Microbubble generation device and method for strengthening ozone mass transfer

Abstract

The invention provides a microbubble generating device and method for strengthening ozone mass transfer, and relates to the technical field of water treatment.The microbubble generating device comprises a pipe body, a porous medium assembly, an impeller and a driver, the pipe body comprises a first section, a middle section and a second section which are communicated in sequence, and the end, away from the middle section, of the first section is suitable for being connected with an ozone source and a water source to be treated; an inner cavity of the first section is constructed to be a Venturi inner cavity so that a gas-liquid mixture formed by ozone and water to be treated can be crushed into bubbles, and the end, away from the middle section, of the second section is suitable for being communicated with the external environment; the porous medium assembly is arranged in an inner cavity of the middle section to divide the bubbles; the impeller is rotatably connected with the inner cavity of the second section, and the driver is in transmission connection with the impeller so that the impeller can shear the bubbles. Small-diameter microbubbles can be generated in a multi-stage shearing mode, so that the gas-liquid contact area is increased, and the mass transfer efficiency of ozone in water is enhanced.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, and in particular to a microbubble generator and method for enhancing ozone mass transfer. Background Technology

[0002] Ozone, as a strong oxidant, has the advantages of strong oxidizing power and no secondary pollution after reaction (i.e., the decomposition product is oxygen), and is widely used in the field of water treatment. The reaction efficiency of ozone with water depends on the mass transfer efficiency of ozone in water, that is, the rate at which ozone is transferred from the gas phase to the liquid phase. The mass transfer efficiency is mainly affected by factors such as bubble diameter, gas-liquid contact time, and gas-liquid mixing intensity.

[0003] Many related technologies employ a synergistic approach, combining ozone generators with microbubble generators such as aeration discs or jet aeration to improve ozone mass transfer efficiency in water. However, this approach presents the following problems in practical applications: 1. Large bubble diameter and small specific surface area: The bubbles generated by the aeration disc typically have a diameter of 1mm-5mm and a specific surface area of ​​only 300m². 2 / m 3 -1000m 2 / m 3 The limited gas-liquid contact area results in low mass transfer efficiency. 2. Bubbles have a short residence time in water. Large-diameter bubbles are strongly buoyed and rise quickly in water (about 0.3m / s-0.5m / s), with a residence time of only 0.5min-1min. Incompletely dissolved ozone is easily released, resulting in resource waste and pressure on exhaust gas treatment. 3. The device has a complex structure or high energy consumption. Although some microbubble generators can produce small-diameter bubbles, they have problems such as complex structure, high maintenance cost and high energy consumption, which makes it difficult to promote and apply them on a large scale. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, one embodiment of the present invention proposes a microbubble generator for enhancing ozone mass transfer. This microbubble generator can generate small-diameter microbubbles through multi-stage shearing to increase the gas-liquid contact area and enhance the mass transfer efficiency of ozone in water.

[0006] Another embodiment of the present invention provides a water treatment system.

[0007] Another aspect of the present invention provides a water treatment method.

[0008] According to an embodiment of the present invention, a microbubble generator for enhancing ozone mass transfer includes a tube body, a porous media assembly, an impeller, and a driver. The tube body includes a first section, a middle section, and a second section connected in sequence. The end of the first section opposite to the middle section is adapted to be connected to an ozone source and a water source to be treated. The inner cavity of the first section is constructed as a Venturi cavity to break the gas-liquid mixture formed by ozone and water to be treated into bubbles. The end of the second section opposite to the middle section is adapted to be connected to the external environment. The porous media assembly is disposed in the inner cavity of the middle section to divide the bubbles. The impeller is rotatably connected to the inner cavity of the second section, and the driver is drivenly connected to the impeller to shear the bubbles.

[0009] According to an embodiment of the present invention, a microbubble generator for enhancing ozone mass transfer involves introducing a gas-liquid mixture of ozone and water to be treated into a pipe. The mixture first enters the Venturi cavity of the first section. Utilizing the principle of "negative pressure generated by high-speed jet at the throat," the Venturi cavity further draws in insufficiently mixed ozone from the environment. Simultaneously, the flow rate difference initially breaks down the bubbles. The bubbles then enter the middle section and contact the porous media component, where they are refined into smaller bubbles. Finally, the smaller bubbles enter the cavity of the second section (or shearing chamber). The actuator drives the impeller to rotate within the shearing chamber, further breaking down the smaller bubbles into microbubbles through mechanical shearing. This increases the specific surface area of ​​the bubbles, thereby increasing the gas-liquid contact area and enhancing the mass transfer efficiency of ozone in water. Therefore, compared to related technologies, the present invention can generate small-diameter microbubbles through multi-stage shearing to increase the gas-liquid contact area and enhance the mass transfer efficiency of ozone in water.

[0010] In some embodiments, the porous media assembly includes at least one porous ceramic membrane arranged along the extension direction of the intermediate segment; The porous ceramic membrane has a pore size of d, and d is 5μm-10μm; The porosity of the porous ceramic membrane is δ, and δ is 40%-60%.

[0011] In some embodiments, the impeller includes a first blade, which is at least one and arranged circumferentially along the second segment. The first blade is provided with a plurality of breaking teeth, which are spaced apart on the first blade. The breaking teeth are serrated. The distance between any two adjacent breaking teeth is s, and s is 1mm-2mm.

[0012] According to an embodiment of the present invention, a water treatment system includes the microbubble generator described in any of the above embodiments.

[0013] The technical advantages of the water treatment system according to the embodiments of the present invention are the same as those of the microbubble generating device described above, and will not be repeated here.

[0014] In some embodiments, the water treatment system further includes a reaction tank, a first baffle, and a second baffle.

[0015] The reaction vessel has a reaction chamber and is provided with a liquid inlet and a water outlet. The liquid inlet is connected to the end of the second section of the microbubble generator that is away from the middle section. The first baffle and the second baffle are disposed in the reaction chamber and arranged at intervals in a first direction, which is orthogonal to the extension direction of the reaction chamber. The first baffle and the second baffle together define an airflow channel in the reaction chamber, and the airflow channel is connected to the liquid inlet and the water outlet. The first baffle and the second baffle are at least one and are arranged at intervals along the extension direction of the reaction chamber. The first baffle and the second baffle are spaced apart and alternately arranged along the extension direction of the reaction chamber.

[0016] In some embodiments, on the projection surface formed by the first direction and the extension direction of the reaction chamber, the projection of each of the first baffle and the second baffle forms an angle α with the extension direction of the reaction chamber, and α is 30°-45°.

[0017] In some embodiments, the water treatment system further includes a dissolved oxygen sensor, which is disposed in the reaction tank and used to monitor the ozone concentration in the reaction chamber; The reaction vessel is also provided with an exhaust port connected to the gas flow channel. The exhaust port is equipped with an ozone decomposer, which is used to decompose undissolved ozone into oxygen and discharge it.

[0018] In some embodiments, the water treatment system further includes an ozone generator, a filter, and a premixing device. The ozone generator is used to generate ozone. The inlet of the filter is adapted to be connected to the water source to be treated. The filter is used to remove large particulate impurities and suspended impurities from the water to be treated. The premixing device includes a housing and a second blade. The housing has a premixing chamber and is provided with an inlet and an outlet communicating with the premixing chamber. The inlet is connected to the air outlet of the ozone generator and the liquid outlet of the filter. The outlet is connected to one end of the first section of the microbubble generator away from the middle section. The second blade is disposed in the premixing chamber and extends spirally along the extension direction of the premixing chamber.

[0019] According to an embodiment of the present invention, a water treatment method based on the water treatment system described in any of the above embodiments includes the following steps: In the first-stage shearing process, the gas-liquid mixture formed by the water to be treated and ozone is passed into a microbubble generator, where the gas-liquid mixture is broken into bubbles by the Venturi cavity of the first stage. In the secondary shearing process, the bubble enters the middle section and is divided into smaller bubbles by the porous media component; In the third-stage shearing process, the small bubbles continue to enter the second-stage shearing chamber, where the driver drives the impeller to rotate and shear the small bubbles into microbubbles.

[0020] The technical advantages of the water treatment method according to the embodiments of the present invention are the same as those of the water treatment system described above, and will not be repeated here.

[0021] In some embodiments, after the three-stage shearing process, the water treatment method further includes the step of: To enhance mass transfer, the microbubbles enter the reaction vessel and form a swirling flow under the action of the first and second baffles in the reaction chamber. The microbubbles stay in the reaction chamber for a set time to allow ozone to dissolve efficiently.

[0022] In some embodiments, prior to the primary shearing operation, the water treatment method further includes the step of: Ozone preparation involves generating ozone using an ozone generator. Water pretreatment involves passing the water to be treated through a filter to remove large particulate impurities and suspended impurities from the water, thereby obtaining filtered water. Gas-liquid premixing involves introducing ozone and filtered water into a premixing device. Under the swirling action of the second blade within the premixing device, the filtered water and ozone are mixed to form the gas-liquid mixture.

[0023] In some embodiments, during the water pretreatment operation, the temperature of the water to be treated is 20°C-30°C, and the pH value of the water to be treated is 6.5-8.5.

[0024] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a microbubble generator for enhancing ozone mass transfer according to an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the connection structure between the impeller and the tube in a microbubble generator for enhanced ozone mass transfer according to an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of the structure of a water treatment system according to an embodiment of the present invention.

[0028] Figure 4 This is a schematic flowchart of a water treatment method according to an embodiment of the present invention.

[0029] Figure label: 10. Water treatment system; 100. Microbubble generator; 200. Reaction vessel; 300. First spoiler; 400. Second spoiler; 500. Dissolved oxygen sensor; 600. Ozone generator; 700, Filter; 800. Premixing device; 1. Pipe body; 11. First section; 12. Middle section; 13. Second section; 2. Porous dielectric components; 3. Impeller; 31. First blade; 4. Driver; 5. Reaction chamber; 51. Liquid inlet; 52. Water outlet; 53. Airflow channel; 54. Exhaust gas outlet; 55. Ozone decomposer; 6. Outer shell; 61. Second blade; 62. Premixing chamber; 63. Inlet; 64. Outlet. Detailed Implementation

[0030] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0031] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a microbubble generator 100 for enhancing ozone mass transfer, comprising a tube body 1, a porous media component 2, an impeller 3, and a driver 4. The tube body 1 includes a first section 11, a middle section 12, and a second section 13 connected in sequence. The end of the first section 11 opposite to the middle section 12 is adapted to be connected to an ozone source and a water source to be treated. The inner cavity of the first section 11 is constructed as a Venturi cavity to break the gas-liquid mixture formed by ozone and water to be treated into bubbles. The end of the second section 13 opposite to the middle section 12 is adapted to be connected to the external environment. The porous media component 2 is disposed in the inner cavity of the middle section 12 to divide the bubbles. The impeller 3 is rotatably connected to the inner cavity of the second section 13, and the driver 4 is drivenly connected to the impeller 3 to shear the bubbles.

[0032] According to an embodiment of the present invention, the microbubble generator 100 for enhancing ozone mass transfer introduces a gas-liquid mixture of ozone and water to be treated into the pipe body 1. The gas-liquid mixture first enters the Venturi cavity of the first section 11. The Venturi cavity utilizes the principle of "high-speed jet generating negative pressure in the throat section" to further draw in insufficiently mixed ozone from the environment. At the same time, the bubbles are initially broken up by the velocity difference. Then, the bubbles enter the middle section 12 and come into contact with the porous media component 2. After passing through the porous media component 2, they are refined into small bubbles. Finally, the small bubbles enter the cavity (or shearing cavity) of the second section 13. The driver 4 drives the impeller 3 to rotate in the shearing cavity. Through mechanical shearing, the small bubbles are further broken into microbubbles, which increases the specific surface area of ​​the bubbles and increases the gas-liquid contact area, thereby improving the mass transfer efficiency of ozone in water. Therefore, compared with related technologies, the present invention can generate small-diameter microbubbles through multi-stage shearing to increase the gas-liquid contact area and enhance the mass transfer efficiency of ozone in water.

[0033] Specifically, the first, middle, and second sections can be arranged sequentially along the extension direction of the tube. The extension direction of each of the first, middle, and second sections can be consistent with the extension direction of the tube. On a projection plane orthogonal to the extension direction of the tube, the projected outer contour of each of the first, middle, and second sections can be a circle, rectangle, or other arbitrary closed curve. The first section can be a Venturi tube section. A pressure sensor can be installed at the inlet of the first section (or the tube inlet). The actuator is not limited to a drive motor.

[0034] Understandably, the microbubble generator forms a three-stage composite structure of "Venturi tube + porous medium + rotary shear".

[0035] like Figure 1 As shown, in some embodiments, the porous media component 2 includes at least one porous ceramic membrane arranged along the extension direction of the intermediate section 12, that is, at least one porous ceramic membrane is connected in series in the inner cavity of the intermediate section.

[0036] The pore size of the porous ceramic membrane is d, which is 5μm-10μm. For example, d can be 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0037] The porosity of the porous ceramic membrane is δ, and δ is 40%-60%.

[0038] Understandably, the porous media component with the above-mentioned structural design allows the gas-liquid mixture to be initially refined into small bubbles of 50μm-100μm when passing through the pores of the porous ceramic membrane. In addition, the porous ceramic membrane has advantages such as high temperature resistance, chemical corrosion resistance, high mechanical strength, strong antimicrobial ability, large permeability, strong cleanability, narrow pore size distribution, good separation performance and long service life, which can further improve the performance of the microbubble generator.

[0039] like Figure 2 As shown, in some embodiments, the impeller 3 includes at least one first blade 31, which is arranged at intervals along the circumference of the second segment 13. The first blade 31 is provided with multiple breaking teeth (not shown in the figure), which are arranged at intervals on the first blade 31. The breaking teeth are serrated. The rotational speed of the impeller can be 1200 rpm to 1800 rpm.

[0040] The distance between any two adjacent crushing teeth is s, and s is 1mm-2mm. For example, s can be 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2mm, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0041] Understandably, designing the impeller blades with the aforementioned structure allows for further breaking down of small bubbles into microbubbles of 10μm-50μm through the mechanical shearing and crushing action generated by the rotation of the first blade, thereby increasing the specific surface area to 5000m². 2 / m 3 above.

[0042] like Figure 3 As shown, a water treatment system 10 according to an embodiment of the present invention includes a microbubble generator 100 according to any of the above embodiments.

[0043] The technical advantages of the water treatment system 10 according to the embodiments of the present invention are the same as those of the microbubble generator 100 described above, and will not be repeated here.

[0044] like Figure 3 As shown, in some embodiments, the water treatment system 10 further includes a reaction tank 200, a first baffle 300, and a second baffle 400.

[0045] The reaction vessel 200 has a reaction chamber 5 and is provided with a liquid inlet 51 and a water outlet 52. The liquid inlet 51 is connected to the end of the second section 13 of the microbubble generator 100 away from the middle section 12.

[0046] The first baffle plate 300 and the second baffle plate 400 are disposed in the reaction chamber 5 and arranged at intervals in a first direction, which is orthogonal to the extension direction of the reaction chamber 5. The first baffle plate 300 and the second baffle plate 400 together define an airflow channel 53 in the reaction chamber 5, and the airflow channel 53 is connected to the liquid inlet 51 and the water outlet 52.

[0047] The first baffle 300 and the second baffle 400 are at least one and are arranged at intervals along the extension direction of the reaction chamber 5. The first baffle 300 and the second baffle 400 are spaced apart and alternately arranged along the extension direction of the reaction chamber 5.

[0048] Understandably, the first and second baffles inside the reaction tank can create a swirling flow field in the reaction chamber for the microbubble gas-liquid mixture, slowing down the rising speed of the bubbles (reducing it to 0.05m / s-0.1m / s) and extending the residence time of the microbubbles in the water to 1.5min-3min, thereby increasing the gas-liquid contact time. At the same time, the swirling flow can enhance gas-liquid turbulence, further promoting ozone mass transfer.

[0049] Specifically, the reaction vessel can extend vertically. The extension direction of the reaction chamber can be the same as the extension direction of the reaction vessel. The liquid inlet can be located near the bottom of the reaction vessel. The water outlet can be located near the top of the reaction vessel. A flow regulating valve can be installed at the water outlet to adjust the flow rate of the treated water and ensure the residence time of the microbubble gas-liquid mixture in the reaction chamber. The primary direction can be the left-right direction shown in the figure.

[0050] like Figure 3 As shown, in some embodiments, on the projection plane formed by the first direction and the extension direction of the reaction chamber 5, the projection of each of the first baffle 300 and the second baffle 400 forms an angle α with the extension direction of the reaction chamber 5, and α is 30°-45°. For example, α can be 30°, 32°, 34°, 36°, 38°, 40°, 42°, 44°, 45°, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0051] like Figure 3 As shown, in some embodiments, the water treatment system 10 also includes a dissolved oxygen sensor 500, which is located in the reaction tank 200 and used to monitor the ozone concentration in the reaction chamber 5. The dissolved oxygen sensor is installed near the top of the reaction tank. The dissolved oxygen sensor can monitor the ozone concentration in the reaction chamber in real time, so as to dynamically adjust the parameters. That is, according to the data monitored by the dissolved oxygen sensor, if the ozone concentration is too low, the ozone flow rate can be increased or the flow rate of the water inlet pump can be reduced. If the pressure sensor shows that the pressure at the pipe inlet (i.e., the venturi inlet) is abnormal, the filter needs to be checked for blockage to ensure stable operation of the device.

[0052] The reaction vessel 200 is also provided with an exhaust port 54 connected to the airflow channel 53. The exhaust port 54 is equipped with an ozone decomposer 55. The exhaust port can be located at the top of the reaction vessel. The ozone decomposer 55 is used to decompose undissolved ozone (≤15%) into oxygen and discharge it, so as to avoid the easy escape of insufficiently dissolved ozone, which would cause resource waste and exhaust gas treatment pressure problems.

[0053] like Figure 3 As shown, in some embodiments, the water treatment system 10 further includes an ozone generator 600, a filter 700, and a premixing device 800. The ozone generator 600 is used to generate ozone. The inlet 51 of the filter 700 is adapted to be connected to the water source to be treated. The filter 700 is used to filter out large particulate impurities and suspended impurities in the water to be treated. The premixing device 800 includes a housing 6 and a second blade 61. The housing 6 has a premixing chamber 62 and is provided with an inlet 63 and an outlet 64 that communicate with the premixing chamber 62. The inlet 63 is connected to the air outlet of the ozone generator 600 and the liquid outlet of the filter 700. The outlet 64 is connected to the end of the first section 11 of the microbubble generator 100 away from the middle section 12. The second blade 61 is disposed in the premixing chamber 62 and extends spirally along the extension direction of the premixing chamber 62. In other words, the second blade is a spiral blade.

[0054] Understandably, filters can remove large particles and suspended impurities from water, preventing blockage of subsequent porous media components, while premixing devices can use built-in spiral blades to create a swirling mixture of ozone and water, initially breaking up ozone agglomeration and laying the foundation for subsequent microbubble refinement.

[0055] Specifically, the ozone generator's outlet can be equipped with a pressure regulating valve and a flow meter to precisely control the ozone pressure (0.2MPa-0.4MPa) and flow rate (5L / min-20L / min), avoiding uneven bubble size caused by pressure fluctuations. The ozone flow rate can be matched to the treated water volume, with the gas-to-water ratio controlled at 1:500-1:1000 to ensure a stable ozone supply. The filter's inlet can be connected to the water source via a water pump, allowing the water to smoothly enter the filter for filtration. The filter's filtration accuracy is approximately 10μm. The premixing device can be an SK-type static mixer. Inside the static mixer, ozone and water are mixed for 10-20 seconds by the swirling action of the spiral blades, forming a uniform gas-liquid mixture and avoiding waste caused by excessively high local ozone concentrations.

[0056] Therefore, compared with related technologies, the present invention has the following advantages: 1) High mass transfer efficiency; microbubbles of 10μm-50μm are produced through three-stage shearing, with a specific surface area ≥5000m². 2 / m 3Combined with the turbulence design of the reaction chamber, the ozone dissolution rate is increased to over 85%, which is more than 30% higher than that of traditional devices (dissolution rate ≤50%). 2) High ozone utilization rate, extending microbubble residence time to 1.5-3 minutes, reducing ozone dissipation and lowering operating costs (based on a treatment capacity of 1000m³). 3 (Based on water consumption calculations, this can save approximately 40% of ozone consumption). 3) It has a simple structure and low energy consumption. It adopts a composite refinement method of "mechanical shearing + fluid mechanics", which eliminates the need for high-energy equipment such as ultrasound and high pressure. The power of the drive motor is only 0.5kW-1.5kW, which reduces energy consumption by more than 60% compared with ultrasonic microbubble devices. 4) Wide applicability; the flow rate of the inlet pump can be adjusted (5m³ / h). 3 / h-50m 3 The ozone supply capacity (5L / min-50L / min) is adapted to different treatment scales and is suitable for various scenarios such as industrial wastewater, drinking water, and aquaculture water. 5) Stable operation and easy maintenance. The filter can prevent clogging, the porous ceramic membrane can be disassembled and cleaned regularly, and the monitoring module (including dissolved oxygen sensor and pressure sensor) can provide real-time early warning, reducing maintenance difficulty.

[0057] In other words, to address the problems of low ozone mass transfer efficiency, low ozone utilization, and high energy consumption in existing technologies, this invention provides a water treatment system. Through a microbubble preparation process of "premixing + multi-stage shearing" and a mass transfer enhancement design of "turbulence to extend residence time", it can stably generate small-diameter microbubbles, extend bubble residence time, and at the same time take into account simple structure and low energy consumption, thus achieving a significant improvement in ozone mass transfer efficiency and ensuring water treatment effect.

[0058] like Figure 4 As shown, an embodiment of the present invention provides a water treatment method based on the water treatment system 10 of any of the above embodiments. The water treatment method includes the following steps: Step S1, primary shearing treatment: the gas-liquid mixture formed by the water to be treated and ozone is passed into the microbubble generator 100. The gas-liquid mixture is broken into bubbles by the Venturi cavity of the first section 11. The gas-liquid mixture passes through the throat section at a flow rate of 8m / s-12m / s. Step S2, secondary shearing process, the bubble enters the middle section 12 and is divided into small bubbles by the porous media component 2; Step S3, three-stage shearing process: the small bubbles continue to enter the shearing chamber of the second segment 13, and the driver 4 drives the impeller 3 to rotate to shear the small bubbles into microbubbles.

[0059] The technical advantages of the water treatment method according to the embodiments of the present invention are the same as those of the water treatment system 10 described above, and will not be repeated here.

[0060] like Figure 4 As shown, in some embodiments, after step S3, the water treatment method further includes the step of: Step S4, enhanced mass transfer treatment: microbubbles enter the reaction tank 200 and form a swirling flow under the action of the first baffle 300 and the second baffle 400 in the reaction chamber 5. The microbubbles stay in the reaction chamber 5 for a set time to enable ozone to dissolve efficiently. The set time can be 1.5 min to 3 min, and the ozone dissolution rate is ≥85%.

[0061] like Figure 4 As shown, in some embodiments, prior to step S1, the water treatment method further includes the following steps: Step S0, ozone preparation, ozone is generated by ozone generator 600; Step S0', water pretreatment, the water to be treated is passed through filter 700 to filter out large particulate impurities and suspended impurities in the water to obtain filtered water; Step S0”, gas-liquid premixing, ozone and filtered water are introduced into the premixing device 800. Under the swirling action of the second blade 61 in the premixing device 800, the filtered water and ozone are mixed into a gas-liquid mixture.

[0062] It should be noted that there is no requirement for a specific order between steps S0 and S0'.

[0063] like Figure 4 As shown, in some embodiments, in step S0', the temperature of the water to be treated is 20℃-30℃, and the pH value of the water to be treated is 6.5-8.5. Because excessively high temperature will reduce ozone solubility, and ozone oxidation activity is optimal under neutral conditions, the water to be treated is set to the aforementioned parameter conditions in the water pretreatment operation.

[0064] Example 1: Treatment and Reuse of Wastewater from Power Plant Circulating Water Due to long-term circulation and concentration, power plant circulating water discharge typically contains high levels of suspended solids (SS), microbial slime, calcium and magnesium hardness ions, and small amounts of residual corrosion and scale inhibitors. It needs to be treated to achieve desulfurization makeup water or ash slag water reuse. This invention addresses the characteristics of this type of wastewater by enhancing ozone mass transfer efficiency to achieve a synergistic effect of oxidation sterilization, organic matter degradation, and assisted air flotation turbidity removal.

[0065] 1) Device parameter settings Ozone supply module: ozone generator output 150g / h, pressure regulator valve adjusts pressure 0.35MPa, flow meter controls flow rate 30L / min (gas-water ratio 1:167). Water supply module: Inlet pump flow rate 50m³ / h 3 / h, filter filtration accuracy 10μm (removes suspended particles and sludge from circulating water to prevent clogging of porous media); Premixing module: SK-25 static mixer, 500mm in length (suitable for initial gas-liquid mixing at high flow rates); Microbubble shearing module: Venturi tube: inlet diameter 100mm, throat diameter 40mm (throat diameter / inlet diameter = 0.4), diffuser cone angle 10° (ensuring a throat velocity of 8m / s-10m / s under high flow rates); Porous media component: porous stainless steel membrane (resistant to slight corrosion from circulating water), pore size 8μm, porosity 55%; Shearing chamber: impeller diameter 150mm, number of blades 6 (enhancing shearing uniformity under high flow rates), serration pitch 1.5mm, rotation speed 1600rpm; Reaction chamber: 500L in volume, with 4 baffles on the inner wall (at an angle of 40° with the axis), a flow regulating valve at the outlet (controlling the hydraulic residence time to 2.5min), and an ozone decomposer connected to the exhaust port at the top (to treat undissolved ozone).

[0066] 2) Operating steps: S1: Power plant circulating water discharge (raw water characteristics: COD=65mg / L, SS=32mg / L, total hardness=420mg / L (calculated as CaCO3), pH=8.5, temperature 35℃, containing a small amount of blue-green algae and slime) is pumped into the filter to remove suspended particles and slime fragments with a particle size ≥10μm. S2: The ozone generator starts, and ozone gas is stably fed into the static mixer through the pressure regulating valve (0.35MPa) and the flow meter (30L / min); S3: After filtration, the wastewater and ozone are mixed in a static mixer by spiral blades for 18 seconds to form a uniform gas-liquid mixture (the swirling flow initially disperses the ozone bubbles, while allowing the ozone to pre-contact with microorganisms and organic matter in the water). S4: The gas-liquid mixture enters the Venturi tube, where the flow velocity in the throat section is 9 m / s, generating negative pressure to further draw in the trace amounts of residual ozone in the pipe. At the same time, the flow velocity difference initially breaks up the bubbles. Subsequently, it passes through a porous stainless steel membrane and is refined into small bubbles of 60-80 μm. Finally, it enters the shear chamber, where the mechanical shearing action of the serrated impeller forms microbubbles of 20-40 μm (this particle size range can ensure both a large specific surface area to improve ozone mass transfer and adsorption of suspended matter through air flotation). S5: The microbubble gas-liquid mixture enters the reaction chamber, forming a strong swirling flow field under the action of four baffles: On the one hand, the rising velocity of the microbubbles decreases to 0.08 m / s, the residence time is extended to 2.5 min, and the ozone is fully dissolved (dissolution rate reaches 89%), decomposing residual organic matter (such as organophosphorus) of corrosion and scale inhibitors through oxidation and killing cyanobacteria (inactivation rate ≥99%); on the other hand, the microbubbles adsorb suspended particles and slime in the wastewater, forming air flocs under the swirling flow, which are enriched in the upper part of the reaction chamber (separated by the subsequent shallow air flotation unit, this is a synergistic effect). S6: The dissolved oxygen sensor monitors the ozone concentration in the reaction chamber in real time, which is 14 mg / L. The pressure sensor shows that the venturi tube inlet pressure is stable at 0.32 MPa. The treated wastewater is discharged through the effluent pipe and enters the subsequent softening unit. The undissolved ozone (about 11%) enters the ozone decomposer through the tail gas outlet, where it is decomposed into oxygen and then discharged into the air (tail gas ozone concentration ≤ 0.08 mg / m³, which meets environmental protection requirements).

[0067] 3) Treatment effect: Water quality indicators: After treatment, the COD of the wastewater was reduced to 22 mg / L (removal rate 66%), the SS was reduced to 4.5 mg / L (removal rate 86%), the cyanobacteria were completely inactivated, and the removal rate of slime and debris was 92%. Reuse compatibility: After subsequent softening treatment (reducing hardness to ≤200mg / L), the treated wastewater can meet the water quality requirements for desulfurization makeup water in power plants (GB / T18920-2020 "Water Quality Standard for Urban Wastewater Reuse for Urban Miscellaneous Use"). Economic efficiency: Ozone utilization rate is 35% higher than that of traditional aeration devices, based on a power plant's daily treatment capacity of 1200m³ of circulating water and wastewater. 3 Calculations show that this saves approximately 2.8 kg of ozone per day and reduces operating costs by over 30,000 yuan per year.

[0068] Example 2: Treatment of High-Hardness Power Plant Circulating Water Discharge (Enhanced Hardness Removal Synergistic) For power plant circulating water discharge with a total hardness ≥500mg / L (such as power plants in high calcium and magnesium areas), the synergistic hardness removal effect of ozone oxidation and microbubble flotation is enhanced by adjusting parameters.

[0069] 1) Parameter adjustment Inlet pump flow rate 30m 3 / h, ozone flow rate 25L / min (air-to-water ratio 1:120). The impeller speed was increased to 1800 rpm, and the microbubble diameter was refined to 15-30 μm; The residence time in the reaction chamber was extended to 3 minutes, and the angle of the baffles was adjusted to 35° (to enhance the swirling intensity and promote the formation of micro-flocs of calcium and magnesium ions and ozone oxidation products).

[0070] 2) Processing effect The raw water had a total hardness of 550 mg / L. After treatment (combining microbubble adsorption and subsequent sedimentation), the total hardness was reduced to 380 mg / L (initial softening rate of 31%), reducing the load on subsequent softening units. With a COD removal rate of 70%, an SS removal rate of 90%, and an ozone dissolution rate of 91%, it is suitable for ash and slag water reuse scenarios where hardness is required.

[0071] Therefore, as can be seen from the above embodiments, the present invention can effectively adapt to the characteristics of power plant circulating water wastewater such as high flow rate, high hardness, and presence of microorganisms. By enhancing ozone mass transfer efficiency, it achieves the synergistic effect of oxidation, sterilization, and air flotation turbidity removal. Moreover, it is stable in operation, has low energy consumption, and is suitable for large-scale application of power plant wastewater treatment and reuse.

[0072] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0073] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0074] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0075] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0076] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0077] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A microbubble generator for enhancing ozone mass transfer, characterized in that, include: The tube body includes a first section, a middle section and a second section connected in sequence. The end of the first section away from the middle section is adapted to be connected to an ozone source and a water source to be treated. The inner cavity of the first section is constructed as a Venturi cavity to break the gas-liquid mixture formed by ozone and water to be treated into bubbles. The end of the second section away from the middle section is adapted to be connected to the external environment. A porous media assembly disposed within the cavity of the intermediate section to divide the air bubbles; An impeller and a driver, the impeller being rotatably connected to the inner cavity of the second section, the driver being driven to the impeller to shear the bubble.

2. The microbubble generator for enhanced ozone mass transfer according to claim 1, characterized in that, The porous media assembly includes at least one porous ceramic membrane, which is arranged along the extension direction of the intermediate section. The porous ceramic membrane has a pore size of d, and d is 5μm-10μm; The porosity of the porous ceramic membrane is δ, and δ is 40%-60%.

3. The microbubble generator for enhanced ozone mass transfer according to claim 1, characterized in that, The impeller includes a first blade, which is at least one and arranged circumferentially along the second segment. The first blade is provided with a plurality of breaking teeth, which are arranged at intervals on the first blade. The breaking teeth are serrated. The distance between any two adjacent breaking teeth is s, and s is 1mm-2mm.

4. A water treatment system, characterized in that, The water treatment system includes the microbubble generator as described in any one of claims 1-3.

5. The water treatment system according to claim 4, characterized in that, Also includes: The reaction vessel has a reaction chamber and is provided with a liquid inlet and a water outlet. The liquid inlet is connected to the end of the second section of the microbubble generator that is away from the middle section. A first baffle plate and a second baffle plate are disposed in the reaction chamber and arranged at a distance in a first direction, which is orthogonal to the extension direction of the reaction chamber. The first baffle plate and the second baffle plate together define an airflow channel in the reaction chamber, and the airflow channel is connected to the liquid inlet and the water outlet. The first baffle and the second baffle are at least one and are arranged at intervals along the extension direction of the reaction chamber. The first baffle and the second baffle are spaced apart and alternately arranged along the extension direction of the reaction chamber.

6. The water treatment system according to claim 5, characterized in that, It also includes a dissolved oxygen sensor, which is located in the reaction vessel and used to monitor the ozone concentration in the reaction chamber; The reaction vessel is also provided with an exhaust port connected to the gas flow channel. The exhaust port is equipped with an ozone decomposer, which is used to decompose undissolved ozone into oxygen and discharge it.

7. The water treatment system according to any one of claims 4-6, characterized in that, Also includes: An ozone generator and a filter, wherein the ozone generator is used to generate ozone, and the inlet of the filter is adapted to be connected to the water source to be treated, and the filter is used to remove large particulate impurities and suspended impurities from the water to be treated. A premixing device includes a housing and a second blade. The housing has a premixing chamber and is provided with an inlet and an outlet communicating with the premixing chamber. The inlet is connected to the air outlet of the ozone generator and the liquid outlet of the filter. The outlet is connected to one end of the first section of the microbubble generator away from the middle section. The second blade is disposed in the premixing chamber and extends spirally along the extension direction of the premixing chamber.

8. A water treatment method, based on the water treatment system as described in any one of claims 4-7, characterized in that, The water treatment method includes the following steps: In the first-stage shearing process, the gas-liquid mixture formed by the water to be treated and ozone is passed into a microbubble generator, where the gas-liquid mixture is broken into bubbles by the Venturi cavity of the first stage. In the secondary shearing process, the bubble enters the middle section and is divided into smaller bubbles by the porous media component; In the third-stage shearing process, the small bubbles continue to enter the second-stage shearing chamber, where the driver drives the impeller to rotate and shear the small bubbles into microbubbles.

9. The water treatment method according to claim 8, characterized in that, Following the three-stage shearing process, the water treatment method further includes the following steps: To enhance mass transfer, the microbubbles enter the reaction vessel and form a swirling flow under the action of the first and second baffles in the reaction chamber. The microbubbles stay in the reaction chamber for a set time to allow ozone to dissolve efficiently.

10. The water treatment method according to claim 8 or 9, characterized in that, Prior to the primary shearing operation, the water treatment method further includes the following steps: Ozone preparation involves generating ozone using an ozone generator. Water pretreatment involves passing the water to be treated through a filter to remove large particulate impurities and suspended impurities from the water, thereby obtaining filtered water. Gas-liquid premixing involves introducing ozone and filtered water into a premixing device. Under the swirling action of the second blade within the premixing device, the filtered water and ozone are mixed to form the gas-liquid mixture.

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