Microporous bubbling aeration two-stage oscillation modulation synergistic system and application method thereof

Abstract

The invention discloses a micropore bubbling aeration two-stage oscillation modulation synergistic system and an application method thereof. The modulation synergistic system comprises a two-stage oscillation device, an air supply unit connected to the upstream of the two-stage oscillation device, and a micropore coil pipe and an aeration tank which are connected to the downstream of the two-stage oscillation device. The two-stage oscillation device comprises a non-feedback oscillation cavity connected with the branch section, a sound wave oscillation cavity sequentially connected with the air inlet section, and a cavity connecting section connected with the non-feedback oscillation cavity and the sound wave oscillation cavity in parallel. Controlled pulsating oscillation airflow is injected into the microporous aeration system through the two-stage oscillation device, and periodic inertia force disturbance is introduced in the bubble generation stage; the pulsating pressure field breaks through gas-liquid interface force balance under traditional steady-state airflow, so that the bubble separation critical size is remarkably reduced, hole opening air film oscillation is accelerated through high-frequency pressure oscillation, necking fracture is promoted, and the bubble separation size is reduced; and meanwhile, transient shear force generated by the pulsating airflow inhibits interaction of adjacent bubble wake flows, and the coalescence probability is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of aeration, and particularly relates to a microporous bubbling aeration two-stage oscillation modulation efficiency enhancement system and an application method thereof. Background Art

[0002] Microporous aeration has been widely used in the activated sludge method for sewage treatment. In the field of sewage treatment, the aeration system provides dissolved oxygen for microbial metabolism. However, the traditional microporous aeration technology is restricted by factors such as microporous manufacturing precision, material deformation, and surface wettability, and it is difficult to continuously and stably generate small-sized bubbles as expected theoretically. The median diameter of the actually generated bubbles generally exceeds the design value (usually reaching 2 - 5 mm). At the same time, the bubble formation mechanism dominated by the gas-liquid interfacial tension under steady-state gas flow conditions is prone to cause the coalescence effect of adjacent bubbles. Especially in a higher gas velocity or complex medium environment, the proportion of the bubble group combining to form millimeter-sized large bubbles increases significantly. Therefore, seeking a technical method that adapts to the microporous bubbling aeration mode, can reduce the bubble size, and strengthen the gas-liquid interfacial mass transfer reaction has thus become a major practical need in the field. Summary of the Invention

[0003] The present invention provides a microporous bubbling aeration two-stage oscillation modulation efficiency enhancement system and an application method thereof to solve technical problems such as breaking the traditional steady-state mass transfer interface, avoiding the low single-stage oscillation frequency, enhancing and precisely controlling the generation of microbubbles, and modular and convenient setting.

[0004] To achieve the above object, the present invention adopts the following technical solutions: A microporous bubbling aeration two-stage oscillation modulation efficiency enhancement system includes a two-stage oscillation device, a gas supply unit connected upstream of the two-stage oscillation device, and a microporous coiled pipe and an aeration tank connected downstream of the two-stage oscillation device; The two-stage oscillation device includes an air inlet section, a branch section connected to one side of the air inlet section, a non-feedback oscillation chamber connected to the branch section, a sound wave oscillation chamber connected in series with the air inlet section, a connecting chamber section connecting the non-feedback oscillation chamber and the sound wave oscillation chamber in parallel, and an air outlet section connected in series to the outlet of the sound wave oscillation chamber; the air outlet section is connected to the downstream microporous coiled pipe; The non-feedback oscillation chamber includes a non-feedback chamber air inlet section connected in series with the branch section, a non-feedback chamber contraction pipe section connected to the non-feedback chamber air inlet section, a non-feedback chamber double-port gas supply section connected in series with the non-feedback chamber contraction pipe section, a counterpulsation oscillation main chamber connected to the non-feedback chamber double-port gas supply section, and a non-feedback chamber outlet shunt section connected after the counterpulsation oscillation main chamber; the non-feedback chamber outlet shunt section is connected in parallel with the sound wave oscillation chamber through the connecting chamber section.

[0005] Further, the gas supply unit includes a gas supply source connected through a pipeline, a valve installed on the downstream pipeline of the gas supply source, a pressure regulating filter installed downstream of the valve, and a flow meter installed downstream of the pressure regulating filter; A double-stage oscillation device is installed correspondingly on the downstream pipeline of the flowmeter.

[0006] Furthermore, the air intake section is the main pipeline, and the main pipeline is connected in series with the downstream pipeline of the flowmeter; a branch section is arranged on one side of the main pipeline; the width or diameter of the branch section is not greater than the width or diameter of the main pipeline; the flow rate of the branch section accounts for 3%-8% of the flow rate of the air intake section.

[0007] Furthermore, the air intake section without a feedback cavity is in a tapered shape, and the width or diameter of the outlet of the air intake section without a feedback cavity corresponds to the width or diameter of the contraction pipe section without a feedback cavity; the included angle between the contraction angle of the air intake section without a feedback cavity and the horizontal line is 12-17 degrees, and the inlet width is selected according to the standard thread diameter; the length of the air intake section without a feedback cavity is greater than or equal to 2 times the length of the contraction pipe section without a feedback cavity; the contraction pipe section without a feedback cavity is a straight pipe, and its length is 3-4 times the width or diameter, and the width or diameter is 1 / 3-1 / 2 of the width or diameter at the inlet of the air intake section without a feedback cavity.

[0008] Furthermore, the double-port air supply section without a feedback cavity is divided into two parts in series with the contraction pipe section without a feedback cavity and symmetrically enters the main counterflow oscillation cavity; the double-port air supply section without a feedback cavity is divided into a straight section and an arc section on one side, the straight section is tapered, and the arc section is set with an equal width or diameter, and the width or diameter of the arc section corresponds to the width or diameter of the outlet of the straight section; The distance from the vertex of the shunt wedge in the double-port air supply section without a feedback cavity to the end of the contraction pipe section without a feedback cavity is 4-8 times the width of the double-port air supply section without a feedback cavity.

[0009] Furthermore, the main counterflow oscillation cavity is in the shape of an elliptical box, and the included angle between the double-port air supply section without a feedback cavity connecting the main counterflow oscillation cavity and the horizontal line is 25-35 degrees; O is the center of the oscillation cavity, H1 is the straight-line distance from the center of the oscillation cavity to the upstream cavity wall, H2 is the straight-line distance from the center of the oscillation cavity to the outlet of the downstream cavity, L0 is the distance between the inlets of the two double-port air supply sections without a feedback cavity, L1 is the distance from the inlet of the double-port air supply section without a feedback cavity to the center of the cavity, L2 is the distance of the outlet straight section, W1 is the width or diameter at the outlet of the arc section of the double-port air supply section without a feedback cavity; W2 is the outlet width or diameter; The parameters are set as follows: H1 is 5-6 times W1, H2 is 4.0-4.5 times W1, L0 is 9-11 times W1, L1 is 6-8 times W1, L2 is 2.5-3.5 times W1, and W2 is 1.8-2.5 times W1; The outlet shunt section without a feedback cavity is divided into two parts in a V-shaped setting at the connection with the main counterflow oscillation cavity; the included angle O1 between the outer side of each outlet edge and the horizontal line is 18-25 degrees, and the included angle O2 between the inner side and the horizontal line is 12-19 degrees; and the outlet on each side is in a gradually expanding shape; The distance H3 from the bifurcation point at the connection to the outlet of the main counterflow oscillation cavity is 4-9 times W2, and the bifurcation point is smoothly set.

[0010] Further, the acoustic oscillation cavity includes an acoustic cavity air inlet section connected to the air inlet section, an acoustic oscillation feedback cavity connected downstream of the acoustic cavity air inlet section, and an acoustic cavity outlet section connected in sequence downstream of the acoustic oscillation feedback cavity; The acoustic cavity air inlet section includes a gradually tapered contraction tube and a throat tube. The contraction angle β of the gradually tapered contraction tube is 10 - 15 degrees; the width or diameter W3 of the throat tube is 9 - 12 times that of W1, and the length of the throat tube is L3, and the length L3 is 3 - 4 times that of W3; The acoustic oscillation feedback cavity is symmetrically water droplet-shaped. The included angle γ between the acoustic oscillation feedback cavities on both sides of the acoustic cavity air inlet section is 10 - 15 degrees, and the width near the throat of the acoustic oscillation feedback cavity is 0.5 - 0.9 times that of W3.

[0011] Further, the acoustic cavity outlet section is arranged in the middle of the two acoustic oscillation feedback cavities and is split into two outlet channels. The distance P between the two tips of the split is 1.5 - 3 times that of W3. The distance H4 from the tip of the split to the middle outlet of the acoustic oscillation feedback cavity is 4 - 11 times the throat width of W3, and the split radius of the split is 0.1 - 2 times that of W3.

[0012] The angle O1 between the outer side of each side of the acoustic cavity outlet section and the horizontal line is 18~25 degrees, and the angle O2 between the inner side and the horizontal line is 12~19 degrees.

[0013] Further, there are two connecting cavity sections. One connecting cavity section connects one outlet side of the non-feedback cavity outlet shunt section and one outlet side of the acoustic cavity outlet section; the other connecting cavity section connects the other outlet side of the non-feedback cavity outlet shunt section and the other outlet side of the acoustic cavity outlet section.

[0014] Further, the application method of the microporous bubble aeration two-stage oscillation modulation and efficiency enhancement system is as follows: Step 1: Supply air through an air supply source, and control the air flow velocity and flow rate through valves and a pressure regulating filter; then the air flow enters the air inlet section of the two-stage oscillation device through a pipeline; Step 2: The air flow is shunted from the air inlet section to the branch section. The air flow enters the non-feedback cavity air inlet section, passes through the non-feedback cavity contraction tube section and the non-feedback cavity double-port air supply section, and enters the counter-oscillation main cavity; Step 3: After the air flow enters the counter-oscillation main cavity, initially the main jet does not show an offset phenomenon, the flow field remains evenly distributed and flows out evenly from the two non-feedback cavity outlet shunt sections; immediately, one of the two supply jets coming in from both sides establishes a main connection with the outlet of the counter-oscillation main cavity and sprays out in the forward direction, and the other supply jet forms a vortex area inside the circular cavity of the counter-oscillation main cavity; Step 4: Due to the turbulence and entrainment effect of the jet itself, and under the influence of the flow splitter, the previous equilibrium state is affected, and a pressure difference appears on both sides of the flow splitter. When the pressure difference reaches a certain order of magnitude, the jet begins to tilt and deflect towards the lower sidewall with lower pressure, and at the same time, a stable wall attachment phenomenon occurs, and it flows out along the outlet pipe on this side at a speed higher than that of the other sidewall. Step 5: Subsequently, since the eddy current region inside the circular cavity is large enough and collides with the jet at the action point, the main connection between the jet and the circular cavity outlet is broken and a new eddy current region gradually forms inside the circular cavity, prompting another supply jet to establish a main connection with the circular cavity outlet and jet out negatively. At this time, due to the inherent turbulence and entrainment effect of the jet itself, a pressure difference relationship opposite to the previous one appears on both sidewalls of the flow splitter, causing the jet to deflect towards the upper sidewall and flow out along the outlet pipe on this side at high speed, and one switching is completed. Finally, due to the action of the internal eddy current region different from the previous stage, the initial supply jet re - establishes a main connection with the circular cavity outlet, and the jet also correspondingly switches to attach to the lower sidewall. The occurrence of oscillation stems from the interaction between the two jets in the circular cavity, and the continuation of oscillation stems from the periodic wall attachment switching behavior of the jet. Step 6: After the air flow in the intake section enters the acoustic oscillation cavity, the boundary layer separation effect forms low - pressure eddy current regions on both sides of the jet; the pressure value of the low - pressure eddy current region on one side is higher, pushing the main jet to the other side and attaching it to the wall; the pressure reduction on the non - attached side causes a large amount of air to be entrained on this side. At the same time, the pulsating jet from the outlet of the non - feedback oscillation cavity intermittently applies a fluctuating pressure through the feedback pipes on both sides of the main jet in the acoustic oscillation cavity. Coupled with the entrainment effect, the pressure on the attached side rises rapidly. After exceeding the non - attached side, it pushes the main jet over to form a new attached side, thus completing a half - cycle of switching; similarly, on the new attached side, which was the previous non - attached side, "entrainment - pushing - switching" occurs to complete the entire cycle of switching; such a cyclic "wall attachment - entrainment - switching" periodic motion enables the incoming main jet to flow out quickly and alternately along the two outlets, forming a high - frequency pulsed oscillating flow. Step 7: Based on the high - frequency pulsed oscillating flow formed in the acoustic oscillation cavity, the gas flows out from the outlet section of the acoustic cavity and is sequentially connected to the microporous coiled pipe and the aeration tank, thereby completing the application of the microporous bubble aeration two - stage oscillation modulation and efficiency - increasing system.

[0015] The beneficial effects of the present invention are as follows: Based on the principle of unsteady gas-liquid interface dynamics, the present invention injects a controlled pulsating oscillating air flow into the microporous aeration system through a two-stage oscillating cavity, introducing periodic inertial force disturbances during the bubble generation stage. When the gas flows through the micropores, the pulsating pressure field breaks the traditional gas-liquid interface force balance (the static balance of surface tension, buoyancy, and viscous force) under steady-state air flow, significantly reducing the critical size for bubble detachment: the high-frequency pressure oscillation accelerates the oscillation of the orifice gas film, promotes necking and fracture, and reduces the bubble detachment volume; at the same time, the transient shear force generated by the pulsating air flow inhibits the interaction between the wakes of adjacent bubbles, reducing the coalescence probability.

[0016] The present invention breaks through the limitations of the traditional static air flow mode and the low oscillation frequency of a single-stage oscillating cavity. By reconstructing the bubble generation dynamics process through a two-stage oscillating cavity, it realizes precise control of bubble size without the need to modify the microporous structure or replace the aeration material. Through the self-cleaning effect generated by the pulsating air flow, it reduces the attachment rate of biofilms / particulates on the microporous surface (the measured fouling cycle is extended by 2-3 times), and is especially suitable for high-suspended solid wastewater scenarios.

[0017] The present invention matches the bubble generation cycle through pulsed air supply, reducing the air volume demand by 15%-25% compared with continuous aeration. Combined with the improvement of mass transfer efficiency, the comprehensive energy saving rate exceeds 40%. The modular two-stage oscillating device can be installed independently of the aerator, is compatible with various microporous aeration systems such as ceramic / rubber / polymer, and the transformation and upgrade cost is only 10%-20% of the traditional technical solution; based on real-time dissolved oxygen feedback, it dynamically adjusts the pulsation parameters (frequency / amplitude) to achieve adaptive optimization of the aeration process, breaking through the bottleneck of the regulation lag of the traditional aeration system.

[0018] The method of modulating pulsating air flow in the unsteady two-stage oscillating cavity proposed by the present invention forms a dynamic shear effect at the microporous gas-liquid interface by constructing a periodic pressure oscillation field, effectively breaking through the physical constraint that the pore diameter determines the bubble size in traditional aeration. The main innovative features of this method are as follows: First, it uses the dynamic pressure pulsation of the air flow to break the continuity of the gas film and realizes active breaking control of bubbles; second, through the coordinated regulation of the modulation frequency and amplitude, it establishes a quantitative response mechanism between the bubble size and the energy input; third, while maintaining the low energy consumption advantage of traditional microporous aeration, it significantly improves the mass transfer efficiency per unit energy consumption. In industrial practice, this technology is compatible with the upgrading and transformation of existing aeration devices, and has a significant effect on enhancing the efficiency in complex working conditions such as the treatment of high-concentration organic wastewater and high-viscosity reaction systems, providing an innovative solution for breaking through the energy efficiency bottleneck of traditional aeration technology. The patented technology equipment can effectively strengthen the mass transfer and reaction at the gas-liquid two-phase interface and is applied to fields such as chemical gas-liquid reactions, separation of volatile substances, and water body aeration and reoxygenation.

[0019] Other features and advantages of the present invention will be set forth in the following description, and in part will be obvious from the description, or may be learned by practice of the present invention; the main objects and other advantages of the present invention can be realized and obtained by the solutions specifically pointed out in the description. Brief Description of the Drawings

[0020] Figure 1 is a three-dimensional schematic diagram of a microporous bubbling aeration two-stage oscillation modulation enhancement system and a two-stage oscillation device; Figure 2 is a cross-sectional schematic diagram of the two-stage oscillation device; Figure 3 is a schematic diagram of the branch section and the non-feedback oscillation cavity structure; Figure 4 is a schematic diagram of the connection structure between the non-feedback cavity double-port air supply section and the counter-jet oscillation main cavity; Figure 5 is a schematic diagram of the sound wave oscillation cavity structure; Figure 6 is a schematic diagram of the simulation of the non-feedback jet oscillation process; Figure 7 is a schematic diagram of the simulation of the non-feedback jet oscillation and the sound wave jet oscillation process driven by the wall attachment effect; Figure 8 is a signal data diagram of the outlet pressure sensor of the two-stage oscillation device; Figure 9 is a comparison diagram of the oxygenation rate of the porous aeration disk 1 when using / not using the present system; Figure 10 is a comparison diagram of the oxygenation rate of the porous aeration disk 2 when using / not using the present system.

[0021] Reference numerals: 1 - air supply source, 2 - valve, 3 - pressure regulating filter, 4 - flow meter, 5 - pipeline, 6 - two-stage oscillation device, 61 - intake section, 62 - branch section, 63 - non-feedback oscillation cavity, 631 - non-feedback cavity intake section, 632 - non-feedback cavity contraction pipe section, 633 - non-feedback cavity double-port air supply section, 634 - counter-jet oscillation main cavity, 635 - non-feedback cavity outlet shunt section, 64 - sound wave oscillation cavity, 641 - sound wave cavity intake section, 642 - sound wave oscillation feedback cavity, 643 - sound wave cavity outlet section, 65 - connecting cavity section, 66 - outlet section, 7 - microporous coil, 8 - aeration tank. Detailed Embodiments

[0022] As Figures 1 to 6 shown, a microporous bubbling aeration two-stage oscillation modulation enhancement system includes a two-stage oscillation device 6, a gas supply unit connected upstream of the two-stage oscillation device 6, and a microporous coil 7 and an aeration tank 8 connected downstream of the two-stage oscillation device 6.

[0023] In this embodiment, the air supply unit includes an air supply source 1 connected by a pipeline 5, a valve 2 installed on the pipeline 5 downstream of the air supply source 1, a pressure regulating filter 3 installed downstream of the valve 2, and a flow meter 4 installed downstream of the pressure regulating filter 3; a double-stage oscillation device 6 is correspondingly installed on the pipeline 5 downstream of the flow meter 4. The intake section 61 is the main pipeline, and the main pipeline is connected in series to the pipeline 5 downstream of the flow meter 4; a branch section 62 is provided on one side of the main pipeline; the width or diameter of the branch section 62 is not greater than the width or diameter of the main pipeline; the flow rate of the branch section 62 accounts for 3% - 8% of the flow rate of the intake section 61.

[0024] Among them, the air supply source 1 is generally a blower such as a Roots blower, a rotary blower or other forms of pressure air sources, and the air supply pressure range can reach 1 bar to 10 bar. The gaseous working medium can be air, oxygen, nitrogen, carbon dioxide, etc. The air supply system is ensured to be stable through the switch valve 2, filter, pressure stabilizing valve, and flow meter 4. The working flow rate depends on actual needs, and it is ensured that both the working pressure and flow rate are between 1 / 3 and 2 / 3 of the range of the pressure gauge and the flow meter 4. The final aeration pressure is generally between 0.2 bar and 1 bar.

[0025] In this embodiment, the double-stage oscillation device 6 includes an intake section 61, a branch section 62 connected to one side of the intake section 61, a non-feedback oscillation cavity 63 connected to the branch section 62, a sound wave oscillation cavity 64 connected in series to the intake section 61, a connecting cavity section 65 connected in parallel to the non-feedback oscillation cavity 63 and the sound wave oscillation cavity 64, and an outlet section 66 connected in series to the outlet of the sound wave oscillation cavity 64; the outlet section 66 is connected to the downstream microporous coiled pipe 7.

[0026] Among them, the double-stage oscillation device 6 is placed on the pipeline 5 between the air supply source 1 and the microporous coiled pipe 7. The main air flow flows into the sound wave oscillation cavity 64, and the branch air flow flows to the non-feedback oscillation cavity 63. The outlet of the non-feedback oscillation cavity 63 is connected to both sides of the sound wave oscillation cavity 64. Pulse air flows can be formed at the two outlets of the sound wave oscillation cavity 64. At the rear end of the air flow in the main pipeline 5, multiple groups of the above double-stage oscillation devices 6 can be connected in parallel to obtain multiple pulse air flow outlets. The double-stage oscillation device 6 can be processed from materials such as stainless steel, copper or acrylic according to the corrosiveness of the gaseous working medium, and the requirements comply with the corresponding pressure safety level. The double-stage oscillation device 6 can be used in any form in fields such as gas-liquid chemical reactions, environmental protection sewage aeration treatment, and agricultural aeration irrigation, and is applicable to any scale in laboratories and engineering sites. However, it is required that the working pressure and flow rate of the microporous air diffusing component match the air supply source 1. The double-stage oscillation device 6 has no restrictions on the microporous pipe plate used at the rear end, and silicone rubber aeration discs, perforated pipes, corundum aeration discs, and ceramic discs can all be used.

[0027] In this embodiment, the non-feedback oscillation cavity 63 includes a non-feedback cavity air inlet section 631 connected in series with the branch section 62, a non-feedback cavity contraction pipe section 632 connected to the non-feedback cavity air inlet section 631, a non-feedback cavity double-port air supply section 633 connected in series with the non-feedback cavity contraction pipe section 632, a counter-flow oscillation main cavity 634 connected to the non-feedback cavity double-port air supply section 633, and a non-feedback cavity outlet shunt section 635 connected after the counter-flow oscillation main cavity 634; the non-feedback cavity outlet shunt section 635 is connected in parallel with the sound wave oscillation cavity 64 through the cavity connection section 65.

[0028] In this embodiment, the non-feedback cavity air inlet section 631 is tapered, and the width or diameter of the outlet of the non-feedback cavity air inlet section 631 corresponds to the width or diameter of the non-feedback cavity contraction pipe section 632; the included angle between the contraction angle of the non-feedback cavity air inlet section 631 and the horizontal line is 12 to 17 degrees, and the inlet width is selected according to the standard thread diameter; the length of the non-feedback cavity air inlet section 631 is greater than or equal to twice the length of the non-feedback cavity contraction pipe section 632; the non-feedback cavity contraction pipe section 632 is a straight pipe, and its length is 3 to 4 times the width or diameter, and the width or diameter is 1 / 3 to 1 / 2 of the width or diameter at the inlet of the non-feedback cavity air inlet section 631.

[0029] In this embodiment, the non-feedback cavity double-port air supply section 633 is divided into two parts in series with the non-feedback cavity contraction pipe section 632 and symmetrically enters the counter-flow oscillation main cavity 634; the non-feedback cavity double-port air supply section 633 is divided into a straight section and an arc section on one side. The straight section is tapered, and the arc section is of equal width or diameter. The width or diameter of the arc section corresponds to the width or diameter of the outlet of the straight section; the distance from the vertex of the shunt wedge in the non-feedback cavity double-port air supply section 633 to the end of the non-feedback cavity contraction pipe section 632 is 4 to 8 times the width of the non-feedback cavity double-port air supply section 633.

[0030] As Figure 4As shown in the figure, the counter-jet oscillation main cavity 634 is in the shape of an elliptical box. The angle between the non-feedback cavity double-port air supply section 633 connected to the counter-jet oscillation main cavity 634 and the horizontal line is the gas incident angle α, and the value of α is 25 to 35 degrees; O is the center of the oscillation cavity, H1 is the straight-line distance between the center of the oscillation cavity and the upstream cavity wall, H2 is the straight-line distance between the center of the oscillation cavity and the downstream cavity outlet, L0 is the distance between the inlets of the two non-feedback cavity double-port air supply sections 633, L1 is the distance from the inlet of the non-feedback cavity double-port air supply section 633 to the cavity center, L2 is the distance of the outlet straight section, and W1 is the width or diameter at the arc-shaped outlet of the non-feedback cavity double-port air supply section 633; W2 is the outlet width or diameter; the parameters are set as follows: H1 is 5 to 6 times W1, H2 is 4.0 to 4.5 times W1, L0 is 9 to 11 times W1, L1 is 6 to 8 times W1, L2 is 2.5 to 3.5 times W1, and W2 is 1.8 to 2.5 times W1; the non-feedback cavity outlet shunt section 635 is bifurcated into two at the connection with the counter-jet oscillation main cavity 634 and is arranged in a V shape; the angle O1 between the outer side of each outlet edge and the horizontal line is 18 to 25 degrees, and the angle O2 between the inner side and the horizontal line is 12 to 19 degrees; and the outlet on each side is arranged in a gradually expanding shape; the distance H3 from the bifurcation point at the connection to the outlet of the counter-jet oscillation main cavity 634 is 4 to 9 times W2, and the bifurcation point is smoothly set.

[0031] As Figure 5 shown in the figure, the sound wave oscillation cavity 64 includes a sound wave cavity air inlet section 641 connected to the air inlet section 61, a sound wave oscillation feedback cavity 642 connected downstream of the sound wave cavity air inlet section 641, and a sound wave cavity outlet section 643 connected in sequence downstream of the sound wave oscillation feedback cavity 642; the sound wave cavity air inlet section 641 includes a gradually tapered contraction tube and a throat tube, and the contraction angle β of the gradually tapered contraction tube is 10 to 15 degrees; the width or diameter of the throat tube W3 is 9 to 12 times W1, and the length of the throat tube is L3, and the length L3 is 3 to 4 times W3; the sound wave oscillation feedback cavity 642 is symmetrically shaped like a water droplet, and the angle γ between the sound wave oscillation feedback cavities 642 on both sides of the sound wave cavity air inlet section 641 is 10 to 15 degrees, and the width near the throat of the sound wave oscillation feedback cavity 642 is 0.5 to 0.9 times W3.

[0032] In this embodiment, the sound wave cavity outlet section 643 is arranged in the middle of the two sound wave oscillation feedback cavities 642 and is split into two outlet channels. The distance P between the two top points of the split is 1.5 to 3 times W3, the distance H4 from the split tip to the middle outlet of the sound wave oscillation feedback cavity 642 is 4 to 11 times the throat width W3, and the split radius is 0.1 to 2 times W3; The angle between the outer side of each side of the sound wave cavity outlet section 643 and the horizontal line is 18 to 25 degrees, and the angle between the inner side and the horizontal line is 12 to 19 degrees.

[0033] In this embodiment, there are two connecting cavity sections 65. One connecting cavity section 65 connects one outlet side of the non-feedback cavity outlet shunt section 635 and one outlet side of the sound wave cavity outlet section 643; the other connecting cavity section 65 connects the other outlet side of the non-feedback cavity outlet shunt section 635 and the other outlet side of the sound wave cavity outlet section 643.

[0034] Combined with Figures 1 to 10 , the application method of the microporous bubble aeration double-stage oscillation modulation efficiency enhancement system is further described as follows: Step 1: Supply air through the air supply source 1, and control the air flow velocity and flow rate through the valve 2 and the pressure regulating filter 3; then the air flow enters the intake section 61 of the double-stage oscillation device 6 through the pipeline 5.

[0035] Step 2: The air flow is split from the intake section 61 to the branch section 62, and the air flow enters the non-feedback cavity intake section 631, passes through the non-feedback cavity contraction pipe section 632 and the non-feedback cavity double-port air supply section 633, and enters the counter-oscillation main cavity 634.

[0036] Step 3: After the air flow enters the counter-oscillation main cavity 634, initially the main jet does not deflect, the flow field remains evenly distributed and flows out evenly from the two non-feedback cavity outlet shunt sections 635, as shown in Figure 6 a; immediately, one of the two supply jets coming in from both sides forms a main connection with the outlet of the counter-oscillation main cavity 634 and jets out in the forward direction, and the other supply jet forms a vortex area inside the circular cavity of the counter-oscillation main cavity 634.

[0037] Step 4: Due to the turbulence and entrainment effect of the jet itself, and affected by the shunt splitter, the previous equilibrium state is affected, and a pressure difference appears on both sides of the shunt splitter. When the pressure difference reaches a certain order of magnitude, the jet begins to tilt and deflect towards the lower side wall with lower pressure, and at the same time, a stable wall attachment phenomenon occurs, and it flows out along the outlet pipe on this side at a speed higher than that of the other side wall, as shown in Figure 6 b; Figure 6 c shows that a low-pressure area can be observed on the wall attachment side.

[0038] Step 5: As shown in Figure 6 d, subsequently, since the vortex area inside the circular cavity is large enough and collides with the jet at the action point, the main connection between the jet and the circular cavity outlet is broken and a new vortex area is gradually formed inside the circular cavity, prompting the other supply jet to form a main connection with the circular cavity outlet and jet out in the negative direction. At this time, due to the inherent turbulence and entrainment effect of the jet itself, a pressure difference relationship opposite to the previous one appears on both side walls of the shunt splitter, causing the jet to deflect towards the upper side wall and flow out along the outlet pipe on this side wall at high speed, and one switching is completed, as shown in Figure 6As shown in Fig. e. Finally, due to the action of the internal eddy current region different from the previous stage, the initial supply jet re - establishes the main connection with the outlet of the circular cavity again, and the injection jet also correspondingly switches and adheres to the lower side wall. The oscillation occurs due to the interaction between the two jets in the circular cavity, and the continuation of the oscillation is due to the periodic wall - attachment switching behavior of the injection jet, as Figure 6 shown in Fig. f.

[0039] Step Six: As Figure 7 shown, after the air flow in the intake section 61 enters the acoustic oscillation cavity 64, the boundary - layer separation effect forms low - pressure eddy current regions on both sides of the jet; the pressure value of the low - pressure eddy current region on one side is higher, which pushes the main jet to the other side and makes it adhere to the wall; based on Bernoulli's principle, the pressure reduction on the non - wall - adhering side causes a large amount of air flow to be entrained on this side. At the same time, the pulsating jet from the outlet of the non - feedback oscillation cavity 63 intermittently applies a fluctuating pressure through the feedback pipes on both sides of the main jet in the acoustic oscillation cavity 64. Coupled with the entrainment effect, the pressure on the wall - adhering side rises rapidly. After exceeding the non - wall - adhering side, it pushes the main jet over to form a new wall - adhering side. Thus, a half - cycle of switching is formed; similarly, on the new wall - adhering side, that is, the previous non - wall - adhering side, "entrainment - pushing - switching" occurs to complete the entire cycle of switching; such a cyclic periodic movement of "wall - attachment - entrainment - switching" enables the incoming main jet to flow out quickly and alternately along the two outlets, forming a high - frequency pulsed oscillating flow.

[0040] Step Seven: Based on the high - frequency pulsed oscillating flow formed in the acoustic oscillation cavity, the gas flows out from the outlet section 643 of the acoustic cavity and is successively connected to the microporous coiled pipe 7 and the aeration tank 8, thereby completing the application of the microporous bubble aeration two - stage oscillation modulation and efficiency - enhancing system.

[0041] In this embodiment, pressure data acquisition and analysis are carried out on the gas pipeline 5 downstream of the two - stage oscillation device 6. The pressure sensor is a current - type sensor of a certain brand. Connecting the data acquisition device can achieve pressure data acquisition at a maximum frequency of 1000 Hz. The Figure 8 following is the signal data diagram of the pressure sensor of the air flow pipeline downstream of the two - stage oscillation modulation element. It can be clearly seen that the outlet pressure of the element shows a fluctuating state, and the pulsation frequency is about 54.88 Hz.

[0042] Carry out a microporous bubble aeration experiment to verify whether the air flow modulated by the above - mentioned two - stage oscillation device 6 brings aeration efficiency improvement; according to Figure 1A micro-aeration simulation system was built. The air source was a certain brand of air compressor. The working pressure of the aeration system was 0.2 MPa, and the flow rate was 30 L / min. The porous aeration disk was a type 2 DN215 commercial aeration disk. The aeration tank 8 was a round barrel with a diameter of 0.6 m and a water depth of 0.8 m (the barrel height was 1.0 m). The aeration performance test was carried out in accordance with the CJ / T 475-2015 standard. Sodium sulfite and cobalt chloride were used to remove the dissolved oxygen in the water to be tested in the initial state, reducing it to less than 2.0 mg / L. Immediately afterwards, a comparative oxygenation experiment was carried out with and without using this technical equipment. The rising speed of the dissolved oxygen concentration in the water was used as an index to measure its mixing and mass transfer effect, and the improvement effect of the self-excited air flow modulation element of this patent on gas-liquid mixing and mass transfer was illustrated by comparison. The results are as Figure 9 and Figure 10 shown.

[0043] As Figure 9 shown, for the porous aeration disk 1, when this patent equipment was not used, the dissolved oxygen increased from 2.00 mg / L to 6.50 mg / L, which took a total of 3.77 minutes. After using this patent equipment, the corresponding time was 2.57 minutes. It can be calculated that the oxygenation time was shortened by 31.83%, and the KLa (dissolved oxygen transfer coefficient) increased by 45.50%. As Figure 10 shown, for the porous aeration disk 2, when this patent equipment was not used, the dissolved oxygen increased from 2.00 mg / L to 6.00 mg / L, which took a total of 6.50 minutes. After using this patent equipment, the corresponding time was 5.34 minutes. It can be calculated that the oxygenation time was shortened by 17.85%, and the KLa increased by 23.20%. The above data show that after using this equipment, the oxygenation efficiency has been greatly improved, which will greatly save the driving energy consumption of the pressurized air source.

[0044] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A microporous bubble aeration two-stage oscillation modulation efficiency enhancement system, characterized in that, It includes a two-stage oscillation device (6), a gas supply unit connected upstream of the two-stage oscillation device (6), and a microporous coiled pipe (7) and an aeration tank (8) connected downstream of the two-stage oscillation device (6); The two-stage oscillation device (6) includes an air inlet section (61), a branch section (62) connected to one side of the air inlet section (61), a non-feedback oscillation chamber (63) connected to the branch section (62), a sound wave oscillation chamber (64) connected in series with the air inlet section (61), a connecting chamber section (65) connected in parallel to the non-feedback oscillation chamber (63) and the sound wave oscillation chamber (64), and an air outlet section (66) connected in series to the outlet of the sound wave oscillation chamber (64); the air outlet section (66) is connected to the microporous coiled pipe (7) downstream; The non-feedback oscillation chamber (63) includes a non-feedback chamber air inlet section (631) connected in series to the branch section (62), a non-feedback chamber contraction pipe section (632) connected to the non-feedback chamber air inlet section (631), a non-feedback chamber double-port gas supply section (633) connected in series to the non-feedback chamber contraction pipe section (632), a counter-flow oscillation main chamber (634) connected to the non-feedback chamber double-port gas supply section (633), and a non-feedback chamber outlet diversion section (635) connected after the counter-flow oscillation main chamber (634); the non-feedback chamber outlet diversion section (635) is connected in parallel to the sound wave oscillation chamber (64) through the connecting chamber section (65).

2. The microporous bubble aeration two-stage oscillation modulation efficiency enhancement system according to claim 1, characterized in that, The gas supply unit includes a gas supply source (1) connected through a pipeline (5), a valve (2) installed on the pipeline (5) downstream of the gas supply source (1), a pressure regulating filter (3) installed downstream of the valve (2), and a flow meter (4) installed downstream of the pressure regulating filter (3); The two-stage oscillation device (6) is correspondingly installed on the pipeline (5) downstream of the flow meter (4).

3. The microporous bubble aeration two-stage oscillation modulation efficiency enhancement system according to claim 2, characterized in that, The air inlet section (61) is the main pipeline, and the main pipeline is connected in series to the pipeline (5) downstream of the flow meter (4); a branch section (62) is provided on one side of the main pipeline; the width or diameter of the branch section (62) is not greater than the width or diameter of the main pipeline; the flow rate of the branch section (62) accounts for 3% - 8% of the flow rate of the air inlet section (61).

4. The microporous bubble aeration two-stage oscillation modulation efficiency enhancement system according to claim 3, characterized in that, The non-feedback chamber air inlet section (631) is in a tapered shape, and the outlet width or diameter of the non-feedback chamber air inlet section (631) corresponds to the width or diameter of the non-feedback chamber contraction pipe section (632); the contraction angle of the non-feedback chamber air inlet section (631) with the horizontal line is between 12 and 17 degrees, and the inlet width is selected according to the standard thread diameter; The length of the non-feedback chamber air inlet section (631) is greater than or equal to 2 times the length of the non-feedback chamber contraction pipe section (632); the non-feedback chamber contraction pipe section (632) is a straight pipe, and its length is 3 - 4 times the width or diameter, and the width or diameter is 1 / 3 - 1 / 2 of the width or diameter at the inlet of the non-feedback chamber air inlet section (631).

5. The microporous bubble aeration two-stage oscillation modulation efficiency enhancement system according to claim 4, characterized in that, The non-feedback chamber double-port gas supply section (633) is divided into two parts from the non-feedback chamber contraction pipe section (632) in series and symmetrically enters the counter-flow oscillation main chamber (634); the non-feedback chamber double-port gas supply section (633) is divided into a straight section and an arc section on one side, the straight section is in a tapered setting, the arc section is in an equal-width or equal-diameter setting, and the width or diameter of the arc section corresponds to the width or diameter of the outlet of the straight section; In the double-port air supply section (633) of the non-feedback cavity, the distance from the vertex of the shunt wedge to the end of the contraction pipe section (632) of the non-feedback cavity is 4 to 8 times the width of the double-port air supply section (633) of the non-feedback cavity.

6. The microporous bubble aeration two-stage oscillation modulation efficiency enhancement system according to claim 5, characterized in that, The counter-jet oscillation main cavity (634) is in the shape of an elliptical box, and the angle between the double-port air supply section (633) connecting the counter-jet oscillation main cavity (634) and the horizontal line is 25° to 35°; O is the center of the oscillation cavity, H1 is the straight-line distance from the center of the oscillation cavity to the upstream cavity wall, H2 is the straight-line distance from the center of the oscillation cavity to the outlet of the downstream cavity, L0 is the distance between the inlets of the two double-port air supply sections (633) of the non-feedback cavity, L1 is the distance from the inlet of the double-port air supply section (633) of the non-feedback cavity to the center of the cavity, L2 is the distance of the outlet straight section, W1 is the width or diameter at the outlet of the arc section of the double-port air supply section (633) of the non-feedback cavity; W2 is the outlet width or diameter; The parameters are set as follows: H1 is 5 to 6 times W1, H2 is 4.0 to 4.5 times W1, L0 is 9 to 11 times W1, L1 is 6 to 8 times W1, L2 is 2.5 to 3.5 times W1, and W2 is 1.8 to 2.5 times W1; The non-feedback cavity outlet shunt section (635) is bifurcated into two parts in a V shape at the connection with the counter-jet oscillation main cavity (634); the angle O1 between the outer side of each outlet edge and the horizontal line is 18° to 25°, and the angle O2 between the inner side and the horizontal line is 12° to 19°; and the outlet on each side is arranged in a gradually expanding shape; The distance H3 from the bifurcation point at the connection to the outlet of the counter-jet oscillation main cavity (634) is 4 to 9 times W2, and the bifurcation point is smoothly set.

7. The microporous bubble aeration two-stage oscillation modulation efficiency enhancement system according to claim 6, characterized in that, The acoustic wave oscillation cavity (64) includes an acoustic wave cavity intake section (641) connected to the intake section (61), an acoustic wave oscillation feedback cavity (642) connected downstream of the acoustic wave cavity intake section (641), and an acoustic wave cavity outlet section (643) connected in sequence downstream of the acoustic wave oscillation feedback cavity (642); The acoustic wave cavity intake section (641) includes a gradually tapered contraction pipe and a throat pipe. The contraction angle β of the gradually tapered contraction pipe is 10° to 15°; the width or diameter of the throat pipe W3 is 9 to 12 times W1, and the length of the throat pipe is L3, and the length L3 is 3 to 4 times W3; The acoustic wave oscillation feedback cavity (642) is symmetrically shaped like a water droplet. The angle γ between the acoustic wave oscillation feedback cavities (642) on both sides of the acoustic wave cavity intake section (641) is 10° to 15°, and the width near the throat of the acoustic wave oscillation feedback cavity (642) is 0.5 to 0.9 times W3.

8. The microporous bubble aeration two-stage oscillation modulation efficiency enhancement system according to claim 7, characterized in that, The acoustic wave cavity outlet section (643) is arranged in the middle of the two acoustic wave oscillation feedback cavities (642) and the shunt wedge is divided into two outlet channels. The distance P between the two tips of the shunt wedge is 1.5 to 3 times W3. The distance H4 from the tip of the shunt wedge to the middle outlet of the acoustic wave oscillation feedback cavity (642) is 4 to 11 times the throat width W3, and the radius of the shunt wedge is 0.1 to 2 times W3; The angle O1 between the outer side of each side of the acoustic wave cavity outlet section (643) and the horizontal line is 18° to 25°, and the angle O2 between the inner side and the horizontal line is 12° to 19°.

9. The microporous bubble aeration two-stage oscillation modulation efficiency enhancement system according to claim 8, characterized in that, There are two connecting cavity sections (65). One connecting cavity section (65) connects one outlet side of the non-feedback cavity outlet shunt section (635) and one outlet side of the acoustic wave cavity outlet section (643); the other connecting cavity section (65) connects the other outlet side of the non-feedback cavity outlet shunt section (635) and the other outlet side of the acoustic wave cavity outlet section (643).

10. An application method of the microporous bubble aeration two-stage oscillation modulation efficiency enhancement system according to claim 9, characterized in that, The specific steps are as follows: Step 1: Supply air through the air supply source (1), and control the air flow velocity and flow rate through the valve (2) and the pressure regulating filter (3); then the air flow enters the intake section (61) of the double-stage oscillation device (6) through the pipeline (5). Step 2: The air flow is shunted from the intake section (61) to the branch section (62), and the air flow enters the non-feedback cavity intake section (631), passes through the non-feedback cavity contraction pipe section (632) and the non-feedback cavity double-port air supply section (633) and enters the counter-jet oscillation main cavity (634). Step 3: After the air flow enters the counter-jet oscillation main cavity (634), initially the main jet does not show an offset phenomenon, the flow field remains evenly distributed and flows out evenly from the two non-feedback cavity outlet shunt sections (635); then one of the two supply jets coming in from the two side inlets establishes a main connection with the outlet of the counter-jet oscillation main cavity (634) and jets out in the positive direction, and the other supply jet forms a vortex region inside the circular cavity of the counter-jet oscillation main cavity (634). Step 4: Due to the turbulence and entrainment effect of the jet itself, and affected by the shunt splitter, the previous equilibrium state is affected, and a pressure difference appears on both sides of the shunt splitter. When the pressure difference reaches a certain order of magnitude, the jet begins to tilt and deflect towards the lower side wall with lower pressure, and at the same time, a stable wall attachment phenomenon appears, and it flows out along the outlet pipe on this side at a speed higher than that of the other side wall. Step 5: Subsequently, since the vortex region inside the circular cavity is large enough and collides with the jet at the action point, the main connection between the jet and the circular cavity outlet is broken and a new vortex region is gradually formed inside the circular cavity, prompting the other supply jet to establish a main connection with the circular cavity outlet and jet out in the negative direction. At this time, due to the inherent turbulence and entrainment effect of the jet itself, a pressure difference relationship opposite to the previous one appears on both side walls of the shunt splitter, causing the jet to deflect towards the upper side wall and flow out along the outlet pipe on this side wall at a high speed, and one switching is completed; finally, due to the action of a different internal vortex region in the previous stage, the initial supply jet re-establishes a main connection with the circular cavity outlet, and the jet also correspondingly switches to attach to the lower side wall; the occurrence of oscillation stems from the interaction between the two jets in the circular cavity, and the continuation of oscillation stems from the periodic wall attachment switching behavior of the jet. Step Six: After the air flow in the intake section (61) enters the acoustic oscillation chamber (64), the boundary layer separation effect causes low-pressure eddy regions to form on both sides of the jet; the pressure value of the low-pressure eddy region on one side is higher, pushing the main jet to the other side and attaching it to the wall; the pressure reduction on the non-attached wall side causes a large amount of air flow to be entrained on this side. At the same time, the pulsating jet from the outlet of the non-feedback oscillation chamber (63) intermittently applies a fluctuating pressure through the feedback tubes on both sides of the main jet in the acoustic oscillation chamber (64). Coupled with the entrainment effect, the pressure on the attached wall side rises rapidly. After exceeding the non-attached wall side, the main jet is pushed back to form a new attached wall side, thus completing the switching of half a cycle; Similarly, on the new attached wall side, which was the previous non-attached wall side, "entrainment - push - switch" occurs to complete the switching of the entire cycle; such a cyclic "attachment - entrainment - switch" periodic motion causes the incoming main jet to flow out rapidly and alternately along the two outlets, forming a high-frequency pulsed oscillating flow; Step Seven: Based on the high-frequency pulsed oscillating flow formed in the acoustic oscillation chamber, the gas flows out from the outlet section (643) of the acoustic chamber and is successively connected to the microporous coiled pipe (7) and the aeration tank (8), thereby completing the application of the microporous bubbling aeration two-stage oscillation modulation efficiency enhancement system.

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