Hyperbolic space needle-shaped discharge gas-liquid ozone mass transfer device, system and method

Abstract

The invention relates to a hyperbolic space needle-shaped discharge gas-liquid ozone mass transfer device, system and method, the hyperbolic space needle-shaped discharge gas-liquid ozone mass transfer device comprises a device body internally provided with a plurality of hyperbolic cavitation discharge channels, and the device body comprises an inlet side and an outlet side; the hyperbolic cavitation discharge channel at least comprises a section of hyperbolic flow channel which is in smooth and gradual shrinkage transition from the expanded middle part to the two sides in a symmetrical shape; the flexible high-voltage discharge needle penetrates through the inside of the hyperbolic cavitation discharge channel; and in the hyperbolic cavitation discharge channel, the arc-shaped micro-air channel of the flexible high-voltage discharge needle is filled with high-pressure gas, so that the gap between the outer surface of the flexible high-voltage discharge needle and the inner wall of the hyperbolic cavitation discharge channel is kept constant and equidistant, and the discharge area is increased under the condition of the same discharge length. The cavitation effect is enhanced by arranging the pressure release groove, a large number of active substances are generated through dielectric barrier discharge, and the degradation efficiency of the industrial degradation-resistant wastewater is further improved in cooperation with the strong cavitation effect generated at the pressure release groove due to sudden pressure reduction.

Description

Technical Field

[0001] The invention relates to the technical field of organic sewage treatment, and in particular to a hyperbolic space needle-shaped discharge gas-liquid ozone mass transfer device, system and method. Background Art

[0002] With the rapid development of modern industrialization and urbanization, the discharge of industrial refractory wastewater has continued to increase, posing a serious threat to the ecological environment. Traditional wastewater treatment technologies, such as Fenton oxidation, photocatalysis and biodegradation, usually have disadvantages such as long treatment time, risk of secondary pollution, and susceptibility to temperature and environment. In recent years, ozone oxidation has attracted attention from the environmental engineering community as a new type of industrial refractory wastewater treatment technology. When ozone is dissolved in water, it not only directly reacts with organic matter to oxidize it, but also decomposes to produce hydroxyl radicals (HO·), which also react with organic molecules. Since hydroxyl radicals (HO·) have stronger oxidizing ability than ozone and a faster reaction rate, they play a leading role in the degradation process. Ozone oxidation technology is considered to be a very promising industrial refractory wastewater treatment technology due to its advantages such as rapid treatment, high pollutant removal rate and no secondary pollution.

[0003] The invention patent "Organic waste gas degradation method based on dielectric barrier discharge" with publication number CN112076596A invented a method for organic waste gas degradation based on dielectric barrier discharge, wherein the dielectric barrier discharge low-temperature plasma reactor is a coaxial tubular dielectric barrier discharge low-temperature plasma reactor, including a high-voltage electrode, a grounding electrode, and a barrier medium tube, wherein the tubular high-voltage electrode located in the center is coaxially sleeved in the barrier medium tube, and the grounding electrode is wrapped on the outer wall of the barrier medium tube, and the discharge area of ​​the device is the gap between the tubular outer wall and the tubular inner wall. Although this traditional tubular dielectric barrier discharge can improve the degradation efficiency of organic waste gas, its equipment is large in size and high in energy consumption, and the tubular high-voltage electrode therein has a single shape, a limited discharge area, and few high-energy active particles are generated, making it difficult to improve the degradation efficiency of industrial difficult-to-degrade wastewater.

[0004] The invention patent "An underwater low-temperature plasma wastewater treatment method and device" with publication number CN105060408B invented an underwater low-temperature plasma wastewater treatment method and device, which consists of a pretreatment device, a high-voltage pulse power supply, a low-temperature plasma box with a built-in conductive electrode, etc. The high-voltage pulse power supply is mainly used to directly discharge the pretreated sewage through the conductive electrode. Although this method can use the high-energy active particles generated by the discharge to degrade organic matter, the degradation method is single and only relies on the high-energy active particles generated by the discharge to degrade, the material transfer efficiency is low, and the degradation efficiency is not high.

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

[0006] First, currently, discharge needles of regular shapes are mostly used. When facing irregular flow channels, the discharge needle cannot make adaptive adjustments following the shape of the pipe, resulting in a non-equidistant distribution of the plasma discharge gap between the surface of the discharge needle and the inner wall of the flow channel. It is impossible to maintain a constant discharge gap, resulting in uneven local discharge and additional energy loss, which seriously limits the discharge effect.

[0007] Second, in the case of difficult-to-degrade wastewater, although the existing technology combines hydrodynamic cavitation with plasma discharge technology, the two are set in separate degradation process units. This separate design makes it difficult for the highly active substances generated by plasma discharge to act on the cavitation bubble group formed in the hydrodynamic cavitation area in a timely manner, which greatly limits the strong oxidizing performance of the active substances, thereby restricting the further improvement of the degradation efficiency.

[0008] Third, the existing devices only achieve the mixing of ozone and wastewater through simple aeration, and lack efficient gas-liquid mixing devices. Since the active substances (such as hydroxyl radicals, high-energy electrons and excited molecules) generated by plasma discharge have the characteristics of short liquid phase half-life, they are easily inactivated by diffusion and non-target reactions, resulting in large-scale consumption. These active substances fail to fully mix with the difficult-to-degrade wastewater, which limits the efficient use of their strong oxidizing properties and affects the degradation effect. Summary of the invention

[0009] 1. Technical issues to be solved

[0010] The object of the present invention is to provide a gas-liquid ozone mass transfer device, system and method for hyperbolic space needle discharge, which realizes uniform flow rate control and equal plasma discharge gap everywhere by setting a flexible and deformable high-voltage discharge needle and a pressure release groove in a hyperbolic cavitation discharge pipeline, thereby improving the degradation effect of industrial wastewater that is difficult to degrade.

[0011] 2. Technical Solution

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

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

[0014] A device body having a plurality of hyperbolic cavitation discharge channels inside, the device body including an inlet side and an outlet side, the hyperbolic cavitation discharge channels communicating between the inlet side and the outlet side, the hyperbolic cavitation discharge channels including at least one hyperbolic flow channel symmetrically and smoothly tapering from an expanded middle portion to both sides;

[0015] A flexible high-voltage discharge needle is inserted into the hyperbolic cavitation discharge channel; in the hyperbolic cavitation discharge channel, the flexible high-voltage discharge needle is filled with high-pressure gas and has an outer wall shape capable of maintaining an equidistant gap with the inner wall of the hyperbolic cavitation discharge channel;

[0016] Among them, the flexible high-voltage discharge needle serves as a high-voltage positive electrode, and the hyperbolic cavitation discharge channel is grounded as a negative electrode; wastewater with dispersed microbubbles flows into the inlet side of the hyperbolic cavitation discharge channel, and dielectric barrier discharge is performed in the hyperbolic flow channel during the flow of the wastewater from the inlet side to the outlet side, so as to ionize the microbubbles in the organic wastewater.

[0017] Furthermore, at least two hyperbolic flow channels are sequentially connected inside the hyperbolic cavitation discharge channel, and the hyperbolic flow channel (231) is designed with a circular cross section in the radial direction, and the cross-sectional shape is designed according to a plurality of continuous half-sine curve configurations in the axial direction;

[0018] The hyperbolic cavitation discharge channel is provided with a pressure release groove at the narrowest point where adjacent hyperbolic flow channels intersect;

[0019] An insulating dielectric coating is evenly distributed on the surfaces of the hyperbolic flow channel and the pressure relief groove through an electroplating process.

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

[0021] Furthermore, the flexible high-voltage discharge needle is formed by 3D printing of conductive rubber, and its outer surface is evenly covered with an insulating dielectric coating by electroplating;

[0022] An arc-shaped micro-airway is formed in the flexible high-voltage discharge needle. In the axial cross section, the inclination angle of the inner wall of the arc-shaped micro-airway relative to the central axis of the flexible high-voltage discharge needle presents a symmetrical gradual change feature: the inclination angle of the flow channel entrance section increases from 0° to 15°, and decreases symmetrically back to 0° after passing through the throat area.

[0023] The outer wall of the flexible high-voltage discharge needle is provided with a plurality of deformable tooth grooves, and the deformable tooth grooves are arranged at the position where the inner diameter of the arc-shaped micro-airway 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 inflated, the deformable tooth grooves bulge outward as weak points to expand and deform the outer wall of the flexible high-voltage discharge needle to be consistent with the shape of the hyperbolic flow channel, and the gap with the inner wall of the hyperbolic flow channel is equidistant at all places.

[0024] Further, the inlet side is sealedly connected with an inlet end cover, the outlet side is sealedly connected with an outlet end cover, a wastewater inlet pipe is arranged on the surface of the inlet end cover, a wastewater outlet pipe is arranged on the surface of the outlet end cover, and the inlet end cover and the outlet end cover are respectively fixed to the inlet side and the outlet side of the device body by bolts;

[0025] A connecting channel corresponding to the hyperbolic cavitation discharge channel in a one-to-one and coaxial manner is formed on a surface of the inlet end cover facing the hyperbolic cavitation discharge channel;

[0026] The outlet end cover is inlaid with a discharge electrode, and the discharge electrode and the outlet end cover are insulated and isolated by an insulating material;

[0027] An elastic fixing device is fixed in the connecting 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 fixing.

[0028] Furthermore, a circular impeller base is fixed in the inlet end cover, an impeller shaft is arranged 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, and a plurality of tangential through holes are evenly spaced in the circumferential direction on the outer wall of the impeller base;

[0029] In the front view direction of the bottom surface of the impeller base, the geometric center of the intersecting contour line of the tangential through hole on the outer wall surface of the impeller base, the radial line connected to 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 center hole is opened at the geometric center of the bottom surface of the base plate. The center hole is coaxially rotatably connected to the impeller shaft, and the impeller blades are evenly and equidistantly distributed in a circular shape around the center hole; the crescent-shaped recess of the impeller blade is directly opposite to the tangential through hole and is arranged to be inclined at the same inclination angle as the tangential through hole.

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

[0032] The present invention provides a hyperbolic space needle-shaped discharge gas-liquid ozone mass transfer method, which is implemented by a hyperbolic space needle-shaped discharge gas-liquid ozone mass transfer system, and comprises the following steps:

[0033] Step 1: Turn off the centrifugal pump, turn on the air pump, and introduce air into the system through the wastewater inlet pipe and the wastewater outlet pipe air pump to fill the entire internal cavity of the system with air;

[0034] Step 2: The discharge electrode is connected to a high-voltage power supply, and the flexible high-voltage discharge needle acts as the positive electrode of the dielectric barrier discharge to start discharging, so that the air in the internal cavity of the entire system is ionized in advance, forming active substances such as ozone that fill the internal cavity of the entire system;

[0035] Step 3: Industrial refractory wastewater is stored in the wastewater pool. The centrifugal pump is turned on to pump the industrial refractory wastewater into the venturi tube, and the flow rate of the centrifugal pump is maintained at 1.5 to 2 times the flow rate of the air pump, so that the wastewater and air are preliminarily mixed with the industrial refractory wastewater; wherein, the large bubbles inside the industrial refractory wastewater are broken at the throat of the venturi tube to generate a large number of microbubbles containing air; the industrial refractory wastewater containing microbubbles is pumped from the wastewater inlet pipe into the inlet end cover;

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

[0037] Step 5: The industrial refractory wastewater with microbubbles enters the hyperbolic cavitation discharge channel, and is ionized to generate a large amount of active substances in the hyperbolic cavitation discharge channel through the needle-shaped dielectric barrier discharge formed by the flexible high-voltage discharge needle and the hyperbolic flow channel. At the same time, after the wastewater in the hyperbolic cavitation discharge channel flows through the minimum cross-sectional position of the hyperbolic flow channel, the strong cavitation effect generated at the pressure release groove degrades the industrial refractory wastewater;

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

[0039] 3. Beneficial Effects

[0040] One or more of the above embodiments have the following advantages or beneficial effects:

[0041] 1. The present invention uses conductive rubber to make a flexible high-voltage discharge needle, and leaves an arc-shaped micro-airway inside the flexible high-voltage discharge needle, and sets a deformed tooth groove outside the flexible high-voltage discharge needle. The combination of the two can change the strength of the flexible high-voltage discharge needle at this location. When high-pressure gas is introduced into the arc-shaped micro-airway, it can expand and deform to achieve the required shape, ensuring that the distance between the flexible high-voltage discharge needle and the plasma discharge gap between the inner wall of the hyperbolic cavitation discharge channel is equal everywhere. It can reduce the energy loss caused by uneven local discharge, improve the energy utilization efficiency, ensure the uniformity of the wastewater degradation process, enhance the degradation effect, and achieve the increase of the discharge area under the same discharge length conditions.

[0042] 2. The present invention strengthens the cavitation effect by setting a pressure release groove in the hyperbolic cavitation discharge channel. The pressure is released only at the pressure release groove to generate cavitation, which does not affect the overall flow rate, ensuring the stability of the flow rate at various locations in the hyperbolic cavitation discharge channel, making the degradation of organic matter more uniform; at the same time, a large amount of active substances such as H2O2 are generated by dielectric barrier discharge, which interact with hydroxyl radicals (·OH) generated at the pressure release groove due to the strong cavitation effect, triggering a chain reaction to generate more hydroxyl radicals. The degradation efficiency of industrial wastewater that is difficult to degrade is further improved.

[0043] 3. In the present invention, the hyperbolic cavitation discharge channel and the flexible high-voltage discharge needle-shaped discharge surface are both set to be hyperbolic, and dielectric barrier discharge is performed on the hyperbolic surface, which increases the discharge area and significantly enhances the discharge effect. The ozone generated during the discharge process can decompose in the air by itself without generating any pollutants, thereby effectively avoiding the problem of secondary pollution.

[0044] 4. In the present invention, the industrial refractory wastewater is first mixed once in the venturi tube. In order to achieve a more sufficient mixing effect, a gas-liquid dispersion impeller is arranged on the inlet side of the hyperbolic cavitation discharge channel to perform secondary mixing on the industrial refractory wastewater. The industrial refractory wastewater enters through the tangential through hole, and the water flow impacts the gas-liquid dispersion impeller to make it rotate. The bubbles in the wastewater are dispersed by the rotation and shearing action of the gas-liquid dispersion impeller. The synergistic effect of the venturi tube and the gas-liquid dispersion impeller is used to achieve uniform mixing of gas and liquid, so that the active substances such as ozone and H2O2 generated by the air after ionization can fully react with the organic pollutants in the industrial refractory wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The above contents and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0046] Figure 1 It is a structural schematic diagram of a gas-liquid ozone mass transfer system with hyperbolic space needle discharge;

[0047] Figure 2 It is a structural schematic diagram of a gas-liquid ozone mass transfer device with hyperbolic space needle discharge;

[0048] Figure 3 It is a schematic diagram of the structure of the flexible high-voltage discharge needle when it is contracted;

[0049] Figure 4 It is a schematic diagram of the structure of the flexible high-voltage discharge needle when it is inflated;

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

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

[0052] Figure 7 It is a structural diagram of the impeller base;

[0053] Figure 8 It is a schematic diagram of the middle cross-sectional structure of the impeller base;

[0054] Fig. 9 It is a schematic diagram of the structure of the gas-liquid dispersion impeller;

[0055] Fig.10 It is a flow chart of a gas-liquid ozone mass transfer method using a hyperbolic space needle discharge;

[0056] 1. Water purification tank; 2. Hyperbolic space needle-shaped discharge gas-liquid ozone mass transfer device; 21. Outlet end cover; 211. Wastewater outlet pipe; 212. Discharge electrode; 22. Flexible high-voltage discharge needle; 221. Arc-shaped micro-airway; 222. Deformed tooth groove; 23. Hyperbolic cavitation discharge channel; 231. Hyperbolic flow channel; 232. Pressure release groove; 233. Insulating medium coating; 24. Elastic fixing device; 241. Inner ring ; 242, elastic band; 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 DESCRIPTION

[0057] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0058] It should be noted that in the drawings, the size and relative size of the elements may be exaggerated for the purpose of clarity and / or description. Thus, the size and relative size of each element are not necessarily limited to the size and relative size shown in the drawings. In the specification and 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 "coupled to" another element, the element may be directly on, directly connected to, or directly coupled 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 coupled to" another element, there are no intermediate elements. Other terms and / or expressions used to describe the relationship between elements should be interpreted in a similar manner, for example, "between" versus "directly between", "adjacent" versus "directly adjacent", or "on" versus "directly on", etc. In addition, the term "connected" 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 parts, components, elements, regions, layers and / or parts, these parts, components, elements, regions, layers and / or parts should not be limited by these terms. Instead, these terms are used to distinguish one part, component, element, region, layer and / or part from another. Thus, for example, the first part, first member, first element, first region, first layer and / or first part discussed below may be referred to as the second part, second member, second element, second region, second layer and / or second part without departing from the teachings of the present invention.

[0061] For ease of description, spatial relational terms, such as "upper", "lower", "left", "right", etc., may be used herein to describe the relationship of one element or feature to another element or feature as shown in the figure. It should be understood that the spatial relational terms are intended to cover other different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the figure is turned upside down, elements described as "below" or "beneath" other elements or features will be oriented "above" or "above" the other elements or features.

[0062] Embodiment 1:

[0063] The present invention provides a hyperbolic space needle discharge gas-liquid ozone mass transfer device 2, please refer to Figure 2 , including a device body 29 with a plurality of hyperbolic cavitation discharge channels 23 inside, and a flexible high-voltage discharge needle 22 running through the hyperbolic cavitation discharge channel 23. The flexible high-voltage discharge needle 22 achieves wastewater degradation through dielectric barrier discharge in the hyperbolic cavitation channel; the hyperbolic cavitation discharge channel 23 is set to a hyperbolic shape, which increases the flow channel length, increases the contact reaction time between industrial refractory wastewater and ozone and some high-energy active substances, and achieves an increase in the discharge area under the same discharge length condition, thereby improving the degradation efficiency of industrial refractory 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, and the hyperbolic cavitation discharge channel 23 includes at least a hyperbolic flow channel 231 that smoothly and symmetrically transitions from an expanded middle portion 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 are designed with a circular cross section in the radial direction, and the cross-sectional shape is designed according to a plurality of continuous half-sine curve configurations in the axial direction. The interval between adjacent hyperbolic flow channels 231 is about 10 to 15 mm. The plurality of hyperbolic flow channels 231 increases the discharge area inside the hyperbolic cavitation discharge channel 23 as a whole.

[0066] In this embodiment, the hyperbolic cavitation discharge channel 23 is provided with a pressure release groove 232 at the narrowest part of the intersection of the adjacent hyperbolic flow channels 231. When the industrial refractory wastewater passes through the narrowest part of the hyperbolic flow channel 231, due to the setting of the pressure release groove 232, the bubbles in the liquid are rapidly formed, expanded and collapsed, resulting in a strong hydraulic cavitation phenomenon. When the bubbles burst, a local high temperature and high pressure instantaneous environment is formed, and a fast micro jet and a strong shock wave are generated at the same time, which promotes the decomposition of water molecules and volatile pollutants to generate 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 plasma discharge to act evenly on the pollutants, and avoid fouling 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. And because the pressure is released at the pressure release groove 232 to generate cavitation, it does not affect the overall flow rate, ensuring that the flow rate at various locations in the hyperbolic cavitation discharge channel 23 is stable, and the degradation effect on organic matter is more uniform.

[0067] The pressure release groove 232 has a parabolic cross section or a rectangular cross section in the axial direction, and its cross-sectional shape is specifically customized according to specific application requirements and flow rate conditions, so as to optimize fluid dynamics and improve the degradation efficiency of industrial refractory wastewater.

[0068] In the hyperbolic cavitation discharge channel 23, high-pressure gas is filled in the flexible high-voltage discharge needle 22, and the surface of the flexible high-voltage discharge needle 22 expands and deforms into a hyperbolic shape to adapt to the inner wall shape of the hyperbolic flow channel 231, and maintains equidistant gaps with the inner wall of the hyperbolic cavitation discharge channel 23, ensuring that the plasma discharge gap is equal everywhere, ensuring that the discharge voltage of the flexible high-voltage discharge needle 22 when discharging inside the hyperbolic flow channel 231 is uniform and stable, thereby enhancing the discharge effect, enhancing the discharge efficiency, and increasing the discharge output of ozone and other active substances; the flexible high-voltage discharge needle 22 can be freely processed according to the required length, and the appropriate length can be selected according to different usage scenarios and degradation requirements to improve the degradation efficiency and save resources to meet the degradation requirements and achieve the best degradation efficiency.

[0069] In this embodiment, the flexible high-voltage discharge needle 22 serves as a high-voltage positive electrode, and the hyperbolic cavitation discharge channel 23 is grounded as a negative electrode; wastewater with dispersed microbubbles flows into the inlet side 29a of the hyperbolic cavitation discharge channel 23, and 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, and the air in the microbubbles in the wastewater is ionized to generate a large amount of active substances such as ozone. At the same time, when the industrial refractory wastewater passes through the narrowest part of the hyperbolic flow channel 231, bubbles are rapidly formed, expanded and collapsed at the pressure release groove 232, generating a strong hydraulic cavitation phenomenon. A large amount of active substances are generated through dielectric barrier discharge, and the strong cavitation effect caused by the sudden pressure reduction at the pressure release groove can significantly improve the generation efficiency of ozone and active substances through synergistic effect. The high concentration of oxygen free radicals generated in the hydrodynamic cavitation process interacts with the active oxides generated by discharge ionization, further promoting the generation of free radicals. For example, when the ·OH generated by hydrodynamic cavitation reacts with the H2O2 generated by discharge ionization, more ·OH will be generated, forming a chain reaction mechanism; in addition, when the bubbles of hydrodynamic cavitation collapse, microbubbles and microjets can enhance the effect of discharge ionization. Microbubbles can serve as a medium for discharge and promote the discharge ionization; microjets can enhance the turbulence of the solution, promote the diffusion and reaction of free radicals, avoid fouling 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 refractory wastewater, which can effectively increase the yield of hydroxyl free radicals, thereby improving the degradation rate of industrial refractory wastewater.

[0070] As an embodiment of the present invention, the flexible high-voltage discharge needle 22 is 3D printed from conductive rubber, and its outer surface is evenly covered with an insulating dielectric coating 233 by electroplating; the conductive rubber has excellent elasticity, can deform when subjected to external force and return to its original state after the external force is removed, and also has good conductivity, ensuring the high-efficiency energy conversion 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 circuit; 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, and the coating can provide continuous protection throughout the service life of the discharge needle, ensuring the long-term stable operation of the device.

[0071] In addition, the insulating dielectric coating 233 is evenly distributed on the surface of the hyperbolic flow channel 231 and the pressure release groove 232 through an electroplating process, ensuring the uniformity and adhesion of the coating, preventing the current from directly contacting the water body and forming a dielectric barrier discharge.

[0072] An arc-shaped micro-airway 221 is formed in the flexible high-voltage discharge needle 22. In the axial cross section, the inclination angle of the inner wall of the arc-shaped micro-airway 221 relative to the central axis of the flexible high-voltage discharge needle 22 presents a symmetrical gradual change feature: the inclination angle of the flow channel entrance section increases from 0° to 15°, and decreases symmetrically back to 0° after passing through the throat area, so as not to weaken the overall strength too much and cause rupture when high-pressure gas is introduced; the outer wall of the flexible high-voltage discharge needle 22 is provided with a plurality of deformable tooth grooves 222, and the deformable tooth grooves 222 are arranged at the place where the inner diameter of the cross section of the arc-shaped micro-airway 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 inflated, the deformable tooth grooves 222 serve as thin The outer wall of the flexible high-voltage discharge needle 22 is expanded and deformed to be consistent with the shape of the hyperbolic flow channel 231, and the gap with the inner wall of the hyperbolic flow channel 231 is equidistant everywhere; that is, the main body is made of flexible conductive rubber, so by introducing high-pressure gas into the arc-shaped micro-airway 221, due to the influence of the arc-shaped micro-airway 221 and the deformed tooth groove 222 on the overall shape and strength of the flexible high-voltage discharge needle 22, the surface of the flexible high-voltage discharge needle 22 is expanded and deformed to form a hyperbolic surface to adapt to the shape of the hyperbolic flow channel 231, control the gap to be consistent at various places of the hyperbolic flow channel 231, make the discharge inside the hyperbolic flow channel 231 more uniform, enhance the discharge efficiency, and increase the ozone and other active substances generated by the discharge.

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

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

[0075] A connecting channel 25 corresponding to the hyperbolic cavitation discharge channel 23 and coaxially corresponding to the hyperbolic cavitation discharge channel 23 is formed on the surface of the inlet end cover 27 on one side facing the hyperbolic cavitation discharge channel 23; an elastic fixing device 24 is fixed in 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 connected to the elastic fixing device 24 for fixation. When the industrial refractory wastewater enters the hyperbolic flow channel 231, the discharge electrode 212 turns on the high voltage, the hyperbolic cavitation discharge pipeline is grounded as the negative electrode, and dielectric barrier discharge is performed in the hyperbolic flow channel 231, so as to ionize the air in the microbubbles in the industrial refractory wastewater and generate a large amount of active substances such as ozone.

[0076] The elastic fixing device 24 is made of corrosion-resistant elastic insulating material as a whole, including an inner ring 241 and an outer ring 243 arranged coaxially, and the inner ring 241 and the outer ring 243 are connected by a plurality of elastic bands 242 arranged at equal intervals; the inner ring 241 is elastic and tightly fitted on 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, and can be specifically set to be embedded in the inner side of the connecting channel 25, or fixed by a detachable method such as a buckle 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 enables the flexible high-voltage discharge needle 22 to quickly return to the normal position when vibrating due to the impact of wastewater, so as to avoid short circuit 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 in the inlet end cover 27, and an impeller shaft 262 is arranged 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, and a plurality of tangential through holes 261 are evenly spaced in the circumferential direction on the outer wall of the impeller base 26. Preferably, 8 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 8 directions; in the front view direction of the bottom surface of the impeller base 26, an angle α of 30° to 45° is formed between the geometric center of the intersecting contour line of the tangential through hole 261 on the outer wall surface of the impeller base 26, the radial line connected to the center of the bottom surface of the impeller base 26, and the central axis of the tangential through hole 261.

[0078] The gas-liquid dispersion impeller 28 includes a base plate and a plurality of crescent-shaped impeller blades 281. A center hole 282 is provided at the geometric center of the bottom surface of the base plate. The center 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 center hole 282, ensuring uniform distribution of the fluid between the impeller blades 281 and optimizing the gas-liquid mixing efficiency. The crescent-shaped recessed portion of the impeller blade 281 is directly opposite to the tangential through hole 261 and is tilted at the same tilt angle as the tangential through hole 261. The crescent-shaped blade helps to improve the fluid dynamics performance, so that the impeller can more effectively absorb and disperse the energy in the water flow. The tilted layout of the tangential through hole 261 and the impeller blade 281 allows the impeller blade 281 to receive the water flow impact from the tangential through hole 261 in an optimal manner, thereby maximizing the 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 and keep the gas-liquid dispersion impeller 28 evenly stressed, so as to fully absorb the impact force brought by the wastewater.

[0079] Industrial refractory wastewater enters the gap between the inlet end cover 27 and the impeller base 26 from the wastewater inlet pipe 271. Under the action of pressure, the industrial refractory wastewater enters tangentially from the tangential through hole 261 of the impeller base 26, and is impacted by the gas-liquid dispersion impeller 28 to cause it to rotate. The gas-liquid dispersion impeller 28 rotates to remove 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 in the wastewater with the 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 tiny bubbles, and make the tiny bubbles evenly distributed in the wastewater, thereby increasing the contact area between the gas and the wastewater and improving the subsequent degradation effect of high-voltage discharge and hydraulic cavitation.

[0080] Embodiment 2:

[0081] The present invention provides a hyperbolic space needle discharge gas-liquid ozone mass transfer system, comprising a hyperbolic space needle discharge gas-liquid ozone mass transfer device 2 as in Example 1, and a wastewater pool 6, a centrifugal pump 5, a venturi tube 3, an air pump 4, and a water purification pool 1; wherein the water inlet end of the centrifugal pump 5 is connected to the wastewater pool 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 pool 1 is connected to the wastewater outlet pipe 211.

[0082] The air is preliminarily mixed with the wastewater in the wastewater pool 6 in the venturi tube 3 through the air pump 4, and the mixed wastewater is sent into the gas-liquid ozone mass transfer device 2 with hyperbolic space needle discharge by the centrifugal pump 5. In the gas-liquid ozone mass transfer device 2 with hyperbolic space needle discharge, needle discharge and cavitation are combined to generate ozone and active substances such as hydroxyl free radicals to degrade industrial refractory wastewater, and finally discharged into the clean water pool 1.

[0083] In this embodiment, the industrial difficult-to-degrade wastewater is mixed once in the Venturi tube 3, and a gas-liquid dispersion impeller 28 is arranged at the inlet for secondary mixing. The industrial difficult-to-degrade wastewater enters through the tangential through hole, and the water flow impacts the gas-liquid dispersion impeller 28 to make it rotate. The bubbles in the wastewater are dispersed by the rotation and shearing action of the gas-liquid dispersion impeller 28. The uniform mixing of gas and liquid is achieved through the combination of the Venturi tube 3 and the gas-liquid dispersion impeller 28, so that the active substances such as ozone generated by the air after ionization can fully react with the organic pollutants in the industrial difficult-to-degrade wastewater.

[0084] Embodiment 3:

[0085] The present invention provides a hyperbolic space needle-shaped discharge gas-liquid ozone mass transfer method, which is implemented by a hyperbolic space needle-shaped discharge gas-liquid ozone mass transfer system as in Example 2, and comprises the following steps:

[0086] Step 1: Turn off the centrifugal pump 5, turn on the air pump 4, the wastewater inlet pipe 271, and the wastewater outlet pipe 211, and the air pump 4 introduces air into the system to fill the entire internal cavity of the system;

[0087] Step 2: The discharge electrode 212 is connected to a high-voltage power supply, and the flexible high-voltage discharge needle 22 acts as the positive electrode of the dielectric barrier discharge to start discharging, so that the air in the internal cavity of the entire system is ionized in advance, forming active substances such as ozone that fill the internal cavity of the entire system;

[0088] Step 3: The wastewater tank 6 stores industrial refractory wastewater. The centrifugal pump 5 is turned on to pump the industrial refractory wastewater into the venturi tube 3. The flow rate of the centrifugal pump 5 is maintained at 1.5 to 2 times the flow rate of the air pump 4, so that the wastewater and air are preliminarily mixed with the industrial refractory wastewater. The large bubbles inside the industrial refractory wastewater are broken at the throat of the venturi tube 3 to generate a large number of microbubbles containing air. The industrial refractory wastewater containing microbubbles is pumped from the wastewater inlet pipe 271 into the inlet end cover 27.

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

[0090] Step 5: The industrial refractory wastewater with microbubbles enters the hyperbolic cavitation discharge channel 23, and is ionized to generate a large amount of active substances in 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. At the same time, after the wastewater in the hyperbolic cavitation discharge channel 23 flows through the minimum cross-sectional position of the hyperbolic flow channel 231, the strong cavitation effect generated at the pressure release groove 232 degrades the industrial refractory wastewater.

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

[0092] Optionally, in step 5, the industrial refractory wastewater is tested after degradation. If the pollutant concentration in the industrial refractory wastewater is too high, the air pump 4 and the centrifugal pump 5 can be adjusted to change the inlet flow rate of different air and industrial refractory wastewater to improve the degradation effect.

[0093] The embodiments of the present invention are described above. However, these embodiments are only for the purpose of illustration, and are not intended to limit the scope of the present invention. Although each embodiment is described above, it does not mean that the measures in each embodiment cannot be used in combination advantageously. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A hyperbolic space needle discharge gas-liquid ozone mass transfer device, characterized in that: include: A device body (29) having a plurality of hyperbolic cavitation discharge channels (23) therein, the device body (29) comprising an inlet side (29a) and an outlet side (29b), the hyperbolic cavitation discharge channels (23) being connected between the inlet side (29a) and the outlet side (29b), the hyperbolic cavitation discharge channels (23) comprising at least one hyperbolic flow channel (231) which smoothly and symmetrically transitions from an enlarged middle portion to both sides; A flexible high-voltage discharge needle (22) is inserted into the hyperbolic cavitation discharge channel (23); and in the hyperbolic cavitation discharge channel (23), the flexible high-voltage discharge needle (22) is in a hollow cylindrical shape before deformation. When high-pressure gas is filled into the arc-shaped micro-air channel (221), the deformed tooth groove (222) of the flexible high-voltage discharge needle (22) is partially expanded and deformed to form an outer wall shape capable of maintaining an equidistant gap from the inner wall of the hyperbolic cavitation discharge channel (23); The flexible high-voltage discharge needle (22) serves as a high-voltage positive electrode, and the hyperbolic cavitation discharge channel (23) is grounded as a negative electrode; organic wastewater containing microbubbles is pumped into the inlet side (29a) of the hyperbolic cavitation discharge channel (23), and 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), thereby discharging and ionizing the microbubbles in the wastewater.

2. The hyperbolic space needle discharge gas-liquid ozone mass transfer device according to claim 1, characterized in that: At least two hyperbolic flow channels (231) are sequentially connected inside the hyperbolic cavitation discharge channel (23), wherein the hyperbolic flow channel (231) is designed with a circular cross section in the radial direction and has a cross-sectional shape designed according to a plurality of continuous half-sine curve configurations in the axial direction; The hyperbolic cavitation discharge channel (23) is provided with a pressure release groove (232) at the narrowest point where adjacent hyperbolic flow channels (231) intersect; An insulating dielectric coating (233) is evenly distributed and coated on the surfaces of the hyperbolic flow channel (231) and the pressure release groove (232) through an electroplating process.

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

4. The hyperbolic space needle discharge gas-liquid ozone mass transfer device according to claim 3, characterized in that: The flexible high-voltage discharge needle (22) is made of conductive rubber by 3D printing, and its outer surface is evenly covered with an insulating dielectric coating (233) by electroplating; An arc-shaped micro-airway (221) is formed in the flexible high-voltage discharge needle (22), and in an axial cross section, the inclination angle 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 flow channel entrance section increases from 0° to 15°, and decreases symmetrically back to 0° after passing through the throat area. The outer wall of the flexible high-voltage discharge needle (22) is provided with a plurality of deformable tooth grooves (222), and the deformable tooth grooves (222) are arranged at a position where the inner diameter of the cross section of the arc-shaped micro-airway (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 inflated, the deformable tooth grooves (222) protrude outwards as weak points, so that the outer wall of the flexible high-voltage discharge needle (22) expands and deforms to be consistent with the shape of the hyperbolic flow channel (231), and the gap with the inner wall of the hyperbolic flow channel (231) is equidistant at all locations.

5. The hyperbolic space needle discharge gas-liquid ozone mass transfer device according to claim 2, characterized in that: The inlet side (29a) is sealedly connected to an inlet end cover (27), and the outlet side (29b) is sealedly connected to an outlet end cover (21). A wastewater inlet pipe (271) is provided on the surface of the inlet end cover (27), and a wastewater outlet pipe (211) is provided on the surface of the outlet end cover (21). The inlet end cover (27) and the outlet end cover (21) are respectively fixed to the inlet side (29a) and the outlet side (29b) of the device body (29) by bolts; A connecting channel (25) is formed on a surface of one side of the inlet end cover (27) facing the hyperbolic cavitation discharge channel (23) and is coaxially corresponding to the hyperbolic cavitation discharge channel (23); The outlet end cover (21) is embedded with a discharge electrode (212), and the discharge electrode (212) and the outlet end cover (21) are insulated and isolated by an insulating material; An elastic fixing device (24) is fixed in 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 space needle discharge gas-liquid ozone mass transfer device according to claim 5, characterized in that: The elastic fixing device (24) comprises an inner ring (241) and an outer ring (243) which are coaxially arranged, and the inner ring (241) and the outer ring (243) are connected by a plurality of elastic bands (242) which are arranged at equal intervals; the inner ring (241) is elastic and is tightly fitted on 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 space needle 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 arranged 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; and a plurality of tangential through holes (261) are evenly spaced in the circumferential direction on the outer wall of the impeller base (26); In the front view direction of the bottom surface of the impeller base (26), an angle α of 30° to 45° is formed between the geometric center of the contour line of the tangential through hole (261) intersecting on the outer wall surface of the impeller base (26), the radial line connected to the center of the bottom surface of the impeller base (26), and the central axis of the tangential through hole (261).

8. The hyperbolic space needle discharge gas-liquid ozone mass transfer device according to claim 7, characterized in that: The gas-liquid dispersion impeller (28) comprises a bottom plate and a plurality of crescent-shaped impeller blades (281); a center hole (282) is provided at the geometric center of the bottom surface of the bottom plate; the center 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 center hole (282); the crescent-shaped recessed portions of the impeller blades (281) are directly opposite to the tangential through holes (261) and are arranged to be inclined at the same inclination angle as the tangential through holes (261).

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

10. A hyperbolic space needle discharge gas-liquid ozone mass transfer method, implemented by using a hyperbolic space needle discharge gas-liquid ozone mass transfer system according to claim 9, characterized in that: The steps include: Step 1: Turn off the centrifugal pump (5), turn on the air pump (4), the wastewater inlet pipe (271), and the wastewater outlet pipe (211), and 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 a high-voltage power supply, and the flexible high-voltage discharge needle (22) acts as a positive electrode of a dielectric barrier discharge to start discharging, so that the air in the internal cavity of the entire system is ionized in advance, forming active substances such as ozone that fill the internal cavity of the entire system; Step 3: Industrial refractory wastewater is stored in the wastewater pool (6), and the centrifugal pump (5) is turned on to pump the industrial refractory wastewater into the venturi tube (3), and the flow rate of the centrifugal pump (5) is maintained at 1.5 to 2 times the flow rate of the air pump (4), so that the wastewater and air are preliminarily mixed with the industrial refractory wastewater; wherein, large bubbles inside the industrial refractory wastewater are broken at the throat of the venturi tube (3), generating a large number of microbubbles containing air; the industrial refractory wastewater containing microbubbles is pumped from the wastewater inlet pipe (271) into the inlet end cover (27); Step 4: the industrial refractory wastewater containing microbubbles flows from the tangential through hole (261) to the crescent-shaped depression of the impeller blade (281), so that the gas-liquid dispersion impeller (28) rotates to disperse the microbubbles in the industrial refractory wastewater, so that the microbubbles are evenly distributed in the wastewater; Step 5: The industrial refractory wastewater with microbubbles enters the hyperbolic cavitation discharge channel (23), and is ionized to generate a large amount of active substances in 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); at the same time, after the wastewater in the hyperbolic cavitation discharge channel (23) flows through the minimum cross-sectional position of the hyperbolic flow channel (231), the strong cavitation effect generated at the pressure release groove (232) degrades the industrial refractory wastewater; Step 6: Check whether the organic matter removal rate of the degraded wastewater meets the standard. If not, the wastewater is introduced into the inlet end cover (27) and steps 4 and 5 are repeated. If it meets the standard, the wastewater is discharged into the clean water tank.

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