Gas self-excitation modulation device, enhanced pollution aeration treatment system and application method thereof

Abstract

The present invention discloses a gas self-excited modulation device, an enhanced pollution aeration treatment system and an application method thereof. Through the setting of the gas self-excited modulation device, an intermittent modulated airflow that matches the orifice bubble generation process is formed, the instantaneous pulse force of the bubble detaching upward is increased, the bubble generation time is shortened, the aeration bubble size is reduced, and the gas-liquid interface mass transfer rate is increased. The present application does not require the replacement of the existing aerators, does not require any modification of the aerator materials, and is widely applicable to any form of microporous aerators; does not require driving the water phase to flow, greatly saves energy consumption, and does not cause adverse disturbances to the target water body; compared with the dissolved air method and the jet air entrainment method, the present technology only drives the gas phase into the liquid phase, which can achieve full treatment of the target liquid while saving energy. In addition, batch applications can be carried out through the segmented setting of the oscillation cavity self-excited unit and the outflow unit.

Description

Technical Field

[0001] The invention relates to the technical field of environmental pollution treatment devices, and in particular to a gas self-excitation modulation device, an enhanced pollution aeration treatment system and an application method thereof. Background Art

[0002] Mixing, stirring, mass transfer and reaction at the water-gas interface are key processes widely involved in the fields of chemical industry, environmental protection, new energy, agriculture, medicine, etc. The gas from the pressurized gas source is transported through the pipeline and dispersed into bubbles through the microporous tube disc into the liquid phase. This is the most common form of gas-liquid interaction, often called the microporous gas diffusion mode, which is seen in industrial scenarios such as sewage aeration treatment, chemical reaction bubbling tower, carbon capture and absorption, aquaculture oxygenation, and mineral flotation. How to promote gas-liquid mixing, increase the gas content of the liquid phase, increase the gas-liquid interface area, and strengthen gas-liquid mass transfer has always been a research hotspot and a major demand for engineering practice in related fields. The improvement of the above performance indicators is of great significance for promoting oxygen mass transfer and aerobic biodegradation in sewage, increasing the output of gas-liquid reaction chemicals, increasing the oxygen concentration and aquaculture density in aquaculture ponds, and improving the efficiency of carbon dioxide absorption. The enhancement and efficiency of the gas-liquid interaction process in different industrial scenarios can generate huge economic value.

[0003] Under normal conditions, when gas enters the aeration tube disk through a pressurized pipeline, it is always difficult to generate sufficient turbulence and small-sized bubbles. The main problems are as follows: ① In practice, the micropore size of the aeration disk is uneven, and the aeration priority flow is always concentrated on the large orifice, while the small orifice does not flow out, resulting in larger bubble size; ② Bubble aggregation under different situations such as bubble wake influence, bubble collision, and bubble chain makes the final bubble size larger; ③ The orifice bubble generation process is constrained by downward viscous resistance, surface tension, etc. Only when the bubble volume increases to a certain extent can it break away from the orifice neck under the action of buoyancy, which results in the conventional orifice bubble diameter being dozens of times the orifice diameter.

[0004] In order to generate smaller bubbles, people have made many attempts to improve the microporous aeration technology, hoping to reduce the bubble size, improve aeration efficiency, and save energy. At present, most of the methods for regulating the size of microporous aeration bubbles are based on the fact that the formation process of orifice bubbles is mainly affected by factors such as gas flow, orifice size, and wettability of the contact plate. Among them, the most widely used control methods are precision machining of the aeration disk to reduce the micropore diameter, improving the wettability of the aeration disk, and using swirl shear aeration. These methods are not suitable for large-scale application in actual engineering. Therefore, it is of great practical significance to develop new energy-saving and consumption-reducing microporous diffuser system gas-liquid interface mass transfer reaction intensification technology from the perspective of gas-liquid mixing and fine bubble generation. Summary of the invention

[0005] The invention provides a gas self-excitation modulation device, an enhanced pollution aeration treatment system and an application method thereof, which are used to solve technical problems such as the degree of self-excitation turbulence of gas, improving the turbulence intensity at the intersection of gas and liquid phases and reducing the size of bubbles.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] The gas self-excitation modulation device comprises a microporous self-excitation modulation component housing and a microporous self-excitation modulation channel arranged inside the microporous self-excitation modulation component housing;

[0008] The micropore self-excitation modulation channel is an integral channel, which is divided into an access unit, an acceleration unit, a reflux self-excitation unit, an oscillation cavity self-excitation unit and an outflow unit based on the gas flow direction;

[0009] The access unit includes a gas access section;

[0010] The acceleration unit comprises a rectifying section connected in series with the gas access section and an accelerating section connected downstream of the rectifying section;

[0011] The reflux self-excitation unit comprises a reflux inlet nozzle section dockingly connected to the acceleration section, a reflux oscillation cavity wall connected to the downstream of the reflux inlet nozzle section, a reflux rectifier block arranged inside the reflux oscillation cavity wall, a reflux oscillation core area arranged between the reflux rectifier blocks, and a reflux diversion area and a reflux branch guide section connected to the downstream of the reflux oscillation cavity wall;

[0012] The oscillation cavity self-excitation unit comprises an oscillation cavity inlet acceleration section connected to each reflux branch guide section, an oscillation cavity inlet nozzle section arranged corresponding to each oscillation cavity inlet acceleration section, a self-excited oscillation cavity arranged corresponding to each oscillation cavity inlet nozzle section, an oscillation cavity collision wall arranged corresponding to each self-excited oscillation cavity, and an oscillation cavity outlet nozzle arranged corresponding to each oscillation cavity collision wall.

[0013] The outflow unit comprises an air outlet section connected to each outlet nozzle of the oscillation chamber.

[0014] Furthermore, the rectifying section is a linear channel, the length of the rectifying section is 3-4 times of the width, and the rectifying section corresponds to a stable airflow setting;

[0015] The acceleration section is a tapered channel, and the cross-sectional area of ​​the flow section of the tapered channel is smaller than the cross-sectional area of ​​the flow section of the rectifying section; the angle between the wall of the acceleration section and the center line of the flow channel is 12°~15°.

[0016] Furthermore, the length of the reflux inlet nozzle section is 2-3 times of its width, and the gas flow rate in the reflux inlet nozzle section is 0.05-0.25 Mach; the reflux outlet nozzle section is a concave wall-attached arc surface, in which the arc segment radius is equal to the length of the core area, and is arranged downstream corresponding to the airflow sweeping flow; the airflow in the reflux diversion area is diverted to several reflux branch guide sections.

[0017] Furthermore, the wall of the reflux oscillation cavity includes a gradually expanding wall, a straight wall connected to the gradually expanding wall, and a rear hook wall; the wall of the reflux oscillation cavity encloses a gas reflux oscillation area and forms a feedback channel with the side adjacent to the rectifier block.

[0018] Furthermore, the reflux oscillation core area is a gradually expanding trumpet-shaped area enclosed by one side of the rectifier block, the gradually expanding trumpet-shaped area is the area where fluid reflux feedback occurs, and the length-to-width ratio of the reflux oscillation core area is 2:3; the reflux oscillation core area and the feedback channel are arranged in series at the upstream and downstream ports.

[0019] Furthermore, the cross-sectional area of ​​the flow section of the acceleration section at the entrance of the oscillation cavity is smaller than the cross-sectional area of ​​the flow section of the return branch guide section, and the angle between the wall surface of the acceleration section at the entrance of the oscillation cavity and the center line of the flow channel is 12°~15°;

[0020] The width of the inlet nozzle section of the oscillation cavity is 1.1 times the width of the inlet nozzle; in the inlet nozzle section, the length of the outlet nozzle of the oscillation cavity is 2-3 times the width.

[0021] Furthermore, the channel width of the self-excited oscillation cavity is 7 to 10 times the width of the nozzle section at the inlet of the oscillation cavity, and the length of the oscillation cavity is 5 to 7 times the width of the nozzle section at the inlet of the oscillation cavity; and a rear hook-type oscillation cavity collision wall is provided at the downstream end of the self-excited oscillation cavity.

[0022] Furthermore, the depth-to-width ratio of the gas outflow section channel is between 1:1 and 8:1; and a pressure sensor is installed at the outlet, and the pressure sensor is connected to the data analysis terminal.

[0023] Further, the pollution aeration treatment system is strengthened, comprising an air supply source, a switch valve connected downstream of the air supply source, a pressure regulating filter device connected downstream of the switch valve, a flow meter connected downstream of the pressure regulating filter device, a gas self-excitation modulation device connected downstream of the flow meter, a microporous aeration disk connected downstream of the gas self-excitation modulation device, and a gas-liquid reaction tank equipped with the microporous aeration disk;

[0024] The gas supply source, the switch valve, the pressure regulating and filtering device, the flow meter, the gas self-excitation modulation device and the microporous aeration plate are connected in series through pipelines; wherein the microporous aeration plate is arranged at the bottom of the gas-liquid reaction tank.

[0025] Further, the application method of the enhanced pollution aeration treatment system is as follows:

[0026] Step 1: Determine the number and size of the gas-liquid reaction pools based on the type and volume of the pollutants to be treated; thereby determine the initial flow rate and volume of the gas supply source, and the number of gas outlet sections in the gas self-excitation modulation device;

[0027] Step 2: Connect the switch valve, the pressure regulating filter device, the flow meter, the gas self-excitation modulation device and the microporous aeration disk in sequence through the pipeline at the downstream of the gas supply source;

[0028] Step 3: After the gas passes through the switch valve, the pressure regulating filter device and the flow meter, it forms a state of stable pressure and flow rate; in this state, it enters the gas self-excitation modulation device;

[0029] Step 4: In the gas self-excitation modulation device, the gas flows through the access section, the rectifying section and the accelerating section, and enters the reflow oscillation core area from the reflow inlet nozzle section. Under the Coanda effect of the fluid, the main jet flows randomly attached to a certain side wall. Based on the flow limiting effect of the reflow outlet nozzle section, part of the fluid enters the feedback channel and refluxes to the control throat, and then fills the area inside the reflow rectifying block in the reflow oscillation core area to form a separation bubble.

[0030] Step 5: The increase of the separation bubble pushes the main jet toward the other side wall and the feedback channel, and the cycle repeats, thereby forming a periodic oscillating jet with a substantially constant jet velocity and a sweeping and swinging jet direction within a designed angle range at the reflux outlet nozzle section;

[0031] Step 6, the oscillating jet flows out in a sweeping manner, passes through the reflux diversion area, the reflux branch guide section, the oscillation cavity inlet acceleration section and the oscillation cavity inlet nozzle section, and enters the self-excited oscillation cavity. When the oscillation cavity inlet nozzle section flows downstream, a series of discrete vortex rings are formed under the fluid shear layer effect. When it reaches the oscillation cavity collision wall and interacts with it, a pressure shock wave is generated in the self-excited oscillation cavity. The wave propagates upstream at the speed of sound, which in turn disturbs the edge shear layer of the main jet, forming a positive feedback, inducing new vortex pulsation, strengthening the vortex flow inside the oscillation cavity, and cutting off the continuous jet to form a self-oscillating jet. Finally, the airflow in the entire channel presents an airflow pulsation state and flows out from the air outlet section.

[0032] Step 7: The pulsating airflow enters the microporous aeration plate, and then forms microbubbles that enter the gas-liquid reaction tank to increase the rate of increase of dissolved oxygen concentration in the water, thereby strengthening the mass transfer and reaction at the water-gas two-phase interface, and then accelerating the removal of pollutants.

[0033] The beneficial effects of the present invention are embodied in:

[0034] The present invention forms an intermittent modulated airflow that matches the orifice bubble generation process through the setting of a gas self-excitation modulation device, increases the instantaneous pulse force of the bubble to detach upward, shortens the bubble generation time, reduces the size of the aeration bubble, and thus improves the gas-liquid interface mass transfer rate; in addition, the self-excitation is generated through the reflux self-excitation unit and the oscillation cavity self-excitation unit, which not only facilitates the generation and strengthening of turbulence, but also ensures the reduction of the size of the bubble; the turbulence of the gas-liquid system is enhanced, the gas-liquid mixing is more complete, and the stirring effect is better; the smaller the bubble, the slower the rising speed, the longer the liquid phase retention-contact time, and the more complete the reaction. The smaller the bubble, the larger the specific surface area, the higher the internal partial pressure, and the faster the mass transfer rate. In addition, batch applications can be carried out through the segmented setting of the oscillation cavity self-excitation unit and the outflow unit.

[0035] This application does not require replacement of the existing aerators, does not require any modification of the aerator materials, and is widely applicable to any form of microporous aerators; it does not require driving the water phase to flow, greatly saving energy consumption, and does not cause adverse disturbances to the target water body; compared with the dissolved air method and the jet air entrainment method, this technology only drives the gas phase into the liquid phase, which saves energy while achieving full treatment of the target liquid. This technology is based on the control of bubble growth, expansion, and detachment behavior, and proposes a self-excited control method for the intake gas, which can achieve a reduction in the size of bubble generation and generate a fully turbulent flow field, thereby increasing the mass transfer reaction rate at the gas-liquid interface.

[0036] Other features and advantages of the present invention will be set forth in the following description, and in part will become apparent from the description, or may be understood by practicing the present invention; the main purpose and other advantages of the present invention may be realized and obtained through the solutions particularly pointed out in the description. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the connection of the enhanced pollution aeration treatment system and the decomposition of the gas self-excitation modulation device;

[0038] Figure 2 It is a schematic diagram of the micropore self-excited modulation channel;

[0039] Figure 3 It is a schematic diagram of the signal data of the pressure sensor of the air outlet section;

[0040] Figure 4 is the comparison of oxygenation rate of microporous aeration disk 1 when using / not using this technology;

[0041] Figure 5 The figure is a comparison of the oxygenation rate of the microporous aeration disk 2 when using and not using this technology.

[0042] Figure markings: 1-gas self-excited modulation device, 11-micropore self-excited modulation component shell, 12-micropore self-excited modulation channel, a-access unit, a1-gas access section, b-acceleration unit, b1-rectifier section, b2-acceleration section, c-reflux self-excited unit, c1-reflux inlet nozzle section, c2-reflux oscillation chamber wall, c3-reflux rectifier block, c4-reflux oscillation core area, c5-reflux outlet nozzle section, c6-reflux diversion area, c7-reflux branch guide section, d-oscillation chamber self-excited unit, d1-oscillation chamber inlet acceleration section, d2-oscillation chamber inlet nozzle section, d3-self-excited oscillation chamber, d4-oscillation chamber collision wall, d5-oscillation chamber outlet nozzle, e-outflow unit, e1-gas outlet section, 2-gas supply source, 3-switch valve, 4-pressure regulating and filtering device, 5-flow meter, 6-micropore aeration disk, 7-gas-liquid reaction tank, 8-pipeline. DETAILED DESCRIPTION

[0043] Take sewage treatment as an example. Figure 1 The enhanced pollution aeration treatment system is constructed as shown, and the enhanced pollution aeration treatment system comprises an air supply source 2, a switch valve 3 connected to the downstream of the air supply source 2, a pressure regulating filter device 4 connected to the downstream of the switch valve 3, a flow meter 5 connected to the downstream of the pressure regulating filter device 4, a gas self-excitation modulation device 1 connected to the downstream of the flow meter 5, a microporous aeration disk 6 connected to the downstream of the gas self-excitation modulation device 1, and a gas-liquid reaction tank 7 with the microporous aeration disk 6 installed. The air supply source 2, the switch valve 3, the pressure regulating filter device 4, the flow meter 5, the gas self-excitation modulation device 1 and the microporous aeration disk 6 are connected in series through a pipeline 8; wherein the microporous aeration disk 6 is arranged at the bottom of the gas-liquid reaction tank 7.

[0044] Among them, Figure 1 and Figure 2 The gas self-excitation modulation device 1 shown comprises a microporous self-excitation modulation component housing 11 and a microporous self-excitation modulation channel 12 arranged inside the microporous self-excitation modulation component housing 11; the microporous self-excitation modulation channel 12 is an integral channel, which is divided into an access unit a, an acceleration unit b, a reflux self-excitation unit c, an oscillation cavity self-excitation unit d and an outflow unit e in sequence based on the gas flow direction. Among them, the access unit a comprises a gas access section a1.

[0045] The acceleration unit b comprises a rectifying section b1 connected in series with the gas access section a1 and an accelerating section b2 connected downstream of the rectifying section b1. The rectifying section b1 is a linear channel, the length of the rectifying section b1 is 3-4 times the width, and the rectifying section b1 corresponds to a stable airflow setting; the accelerating section b2 is a tapered channel, and the cross-sectional area of ​​the flow section of the tapered channel is smaller than the cross-sectional area of ​​the flow section of the rectifying section b1; the angle between the wall of the accelerating section b2 and the center line of the flow channel is 12°~15°.

[0046] In this embodiment, the reflux self-excitation unit c includes a reflux inlet nozzle section c1 docked with the acceleration section b2, a reflux oscillation chamber wall c2 connected to the downstream of the reflux inlet nozzle section c1, a reflux rectifier block c3 arranged inside the reflux oscillation chamber wall c2, a reflux oscillation core area c4 arranged between the reflux rectifier blocks c3, and a reflux diversion area c6 and a reflux branch guide section c7 connected to the downstream of the reflux oscillation chamber wall c2.

[0047] In this embodiment, the length of the reflux inlet nozzle section c1 is 2-3 times of its width, and the gas flow rate in the reflux inlet nozzle section c1 is 0.05-0.25 Mach; the reflux outlet nozzle section c5 is a concave wall-attached arc surface, in which the arc radius is equal to the length of the core area, and is set to flow downstream in a corresponding airflow sweeping manner; the airflow in the reflux diversion area c6 is diverted to several reflux branch guide sections c7.

[0048] In this embodiment, the reflux oscillation cavity wall surface c2 includes a gradually expanding segment wall surface, a straight segment wall surface connected to the gradually expanding segment wall surface, and a rear hook segment wall surface; the reflux oscillation cavity wall surface c2 encloses a gas reflux oscillation area and forms a feedback channel with the side adjacent to the rectifier block.

[0049] In this embodiment, the reflux oscillation core area c4 is a gradually expanding trumpet-shaped area enclosed by one side of the rectifier block. The gradually expanding trumpet-shaped area is the area where fluid reflux feedback occurs. The length-to-width ratio of the reflux oscillation core area c4 is 2:3; the reflux oscillation core area c4 and the feedback channel are arranged in series at the upstream and downstream ports.

[0050] In this embodiment, the oscillation cavity self-excitation unit d includes an oscillation cavity inlet acceleration section d1 connected to each return branch guide section c7, an oscillation cavity inlet nozzle section d2 arranged corresponding to each oscillation cavity inlet acceleration section d1, a self-excited oscillation cavity d3 arranged corresponding to each oscillation cavity inlet nozzle section d2, an oscillation cavity collision wall d4 arranged corresponding to each self-excited oscillation cavity d3, and an oscillation cavity outlet nozzle d5 arranged corresponding to each oscillation cavity collision wall d4.

[0051] In this embodiment, the flow cross-sectional area of ​​the acceleration section d1 at the oscillation cavity inlet is smaller than the flow cross-sectional area of ​​the return branch guide section c7, and the angle between the wall surface of the acceleration section d1 at the oscillation cavity inlet and the center line of the flow channel is 12°~15°; the width of the nozzle section d2 at the oscillation cavity inlet is 1.1 times the width of the inlet nozzle; in the inlet nozzle section, the length of the oscillation cavity outlet nozzle d5 is 2-3 times the width.

[0052] The channel width of the self-excited oscillation cavity d3 is 7 to 10 times the width of the oscillation cavity inlet nozzle section d2, and the oscillation cavity length is 5 to 7 times the width of the oscillation cavity inlet nozzle section d2; the self-excited oscillation cavity d3 is provided with a rear hook type oscillation cavity collision wall d4 at the downstream end.

[0053] In this embodiment, the outflow unit e comprises an outlet section e1 connected to each oscillation cavity outlet nozzle d5. The depth-to-width ratio of the gas outflow section channel is between 1:1 and 8:1; and a pressure sensor is installed at the outlet, and the pressure sensor is connected to the data analysis terminal.

[0054] Combination Figures 1 to 5 , further explain the application method of enhanced pollution aeration treatment system, the specific steps are as follows:

[0055] Step 1: Determine the number and size of the gas-liquid reaction pools 7 based on the type and volume of the pollutants to be treated; thereby determine the initial flow rate and volume of the gas supply source 2, and the number of gas outlet sections e1 in the gas self-excitation modulation device 1.

[0056] Step 2: Connect the switch valve 3, the pressure regulating and filtering device 4, the flow meter 5, the gas self-excitation modulation device 1 and the microporous aeration disk 6 in sequence through the pipeline 8 at the downstream of the gas supply source 2.

[0057] Gas supply source 2 is generally a pressure gas tank or fan, and the pressure is required to overcome the liquid back pressure of the terminal gas-liquid reaction unit, along the process and local pressure loss, and consider the system exposure and pressure safety, generally between 0.5 bar and 0.8 bar. Gas supply source 2 should have independent supporting leakage detection and safety valve control opening and closing.

[0058] Generally, filter dehydration components are installed to remove moisture and particulate impurities in the intake air to avoid damage to the equipment and subsequent gas-liquid mixing units. Pressure stabilizing components are installed to stabilize the system intake pressure, provide sufficient aeration power, and maintain stable operation of the system. Considering the system aeration and pressure safety, it is generally between 0.3 bar and 1 bar. The selection of flow meter 5 shall be based on the actual flow range requirements, and the working flow should be between 1 / 3 and 2 / 3 of the range.

[0059] The self-excited airflow modulation and diffusion element is the core of this patent and is made of stainless steel, galvanized sheet or other rigid materials. Figure 1 As shown, the self-excited airflow modulation and diffusion element is a rectangular parallelepiped as a whole, with a main air inlet arranged on the left side and several air outlets on the right end.

[0060] This patent is only for the modulation of orifice bubbles. Therefore, the effective diffuser must have a microporous structure, and the gas can grow and detach through the micropores. The material is not limited, and it is widely applicable to corundum, ceramic, silicone rubber aeration tubes, and microporous membranes. Considering the airflow modulation effect, the micropore diameter is generally required to be less than 1~2 mm.

[0061] Step 3: After the gas passes through the switch valve 3, the pressure regulating filter device 4 and the flow meter 5, a state of stable pressure and flow rate is formed; in this state, the gas enters the gas self-excitation modulation device 1.

[0062] Step 4: In the gas self-excitation modulation device 1, the gas flows through the access section, the rectifying section b1 and the accelerating section b2, and enters the reflux oscillation core area c4 from the reflux inlet nozzle section c1. Under the Coanda effect of the fluid, the main jet flows randomly attached to a certain side wall. Based on the flow limiting effect of the reflux outlet nozzle section c5, part of the fluid enters the feedback channel and refluxes to the control throat, and then fills the area inside the reflux rectifying block c3 in the reflux oscillation core area c4 to form a separation bubble.

[0063] Step 5: The increase of the separation bubble pushes the main jet to the other side wall and the feedback channel, over and over again, thereby forming a periodic oscillating jet with a basically constant jet velocity and a sweeping and oscillating jet direction within the designed angle range at the reflux outlet nozzle section c5.

[0064] Step six, the oscillating jet sweeps out, passes through the reflux diversion area c6, the reflux branch guide section c7, the oscillation cavity inlet acceleration section d1 and the oscillation cavity inlet nozzle section d2, and enters the self-excited oscillation cavity d3. When the oscillation cavity inlet nozzle section d2 flows downstream, a series of discrete vortex rings are formed under the fluid shear layer effect. When it reaches the oscillation cavity collision wall d4 and interacts with it, a pressure shock wave is generated in the self-excited oscillation cavity d3. The wave propagates upstream at the speed of sound, which in turn disturbs the edge shear layer of the main jet, forming a positive feedback, inducing new vortex pulsation, strengthening the vortex flow inside the oscillation cavity, and cutting off the continuous jet to form a self-oscillating jet. Finally, the airflow in the entire channel presents an airflow pulsation state and flows out from the air outlet section e1.

[0065] Step 7: The pulsating airflow enters the microporous aeration disk 6, and then forms microbubbles that enter the gas-liquid reaction tank 7 to increase the rising speed of the dissolved oxygen concentration in the water, thereby strengthening the mass transfer and reaction at the water-gas two-phase interface, and further accelerating the removal of pollutants.

[0066] Figure 3 This is a schematic diagram of the signal data of the pressure sensor in the outlet section e1. It can be clearly seen that the outlet pressure of the component is fluctuating, and the pulsation frequency is about 22.5Hz.

[0067] according to Figure 1 The enhanced pollution aeration treatment system is shown in the figure. An air compressor is used to supply air flow 1VVM to the water at a constant pressure of 1 bar. The microporous medium is two commercial oxygenated porous discs made of silicone rubber and corundum. Sodium sulfite is used to consume the dissolved oxygen in the water in the initial state to reduce it to below 2.0 mg / L, and then a comparative oxygenation experiment with and without this technology is started. The rising speed of dissolved oxygen concentration in water is used as an indicator to measure its mixing and mass transfer effect. The improvement effect of the self-excited airflow modulation device of this patent on gas-liquid mixing and mass transfer is explained by comparison.

[0068] The comparison of oxygenation rate of microporous aeration plate 61 when using / not using this technology is as follows: Figure 4 As shown in the figure, when this technology is not used, it takes 6.16 minutes for the dissolved oxygen to increase from 2.00 mg / L to 6.00 mg / L. After using this technology, the corresponding time is 5.16 minutes. Calculation shows that the oxygenation time is shortened by 16.23%. Comparison of oxygenation rate of microporous aeration plate 62 when using and not using this technology Figure 5 As shown in the figure, when this technology is not used, the dissolved oxygen increases from 2.00mg / L to 6.00mg / L, which takes a total of 6.96 minutes. After using this technology, the corresponding time is 5.08 minutes. Calculation shows that the oxygenation time is shortened by 27.01%. The above data shows that after using this equipment, the oxygenation efficiency is greatly improved, which will greatly save the driving energy consumption of the pressurized gas source.

[0069] In summary, this patented technical equipment can effectively enhance the mass transfer and reaction at the water-gas two-phase interface, and is applied to the fields of chemical gas-liquid reaction, volatile substance separation, water aeration and reoxygenation, etc. Compared with the steady-state gas-liquid reaction system, the mass transfer enhancement effect caused by the interface turbulence can reach several times to dozens of times. At the same time, if the diameter of a bubble is 1 / 3 of that of another bubble, its gas-liquid reaction time is extended by 10 times, and the gas-liquid mass transfer coefficient KLa can be increased several times. Therefore, seeking technical methods that adapt to the microporous gas diffusion system mode, create a gas-liquid turbulent scene, reduce the bubble size, and enhance the gas-liquid interface mass transfer reaction has become a major practical need in the field. This technology can increase the turbulence intensity of the water-gas two-phase system, making the generated bubbles smaller in size. It is applicable in the following fields: environmental protection: aeration biological treatment of sewage and wastewater, deep treatment of ozone oxidation, aeration remediation of groundwater pollution; food processing: ozone aeration disinfection; chemical industry: bubbling reaction, aeration stripping reaction; new energy field: carbon dioxide capture and absorption, liquid phase hydrogenation reaction; agricultural field: aeration aeration for aquaculture, carbon dioxide hydroponic planting; mining industry: aeration flotation, particle flotation.

[0070] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that a technician familiar with the technical field can think of within the technical scope disclosed in the present invention should be covered within the protection scope of the present invention.

Claims

1. A gas self-excitation modulation device, characterized in that: It comprises a micropore self-excitation modulation component housing (11) and a micropore self-excitation modulation channel (12) arranged inside the micropore self-excitation modulation component housing (11); The micropore self-excitation modulation channel (12) is an integral channel, which is divided into an access unit (a), an acceleration unit (b), a reflux self-excitation unit (c), an oscillation cavity self-excitation unit (d) and an outflow unit (e) in sequence based on the gas flow direction; The access unit (a) comprises a gas access section (a1); The acceleration unit (b) comprises a rectifying section (b1) connected in series with the gas access section (a1) and an accelerating section (b2) connected downstream of the rectifying section (b1); The reflux self-excitation unit (c) comprises a reflux inlet nozzle section (c1) docked with the acceleration section (b2), a reflux oscillation cavity wall (c2) connected to the downstream of the reflux inlet nozzle section (c1), a reflux rectifier block (c3) arranged inside the reflux oscillation cavity wall (c2), a reflux oscillation core area (c4) arranged between the reflux rectifier blocks (c3), and a reflux diversion area (c6) and a reflux branch guide section (c7) connected to the downstream of the reflux oscillation cavity wall (c2); The wall surface (c2) of the reflux oscillation cavity includes a gradually expanding wall surface, a straight wall surface connected to the gradually expanding wall surface, and a rear hook wall surface; the wall surface (c2) of the reflux oscillation cavity encloses a gas reflux oscillation region and forms a feedback channel with a side adjacent to the rectifier block; The reflux outlet nozzle section (c5) is a concave wall-attached arc surface, wherein the arc section radius is equal to the length of the reflux oscillation core area (c4), and is arranged downstream corresponding to the airflow sweeping flow direction; the airflow in the reflux diversion area (c6) is diverted to a plurality of reflux branch guide sections (c7); The reflux oscillation core area (c4) is a gradually expanding trumpet-shaped area enclosed by one side of the rectifier block, and the gradually expanding trumpet-shaped area is the occurrence area of ​​fluid reflux feedback; the reflux oscillation core area (c4) and the feedback channel are arranged in series at the upstream port and the downstream port; the oscillation cavity self-excitation unit (d) comprises an oscillation cavity inlet acceleration section (d1) connected to each reflux branch guide section (c7), an oscillation cavity inlet nozzle section (d2) arranged corresponding to each oscillation cavity inlet acceleration section (d1), a self-excited oscillation cavity (d3) arranged corresponding to each oscillation cavity inlet nozzle section (d2), an oscillation cavity collision wall surface (d4) arranged corresponding to each self-excited oscillation cavity (d3), and an oscillation cavity outlet nozzle (d5) arranged corresponding to each oscillation cavity collision wall surface (d4); The outflow unit (e) comprises an air outlet section (e1) connected to each oscillation chamber outlet nozzle (d5).

2. The gas self-excitation modulation device according to claim 1, characterized in that: The rectifying section (b1) is a linear channel, the length of the rectifying section (b1) is 3-4 times the width, and the rectifying section (b1) corresponds to a stable airflow setting; The acceleration section (b2) is a tapered channel, and the cross-sectional area of ​​the flow passage of the tapered channel is smaller than the cross-sectional area of ​​the flow passage of the rectifying section (b1); the angle between the wall of the acceleration section (b2) and the center line of the flow passage is 12°~15°.

3. The gas self-excitation modulation device according to claim 1, characterized in that: The length of the reflux inlet nozzle section (c1) is 2-3 times of its width, and the gas flow rate in the reflux inlet nozzle section (c1) is 0.05-0.25 Mach.

4. The gas self-excitation modulation device according to claim 1, characterized in that: The length-to-width ratio of the reflux oscillation core region (c4) is 2:

3.

5. The gas self-excitation modulation device according to claim 1, characterized in that: The cross-sectional area of ​​the flow section of the acceleration section (d1) at the entrance of the oscillation cavity is smaller than the cross-sectional area of ​​the flow section of the return branch guide section (c7), and the angle between the wall surface of the acceleration section (d1) at the entrance of the oscillation cavity and the center line of the flow channel is 12°~15°; The width of the inlet nozzle section (d2) of the oscillation cavity is 1.1 times the width of the inlet nozzle; the length of the inlet nozzle section, the outlet nozzle (d5) of the oscillation cavity is 2-3 times the width.

6. The gas self-excitation modulation device according to claim 1, characterized in that: The channel width of the self-excited oscillation cavity (d3) is 7 to 10 times the width of the oscillation cavity inlet nozzle section (d2), and the oscillation cavity length is 5 to 7 times the width of the oscillation cavity inlet nozzle section (d2); the self-excited oscillation cavity (d3) is provided with a rear hook type oscillation cavity collision wall (d4) at the downstream end.

7. The gas self-excitation modulation device according to claim 1, characterized in that: The depth-to-width ratio of the gas outflow section channel is between 1:1 and 8:1; and a pressure sensor is installed at the outlet, and the pressure sensor is connected to the data analysis terminal.

8. An enhanced pollution aeration treatment system comprising the self-excited modulation device according to any one of claims 1 to 7, characterized in that: It comprises a gas supply source (2), a switch valve (3) connected downstream of the gas supply source (2), a pressure regulating filter device (4) connected downstream of the switch valve (3), a flow meter (5) connected downstream of the pressure regulating filter device (4), a gas self-excitation modulation device (1) connected downstream of the flow meter (5), a microporous aeration disk (6) connected downstream of the gas self-excitation modulation device (1), and a gas-liquid reaction tank (7) on which the microporous aeration disk (6) is installed; The gas supply source (2), the switch valve (3), the pressure regulating and filtering device (4), the flow meter (5), the gas self-excitation modulation device (1) and the microporous aeration disk (6) are connected in series via a pipeline (8); wherein the microporous aeration disk (6) is arranged at the bottom of the gas-liquid reaction tank (7).

9. An application method of the enhanced pollution aeration treatment system according to claim 8, characterized in that: The specific steps are as follows: Step 1: Based on the type and volume of the pollutants to be treated, determine the number and size of the gas-liquid reaction pools (7); thereby determining the initial flow rate and volume of the gas supply source (2), and the number of gas outlet sections (e1) in the gas self-excitation modulation device (1); Step 2: Connect the switch valve (3), the pressure regulating filter device (4), the flow meter (5), the gas self-excitation modulation device (1) and the microporous aeration disk (6) in sequence through the pipeline (8) downstream of the gas supply source (2); Step 3: After the gas passes through the switch valve (3), the pressure regulating and filtering device (4) and the flow meter (5), a state of stable pressure and flow rate is formed; in this state, the gas enters the gas self-excitation modulation device (1); Step 4: In the gas self-excitation modulation device (1), the gas flows through the access section, the rectifying section (b1) and the accelerating section (b2), and enters the reflow oscillation core area (c4) from the reflow inlet nozzle section (c1). Under the Coanda effect of the fluid, the main jet flows randomly attached to a certain side wall. Based on the flow limiting effect of the reflow outlet nozzle section (c5), part of the fluid enters the feedback channel and flows back to the control throat, and then fills the area inside the reflow rectifying block (c3) in the reflow oscillation core area (c4), forming a separation bubble; Step 5: The increase of the separation bubble pushes the main jet toward the other side wall and the feedback channel, and the process repeats over and over again, thereby forming a periodic oscillating jet at the reflux outlet nozzle section (c5) with a substantially constant jet velocity and a sweeping and oscillating jet direction within a designed angle range; Step 6, the oscillating jet flows out in a sweeping manner, passes through the reflux diversion area (c6), the reflux branch guide section (c7), the oscillation chamber inlet acceleration section (d1) and the oscillation chamber inlet nozzle section (d2), and enters the self-excited oscillation chamber (d3). When the oscillation chamber inlet nozzle section (d2) flows downstream, a series of discrete vortex rings are formed under the fluid shear layer effect. When it reaches the oscillation chamber collision wall (d4) and interacts with it, a pressure shock wave is generated in the self-excited oscillation chamber (d3). The wave propagates upstream at the speed of sound, in turn disturbing the edge shear layer of the main jet, forming a positive feedback, inducing new vortex pulsation, strengthening the vortex flow inside the oscillation chamber, cutting off the continuous jet to form a self-oscillating jet, and finally the airflow in the entire channel presents an airflow pulsation state and flows out from the air outlet section (e1); Step 7: The pulsating airflow enters the microporous aeration disk (6), and then forms microbubbles that enter the gas-liquid reaction tank (7) to increase the rate of increase of dissolved oxygen concentration in the water, thereby strengthening the mass transfer and reaction at the water-gas two-phase interface, and further accelerating the removal of pollutants.

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