A double curved space needle discharge gas-liquid ozone mass transfer device, system and method

Abstract

The application relates to a gas-liquid ozone mass transfer device, system and method of double-curved space needle-shaped discharge, which comprises a device body with a plurality of double-curved cavitation discharge channels inside, the device body comprises an inlet side and an outlet side, the double-curved cavitation discharge channel at least comprises a double-curved flow channel which is smoothly and symmetrically tapered from an enlarged middle part to both sides; a flexible high-voltage discharge needle is penetrated into the double-curved cavitation discharge channel; and in the double-curved cavitation discharge channel, high-pressure gas is filled into the arc-shaped micro gas channel of the flexible high-voltage discharge needle, so that the gap between the outer surface of the flexible high-voltage discharge needle and the inner wall of the double-curved cavitation discharge channel is kept constant and equidistant, the discharge area is improved under the condition of the same discharge length, the cavitation effect is strengthened through the setting of a pressure release groove, a large amount of active substances are generated through dielectric barrier discharge, the strong cavitation effect caused by the sudden pressure reduction at the pressure release groove is further improved, and the degradation efficiency of industrial refractory wastewater is further improved.

Description

Technical Field

[0001] This invention relates to the field of organic wastewater treatment technology, specifically to a hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer device, system, and method. Background Technology

[0002] With the rapid development of modern industrialization and urbanization, the discharge of recalcitrant industrial wastewater is constantly increasing, posing a serious threat to the ecological environment. Traditional wastewater treatment technologies, such as Fenton oxidation, photocatalysis, and biodegradation, typically suffer from drawbacks such as long treatment times, the risk of secondary pollution, and susceptibility to temperature fluctuations. In recent years, ozone oxidation has attracted attention from the environmental engineering community as a novel technology for treating recalcitrant industrial wastewater. When ozone dissolves in water, it not only directly oxidizes organic matter but also decomposes to produce hydroxyl radicals (HO·), which also react with organic molecules. Because hydroxyl radicals (HO·) have a stronger oxidizing power than ozone and a faster reaction rate, they play a dominant role in the degradation process. Ozone oxidation technology is considered a very promising technology for treating recalcitrant industrial wastewater due to its advantages such as rapid treatment, high pollutant removal rate, and no secondary pollution.

[0003] The invention patent CN112076596A, entitled "Method for Degrading Organic Waste Gas Based on Dielectric Barrier Discharge," discloses a method for degrading organic waste gas based on dielectric barrier discharge. The dielectric barrier discharge low-temperature plasma reactor is a coaxial tubular dielectric barrier discharge low-temperature plasma reactor, comprising a high-voltage electrode, a grounding electrode, and a dielectric barrier tube. The centrally located tubular high-voltage electrode is coaxially fitted inside the dielectric barrier tube, and the grounding electrode is wrapped around the outer wall of the dielectric barrier tube. The discharge area of ​​this device is the gap between the outer and inner walls of the tubular electrode. Although this traditional tubular dielectric barrier discharge can improve the degradation efficiency of organic waste gas, its equipment is large, energy-intensive, and the tubular high-voltage electrode has a simple shape, limited discharge area, and produces few high-energy active particles, making it difficult to improve the degradation efficiency of recalcitrant industrial wastewater.

[0004] The invention patent CN105060408B, entitled "A Method and Apparatus for Underwater Low-Temperature Plasma Wastewater Treatment," describes a method and apparatus for underwater low-temperature plasma wastewater treatment, comprising a pretreatment device, a high-voltage pulse power supply, and a low-temperature plasma chamber with built-in conductive electrodes. It primarily utilizes the high-voltage pulse power supply to directly discharge pretreated wastewater through the conductive electrodes. However, while this method can utilize the high-energy active particles generated by the discharge to degrade organic matter, the degradation method is singular, relying solely on the high-energy active particles generated by the discharge, resulting in low mass transfer efficiency and low degradation efficiency.

[0005] In summary, existing ozone degradation methods and devices for recalcitrant wastewater still have the following problems in practical applications:

[0006] Firstly, most discharge needles currently used are of regular shape. When faced with irregularly shaped channels, the discharge needle cannot adapt to the shape of the channel, resulting in a non-equidistant distribution of the plasma discharge gap between the surface of the discharge needle and the inner wall of the channel. This makes it impossible to maintain a constant discharge gap, causing uneven local discharge and additional energy loss, which severely limits the discharge effect.

[0007] Secondly, in recalcitrant wastewater, although existing technologies combine hydraulic cavitation and plasma discharge technologies, they are set up in separate degradation process units. This separate design makes it difficult for the highly reactive substances generated by plasma discharge to act on the cavitation bubble clusters formed in the hydraulic cavitation region in a timely manner. This greatly limits the strong oxidizing properties of the reactive substances, thus restricting further improvement in degradation efficiency.

[0008] Third, existing devices only achieve ozone mixing with wastewater through simple aeration, lacking efficient gas-liquid mixing devices. Because the active substances generated by plasma discharge (such as hydroxyl radicals, high-energy electrons, and excited-state molecules) have short liquid-phase half-lives, they are easily deactivated by diffusion and non-target reactions, leading to significant consumption. These active substances fail to mix fully with the recalcitrant wastewater, limiting their efficient exertion of strong oxidizing properties and affecting the degradation effect. Summary of the Invention

[0009] I. Technical problems to be solved

[0010] The purpose of this invention is to provide a gas-liquid ozone mass transfer device, system and method for hyperbolic spatial needle discharge. By setting up a flexible and deformable high-voltage discharge needle and a pressure release tank in the hyperbolic cavitation discharge pipe, the flow rate is controlled to be uniform and the plasma discharge gap is equal everywhere, thereby improving the degradation effect of industrial recalcitrant wastewater.

[0011] II. Technical Solution

[0012] The present invention is achieved through the following technical solution:

[0013] According to a first aspect of the present invention, a hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer device is provided, comprising:

[0014] The device body has several hyperbolic cavitation discharge channels inside. The device body includes an inlet side and an outlet side. The hyperbolic cavitation discharge channels are connected between the inlet side and the outlet side. The hyperbolic cavitation discharge channels include at least one section of hyperbolic flow channel that smoothly and symmetrically tapers from the expanded middle part to both sides.

[0015] A flexible high-voltage discharge needle penetrates the interior of a hyperbolic cavitation discharge channel; and within the hyperbolic cavitation discharge channel, the flexible high-voltage discharge needle is filled with high-pressure gas and has an outer wall shape that maintains equidistant distance from the inner wall of the hyperbolic cavitation discharge channel at all points.

[0016] The flexible high-voltage discharge needle serves as the high-voltage positive electrode, and the hyperbolic cavitation discharge channel is grounded as the negative electrode. Wastewater containing dispersed microbubbles flows into the inlet side of the hyperbolic cavitation discharge channel. As the wastewater flows from the inlet side to the outlet side, dielectric barrier discharge occurs within the hyperbolic channel, ionizing the microbubbles in the organic wastewater.

[0017] Furthermore, at least two hyperbolic flow channels are sequentially connected inside the hyperbolic cavitation discharge channel. The hyperbolic flow channel (231) adopts a circular cross-section design in the radial direction and a cross-sectional shape designed according to a multi-segment continuous half-sine curve configuration in the axial direction.

[0018] The hyperbolic cavitation discharge channel is provided with a pressure relief groove at the narrowest point of the junction of adjacent hyperbolic flow channels;

[0019] An insulating dielectric coating is uniformly applied to the surfaces of the hyperbolic flow channel and pressure relief groove using an electroplating process.

[0020] Furthermore, the pressure relief groove has a parabolic or rectangular flow channel in the axial direction.

[0021] Furthermore, the flexible high-voltage discharge needle is 3D printed from conductive rubber, and its outer surface is uniformly covered with an insulating dielectric coating by electroplating.

[0022] The flexible high-voltage discharge needle has an arc-shaped micro-airway formed inside. On the axial cross-section, the angle of inclination of the inner wall of the arc-shaped micro-airway relative to the central axis of the flexible high-voltage discharge needle shows a symmetrical gradual change: the inclination angle of the inlet section of the flow channel increases from 0° to 15°, and then decreases symmetrically back to 0° after passing through the throat region.

[0023] The flexible high-voltage discharge needle has multiple deformable grooves on its outer wall. These grooves are located at the point where the inner diameter of the arc-shaped micro-air channel cross-section is the largest and the outer wall of the flexible high-voltage discharge needle is the thinnest. When the flexible high-voltage discharge needle is filled with air, the deformable grooves bulge outward as weak points, causing the outer wall of the flexible high-voltage discharge needle to expand and deform to conform to the shape of the hyperbolic flow channel and be equidistant from the gaps in the inner wall of the hyperbolic flow channel.

[0024] Furthermore, the inlet side is sealed with an inlet end cap, the outlet side is sealed with an outlet end cap, the surface of the inlet end cap is provided with a wastewater inlet pipe, the surface of the outlet end cap is provided with a wastewater outlet pipe, and the inlet end cap and outlet end cap are respectively fixed to the inlet side and outlet side of the device body by bolts.

[0025] The surface of the inlet end cap facing the hyperbolic cavitation discharge channel is formed with a connecting channel that is coaxial with the hyperbolic cavitation discharge channel.

[0026] The outlet end cap is inlaid with a discharge electrode, and the discharge electrode is insulated from the outlet end cap by an insulating material.

[0027] An elastic fixing device is fixed inside the connection channel. One end of the flexible high-voltage discharge needle is inserted into the discharge electrode, and the other end is connected to the elastic fixing device for fixation.

[0028] Furthermore, a circular impeller base is fixed inside the inlet end cover, and an impeller shaft is provided at the center of the bottom surface of the impeller base. A gas-liquid dispersion impeller is rotatably connected to the impeller shaft through a bearing. Several tangential through holes are evenly spaced on the outer circumferential side of the impeller base.

[0029] In the frontal view of the bottom surface of the impeller base, the geometric center of the outline of the tangential through hole on the outer wall of the impeller base, the radial line connecting the center of the bottom surface of the impeller base, and the central axis of the tangential through hole form an angle α of 30° to 45°.

[0030] Furthermore, the gas-liquid dispersion impeller includes a base plate and a plurality of crescent-shaped impeller blades. A central hole is provided at the geometric center of the bottom surface of the base plate. The central hole is rotatably connected to the impeller shaft on the same axis. The impeller blades are evenly and equidistantly distributed around the central hole in a circular shape. The crescent-shaped recesses of the impeller blades are directly opposite the tangential through holes and are inclined at the same angle as the tangential through holes.

[0031] This invention provides a hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer system, comprising a hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer device, a wastewater tank, a centrifugal pump, a venturi tube, an air pump, and a purified water tank; wherein, the inlet end of the centrifugal pump is connected to the wastewater tank and the outlet end is connected to the inlet end of the venturi tube, the inlet end of the venturi tube is connected to the air pump and the outlet end is connected to the wastewater inlet pipe, and the purified water tank is connected to the wastewater outlet pipe.

[0032] This invention provides a gas-liquid ozone mass transfer method based on hyperbolic spatial needle-shaped discharge, which is implemented using a hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer system, and includes the following steps:

[0033] Step 1: Turn off the centrifugal pump and turn on the air pump. Through the wastewater inlet pipe and wastewater outlet pipe, the air pump introduces air into the system, filling the entire internal cavity of the system with air.

[0034] Step 2: Connect the discharge electrode to the high-voltage power supply. The flexible high-voltage discharge needle, as the positive electrode of the dielectric barrier discharge, begins to discharge, causing the air in the internal cavity of the entire system to ionize in advance, forming ozone and other active substances that fill the internal cavity of the entire system.

[0035] Step 3: The wastewater tank contains industrial recalcitrant wastewater. Turn on the centrifugal pump to pump the industrial recalcitrant wastewater into the venturi tube, keeping the flow rate of the centrifugal pump 1.5 to 2 times that of the air pump, so that the wastewater and air are initially mixed with the industrial recalcitrant wastewater. During this process, the large air bubbles inside the industrial recalcitrant wastewater break down at the throat of the venturi tube, generating a large number of microbubbles containing air. The industrial recalcitrant wastewater containing microbubbles is pumped into the inlet end cap from the wastewater inlet pipe.

[0036] Step 4: The industrial wastewater containing microbubbles flows from the tangential through-hole to the crescent-shaped depression of the impeller blades, causing the gas-liquid dispersion impeller to rotate and break up the microbubbles in the industrial wastewater, so that the microbubbles are evenly distributed in the wastewater.

[0037] Step 5: The industrial recalcitrant wastewater containing microbubbles enters the hyperbolic cavitation discharge channel. The needle-shaped dielectric barrier discharge formed by the flexible high-voltage discharge needle and the hyperbolic flow channel ionizes and generates a large number of active substances in the hyperbolic cavitation discharge channel. At the same time, after the wastewater flows through the minimum cross-section of the hyperbolic flow channel, the strong cavitation effect generated at the pressure relief tank degrades the industrial recalcitrant wastewater.

[0038] Step 6: Check whether the organic matter removal rate of the degraded wastewater meets the standard. If it does not meet the standard, introduce the wastewater into the inlet end cap and repeat steps 4 and 5. If it meets the standard, discharge the wastewater into the water purification tank.

[0039] III. Beneficial Effects

[0040] The above one or more embodiments have the following advantages or benefits:

[0041] 1. This invention utilizes conductive rubber to fabricate a flexible high-voltage discharge needle, with an arc-shaped micro-channel inside and deformable grooves on the outside. The combination of these two elements alters the needle's strength at specific locations. When high-pressure gas is introduced into the arc-shaped micro-channels, it expands and deforms to achieve the desired shape, ensuring that the distance between the flexible high-voltage discharge needle and the inner wall of the hyperbolic cavitation discharge channel is uniform throughout. This reduces energy loss due to uneven local discharge, improves energy utilization efficiency, ensures uniformity in wastewater degradation, enhances degradation effectiveness, and increases the discharge area under the same discharge length conditions.

[0042] 2. This invention enhances the cavitation effect by incorporating a pressure release tank within a hyperbolic cavitation discharge channel. Cavitation is generated only at the pressure release tank, without affecting the overall flow rate, ensuring stable flow velocity throughout the hyperbolic cavitation discharge channel and resulting in more uniform degradation of organic matter. Simultaneously, the dielectric barrier discharge generates a large amount of active substances such as H2O2, which interact with hydroxyl radicals (·OH) produced by the strong cavitation effect at the pressure release tank, triggering a chain reaction that generates even more hydroxyl radicals. This further improves the degradation efficiency of recalcitrant industrial wastewater.

[0043] 3. In this invention, both the hyperbolic cavitation discharge channel and the flexible high-voltage discharge needle-shaped discharge surface are set to hyperbolic shape. Dielectric barrier discharge is performed on the hyperbolic surface, which increases the discharge area and thus significantly enhances the discharge effect. The ozone generated during the discharge process can decompose on its own in the air without producing any pollutants, effectively avoiding the problem of secondary pollution.

[0044] 4. In this invention, the industrial recalcitrant wastewater is first mixed in a Venturi tube. To achieve a more thorough mixing effect, a gas-liquid dispersion impeller is installed at the inlet side of the hyperbolic cavitation discharge channel to perform a secondary mixing of the industrial recalcitrant wastewater. The industrial recalcitrant wastewater enters through a tangential through-hole, and the water flow impacts the gas-liquid dispersion impeller, causing it to rotate. The rotation and shearing action of the gas-liquid dispersion impeller disperses the air bubbles in the wastewater. Through the synergistic effect of the Venturi tube and the gas-liquid dispersion impeller, uniform mixing of gas and liquid is achieved, so that the ozone, H2O2 and other active substances generated after air ionization can fully react with the organic pollutants in the industrial recalcitrant wastewater. Attached Figure Description

[0045] The above-described features, other objects, and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0046] Figure 1 This is a schematic diagram of a hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer system;

[0047] Figure 2 This is a schematic diagram of a hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer device.

[0048] Figure 3 This is a schematic diagram of the flexible high-voltage discharge needle during retraction;

[0049] Figure 4 This is a schematic diagram of the flexible high-voltage discharge needle during inflation and expansion.

[0050] Figure 5 This is a schematic diagram of the device body;

[0051] Figure 6This is a schematic diagram of the structure of the elastic fixing device;

[0052] Figure 7 This is a schematic diagram of the impeller base structure;

[0053] Figure 8 This is a schematic diagram of the middle section structure of the impeller base;

[0054] Figure 9 This is a schematic diagram of the structure of a gas-liquid dispersion impeller;

[0055] Figure 10 This is a flowchart of a gas-liquid ozone mass transfer method using hyperbolic spatial needle-shaped discharge;

[0056] 1. Water purification tank; 2. Hyperbolic space needle-shaped discharge gas-liquid ozone mass transfer device; 21. Outlet end cap; 211. Wastewater outlet pipe; 212. Discharge electrode; 22. Flexible high-voltage discharge needle; 221. Arc-shaped micro-air channel; 222. Deformed toothed groove; 23. Hyperbolic cavitation discharge channel; 231. Hyperbolic flow channel; 232. Pressure relief groove; 233. Insulating dielectric coating; 24. Elastic fixing device; 241. Inner ring ; 242, Elastic belt; 243, Outer ring; 25, Connecting channel; 26, Impeller base; 261, Tangential through hole; 262, Impeller shaft; 27, Inlet end cover; 271, Wastewater inlet pipe; 28, Gas-liquid dispersion impeller; 281, Impeller blades; 282, Center hole; 29, Device body; 29a-Inlet side; 29b-Outlet side; 3, Venturi tube; 4, Air pump; 5, Centrifugal pump; 6, Wastewater tank. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0058] It should be noted that, for clarity and / or descriptive purposes, the dimensions and relative dimensions of components may be enlarged in the accompanying drawings. Therefore, the dimensions and relative dimensions of the individual components are not necessarily limited to those shown in the drawings. In the specification and accompanying drawings, the same or similar reference numerals indicate the same or similar parts.

[0059] When an element is described as being "on" another element, "connected" to another element, or "bonded" to another element, the element may be directly on, directly connected to, or directly bonded to the other element, or there may be intermediate elements. However, when an element is described as being "directly on" another element, "directly connected" to another element, or "directly bonded" to another element, there are no intermediate elements. Other terms and / or expressions used to describe relationships between elements should be interpreted in a similar manner, such as "between" to "directly between," "adjacent" to "directly adjacent," or "on" to "directly on," etc. Furthermore, the term "connection" may refer to a physical connection, an electrical connection, a communication connection, and / or a fluid connection.

[0060] It should be noted that although the terms "first," "second," etc., may be used herein to describe various components, members, elements, regions, layers, and / or portions, these components, members, elements, regions, layers, and / or portions should not be limited by these terms. Rather, these terms are used to distinguish one component, member, element, region, layer, and / or portion from another. Thus, for example, the first component, first member, first element, first region, first layer, and / or first portion discussed below may be referred to as a second component, second member, second element, second region, second layer, and / or second portion without departing from the teachings of the invention.

[0061] For ease of description, spatial relation terms, such as “above,” “below,” “left,” “right,” etc., may be used herein to describe the relationship between one element or feature and another element or feature as shown in the figure. It should be understood that spatial relation terms are intended to cover other orientations of the device in use or operation besides those described in the figure. For example, if the device in the figure were inverted, an element described as “below” or “under” other elements or features would be oriented “above” or “on top” other elements or features.

[0062] Example 1:

[0063] This invention provides a hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer device 2. Please refer to [link / reference]. Figure 2 The device includes a main body 29 with several hyperbolic cavitation discharge channels 23 inside, and a flexible high-voltage discharge needle 22 penetrating inside the hyperbolic cavitation discharge channels 23. The flexible high-voltage discharge needle 22 degrades wastewater by discharging through a dielectric barrier within the hyperbolic cavitation channels. By setting the hyperbolic cavitation discharge channels 23 to a hyperbolic shape, the flow channel length is increased, extending the contact and reaction time between the industrial recalcitrant wastewater and ozone, as well as some high-energy active substances. This also increases the discharge area under the same discharge length conditions, thereby improving the degradation efficiency of the industrial recalcitrant wastewater.

[0064] Combined with reference Figure 5 In some specific embodiments, the device body 29 includes an inlet side 29a and an outlet side 29b, and the hyperbolic cavitation discharge channel 23 is connected between the inlet side 29a and the outlet side 29b. The hyperbolic cavitation discharge channel 23 includes at least a hyperbolic flow channel 231 that smoothly and symmetrically transitions from an enlarged middle section to both sides.

[0065] Preferably, at least two hyperbolic flow channels 231 are sequentially connected inside the hyperbolic cavitation discharge channel 23. The hyperbolic flow channels 231 adopt a circular cross-section design in the radial direction and a cross-sectional shape designed according to a multi-segment continuous half-sine curve configuration in the axial direction. The interval between adjacent hyperbolic flow channels 231 is about 10 to 15 mm. The multiple hyperbolic flow channels 231 increase the discharge area inside the hyperbolic cavitation discharge channel 23 as a whole.

[0066] In this embodiment, a pressure relief tank 232 is provided at the narrowest point of the hyperbolic cavitation discharge channel 23 at the junction of adjacent hyperbolic channels 231. When industrial recalcitrant wastewater passes through the narrowest point of the hyperbolic channel 231, due to the setting of the pressure relief tank 232, bubbles in the liquid rapidly form, expand, and collapse, generating a strong hydraulic cavitation phenomenon. When the bubbles collapse, a local high-temperature and high-pressure instantaneous environment is formed, and rapid micro-jet and strong shock waves are generated. This promotes the decomposition of water molecules and volatile pollutants, generating active substances such as hydroxyl radicals, hydrogen radicals, hydrogen peroxide radicals, and hydrogen peroxide. During the cavitation process, turbulence and pressure fluctuations optimize the mass transfer efficiency of the discharge area, promote the uniform action of plasma discharge on pollutants, and avoid scale buildup on the surface of the flexible high-voltage discharge needle. In addition, the energy released by cavitation collapse can also reduce the external energy input required for discharge. Moreover, since cavitation is generated by releasing pressure at the pressure relief tank 232, it does not affect the overall flow rate, ensuring stable flow velocity throughout the hyperbolic cavitation discharge channel 23, resulting in a more uniform degradation effect on organic matter.

[0067] The pressure relief tank 232 has a parabolic or rectangular cross-section in the axial direction. The specific cross-sectional shape is customized according to specific application requirements and flow velocity conditions, thereby optimizing fluid dynamics and improving the degradation efficiency of industrial recalcitrant wastewater.

[0068] Within the hyperbolic cavitation discharge channel 23, the flexible high-pressure discharge needle 22 is filled with high-pressure gas. The surface of the flexible high-pressure discharge needle 22 expands and deforms into a hyperbolic shape to adapt to the inner wall shape of the hyperbolic flow channel 231, maintaining equidistant spacing with the inner wall of the hyperbolic cavitation discharge channel 23 at all points. This ensures that the plasma discharge gap is equal everywhere, guaranteeing a uniform and stable discharge voltage when the flexible high-pressure discharge needle 22 discharges inside the hyperbolic flow channel 231. This enhances the discharge effect, strengthens the discharge efficiency, and increases the discharge output of ozone and other active substances. The flexible high-pressure discharge needle 22 can be freely processed according to the required length. Depending on different usage scenarios and degradation requirements, an appropriate length can be selected to improve degradation efficiency, save resources, meet degradation requirements, and achieve optimal degradation efficiency.

[0069] In this embodiment, the flexible high-voltage discharge needle 22 serves as the high-voltage positive electrode, and the hyperbolic cavitation discharge channel 23 is grounded as the negative electrode. Wastewater containing dispersed microbubbles flows into the inlet side 29a of the hyperbolic cavitation discharge channel 23. As the wastewater flows from the inlet side 29a to the outlet side 29b, dielectric barrier discharge occurs within the hyperbolic channel 231, ionizing the air within the microbubbles and generating a large amount of active substances such as ozone. Simultaneously, when the recalcitrant industrial wastewater passes through the narrowest point of the hyperbolic channel 231, bubbles rapidly form, expand, and collapse at the pressure release tank 232, generating a strong hydraulic cavitation phenomenon. The generation of a large amount of active substances through dielectric barrier discharge, combined with the strong cavitation effect caused by the sudden pressure drop at the pressure relief tank, significantly improves the generation efficiency of ozone and active substances. The high concentration of oxygen free radicals generated during hydraulic cavitation interacts with the active oxides generated by discharge ionization, further promoting the generation of free radicals. For example, when the ·OH generated by hydraulic cavitation reacts with the H2O2 generated by discharge ionization, more ·OH is generated, forming a chain reaction mechanism. In addition, the collapse of bubbles in hydraulic cavitation and the microbubbles and microjets can enhance the discharge ionization effect. Microbubbles can act as a discharge medium to promote discharge ionization, while microjets can enhance the turbulence of the solution, promote the diffusion and reaction of free radicals, avoid scale buildup on the surface of the flexible high-voltage discharge needle, and increase the contact area and reaction time between ozone and active substances and industrial recalcitrant wastewater, effectively increasing the yield of hydroxyl free radicals and thus improving the degradation rate of industrial recalcitrant wastewater.

[0070] In one embodiment of the present invention, the flexible high-voltage discharge needle 22 is 3D printed from conductive rubber, and its outer surface is uniformly covered with an insulating dielectric coating 233 by electroplating. The conductive rubber has excellent elasticity, can deform under external force and return to its original shape after the external force is removed, and also has good conductivity, ensuring the high efficiency and stability of the discharge needle during operation. The electroplating process ensures the uniformity of the coating, provides consistent insulation performance, and prevents current leakage and short circuits. The insulating dielectric coating 233 is preferably made of polyvinylidene fluoride resin, which has good chemical stability, thermal stability and compatibility with the conductive rubber substrate. The coating can provide continuous protection throughout the entire service life of the discharge needle, ensuring the long-term stable operation of the device.

[0071] In addition, an insulating dielectric coating 233 is uniformly coated on the surfaces of the hyperbolic flow channel 231 and the pressure relief tank 232 by electroplating, which ensures the uniformity and adhesion of the coating and prevents the current from directly contacting the water body and forming a dielectric barrier discharge.

[0072] The flexible high-voltage discharge needle 22 has an arc-shaped micro-airway 221 formed inside. In the axial cross-section, the angle of inclination of the inner wall of the arc-shaped micro-airway 221 relative to the central axis of the flexible high-voltage discharge needle 22 exhibits a symmetrical gradient: the inclination angle at the inlet section increases from 0° to 15°, and then symmetrically decreases back to 0° after passing through the throat region, preventing excessive weakening of the overall strength and thus avoiding rupture when high-pressure gas is introduced. The outer wall of the flexible high-voltage discharge needle 22 is provided with multiple deformable grooves 222, located at the point where the inner diameter of the arc-shaped micro-airway 221 is largest and the outer wall of the flexible high-voltage discharge needle 22 is thinnest. When the flexible high-voltage discharge needle 22 is filled with gas, the deformable grooves 222 act as thinner... The weak points bulge outwards, causing the outer wall of the flexible high-voltage discharge needle 22 to expand and deform to match the shape of the hyperbolic flow channel 231 and to be equidistant from the gaps in the inner wall of the hyperbolic flow channel 231. That is, the main body is made of flexible conductive rubber. Therefore, by introducing high-pressure gas into the arc-shaped micro-air channel 221, the influence of the arc-shaped micro-air channel 221 and the deformed groove 222 on the overall shape and strength of the flexible high-voltage discharge needle 22 causes the surface of the flexible high-voltage discharge needle 22 to expand and deform into a hyperbolic surface, which is used to adapt to the shape of the hyperbolic flow channel 231 and control the gaps in all parts of the hyperbolic flow channel 231 to maintain consistency. This makes the discharge inside the hyperbolic flow channel 231 more uniform, enhances the discharge efficiency, and increases the ozone and other active substances generated by the discharge.

[0073] The inlet side 29a is sealed with an inlet end cap 27, and the outlet side 29b is sealed with an outlet end cap 21. The surface of the inlet end cap 27 is provided with a wastewater inlet pipe 271, and the surface of the outlet end cap 21 is provided with a wastewater outlet pipe 211. The inlet end cap 27 and the outlet end cap 21 are respectively fixed to the inlet side 29a and the outlet side 29b of the device body 29 by bolts.

[0074] The discharge electrode 212 is embedded inside the outlet end cap 21, and the discharge electrode 212 is insulated from the outlet end cap 21 by an insulating material.

[0075] The inlet end cap 27 has a connecting channel 25 formed on the side facing the hyperbolic cavitation discharge channel 23, which is coaxial with the hyperbolic cavitation discharge channel 23. An elastic fixing device 24 is fixed inside the connecting channel 25. One end of the flexible high-voltage discharge needle 22 is inserted into the discharge electrode 212 and the other end is fixed by the elastic fixing device 24. When the industrial recalcitrant wastewater enters the hyperbolic flow channel 231, the discharge electrode 212 turns on the high voltage, and the hyperbolic cavitation discharge pipe is grounded as the negative electrode. Dielectric barrier discharge is performed in the hyperbolic flow channel 231 to ionize the air in the microbubbles in the industrial recalcitrant wastewater and generate a large number of active substances such as ozone.

[0076] The elastic fixing device 24 is made entirely of corrosion-resistant elastic insulating material and includes an inner ring 241 and an outer ring 243 coaxially arranged. The inner ring 241 and the outer ring 243 are connected by multiple equally spaced elastic bands 242. The inner ring 241 is elastically and tightly fitted onto the outer end of the flexible high-voltage discharge needle 22. The outer ring 243 is fixed to the inner wall of the connecting channel 25, specifically by embedding it into the inner side of the connecting channel 25, or by a detachable method such as a snap-fit ​​for easy replacement. The inner ring 241 stabilizes the relative position of the flexible high-voltage discharge needle 22 and the connecting channel 25, and at the same time allows the flexible high-voltage discharge needle 22 to quickly return to its original position when it vibrates due to the impact of wastewater, avoiding short circuits caused by direct contact with the hyperbolic cavitation discharge pipe or the connecting channel 25 during the discharge process.

[0077] In some embodiments, a circular impeller base 26 is fixed inside the inlet end cap 27, and an impeller shaft 262 is provided at the center of the bottom surface of the impeller base 26. A gas-liquid dispersion impeller 28 is rotatably connected to the impeller shaft 262 via a bearing. A plurality of tangential through holes 261 are evenly spaced on the outer circumference of the outer wall of the impeller base 26. Preferably, eight tangential through holes 261 are circumferentially distributed on the outer wall of the impeller base 26, and wastewater enters the chamber of the impeller base 26 evenly from eight directions. In the frontal view of the bottom surface of the impeller base 26, the geometric center of the contour line of the intersection of the tangential through holes 261 on the outer wall surface of the impeller base 26, the radial line connecting the center of the bottom surface of the impeller base 26, and the central axis of the tangential through hole 261 form an angle α of 30° to 45°.

[0078] The gas-liquid dispersion impeller 28 includes a base plate and a plurality of crescent-shaped impeller blades 281. A central hole 282 is provided at the geometric center of the bottom surface of the base plate. The central hole 282 is coaxially rotatably connected to the impeller shaft 262. The impeller blades 281 are evenly and equidistantly distributed in a circular shape around the central hole 282 to ensure uniform distribution of fluid among the impeller blades 281 and optimize gas-liquid mixing efficiency. The crescent-shaped recesses of the impeller blades 281 are directly opposite the tangential through hole 261 and are inclined at the same tilt angle as the tangential through hole 261. The crescent-shaped blades help improve fluid dynamic performance, enabling the impeller to more effectively absorb and disperse energy in the water flow. The inclined arrangement of the tangential through hole 261 and the impeller blades 281 allows the impeller blades 281 to receive the water flow impact from the tangential through hole 261 in the best way, thereby maximizing energy conversion efficiency. When wastewater enters the impeller base 26 through the tangential through-hole 261, the kinetic energy of the water flow is absorbed by the impeller blades 281 and converted into the rotational kinetic energy of the gas-liquid dispersion impeller 28. Preferably, there are 10 impeller blades 281 in total, which balance the flow rate and keep the gas-liquid dispersion impeller 28 under uniform force, thus fully absorbing the impact force brought by the wastewater.

[0079] Industrial recalcitrant wastewater enters the gap between the inlet end cover 27 and the impeller base 26 through the wastewater inlet pipe 271. Under pressure, the wastewater enters tangentially through the tangential through hole 261 of the impeller base 26 and rotates by impacting the gas-liquid dispersion impeller 28. The rotation of the gas-liquid dispersion impeller 28 dissipates the impact kinetic energy generated by the wastewater, reducing the impact on the flexible high-voltage discharge needle 22. At the same time, the stirring action of the gas-liquid dispersion impeller 28 can fully mix the gas and wastewater. The rotation of the gas-liquid dispersion impeller 28 can also produce a certain cavitation effect, and disperse the large bubbles in the wastewater into small bubbles and make the small bubbles evenly distributed in the wastewater, increasing the contact area between the gas and the wastewater, and improving the degradation effect of subsequent high-voltage discharge and hydraulic cavitation.

[0080] Example 2:

[0081] This invention provides a hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer system, comprising a hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer device 2 as shown in Example 1, a wastewater tank 6, a centrifugal pump 5, a venturi tube 3, an air pump 4, and a purified water tank 1; wherein, the inlet end of the centrifugal pump 5 is connected to the wastewater tank 6, and the outlet end is connected to the inlet end of the venturi tube 3, the inlet end of the venturi tube 3 is also connected to the air pump 4, and the outlet end is connected to the wastewater inlet pipe 271, and the purified water tank 1 is connected to the wastewater outlet pipe 211.

[0082] Air is initially mixed with wastewater in wastewater tank 6 by the air pump 4 in the venturi tube 3. The mixed wastewater is then sent by the centrifugal pump 5 into the hyperbolic space needle discharge gas-liquid ozone mass transfer device 2. In the hyperbolic space needle discharge gas-liquid ozone mass transfer device 2, ozone and active substances such as hydroxyl radicals are generated through a combination of needle discharge and cavitation to degrade the industrial wastewater, which is finally discharged into the water purification tank 1.

[0083] In this embodiment, the industrial recalcitrant wastewater is mixed once in the Venturi tube 3 and then mixed a second time at the inlet by a gas-liquid dispersion impeller 28. The industrial recalcitrant wastewater enters through the tangential through-hole, and the water flow impacts the gas-liquid dispersion impeller 28, causing it to rotate. The rotation and shearing action of the gas-liquid dispersion impeller 28 disperses the air bubbles in the wastewater. The combination of the Venturi tube 3 and the gas-liquid dispersion impeller 28 achieves uniform mixing of gas and liquid, allowing active substances such as ozone generated after air ionization to fully react with the organic pollutants in the industrial recalcitrant wastewater.

[0084] Example 3:

[0085] This invention provides a gas-liquid ozone mass transfer method based on hyperbolic spatial needle-shaped discharge, which is implemented using a hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer system as described in Example 2, and includes the following steps:

[0086] Step 1: Turn off centrifugal pump 5, turn on air pump 4, wastewater inlet pipe 271, and wastewater outlet pipe 211. Air pump 4 introduces air into the system, so that the air fills the entire internal cavity of the system.

[0087] Step 2: The discharge electrode 212 is connected to the high-voltage power supply. The flexible high-voltage discharge needle 22, as the positive electrode of the dielectric barrier discharge, begins to discharge, causing the air in the internal cavity of the entire system to be ionized in advance, forming ozone and other active substances that fill the internal cavity of the entire system.

[0088] Step 3: Wastewater tank 6 contains industrial recalcitrant wastewater. Centrifugal pump 5 is turned on to pump the industrial recalcitrant wastewater into venturi tube 3. The flow rate of centrifugal pump 5 is maintained at 1.5 to 2 times that of air pump 4, so that the wastewater and air are initially mixed with the industrial recalcitrant wastewater. During this process, the large air bubbles inside the industrial recalcitrant wastewater break down at the throat of venturi tube 3, generating a large number of microbubbles containing air. The industrial recalcitrant wastewater containing microbubbles is pumped from wastewater inlet pipe 271 into inlet end cap 27.

[0089] Step 4: The industrial wastewater containing microbubbles flows from the tangential through-hole 261 to the crescent-shaped depression of the impeller blade 281, causing the gas-liquid dispersion impeller 28 to rotate and break up the microbubbles in the industrial wastewater, so that the microbubbles are evenly distributed in the wastewater.

[0090] Step 5: The industrial recalcitrant wastewater containing microbubbles enters the hyperbolic cavitation discharge channel 23. Through the needle-shaped dielectric barrier discharge formed by the flexible high-voltage discharge needle 22 and the hyperbolic flow channel 231, a large number of active substances are generated in the hyperbolic cavitation discharge channel 23. At the same time, after the wastewater flows through the minimum cross-section of the hyperbolic flow channel 231, the strong cavitation effect generated at the pressure release tank 232 degrades the industrial recalcitrant wastewater.

[0091] Step 6: Check whether the organic matter removal rate of the degraded wastewater meets the standard. If it does not meet the standard, introduce the wastewater into the inlet end cap 27 and repeat steps 4 and 5. If it meets the standard, discharge the wastewater into the water purification tank 1.

[0092] Optionally, in step 5, the degraded industrial recalcitrant wastewater is tested. If the concentration of pollutants in the industrial recalcitrant wastewater is too high, the inlet flow rates of the air pump 4 and the centrifugal pump 5 can be adjusted to change the inlet flow rates of the air and the industrial recalcitrant wastewater, thereby improving the degradation effect.

[0093] The embodiments of the present invention have been described above. However, these embodiments are merely illustrative and not intended to limit the scope of the invention. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of the invention, and all such substitutions and modifications should fall within the scope of the invention.

Claims

1. A hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer device, characterized in that, include: The device body (29) has several hyperbolic cavitation discharge channels (23) inside. The device body (29) includes an inlet side (29a) and an outlet side (29b). The hyperbolic cavitation discharge channels (23) are connected between the inlet side (29a) and the outlet side (29b). The hyperbolic cavitation discharge channels (23) include at least a section of hyperbolic flow channel (231) that smoothly and symmetrically tapers from the expanded middle part to both sides. A flexible high-voltage discharge needle (22) penetrates the interior of the hyperbolic cavitation discharge channel (23); and inside the hyperbolic cavitation discharge channel (23), the flexible high-voltage discharge needle (22) is a hollow cylinder before deformation. When high-pressure gas is injected into the arc-shaped micro-air channel (221), the deformable tooth groove (222) of the flexible high-voltage discharge needle (22) expands and deforms to form an outer wall shape that can maintain equidistant from the gap between the inner wall of the hyperbolic cavitation discharge channel (23); The flexible high-voltage discharge needle (22) serves as the high-voltage positive electrode, and the hyperbolic cavitation discharge channel (23) is grounded as the negative electrode. Organic wastewater containing microbubbles is pumped into the inlet side (29a) of the hyperbolic cavitation discharge channel (23). During the flow of the wastewater from the inlet side (29a) to the outlet side (29b), dielectric barrier discharge is performed in the hyperbolic flow channel (231) to discharge and ionize the microbubbles in the wastewater.

2. The hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer device according to claim 1, characterized in that, The hyperbolic cavitation discharge channel (23) is connected in sequence with at least two hyperbolic flow channels (231). The hyperbolic flow channel (231) adopts a circular cross-section design in the radial direction and the cross-sectional shape is designed according to a multi-segment continuous half-sine curve configuration in the axial direction. The hyperbolic cavitation discharge channel (23) is provided with a pressure relief groove (232) at the narrowest point of the junction of adjacent hyperbolic flow channels (231); An insulating dielectric coating (233) is uniformly applied to the surfaces of the hyperbolic flow channel (231) and the pressure relief groove (232) by an electroplating process.

3. The hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer device according to claim 2, characterized in that, The pressure relief groove (232) has a parabolic or rectangular flow channel in the axial direction.

4. The hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer device according to claim 3, characterized in that, The flexible high-voltage discharge needle (22) is 3D printed from conductive rubber, and its outer surface is also uniformly covered with an insulating dielectric coating (233) by electroplating. The flexible high-voltage discharge needle (22) has an arc-shaped micro-airway (221) inside. On the axial cross-section, the angle of inclination of the inner wall of the arc-shaped micro-airway (221) relative to the central axis of the flexible high-voltage discharge needle presents a symmetrical gradual change feature: the inclination angle of the inlet section of the flow channel increases from 0° to 15°, and then decreases back to 0° symmetrically after passing through the throat region. The flexible high-voltage discharge needle (22) has multiple deformable grooves (222) on its outer wall. The deformable grooves (222) are located at the point where the inner diameter of the arc-shaped micro-air channel (221) is the largest and the outer wall of the flexible high-voltage discharge needle (22) is the thinnest. When the flexible high-voltage discharge needle (22) is filled with air, the deformable grooves (222) bulge outward as weak points, causing the outer wall of the flexible high-voltage discharge needle (22) to expand and deform to be consistent with the shape of the hyperbolic flow channel (231) and equidistant from the gaps in the inner wall of the hyperbolic flow channel (231).

5. The hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer device according to claim 2, characterized in that, An inlet end cap (27) is sealed to the inlet side (29a), and an outlet end cap (21) is sealed to the outlet side (29b). A wastewater inlet pipe (271) is provided on the surface of the inlet end cap (27), and a wastewater outlet pipe (211) is provided on the surface of the outlet end cap (21). The inlet end cap (27) and the outlet end cap (21) are respectively fixed to the inlet side (29a) and the outlet side (29b) of the device body (29) by bolts. The inlet end cap (27) has a connecting channel (25) on one side of the hyperbolic cavitation discharge channel (23) that is coaxial with the hyperbolic cavitation discharge channel (23); The outlet end cap (21) is inlaid with a discharge electrode (212), and the discharge electrode (212) and the outlet end cap (21) are insulated and isolated by an insulating material; An elastic fixing device (24) is fixed inside the connection channel (25). One end of the flexible high-voltage discharge needle (22) is inserted into the discharge electrode (212), and the other end is connected to the elastic fixing device (24) for fixing.

6. The hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer device according to claim 5, characterized in that, The elastic fixing device (24) includes an inner ring (241) and an outer ring (243) arranged coaxially. The inner ring (241) and the outer ring (243) are connected by multiple elastic bands (242) arranged at equal intervals. The inner ring (241) is elastically and tightly fitted to the outer side of the end of the flexible high-voltage discharge needle (22), and the outer ring (243) is fixed to the inner wall of the connecting channel (25).

7. The hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer device according to claim 5, characterized in that, A circular impeller base (26) is fixed inside the inlet end cover (27). An impeller shaft (262) is provided at the center of the bottom surface of the impeller base (26). A gas-liquid dispersion impeller (28) is rotatably connected to the impeller shaft (262) through a bearing. Several tangential through holes (261) are evenly spaced on the outer side wall of the impeller base (26). In the frontal view of the bottom surface of the impeller base (26), the geometric center of the outline of the tangential through hole (261) intersecting the outer wall surface of the impeller base (26) and the radial line connecting the center of the bottom surface of the impeller base (26) and the central axis of the tangential through hole (261) form an angle α of 30° to 45°.

8. The hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer device according to claim 7, characterized in that, The gas-liquid dispersion impeller (28) includes a base plate and several crescent-shaped impeller blades (281). A central hole (282) is provided at the geometric center of the bottom surface of the base plate. The central hole (282) is coaxially rotatably connected to the impeller shaft (262). The impeller blades (281) are evenly and equidistantly distributed around the central hole (282). The crescent-shaped recesses of the impeller blades (281) are directly opposite the tangential through hole (261) and are inclined at the same angle as the tangential through hole (261).

9. A hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer system, characterized in that, The device includes a hyperbolic spatial needle-shaped discharge gas-liquid ozone mass transfer device as described in claims 1-8, and a wastewater tank (6), a centrifugal pump (5), a venturi tube (3), an air pump (4), and a water purification tank (1); wherein the inlet end of the centrifugal pump (5) is connected to the wastewater tank (6), and the outlet end is connected to the inlet end of the venturi tube (3); the inlet end of the venturi tube (3) is also connected to the air pump (4), and the outlet end is connected to the wastewater inlet pipe (271); and the water purification tank is connected to the wastewater outlet pipe (211).

10. A gas-liquid ozone mass transfer method using hyperbolic spatial needle-shaped discharge, implemented using the gas-liquid ozone mass transfer system of hyperbolic spatial needle-shaped discharge as described in claim 9, characterized in that... Includes the following steps: Step 1: Turn off the centrifugal pump (5), turn on the air pump (4), wastewater inlet pipe (271), and wastewater outlet pipe (211). The air pump (4) introduces air into the system, so that the air fills the entire internal cavity of the system. Step 2: The discharge electrode (212) is connected to the high voltage power supply, and the flexible high voltage discharge needle (22) starts to discharge as the positive electrode of the dielectric barrier discharge, so that the air in the cavity inside the entire system is ionized in advance, forming ozone and other active substances that fill the cavity inside the entire system. Step 3: The wastewater tank (6) contains industrial recalcitrant wastewater. The centrifugal pump (5) is turned on to pump the industrial recalcitrant wastewater into the venturi tube (3). The flow rate of the centrifugal pump (5) is kept 1.5 to 2 times that of the air pump (4) to allow the wastewater and air to be initially mixed with the industrial recalcitrant wastewater. The large air bubbles inside the industrial recalcitrant wastewater break at the throat of the venturi tube (3) to generate a large number of microbubbles with air. The industrial recalcitrant wastewater with microbubbles is pumped from the wastewater inlet pipe (271) into the inlet end cap (27). Step 4: The industrial wastewater containing microbubbles flows from the tangential through hole (261) to the crescent-shaped depression of the impeller blade (281), causing the gas-liquid dispersion impeller (28) to rotate and break up the microbubbles in the industrial wastewater, so that the microbubbles are evenly distributed in the wastewater. Step 5: The industrial recalcitrant wastewater containing microbubbles enters the hyperbolic cavitation discharge channel (23). Through the needle-shaped dielectric barrier discharge formed by the flexible high-voltage discharge needle (22) and the hyperbolic flow channel (231), a large amount of active substances are generated in the hyperbolic cavitation discharge channel (23). At the same time, after the wastewater in the hyperbolic cavitation discharge channel (23) flows through the minimum cross-section of the hyperbolic flow channel (231), the strong cavitation effect generated at the pressure release tank (232) degrades the industrial recalcitrant wastewater. Step 6: Check whether the organic matter removal rate of the degraded wastewater meets the standard. If it does not meet the standard, introduce the wastewater into the inlet end cap (27) and repeat steps 4 and 5. If it meets the standard, discharge the wastewater into the water purification tank.

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