the feedback pipe 104 and the pulsation source pipe 106 and is used to generate a turbulent sound source upstream of the pulsation source pipe 106.

[0038] In one embodiment of the present invention, the turbulent fluid 108 is a columnar structure, perpendicular to the extending direction of the outflow channel 102, and is fixedly installed in the internal cavity of the outflow channel 102 at a position corresponding to the feedback pipe 104 and close to the pulsation source pipe 106. Its installation position is precisely in the flow channel region between the feedback pipe 104 and the pulsation source pipe 106, which neither affects the communication effect between the feedback pipe 104 and the outflow channel 102, nor hinders the pressure pulsation transmission of the pulsation source pipe 106.

[0039] The turbulent fluid 108 has a regular shape and a smooth surface, with a uniform flow gap between it and the inner wall of the outlet channel 102 to ensure smooth airflow. When the airflow passes through the turbulent fluid 108, periodic vortices are formed and detached behind it. This vortex motion causes pressure fluctuations in the airflow within the channel, thereby generating a continuous turbulence sound source. This sound source, as the initial excitation, enhances the instability of the flow field, providing the necessary disturbance conditions for the subsequent vortex resonance mechanism within the pulsating source pipe 106, and promoting the formation and intensification of pressure pulsations.

[0040] The turbulent sound source generated by the turbulent fluid 108 provides initial excitation for the vortex resonance in the pulsating source tube 106, which can quickly activate the resonance mechanism, making the formation of pressure pulsation more rapid and stable, avoiding the problem of resonance start-up lag or instability, and ensuring that the jet switches regularly and continuously between the two outflow channels 102.

[0041] The pressure fluctuations generated by the periodic vortex shedding have fixed frequency characteristics, which can couple with the resonant frequency of the pulse source tube 106, making the final pulse airflow frequency more stable and the pulsation intensity more uniform. This effectively improves the modulation quality of the pulse airflow and provides a high-quality pulse air source for subsequent applications such as aeration.

[0042] According to one embodiment of the present invention, the ratio of the diameter of the turbulent fluid 108 to the width of the outflow channel 102 ranges from 1 / 10 to 1 / 5; The distance between the intersection of the outflow channel 102 and the starting end of the gradually expanding channel 103 is L1, and the ratio of L1 to the width of the outflow channel ranges from 8 to 12.

[0043] In one embodiment of the present invention, the ratio of the diameter of the turbulent fluid 108 to the width of the outflow channel 102 is within a reasonable range. This ensures that the turbulent fluid 108 can generate sufficiently strong vortex shedding and pressure fluctuations to effectively excite the turbulence sound source, while preventing excessive reduction in the cross-sectional area of ​​the flow channel due to an excessively large diameter of the turbulent fluid 108, which would cause a surge in airflow resistance or obstructed flow. This reasonable ratio design allows the airflow to form a stable vortex motion around the turbulent fluid 108 while maintaining high flow efficiency.

[0044] The ratio of the distance L1 between the confluence point of the outflow channel 102 and the starting end of the expanding channel 103 to the width of the outflow channel is within a reasonable range. This distance provides sufficient initial development space for the jet ejected from the inflow channel 100, ensuring that the jet can fully diffuse and stably adhere to the inner wall of the outflow channel 102, laying the foundation for subsequent feedback regulation and jet switching. If the distance is too short, the jet will enter the switching region before it has fully developed, resulting in poor stability; if the distance is too long, it will increase the channel resistance and energy loss, affecting the oscillation efficiency.

[0045] The size ratio of the turbulent fluid 108 to the outflow channel 102 ensures the frequency stability of the vortex shedding, and the intensity of the generated turbulent sound source is moderate, which can accurately match the resonance requirements of the pulsating source tube 106, so that the frequency of the pulsed airflow remains stable and avoids pulse disorder caused by insufficient or excessive turbulence.

[0046] The reasonable ratio of L1 to the width of the outflow channel 102 provides ample room for the jet to develop, enabling the jet to flow stably against the wall, reducing random fluctuations in the jet, and ensuring that the jet can smoothly and regularly switch between the two outflow channels 102 under the action of the feedback tube 104 and the pulsation source tube 106, thereby improving the working reliability of the oscillator.

[0047] According to one embodiment of the present invention, the inlet channel 100 includes a fluid inlet section 110 with an inlet width of W1 and a contraction acceleration section 112 with an outlet width of W2, wherein W2 / W1≦1 / 3, the length of the fluid inlet section 110 is L2, and L2 / W1≥6.

[0048] In one embodiment of the present invention, the fluid inlet section 110 is a cylindrical straight pipe structure with a large ratio of length to inlet width, which can effectively stabilize the incoming airflow, eliminate airflow disturbance and non-uniformity within the pipe, and allow the airflow to enter the contraction and acceleration section 112 with a smooth and uniform velocity profile. Its inner wall is smooth, without any protrusions or depressions, reducing airflow resistance along the flow path and ensuring stable airflow delivery.

[0049] The contraction acceleration section 112 is connected downstream of the fluid inlet section 110. Its cross-section is abruptly narrowed, with the outlet width much smaller than the inlet width, achieving rapid airflow acceleration through the Venturi effect. The inner wall of the contraction acceleration section 112 features a smooth arc transition, avoiding airflow separation and vortex generation caused by right-angle or acute-angle turns. This ensures that pressure potential energy is efficiently converted into kinetic energy, allowing the airflow to form a high-speed jet at the outlet of the contraction acceleration section 112, providing sufficient kinetic energy for subsequent jet adhesion, deflection, and switching.

[0050] The width ratio of the contraction acceleration section 112 enables the airflow to achieve a significant acceleration effect, forming a high-speed jet with sufficient kinetic energy to achieve wall-attached flow and rapid switching, providing core power support for the pulse modulation function of the oscillator.

[0051] The length and width ratio of the fluid inlet section 110 ensures sufficient airflow stability, eliminates the uneven disturbance of the initial airflow, stabilizes the airflow state entering the contraction acceleration section 112, and thus ensures the stability and consistency of the jet, reducing the impact of external disturbances on the pulse modulation effect.

[0052] According to one embodiment of the present invention, the angle α between the central axis of the outflow channel 102 and the central axis of the inflow channel 100 ranges from 10 to 15 degrees.

[0053] In one embodiment of the present invention, two outflow channels 102 are symmetrically distributed on both sides of the inflow channel 100, and their central axes form the same angle with the central axis of the inflow channel 100. This angle design ensures that the high-speed jet ejected from the inflow channel 100 can smoothly enter either outflow channel 102 and stably adhere to the wall, while also reserving a reasonable spatial angle for the deflection and switching of the jet.

[0054] If the included angle is too small, the two outflow channels 102 will be too close together, making it easy for the jet to collide or interfere during switching, affecting the smoothness of the switching. If the included angle is too large, it will increase the flow channel resistance, resulting in excessive jet kinetic energy loss, and will also increase the overall size of the oscillator, which is not conducive to integrated installation. A reasonable included angle design makes the jet uniformly stressed when flowing on the wall, and requires less feedback pressure during switching, enabling fast and efficient jet deflection.

[0055] The inner wall of the outflow channel 102 is kept parallel to the central axis, ensuring that the jet can flow stably in a straight line within the channel, reducing lateral diffusion of airflow and energy loss, and further improving the stability and regularity of jet switching.

[0056] The reasonable angle design allows the high-speed jet to smoothly enter the outlet channel 102 and adhere stably to the wall, reducing jet separation and eddy generation. At the same time, it provides a suitable angle space for the jet to switch between the two outlet channels 102, ensuring that the switching process is fast and smooth, without any jamming or stagnation.

[0057] This angle design effectively controls the resistance loss of airflow at the bend in the flow channel, allowing the kinetic energy of the jet to be fully utilized, avoiding energy waste caused by excessive angle, and improving the energy utilization efficiency of the entire system.

[0058] According to one embodiment of the present invention, the ratio of the width of the feedback tube to the width of the outflow channel ranges from 1 / 6 to 1 / 3; Along the length of the outflow channel 102, the distance between the starting end of the gradually expanding channel 103 and the feedback pipe 104 is L3, and the ratio of L3 to the width of the outflow channel ranges from 2 to 4. Along the length of the outflow channel 102, the distance between the feedback pipe 104 and the end of the outflow channel 102 is L4, and the ratio of L4 to the width of the outflow channel 102 ranges from 3 to 7.

[0059] In one embodiment of the present invention, the width of the feedback tube is smaller than the width of the outflow channel, and the ratio between the two is within a reasonable range. This ensures that the feedback tube 104 can achieve pressure and airflow communication between the two outflow channels 102, while preventing excessive airflow diversion in the outflow channel 102 due to an excessively large width of the feedback tube 104, which would affect the flow of the main airflow and the pulse effect. Both ends of the feedback tube 104 are connected to the sidewalls of the two outflow channels 102, with a smooth transition at the connection point, reducing airflow resistance and vortex generation at the connection.

[0060] The ratio of L3 to the width of the outflow channel 102 is within a reasonable range. This distance ensures that the connection position of the feedback pipe 104 is located in the flow channel region after the jet stabilizes and attaches to the wall, enabling accurate capture of pressure changes within the outflow channel 102 and making the pressure feedback more sensitive and accurate. The ratio of L4 to L3 is also within a reasonable range, providing sufficient space for further airflow and pressure transmission within the outflow channel 102. This ensures that the feedback pressure can effectively couple with the pressure pulsation of the pulsation source pipe 106, promoting rapid jet switching.

[0061] The width ratio of the feedback tube 104 to the outflow channel 102 ensures the timeliness and accuracy of pressure feedback, and can quickly transmit the pressure difference between the two outflow channels 102; the reasonable L3 and L4 ratio enables the feedback pressure to effectively cooperate with the resonance effect of the pulsation source tube 106, accelerate the deflection switching of the jet, and improve the frequency and stability of the pulse airflow.

[0062] The width design of the feedback tube avoids excessive diversion of the main airflow, ensuring that the main airflow can maintain sufficient strength and kinetic energy so that the pulsation amplitude of the pulsed airflow meets the application requirements. At the same time, the sufficient L4 length allows the airflow to develop fully within the outflow channel 102, further enhancing the pressure pulsation effect and improving the pulse modulation quality.

[0063] This size ratio makes the airflow distribution within the channel more uniform, avoiding energy loss caused by local pressure concentration or airflow separation, improving the system's energy utilization efficiency, and ensuring that the energy of the input airflow can be efficiently converted into pulse kinetic energy.

[0064] According to one embodiment of the present invention, the ratio of the diameter of the pulsation source pipe 106 to the width of the outflow channel ranges from 0.4 to 0.7.

[0065] In one embodiment of the present invention, the pulsation source pipe 106 is a cylindrical pipe, with both ends connected to two outflow channels 102, and is installed downstream of the feedback pipe 104. Its diameter is appropriately proportioned to the width of the outflow channels, ensuring sufficient space inside the pulsation source pipe 106 to form stable vortex resonance, while preventing excessively large pipe diameters from causing airflow dispersion and affecting resonance intensity; and also preventing excessively small pipe diameters from causing excessive airflow resistance and hindering the transmission of pressure pulsations.

[0066] The inner wall of the pulsation source pipe 106 is smooth and free of any impurities or protrusions, ensuring that the airflow can flow smoothly inside the pipe and that vortex motion can be stably formed and developed. When the airflow passes through the connection between the pulsation source pipe 106 and the outlet channel 102, a shear layer is formed at the pipe opening. The instability of the shear layer interacts with the vortex generated by the turbulent fluid 108, triggering strong vortex resonance and generating continuous and stable pressure pulsation. This pressure pulsation propagates and reflects within the pipe at the speed of sound, causing the jet to switch rapidly between the two outlet channels 102.

[0067] The reasonable diameter ratio enables the pulse source tube 106 to form a strong vortex resonance, resulting in a large pressure pulsation intensity and stable frequency. This can efficiently promote jet switching, significantly increase the frequency of the pulse airflow, and meet the high-frequency pulse requirements of applications such as aeration.

[0068] The diameter design of the pulsation source tube 106 ensures the smooth propagation and reflection of pressure pulsation within the tube, avoiding pressure loss or distortion. This allows the pressure pulsation to act evenly on the jets of the two outflow channels 102, ensuring regular and orderly jet switching and improving the uniformity and stability of the pulsed airflow.

[0069] According to one embodiment of the present invention, a pressurization section 114 is provided downstream of each of the two outflow channels 102. Each pressurization section 114 includes a gradually expanding section 116 and a guiding section 118. The gradually expanding section 116 is connected between the guiding section 118 and the outflow channel 102.

[0070] In one embodiment of the present invention, the diffuser section 116 is connected downstream of the outlet channel 102, and the channel cross-section is gradually enlarging, which enables the high-speed pulsed airflow flowing out of the outlet channel 102 to decelerate and pressurize. Its inner wall adopts a smooth arc transition, avoiding airflow separation and vortex generation, ensuring that the airflow can smoothly transition from the outlet channel 102 to the diffuser section 116, and the pressure potential energy is steadily restored.

[0071] The guide section 118 is connected downstream of the diffuser section 116. It is a cylindrical straight pipe structure with a reasonable length design, which can stabilize and guide the airflow after it has been pressurized by the diffuser section 116. The inner wall of the guide section 118 is smooth, ensuring that the airflow flows out in a uniform and stable state, avoiding airflow disturbance and diffusion, and enabling the pulsed airflow to be accurately delivered to subsequent components such as aerator heads.

[0072] The overall structure of the booster section 114 is smoothly connected to the outflow channel 102 without obvious steps or turns, which reduces the local resistance and energy loss of the airflow and ensures that the pressure and kinetic energy of the pulsed airflow can be effectively transmitted to meet the downstream application's requirements for airflow pressure and stability.

[0073] The deceleration and pressurization effect of the gradually expanding section 116 increases the pressure of the pulse airflow, which can effectively overcome the back pressure of downstream aeration heads and other components, ensuring smooth airflow output; the flow stabilization effect of the guide section 118 makes the flow state of the pulse airflow more stable, reduces airflow fluctuations, and improves the compatibility with downstream components.

[0074] The smooth transition structure of the booster section 114 reduces the energy loss of the airflow, ensures that the pulsation intensity and frequency of the pulsed airflow remain stable, avoids the attenuation of the pulse effect due to pressure loss, and ensures the modulation quality of the oscillator.

[0075] According to one embodiment of the present invention, the ratio of the width of the expanding section 116 to the width of the outflow channel 102 ranges from 1.5 to 2. The ratio of the length to the width of the guide section 118 ranges from 2 to 4.

[0076] In one embodiment of the present invention, the ratio of the maximum width of the diffuser section 116 to the width of the outlet channel 102 is relatively large, which can achieve a significant deceleration and pressurization effect. This allows the high-speed pulsed airflow exiting the outlet channel 102 to be sufficiently decelerated within the diffuser section 116, resulting in a smooth pressure increase to meet the airflow pressure requirements of downstream components. The expansion angle of the diffuser section 116 is optimized and matched with the width ratio to ensure that the airflow does not separate during expansion, thus avoiding vortex generation and energy loss.

[0077] The length-to-width ratio of the guide section 118 is reasonable, which can effectively stabilize the pressurized airflow, eliminate the minor disturbances generated in the diffuser section 116, and allow the airflow to flow out with a uniform and stable velocity profile. The width of the guide section 118 is consistent with the maximum width of the diffuser section 116, ensuring the continuity and smoothness of the airflow and avoiding pressure fluctuations and energy losses caused by abrupt changes in cross-section.

[0078] The width ratio of the gradually expanding section 116 enables the airflow to obtain sufficient pressurization effect, significantly increasing the pressure of the output airflow. This effectively overcomes the back pressure of downstream aerators, pipes, and other components, ensuring smooth delivery of pulsed airflow and improving the applicability of the oscillator in high back pressure scenarios.

[0079] The length and width ratio of the guide section 118 ensures sufficient airflow stability, making the output pulsed airflow more uniform and stable, reducing airflow fluctuations and diffusion, ensuring that the pulse effect can be accurately transmitted to downstream application components, and improving the effect of aeration and other applications.

[0080] like Figure 8 As shown, a second aspect of the present invention provides an aeration device, including the fluid oscillator as described above.

[0081] According to the aeration device provided in the second aspect of the present invention, the high-frequency pulsed airflow generated by the fluid oscillator can effectively break up bubbles, significantly reducing bubble size and increasing specific surface area, while extending the residence time of bubbles in the water, thus greatly improving gas-liquid mass transfer efficiency. Compared with traditional steady-state aeration devices, this aeration device significantly accelerates oxygen dissolution, rapidly increasing the dissolved oxygen level in the water and meeting the high-efficiency requirements of maintaining aerobic microbial activity and oxygenation in aquaculture. The oscillator achieves pulse modulation through vortex resonance, requiring no additional power drive, significantly reducing energy loss compared to traditional mechanical valve-type pulse aeration devices; simultaneously, the high mass transfer efficiency of microbubbles significantly reduces energy consumption per unit of dissolved oxygen, effectively saving operating energy consumption of the air supply unit while achieving the same aeration effect, and significantly reducing operating costs in the long term.

[0082] Please continue reading Figure 9 The aeration device provided in the second aspect of the present invention uses a fluid oscillator as the core and combines it with supporting structures such as air supply and airflow regulation to construct a high-efficiency pulse aeration system.

[0083] The fluid oscillator, as the core component of the aeration device, is connected in series between the airflow control unit and the downstream aeration components. Its inlet channel 100 receives pre-treated continuous airflow, which is then converted into a high-speed jet through the contraction acceleration section 112. This jet, through the synergistic action of the dual outflow channels 102, feedback pipe 104, and pulse source pipe 106, modulates the continuous airflow into a high-frequency pulsed airflow using a vortex resonance mechanism. The modulated pulsed airflow features stable frequency and high pulsation intensity, effectively breaking up bubbles generated during aeration, reducing bubble size, and improving gas-liquid mass transfer efficiency.

[0084] like Figure 7As shown, the air source is a certain brand of air compressor. The aeration system operates at a pressure of 0.1 MPa and a flow rate of 40 L / min. The aeration discs are two DN215 silicone rubber discs. The aeration tank is 1.0 m long, 0.8 m wide, and 0.6 m deep (total tank height 0.8 m), with an average water temperature of 19.3 degrees Celsius. Aeration performance tests were conducted according to established standards. First, nitrogen gas was introduced through aeration stones to displace and remove the initial dissolved oxygen in the test water, reducing it to below 2.0 mg / L. Then, a comparative oxygenation experiment was conducted with and without the fluid oscillator. The rate of increase in dissolved oxygen concentration in the water was used as an indicator to measure the mixing and mass transfer effect. The comparison demonstrates the improved gas-liquid mixing and mass transfer effect of the fluid oscillator.

[0085] As shown in the figure, without using the fluid oscillator, it took 2.91 minutes for dissolved oxygen to increase from 1.80 mg / L to 7.00 mg / L. With the fluid oscillator, the corresponding time was 2.13 minutes. Calculations show that the oxygenation time was shortened by 26.80%, and the KLa efficiency was increased by 42.10%. The above data shows that using the fluid oscillator significantly improves oxygenation efficiency, greatly saving the driving energy consumption of the pressurized gas source.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fluid oscillator, characterized in that, include: Inlet channel, used to accelerate the inlet fluid to form a jet; Two outflow channels are in fluid communication with the inflow channel through a gradually expanding channel; Feedback tube, the feedback tube being connected to the two outflow channels; A pulsation source tube, located downstream of the feedback tube and connected to the two outflow channels, is used to generate pressure pulsations to cause the jet to switch between the two outflow channels.

2. The fluid oscillator according to claim 1, characterized in that, A turbulent fluid is provided in the outflow channel at a position corresponding to the feedback tube. The turbulent fluid is located between the feedback tube and the pulsation source tube and is used to generate a turbulent sound source upstream of the pulsation source tube.

3. The fluid oscillator according to claim 2, characterized in that, The ratio of the diameter of the turbulent fluid to the width of the outflow channel ranges from 1 / 10 to 1 / 5. The distance between the intersection of the outflow channels and the starting end of the gradually expanding channel is L1, and the ratio of L1 to the width of the outflow channel ranges from 8 to 12.

4. The fluid oscillator according to claim 1, characterized in that, The inflow channel includes a fluid inlet section with an inlet width of W1 and a contraction acceleration section with an outlet width of W2, wherein W2 / W1≦1 / 3, and the length of the fluid inlet section is L2, and L2 / W1≥6.

5. The fluid oscillator according to claim 1, characterized in that, The angle α between the central axis of the outflow channel and the central axis of the inflow channel ranges from 10 to 15 degrees.

6. The fluid oscillator according to claim 1, characterized in that, The ratio of the width of the feedback tube to the width of the outflow channel ranges from 1 / 6 to 1 / 3. Along the length of the outflow channel, the distance between the starting end of the gradually expanding channel and the feedback tube is L3, and the ratio of L3 to the width of the outflow channel ranges from 2 to 4. Along the length of the outflow channel, the distance between the feedback pipe and the end of the outflow channel is L4, and the ratio of L4 to the width of the outflow channel ranges from 3 to 7.

7. The fluid oscillator according to claim 1, characterized in that, The ratio of the diameter of the pulsating source pipe to the width of the outflow channel ranges from 0.4 to 0.

7.

8. The fluid oscillator according to claim 1, characterized in that, A pressurization section is provided at the end of each of the two outflow channels. Each pressurization section includes a gradually expanding section and a guiding section. The gradually expanding section is connected between the guiding section and the outflow channel.

9. The fluid oscillator according to claim 8, characterized in that, The ratio of the width of the expanding section to the width of the outflow channel ranges from 1.5 to 2. The ratio of the length to the width of the guide section ranges from 2 to 4.

10. An aeration device, characterized in that, Includes the fluid oscillator as described in any one of claims 1-9.

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