Hydrodynamic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge

Abstract

The invention discloses a hydrodynamic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge, which comprises a cavitation generator, an excitation coil is arranged outside a cavitation reactor, a plasma discharge cavity and a cavitation reaction cavity are arranged inside the cavitation reactor, and a rotatable hemispherical cavitation rotor is arranged in the cavitation reaction cavity. The system fuses a plasma discharge technology, a magnetic field enhancement technology and a hydrodynamic cavitation technology, magnetic field enhanced plasma discharge is utilized to generate active substances such as ozone and hydroxyl radicals, and the hydrodynamic cavitation technology is assisted to enhance degradation of organic wastewater, so that the wastewater degradation effect is improved; an external rotating magnetic field is arranged, so that ionized particles run more violently, the collision frequency and contact time of the particles and pollutants are increased, and the reaction is more sufficient; the hemispherical cavitation rotor is provided with upper and lower rows of teeth with opposite inclination angles, so that the hemispherical cavitation rotor generates shearing force on fluid in the rotating process, the frequency of generating and collapsing cavitation bubbles is improved, and the degradation efficiency of organic wastewater is further improved.

Description

Technical Field

[0001] The present invention relates to a hydraulic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge, and belongs to the technical field of organic wastewater degradation. Background Art

[0002] Organic wastewater usually contains a large number of organic pollution components that are difficult to degrade. Therefore, the organic wastewater degradation process has become a research hotspot in the field of environmental engineering. The synergistic technology of ozone oxidation and hydraulic cavitation is considered to be a new method for treating organic wastewater. During the plasma discharge process, when the voltage applied between the electrodes reaches a certain level, the gas medium will be broken down to generate a low-temperature plasma rich in active substances such as ozone, free radicals, electrons, and excited molecules. These active substances can effectively promote the degradation of organic wastewater. However, the solubility of ozone molecules is relatively low, and it is necessary to combine with hydraulic cavitation technology to enhance the mass transfer efficiency at the gas-liquid interface to promote the hydrolysis reaction of ozone. In addition to ozone, the other active substances (such as free radicals) generated in the plasma have extremely short lifetimes, usually at the millisecond or microsecond level. The chemical thermal effect generated by the collapse of cavitation bubbles can stimulate the generation of hydroxyl radicals (·OH) and other active substances, thereby further strengthening the degradation process of organic wastewater. Moreover, when a rotating magnetic field is introduced into the system, it promotes the rotational motion of molecules and ions in the wastewater through the magnetic force effect, further strengthening the contact frequency between the oxidizing substances and pollutants during the plasma discharge process. The action of this magnetic field improves the utilization rate of active substances and effectively reduces material waste. The rotating magnetic field can also improve the fluid flow pattern, enabling the cavitation reaction and ionization effect to be enhanced over a larger range, improving the gas-liquid mass transfer efficiency, and thus significantly enhancing the degradation effect of the wastewater. Therefore, the degradation technology that synergistically combines hydraulic cavitation technology, plasma discharge technology, and rotating magnetic field technology shows good application prospects and has strong ability to remove refractory organic compounds.

[0003] The invention patent "An organic wastewater three-stage hydraulic cavitation treatment system" (publication number: CN109824173B) discloses an organic wastewater three-stage hydraulic cavitation treatment system. This system combines a three-stage hydraulic cavitation treatment system with the Fenton process. First, a precipitant is added to the organic wastewater for pretreatment to remove suspended particles, and then a rotating hydraulic cavitator and Fenton reagent are used together to degrade organic pollutants. Then, cavitation jets and ultrasonic cavitation are used for further treatment, and finally the degradation of the wastewater is achieved. This system improves the degradation efficiency by utilizing the synergistic effect of hydraulic cavitation and Fenton oxidation and can effectively reduce the treatment time. However, the disadvantages are that the system equipment is complex, the investment cost is high, and continuous supply of Fenton reagent is required, which may bring additional operating costs and environmental impacts, especially the problem of corrosive sludge generated during the Fenton reaction.

[0004] The patent "An underwater pulsed discharge plasma device for treating organic wastewater" (Publication No.: CN212982539U) proposes an underwater pulsed discharge plasma technology for effectively degrading pollutants in organic wastewater. Its working principle is to introduce organic wastewater into the device through plasma discharge technology. The wastewater flows through the holes on the cathode plate and enters multiple electric field regions to promote the electric field effect. At the same time, the device introduces air through the ventilation groove to provide oxygen atoms for the oxidation reaction, thereby generating strong oxidants such as hydroxyl radicals and hydrogen peroxide to promote the degradation of organic wastewater. However, the lifespan of active substances such as hydroxyl radicals and hydrogen peroxide is short, so they are consumed within a short time, resulting in energy waste and affecting the degradation efficiency of organic wastewater and the energy utilization rate during the treatment process. This limits the efficiency and sustainability of this technology in practical applications.

[0005] The invention patent "A system and method for degrading organic wastewater by hydraulic cavitation synergistic plasma" (Publication No.: CN119118415A) proposes a system and method for degrading organic wastewater by hydraulic cavitation synergistic plasma. In this system, the wastewater generates microbubbles through an aeration device and then enters the plasma rotary cavitation reactor. The rotor rotates to generate a cavitation effect and release hydroxyl radicals. The wastewater enters the plasma discharge cavity through the downflow cavitation channel, and the fan-shaped electrode discharges to generate ozone and hydroxyl radicals to further degrade organic matter. The wastewater circulates between the cavitation reaction cavity and the discharge cavity to strengthen the degradation effect, and the water pump flow rate is adjusted in real time according to the pollutant removal rate. Although this device combines hydraulic cavitation and plasma discharge, the movement trajectory of particles in the plasma discharge cavity is relatively single, and the contact frequency between the oxidation substances and the pollutants is not high, resulting in waste of oxidation substances. Therefore, there is still room for further improvement in the performance of this system.

[0006] In summary, the existing organic wastewater degradation devices that combine plasma discharge and hydraulic cavitation still have the following deficiencies:

[0007] 1. Low degree of integration. The plasma discharge device and the hydraulic cavitation device are set separately. A separate plasma discharge device is required to generate active substances such as ozone, and then the generated active substances are input into the hydraulic cavitation device, resulting in a low degree of integration of the organic wastewater degradation device.

[0008] 2. The lifespan of active substances such as ozone and hydroxyl radicals is short, and the device cannot effectively utilize the active substances. The separately generated active substances need to travel a certain distance to enter the cavitation device, which will cause attenuation of the active substances and a low effective utilization rate. At the same time, the contact frequency between the active substances and the substances to be degraded is low, further affecting the degradation effect of organic wastewater, and the degradation efficiency still needs to be improved.

[0009] 3. The utilization rate of active ingredients is relatively low. Before the fluid enters the cavitation region, the movement of active ingredients mainly relies on the water pump and the unidirectional parallel magnetic field, with a single running trajectory and insufficient contact frequency with pollutants. At the same time, the contact time is short and the reaction process is incomplete, affecting the overall reaction efficiency. Summary of the Invention

[0010] To solve the above technical problems, the present invention provides a hydraulic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge, providing a new technical solution for the efficient degradation of organic wastewater. The present invention combines plasma discharge technology, hydraulic cavitation technology and magnetic field enhancement technology, designs a hydraulic cavitation reactor with magnetic field enhanced plasma discharge, sets an aeration device to generate micron-sized bubbles in the organic wastewater, pumps the organic wastewater rich in microbubbles into the organic wastewater inlet on the side of the hydraulic cavitation reactor with magnetic field enhanced plasma discharge through a water pump, and uses dielectric barrier magnetic field enhanced plasma discharge to generate active substances such as ozone and hydroxyl radicals, combines with hydraulic cavitation technology to strengthen the degradation of organic wastewater, and improves the degradation effect of wastewater; an external rotating magnetic field is set, making the running trajectory of the ionized particles more complex, increasing the collision frequency between the particles and pollutants, increasing the contact time between the two, and making the reaction more complete; the hemispherical cavitation rotor has upper and lower rows of teeth with opposite inclinations, so that during the rotation of the hemispherical cavitation rotor, a shear force is generated on the fluid, increasing the generation and collapse frequency of cavitation bubbles, and thus improving the degradation efficiency of organic wastewater.

[0011] The technical solution adopted by the present invention is as follows:

[0012] On the one hand, the present invention provides a hydraulic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge, including a gas-liquid mixing and conveying device, a wastewater outlet, a rotating magnetic field generator, a cavitation generator, a plasma generating device and a power driving device; the cavitation generator includes a cavitation reaction cavity, and an exciting coil for enhancing the magnetic field is arranged on the cavitation reaction cavity, and the exciting coil is powered by a rotating magnetic field power supply; the cavitation generator includes a lower end cover, an organic wastewater inlet is arranged on one side of the lower end cover, and an organic wastewater outlet is arranged on the other side; the gas-liquid mixing and conveying device is communicated with the organic wastewater inlet through a water pump; the wastewater outlet is connected with the organic wastewater outlet through an overflow valve;

[0013] Inside the cavitation reaction cavity, a plasma discharge cavity and a cavitation reaction cavity are provided. The plasma discharge cavity and the cavitation reaction cavity are connected through a plurality of organic waste liquid channels. A sector electrode is provided on the outer wall of the plasma discharge cavity, and the sector electrode is fixed in a card slot provided on the outer wall of the plasma discharge cavity. A rotatable hemispherical cavitation rotor is provided in the cavitation reaction cavity. The power driving device is drivingly connected to the hemispherical cavitation rotor, and the hemispherical cavitation rotor is provided with upper row teeth and lower row teeth.

[0014] In an embodiment of the present invention, the power driving device includes a hemispherical cavitation rotor motor. The hemispherical cavitation rotor motor is fixed on a motor bracket, and the motor bracket is fixed on an inclined bracket. The inclined bracket is fixedly connected to an upper flange provided on the cavitation reaction cavity through an inclined bracket flange. The output end of the hemispherical cavitation rotor motor is connected with a hemispherical cavitation rotor main shaft through a coupling. A slip ring is provided on the hemispherical cavitation rotor main shaft, and a high-voltage power supply supplies power to the hemispherical cavitation rotor through the slip ring. A threaded hole is provided along the axial center line of the hemispherical cavitation rotor, and the hemispherical cavitation rotor main shaft is fixedly connected to the threaded hole in the hemispherical cavitation rotor. The wastewater stored in the gas-liquid mixing and conveying device generates a gas-liquid two-phase solution with microbubbles through an aeration device. A water pump conveys the gas-liquid two-phase solution from the organic wastewater inlet to the plasma discharge cavity. The hemispherical cavitation rotor motor drives the hemispherical cavitation rotor to rotate through a coupling and the hemispherical cavitation rotor main shaft. During the rotation of the hemispherical cavitation rotor, the pressure of the fluid increases when it passes through the upper row teeth and the lower row teeth, and the pressure decreases when it passes through the grooves between adjacent rows of teeth. At the same time, the row teeth of the hemispherical cavitation rotor generate a shear force by changing the flow direction and speed of the fluid to further increase the cavitation efficiency.

[0015] In an embodiment of the present invention, the spiral direction of the upper row teeth is left-handed, and the spiral direction of the lower row teeth is right-handed. When the hemispherical cavitation rotor rotates at a high speed, the flow direction and speed of the fluid are changed, and the fluid is squeezed towards the junction of the upper row teeth and the lower row teeth to increase the fluid pressure. When the fluid flows into the grooves between adjacent rows of teeth, the pressure is released, thereby realizing the cavitation reaction.

[0016] In an embodiment of the present invention, the material of the plasma discharge cavity is quartz glass or a material with a relative dielectric constant greater than 3.8.

[0017] In an embodiment of the present invention, the sector electrodes are distributed in a circumferential manner around the outer wall of the plasma discharge chamber. On one side of the outer wall of the plasma discharge chamber close to the hemispherical cavitation rotor, a layer of sector electrodes is installed as the positive electrode, and on the side of the outer wall of the plasma discharge chamber far from the hemispherical cavitation rotor, a layer of sector electrodes is installed as the negative electrode; the sector electrodes are connected to a high-voltage power supply through wires, and a dielectric barrier plasma discharge phenomenon is formed by applying a voltage between the two electrodes to generate active substances such as ozone and hydroxyl radicals in water.

[0018] In an embodiment of the present invention, the cavitation reaction chamber includes an upper flange connected to an inclined support and a lower flange connected to a lower end cover. The upper end of the lower end cover is provided with a lower end cover flange, and the lower end cover flange is connected to the lower flange. The organic wastewater inlet is communicated with the plasma discharge chamber through a channel between the lower end cover flange and the lower flange, and the plasma discharge chamber is communicated with the cavitation reaction chamber through an organic waste liquid channel.

[0019] In an embodiment of the present invention, the inclination angle between the upper row of teeth and the lower row of teeth of the hemispherical cavitation rotor and the axial direction of the hemispherical cavitation rotor is 30°. The hemispherical cavitation rotor is installed in an inclined manner so that during the rotation of the hemispherical cavitation rotor, part of the organic waste liquid at the bottom of the cavitation reaction chamber is brought into the top of the cavitation reaction chamber along with the teeth of the hemispherical cavitation rotor, and the organic waste liquid flows through the cavitation reaction area again when flowing into the cavitation reaction chamber to achieve repeated cavitation.

[0020] In an embodiment of the present invention, the rotating magnetic field generator includes an electric rotating magnetic field power supply and an excitation coil. The excitation coil is arranged on the cavitation reaction chamber body, so that the rotating magnetic field is distributed circumferentially along the cavitation reaction chamber body. The rotating magnetic field is in the x-y plane, and its rotating magnetic field intensity is expressed as:

[0021]

[0022] In the formula, ω is the frequency, B1 is the magnitude of the rotating magnetic field, is the magnetic field component in the x direction, is the magnetic field component in the y direction;

[0023] Assume that the parallel magnetic field is distributed along the θ direction of the cylindrical coordinate system, and its magnitude is B0; in the Cartesian coordinate system, it is expressed as:

[0024]

[0025] In the formula,

[0026] The total magnetic field is:

[0027]

[0028] The motion of charged particles (such as ozone ions, superoxide anion free radicals, etc.) in a magnetic field is determined by the Lorentz force:

[0029] F = q(v × B) (4)

[0030] Among them, F is the Lorentz force acting on the charged particle, q is the particle charge, v is the particle velocity, and B is the magnetic field strength; According to Newton's second law:

[0031]

[0032] Among them, m is the particle mass;

[0033] Decompose the velocity and the magnetic field into x, y, and z components:

[0034]

[0035] The components of the Lorentz force are:

[0036]

[0037] After expansion, we get:

[0038]

[0039] Therefore, the motion equation is:

[0040]

[0041] In an embodiment of the present invention, the magnetic field generator further includes an MCU main control element, an amplification circuit, and a MOS transistor; the MCU main control element controls the on-off of the MOS transistor through the amplification circuit to precisely control the current intensity, frequency, and phase of the excitation coil (31), generating a rotatable magnetic field with adjustable intensity and controllable direction; this rotatable magnetic field forms a composite electromagnetic field with the electrostatic field generated by the sector electrodes (53) in the plasma discharge chamber (52), enabling the charged particles to exhibit a three-dimensional helical motion trajectory and increasing the collision probability between the particles and the pollutants.

[0042] On the other hand, the present invention provides a method for degrading hydraulic cavitation wastewater based on magnetic field-enhanced plasma discharge. Using the hydraulic cavitation wastewater degradation system based on magnetic field-enhanced plasma discharge, the method includes:

[0043] Step 1: Open the organic wastewater inlet and the organic wastewater outlet, and turn on the water pump so that the organic wastewater in the gas-liquid mixture state in the gas-liquid mixing and conveying device enters the organic wastewater inlet through the water pump at a certain flow rate;

[0044] Step 2: Turn on the high-voltage power supply to discharge the sector electrode, forming a dielectric barrier plasma discharge, generating ozone and hydroxyl radicals in water. Both are strong oxidants and can effectively degrade organic pollutants in wastewater;

[0045] Step 3: Start the rotating magnetic field power supply to generate a rotating magnetic field through the excitation coil; the rotating magnetic field promotes the movement of molecules and ions in the wastewater through the magnetic force effect, enhances the degradation effect of the oxidizing substances generated by the discharge, and improves the wastewater treatment efficiency;

[0046] Step 4: The organic wastewater enters the cavitation reaction chamber from the plasma discharge chamber through the liquid channel. The inner wall of the cavitation reaction chamber and the edge of the hemispherical cavitation rotor form a cavitation region. The high-speed rotating hemispherical cavitation rotor causes the organic wastewater to degrade in the cavitation region, and the degraded wastewater is discharged through the organic waste liquid outlet;

[0047] Step 5: Detect the pollutant removal rate of the liquid flowing out of the organic waste liquid outlet, and adjust the flow rate of the water pump in real time to achieve the efficient degradation of organic wastewater.

[0048] The beneficial effects of the present invention are as follows:

[0049] (1) It combines the plasma discharge technology and the hydrodynamic cavitation technology. A low-temperature plasma rich in active substances such as ozone, free radicals, electrons and excited molecules is generated in the organic wastewater through the dielectric barrier discharge (DBD) technology. The local high temperature, high pressure and mechanical shock waves generated during the collapse of cavitation bubbles interact with the active substances in the plasma, promoting the efficient reaction of ozone molecules and other active substances with the organic pollutants in the wastewater, and significantly improving the utilization rate of active substances. This synergistic effect can not only degrade organic matter more thoroughly, but also effectively shorten the degradation time and reduce the energy consumption.

[0050] (2) The hemispherical cavitation rotor is designed with upper row teeth and lower row teeth with different rotation directions, enhancing the shear force of the wastewater in the cavitation region and promoting the generation and rupture of bubbles. In addition, the tooth groove design with opposite inclination angles improves the flow pattern of the wastewater, accelerates the circulating flow of the wastewater between the cavitation area and the discharge area, thereby strengthening the cavitation effect and ionization effect, improving the gas-liquid mass transfer efficiency, and further enhancing the degradation effect of organic wastewater.

[0051] (3) An excitation coil is arranged outside the cavitation reaction housing, which is connected to a three-phase AC power supply to generate a rotating magnetic field. The rotating magnetic field interacts with the parallel magnetic field generated by the electrode, making the movement trajectory of the plasma in the fluid in the plasma discharge chamber a complex spiral motion. Since the magnetic field generated by the excitation coil is rotating, when interacting with the parallel magnetic field generated by the electrode, the axis and radius of the spiral will change periodically, increasing the contact frequency between particles and pollutants and effectively increasing the wastewater degradation efficiency. Brief Description of the Drawings

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0053] Figure 1 It is a schematic structural diagram of a hydraulic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge provided by an embodiment of the present invention.

[0054] Figure 2 It is a cross-sectional view of a plasma cavitation reactor provided by an embodiment of the present invention.

[0055] Figure 3 It is a schematic structural diagram of a cavitation reaction cavity provided by an embodiment of the present invention.

[0056] Figure 4 It is a schematic structural diagram of a lower end cover provided by an embodiment of the present invention.

[0057] Figure 5 It is a schematic structural diagram of a hemispherical cavitation rotor provided by an embodiment of the present invention.

[0058] Figure 6 It is a schematic circuit diagram of a rotating magnetic field provided by an embodiment of the present invention.

[0059] Figure 7 It is a flowchart of a hydraulic cavitation wastewater degradation method based on magnetic field enhanced plasma discharge provided by an embodiment of the present invention.

[0060] The labels of each part in the figure are as follows: 1. Gas-liquid mixing and conveying device; 2. Wastewater outlet; 3. Rotating magnetic field generator; 31. Excitation coil; 4. Cavitation generator; 41. Hemispherical cavitation rotor; 411. Threaded hole; 412. Upper row of teeth; 413. Lower row of teeth; 42. Cavitation reaction chamber; 43. Cavitation reaction cavity; 431. Upper flange; 432. Lower flange; 44. Lower end cover; 441. Organic waste liquid inlet; 442. Organic waste liquid outlet; 443. Lower end cover flange; 5. Electromagnetic generating device; 51. Slip ring; 52. Plasma discharge chamber; 53. Sector electrode; 54. Organic waste liquid channel; 6. Power driving device; 61. Hemispherical cavitation rotor motor; 62. Motor bracket; 63. Coupling; 64. Hemispherical cavitation rotor main shaft; 65. Inclined bracket; 66. Inclined bracket flange. Detailed Embodiments

[0061] The embodiments of the present invention are described in detail below. In the following paragraphs, different aspects of the embodiments will be further defined. These aspects can be used alone or in combination with other aspects, unless explicitly stated that combination is not allowed. In particular, any feature considered to be preferred or advantageous can be combined with other preferred or advantageous features.

[0062] The terms "first", "second", etc. used in the present invention are only for distinguishing different components with the same name, and do not indicate the sequence or primary-secondary relationship between them.

[0063] In addition, when describing that a certain component is "on" another component, it means that the component can be directly placed on the said component, or indirectly placed through one or more intermediate components. Similarly, if a component is described as "connected to" another component, it can be directly connected or indirectly connected through one or more intermediate components.

[0064] The orientation terms such as "up", "down", "top", "bottom", "front", "rear", "inner" and "outer" mentioned in the present invention are only for convenient description, and do not indicate or limit the actual direction or operation mode of the device. Therefore, these orientation terms should not be construed as limiting the protection scope of the present invention.

[0065] As Figures 1 to 5 shown, the present invention provides a hydraulic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge. In some embodiments, the system includes a magnetic field enhanced plasma cavitation reactor, a gas-liquid mixing and conveying device 1, and a wastewater outlet 2. The magnetic field enhanced plasma cavitation reactor includes a rotating magnetic field generator 3, a cavitation generator 4, an electromagnetic generating device 5, and a power driving device 6. The cavitation generator 4 includes a cavitation reaction cavity 43 and a lower end cover 44. An exciting coil 31 for enhancing the magnetic field is arranged on the cavitation reaction cavity 43, and the exciting coil 31 is powered by a rotating magnetic field power supply; an organic wastewater inlet 441 is arranged on one side of the lower end cover 44, and an organic wastewater outlet 442 is arranged on the other side; the gas-liquid mixing and conveying device 1 is communicated with the organic wastewater inlet 441 through a water pump; the wastewater outlet 2 is connected to the organic wastewater outlet 442 through an overflow valve. The organic wastewater in the gas-liquid mixing and conveying device 1 generates a gas-liquid two-phase solution with microbubbles through an aeration device, and the water pump pumps the gas-liquid two-phase solution into the magnetic field enhanced plasma cavitation reactor; the magnetic field enhanced plasma cavitation reactor ionizes, cavitates and degrades the gas-liquid two-phase solution.

[0066] As Figure 2 and Figure 4As shown, in some embodiments, the cavitation generator 4 further includes a hemispherical cavitation rotor 41 and a lower end cover 44. After the magnetic field enhanced plasma cavitation reactor is filled with solution, the degraded organic wastewater flows out from the organic wastewater outlet 442 of the lower end cover 44 by water pressure. The electromagnetic generating device 5 includes a slip ring 51, a plasma discharge chamber 52, a sector electrode 53, and a liquid channel 54. The power driving device 6 includes a hemispherical cavitation rotor motor 61, a motor bracket 62, a coupling 63, and a hemispherical cavitation rotor main shaft 64. The hemispherical cavitation rotor motor 61 is fixed to the motor bracket 62 by bolts. The motor bracket 62 is fixed to the inclined bracket 65 by bolts. The inclined bracket 65 is bolted to the upper flange 431 provided on the cavitation reaction chamber body 43 through an inclined bracket flange 66. The output end of the hemispherical cavitation rotor motor 61 is connected to the hemispherical cavitation rotor main shaft 64 through a coupling 63. The cavitation reaction chamber body 43 provides support and fixation for the internal components of the entire magnetic field enhanced plasma cavitation reactor. A plasma discharge chamber 52, a sector electrode 53, and a cavitation reaction chamber 42 are provided inside the cavitation reaction chamber body 43.

[0067] As Figure 2 and Figure 5 As shown, in some embodiments, a hemispherical cavitation rotor 41 is provided inside the cavitation reaction chamber 42. A threaded hole 411 is provided at the center of the hemispherical cavitation rotor 41, and upper row teeth 412 and lower row teeth 413 are provided at the edge. The helix direction of the upper row teeth 412 is left-handed, and the helix direction of the lower row teeth 413 is right-handed. The hemispherical cavitation rotor main shaft 64 is threadedly connected and fixed to the hemispherical cavitation rotor 41. The hemispherical cavitation rotor motor 61 drives the hemispherical cavitation rotor 41 to rotate through the coupling 63 and the hemispherical cavitation rotor main shaft 64.

[0068] Preferably, the rotation speed of the hemispherical cavitation rotor 41 is set to 1800 r / min, the inclination angle of the upper row teeth 412 and the lower row teeth 413 is 15°, and the hemispherical cavitation rotor 41 is installed in a manner that is axially inclined 30° with respect to the cavitation reaction chamber body 43.

[0069] As Figure 2 and Figure 3As shown, in some embodiments, six liquid channels 54 are evenly distributed on the inner wall of the cavitation reaction chamber 42. The liquid channels 54 connect the plasma discharge chamber 52 and the cavitation reaction chamber 42. The bottom of the cavitation reaction chamber 42 is connected to the organic waste liquid outlet 442. During the rotation of the hemispherical cavitation rotor 41, the organic waste liquid flows from the organic waste liquid channel 54 to the top of the cavitation reaction chamber 42. Under the action of the water pump and gravity, the organic waste liquid flows downward. The organic waste liquid first flows through the upper row of teeth 412 in the hemispherical cavitation rotor 41, then flows to the lower row of teeth 413, and reaches the bottom of the cavitation reaction chamber 42. Since the hemispherical cavitation rotor 41 is installed at an inclination of 30°, and the upper and lower rows of teeth have different helix directions, part of the organic waste liquid will flow to the top of the cavitation reaction chamber 42 along with the rotation of the hemispherical cavitation rotor 41 and undergo the cavitation process again. Another part of the organic waste liquid will flow through the pipeline provided at the bottom of the cavitation reaction chamber body 43 to the organic waste liquid outlet 442. Inside the cavitation reaction chamber 42, a narrow flow channel is formed between the upper row of teeth 412 and the lower row of teeth 413 of the hemispherical cavitation rotor 41 and the inner wall of the cavitation reaction chamber 42, while a wide flow channel is formed between the grooves between adjacent rows of teeth and the inner wall of the cavitation reaction chamber 42. When the organic waste liquid flows through the narrow flow channel, the flow rate increases significantly and the pressure decreases accordingly; while in the wide flow channel, the flow rate decreases and the pressure rises accordingly. In addition, due to the opposite helix directions of the upper row of teeth 412 and the lower row of teeth 413, the hemispherical cavitation rotor 41 exerts a shear force on the organic waste liquid during rotation. This shear force promotes the formation of cavitation bubbles by accelerating fluid flow, reducing local pressure, and enhances the energy released during the bubble collapse process. At the same time, the shear force also increases the frequency of bubble generation and rupture, thereby further enhancing the efficiency of the cavitation reaction.

[0070] As Figure 3 shown, in some examples, an exciting coil 31 is provided on the cavitation reaction chamber body 43, and the exciting coil 31 is powered by a rotating magnetic field power supply; the sector electrode 53 ionizes the organic waste liquid in the plasma discharge chamber 52. The rotating magnetic field generated by the exciting coil 31 forms a synergistic effect with the hydrodynamic cavitation effect: the rotating magnetic field acts on the charged particles in the cavitation bubbles, enhancing the local high temperature and high pressure effect when the bubbles burst. At the same time, it optimizes the liquid flow characteristics through the magnetohydrodynamic effect (MHD effect) and improves the uniformity of the cavitation effect. In addition, the rotating magnetic field and the plasma discharge have a synergistic effect: the magnetic field guides the charged particles generated by the plasma discharge to move along a helical trajectory, and due to the rotating characteristics of the magnetic field, the trajectory of the particles shows complex three-dimensional characteristics. The axis and radius of its helical trajectory change dynamically with the rotation of the magnetic field. This complex movement significantly increases the particle collision probability, thereby promoting the full reaction between the active substances and the organic waste and improving the reaction efficiency.

[0071] As Figure 2 , Figure 3 and Figure 4As shown, in some embodiments, a plasma discharge chamber 52, a sector electrode 53, and a cavitation reaction chamber 42 are disposed inside the cavitation reaction cavity 43; a machine wastewater outlet 442 communicating with the cavitation reaction chamber 42 is provided on the lower end cover 44, and the plasma discharge chamber 52 communicates with the organic wastewater inlet 441; the cavitation reaction cavity 43 includes an upper flange 431 connecting the inclined support 65 and a lower flange 432 connecting the lower end cover 44. An upper end cover flange 443 is provided at the upper end of the lower end cover 44, and the upper end cover flange 443 is connected to the lower flange 432. The organic wastewater inlet 441 communicates with the plasma discharge chamber 52 through a channel between the upper end cover flange 443 and the lower flange 432, and the plasma discharge chamber 52 communicates with the cavitation reaction chamber 42 through an organic waste liquid channel 54.

[0072] As Figure 1 , Figure 2 and Figure 4 shown, the organic wastewater with microbubbles enters the plasma discharge chamber 52 from the organic wastewater inlet 441, is discharged by the sector electrode 53 in the plasma discharge chamber 52, and the ions rotate under the action of the rotating magnetic field, increasing the contact frequency between the oxidizing substances and the organic wastewater. Then it enters the cavitation reaction chamber 42 through the liquid channel 54. During the rotation of the hemispherical cavitation rotor 41, a cavitation region is formed between the upper row of teeth 412 and the lower row of teeth 413 and the inner wall of the cavitation reaction chamber 42.

[0073] Inside the cavitation reaction chamber 42, the high-speed flow and cavitation bubbles induced by the rotation of the hemispherical cavitation rotor 41 result in extremely high temperatures and pressures in the liquid. The cavitation bubbles interact with the active oxidizing substances generated by the dielectric barrier discharge, and the shock waves released by the collapsing cavitation bubbles further promote the decomposition of organic matter, thus significantly improving the degradation efficiency.

[0074] Furthermore, dielectric barrier layers are provided on both sides of the plasma discharge chamber 52, and a sector electrode 53 is configured. The height of each sector electrode 53 is 50 mm, the thickness is 2 mm, and the included angle between the two side edges is 59°. In the cavitation reaction cavity 43, six sector electrodes 53 are evenly distributed in the circumferential direction to ensure the uniformity and efficiency of plasma discharge.

[0075] On one side of the outer wall of the plasma discharge chamber 52, a sector-shaped electrode 53 is installed as the positive electrode, and on one side of the inner wall of the plasma discharge chamber 52, a sector-shaped electrode 53 is installed as the negative electrode; the slip ring 51 and the sector-shaped electrode 53 are connected to a high-voltage power supply through wires, and a dielectric barrier plasma discharge phenomenon is formed by applying a sufficiently high voltage between the outer electrode, the inner electrode and the hemispherical cavitation rotor 41 to generate active substances such as ozone and hydroxyl radicals in water. Preferably, the material of the plasma discharge chamber 52 is quartz glass or a material with a relative dielectric constant greater than 3.8, and the wall thickness of the plasma discharge chamber 52 is 3 mm.

[0076] As Figure 3 and Figure 6 shown, the rotating magnetic field generator 3 includes a power supply rotating magnetic field power supply and an exciting coil 31, and the exciting coil 31 is arranged on the cavitation reaction cavity 43. Taking Figure 6 as an example, Q1 to Q6 are six MOS transistors to control the on and off of each circuit. The left side of the MOS transistor is an amplifier circuit, and the MCU main control element controls the on and off of the MOS transistor through the amplifier circuit. a, b, and c are three coils. When Q1 and Q4 are turned on, coil a and coil b are connected; when Q1 and Q6 are turned on, coil a and coil c are connected; when Q3 and Q2 are turned on, coil b and coil a are connected; when Q3 and Q6 are turned on, coil b and coil c are connected; when Q5 and Q2 are turned on, coil c and coil a are connected; when Q5 and Q4 are turned on, coil c and coil b are connected. When current flows in coil a, the magnetic field direction is determined according to the current direction. Assuming the current direction is from top to bottom, then a downward magnetic field will be generated in coil a. When current flows in coil b, the phase of the current is 120°. According to the right-hand rule, if the current direction is from top to bottom, the magnetic field direction is still downward. When current flows in coil c, the current phase is 240°. Assuming the current direction is still from top to bottom, the magnetic field direction is also downward. Among them, there will be a dead zone every time the connection alternates to prevent the upper and lower MOS transistors from directly connecting to form a short circuit, resulting in damage to the components in the circuit. When a rotating magnetic field is generated, the magnetic field state changes with time, and its rotating magnetic field intensity can be expressed as:

[0077]

[0078] In the formula, ω is the frequency, B1 is the magnitude of the rotating magnetic field, is the magnetic field component in the x direction, is the magnetic field component in the y direction.

[0079] Assume that the parallel magnetic field is distributed along the θ direction of the cylindrical coordinate system, and its magnitude is B0. In the Cartesian coordinate system, it can be expressed as:

[0080]

[0081] In the formula,

[0082] the total magnetic field is:

[0083]

[0084] The motion of charged particles (such as ozone ions, superoxide anion free radicals, etc.) in a magnetic field is determined by the Lorentz force:

[0085] F = q(v × B) (4)

[0086] where F is the Lorentz force acting on the charged particle, q is the particle charge, v is the particle velocity, and B is the magnetic field strength.

[0087] According to Newton's second law:

[0088]

[0089] where m is the particle mass.

[0090] Decompose the velocity and magnetic field into x, y, and z components:

[0091]

[0092] The components of the Lorentz force are:

[0093]

[0094] After expansion, we get:

[0095]

[0096] Therefore, the equation of motion is:

[0097]

[0098] In addition, as Figure 7 shown, the present invention also provides a method for degrading hydraulic cavitation wastewater based on magnetic field enhanced plasma discharge. Using the above-mentioned hydraulic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge, it includes the following steps:

[0099] Step 1: Open the organic wastewater inlet 441 and the organic wastewater outlet 442, turn on the water pump, so that the organic wastewater in the gas-liquid mixture state in the gas-liquid mixing and conveying device 1 enters the organic wastewater inlet 441 through the water pump at a certain flow rate;

[0100] Step 2: Connect the high-voltage power supply to make the sector electrode 53 discharge, forming a dielectric barrier plasma discharge, generating ozone and hydroxyl radicals in the water. Both are strong oxidants and can effectively degrade the organic pollutants in the wastewater;

[0101] Step 3: Start the rotating magnetic field power supply to generate a rotating magnetic field through the exciting coil 31. The rotating magnetic field promotes the movement of molecules and ions in the wastewater through the magnetic force effect, thereby enhancing the degradation effect of the oxidizing substances (such as ozone and hydroxyl radicals) generated by the discharge and improving the wastewater treatment efficiency.

[0102] Step 4: The organic wastewater enters the cavitation reaction chamber 42 from the plasma discharge chamber 52 through the liquid channel 54. A cavitation region is formed between the inner wall of the cavitation reaction chamber 42 and the edge of the hemispherical cavitation rotor 41. The high-speed rotating hemispherical cavitation rotor 41 causes the organic wastewater to degrade in the cavitation region, and the degraded wastewater is discharged through the organic waste liquid outlet 442.

[0103] Step 5: Detect the pollutant removal rate of the liquid flowing out of the organic waste liquid outlet 442 and adjust the flow rate of the water pump in real time to achieve the efficient degradation of the organic wastewater.

[0104] Although the present invention has been described in detail through the above embodiments, those skilled in the art can still appropriately modify the technical solutions in these embodiments according to actual needs, or make equivalent replacements for some technical features. However, these modifications, replacements or improvements shall not deviate from the core idea and basic principles of the present invention, and they still fall within the protection scope of the present invention. Therefore, any adjustment and optimization based on the spirit and purpose of the present invention shall be regarded as the content covered by the present invention.

Claims

1. A hydraulic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge, characterized in that It includes a gas-liquid mixing and conveying device (1), a wastewater outlet (2), a rotating magnetic field generator (3), a cavitation generator (4), a plasma generating device (5) and a power driving device (6); the cavitation generator (4) includes a cavitation reaction cavity (43), and an exciting coil (31) for enhancing the magnetic field is arranged on the cavitation reaction cavity (43), and the exciting coil (31) is powered by a rotating magnetic field power supply; the cavitation generator (4) includes a lower end cover (44), an organic wastewater inlet (441) is arranged on one side of the lower end cover (44), and an organic wastewater outlet (442) is arranged on the other side; the gas-liquid mixing and conveying device (1) is communicated with the organic wastewater inlet (441) through a water pump; the wastewater outlet (2) is connected to the organic wastewater outlet (442) through an overflow valve; A plasma discharge cavity (52) and a cavitation reaction cavity (42) are arranged inside the cavitation reaction cavity (43), and the plasma discharge cavity (52) and the cavitation reaction cavity (42) are communicated through a plurality of organic waste liquid channels (54); a sector electrode (53) is arranged on the outer wall of the plasma discharge cavity (52), and the sector electrode (53) is fixed in a card slot arranged on the outer wall of the plasma discharge cavity (52); a rotatable hemispherical cavitation rotor (41) is arranged in the cavitation reaction cavity (42), the power driving device (6) is drivingly connected to the hemispherical cavitation rotor (41), and the hemispherical cavitation rotor (41) is provided with upper row teeth (412) and lower row teeth (413).

2. The hydraulic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge according to claim 1, wherein The power driving device (6) includes a hemispherical cavitation rotor motor (61), the hemispherical cavitation rotor motor (61) is fixed on a motor bracket (62), the motor bracket (62) is fixed on an inclined bracket (65), the inclined bracket (65) is fixedly connected to an upper flange (431) provided on a cavitation reaction cavity (43) through an inclined bracket flange (66), an output end of the hemispherical cavitation rotor motor (61) is connected with a hemispherical cavitation rotor main shaft (64) through a coupling (63), a slip ring (51) is provided on the hemispherical cavitation rotor main shaft (64), and a high-voltage power supply supplies power to a hemispherical cavitation rotor (41) through the slip ring (51); a threaded hole (411) is provided on the hemispherical cavitation rotor (41) along an axial center line, and the hemispherical cavitation rotor main shaft (64) is fixedly connected with the threaded hole (411) in the hemispherical cavitation rotor (41); wastewater stored in the gas-liquid mixing and conveying device (1) generates a gas-liquid two-phase solution with microbubbles through an aeration device, and a water pump conveys the gas-liquid two-phase solution from the organic wastewater inlet (441) to a plasma discharge chamber (52), and the hemispherical cavitation rotor motor (61) drives the hemispherical cavitation rotor (41) to rotate through the coupling (63) and the hemispherical cavitation rotor main shaft (64); during the rotation of the hemispherical cavitation rotor (41), the pressure of the fluid increases when passing through upper row teeth (412) and lower row teeth (413), and the pressure decreases when passing through grooves between adjacent rows of teeth. At the same time, the row teeth of the hemispherical cavitation rotor (41) generate a shear force by changing the flow direction and velocity of the fluid to further increase the cavitation efficiency.

3. The hydraulic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge according to claim 2, characterized in that The spiral direction of the upper row teeth (412) is left-handed, and the spiral direction of the lower row teeth (413) is right-handed; when the hemispherical cavitation rotor (41) rotates at a high speed, the flow direction and velocity of the fluid are changed, and the fluid is squeezed towards the junction of the upper row teeth (412) and the lower row teeth (413) to increase the fluid pressure. When the fluid flows into the grooves between adjacent rows of teeth, the pressure is released, thereby realizing a cavitation reaction.

4. The hydro-cavitation wastewater degradation system based on magnetic field enhanced plasma discharge according to claim 1, characterized in that The plasma discharge chamber (52) is made of quartz glass or a material with a relative dielectric constant greater than 3.

8.

5. The hydraulic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge according to claim 3, wherein The sector electrodes (53) are distributed in a circumferential surrounding pattern on the outer wall of the plasma discharge chamber (52). A layer of sector electrodes (53) is installed on one side of the outer wall of the plasma discharge chamber (52) close to the hemispherical cavitation rotor (41) as the positive electrode, and a layer of sector electrodes (53) is installed on the side of the outer wall of the plasma discharge chamber (52) far from the hemispherical cavitation rotor (41) as the negative electrode; the sector electrodes (53) are connected to a high-voltage power supply through wires, and a dielectric barrier plasma discharge phenomenon is formed by applying a voltage between the two electrodes to generate active substances such as ozone and hydroxyl radicals in water.

6. The hydraulic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge according to claim 5, wherein The cavitation reaction cavity (43) includes an upper flange (431) connected to the inclined support (65) and a lower flange (432) connected to the lower end cover (44). An upper end cover flange (443) is provided at the upper end of the lower end cover (44), and the upper end cover flange (443) is connected to the lower flange (432). The organic wastewater inlet (441) communicates with the plasma discharge cavity (52) through a channel between the upper end cover flange (443) and the lower flange (432), and the plasma discharge cavity (52) communicates with the cavitation reaction cavity (42) through an organic waste liquid channel (54).

7. The hydraulic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge according to claim 6, wherein The inclination angles of the upper row of teeth (412) and the lower row of teeth (413) of the hemispherical cavitation rotor (41) with respect to the axial direction of the hemispherical cavitation rotor (41) are 30°. The hemispherical cavitation rotor (41) is installed in an inclined manner so that during the rotation of the hemispherical cavitation rotor (41), part of the organic waste liquid at the bottom of the cavitation reaction cavity (42) is brought into the top of the cavitation reaction cavity (42) along with the teeth of the hemispherical cavitation rotor (41), and when the organic waste liquid flows towards the cavitation reaction cavity (42), it flows through the cavitation reaction area again to achieve repeated cavitation.

8. The hydraulic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge according to claim 7, wherein, The rotating magnetic field generator (3) includes an electric rotating magnetic field power supply and an excitation coil (31). The excitation coil (31) is arranged on the cavitation reaction cavity (43) so that the rotating magnetic field is distributed circumferentially along the cavitation reaction cavity (43). The rotating magnetic field is in the x-y plane, and its rotating magnetic field intensity is expressed as: where ω is the frequency, B1 is the magnitude of the rotating magnetic field, is the magnetic field component in the x direction, is the magnetic field component in the y direction; Assume that the parallel magnetic field is distributed along the θ direction of the cylindrical coordinate system with a magnitude of B0; in the Cartesian coordinate system, it is expressed as: In the formula, The total magnetic field is: The motion of charged particles in the magnetic field is determined by the Lorentz force: F = q(v × B) (4) where F is the Lorentz force on the charged particle, q is the particle charge, v is the particle velocity, and B is the magnetic field intensity; according to Newton's second law: where m is the particle mass; Decompose the velocity and magnetic field into x, y, and z components: The components of the Lorentz force are: After expansion, we get: Therefore, the motion equation is:

9. The hydraulic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge according to claim 8, wherein The magnetic field generator (3) further includes an MCU main control element, an amplifier circuit, and a MOS transistor; the MCU main control element controls the on / off of the MOS transistor through the amplifier circuit to precisely control the current intensity, frequency, and phase of the excitation coil (31), generating a rotating magnetic field with adjustable intensity and controllable direction; this rotating magnetic field forms a composite electromagnetic field with the electrostatic field generated by the sector electrodes (53) in the plasma discharge cavity (52), making the charged particles present a three-dimensional helical motion trajectory and increasing the collision probability between the particles and the pollutants.

10. A method for degrading hydraulic cavitation wastewater based on magnetic field enhanced plasma discharge, characterized in that, Using the hydraulic cavitation wastewater degradation system based on magnetic field-enhanced plasma discharge according to any one of claims 1 to 9, the method includes: Step 1: Open the organic wastewater inlet (441) and the organic wastewater outlet (442), turn on the water pump, and make the organic wastewater in the gas-liquid mixture state in the gas-liquid mixing and conveying device (1) enter the organic wastewater inlet (441) at a certain flow rate through the water pump. Step 2: Turn on the high-voltage power supply to discharge the sector electrode (53), forming a dielectric barrier plasma discharge to generate ozone and hydroxyl radicals in water. Both are strong oxidants and can effectively degrade organic pollutants in wastewater; Step 3: Start the rotating magnetic field power supply to generate a rotating magnetic field through the exciting coil (31); the rotating magnetic field promotes the movement of molecules and ions in the wastewater through the magnetic force effect, enhances the degradation effect of the oxidizing substances generated by the discharge, and improves the wastewater treatment efficiency; Step 4: The organic wastewater enters the cavitation reaction chamber (42) from the plasma discharge chamber (52) through the liquid channel (54). The inner wall of the cavitation reaction chamber (42) and the edge of the hemispherical cavitation rotor (41) form a cavitation region. The high-speed rotating hemispherical cavitation rotor (41) causes the organic wastewater to degrade in the cavitation region, and the degraded wastewater is discharged through the organic waste liquid outlet (442); Step 5: Detect the pollutant removal rate of the liquid flowing out of the organic waste liquid outlet (442) and adjust the flow rate of the water pump in real time to achieve the efficient degradation of the organic wastewater.

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