A wastewater degradation system based on magnetic field enhanced plasma discharge

Abstract

The application discloses a kind of wastewater degradation systems based on magnetic field enhanced plasma discharge of hydraulic cavitation, including cavitation generator, excitation coil is arranged outside cavitation reactor, and plasma discharge cavity and cavitation reaction cavity are arranged inside, and rotatable hemispherical cavitation rotor is arranged in cavitation reaction cavity.The system fuses plasma discharge technology, magnetic field enhancement technology and hydraulic cavitation technology, utilizes magnetic field enhanced plasma discharge to generate active substances such as ozone, hydroxyl radical, is supplemented with hydraulic cavitation technology to strengthen degradation organic wastewater, improves wastewater degradation effect;Setting additional rotating magnetic field, the operation of ionized particle is more violent, increase the frequency of particle and pollutant collision, contact time, make reaction more fully;Hemispherical cavitation rotor has upper and lower rows of teeth with opposite inclination, so that shear force is generated to fluid during the rotation of hemispherical cavitation rotor, improve the frequency of cavitation bubble generation and collapse, and further improve the degradation efficiency of organic wastewater.

Description

Technical Field

[0001] This invention relates to a hydraulic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge, belonging to the field of organic wastewater degradation technology. Background Technology

[0002] Organic wastewater typically contains a large amount of recalcitrant organic pollutants, making its degradation a hot research topic in environmental engineering. The synergistic technology of ozone oxidation and hydraulic cavitation is considered an emerging method for treating organic wastewater. During plasma discharge, when the voltage applied between electrodes reaches a certain level, the gas medium breaks down, generating a low-temperature plasma rich in ozone, free radicals, electrons, and excited-state molecules. These active substances effectively promote the degradation of organic wastewater. However, ozone molecules have low solubility, necessitating the use of hydraulic cavitation technology to enhance the mass transfer efficiency at the gas-liquid interface and promote ozone hydrolysis. Besides ozone, other active substances generated in the plasma (such as free radicals) have extremely short lifetimes, typically on the order of milliseconds or microseconds. The chemothermal effect of cavitation bubble collapse can stimulate the generation of hydroxyl radicals (·OH) and other active substances, further enhancing the degradation process of organic wastewater. Furthermore, when a rotating magnetic field is introduced into the system, it promotes the rotational motion of molecules and ions in the wastewater through magnetic effects, further increasing the contact frequency between oxidants and pollutants during the plasma discharge process. The magnetic field enhances the utilization rate of active materials and effectively reduces waste. The rotating magnetic field also improves fluid flow patterns, allowing cavitation reactions and ionization effects to be enhanced over a wider range, thus improving gas-liquid mass transfer efficiency and significantly enhancing wastewater degradation. Therefore, the synergistic degradation technology combining hydraulic cavitation, plasma discharge, and rotating magnetic field technologies shows promising application prospects and possesses a strong ability to remove recalcitrant organic matter.

[0003] The invention patent "A Three-Stage Hydraulic Cavitation Treatment System for Organic Wastewater" (Publication No.: CN109824173B) discloses a three-stage hydraulic cavitation treatment system for organic wastewater. 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. Then, a rotating hydraulic cavitation device and Fenton reagent work together to degrade organic pollutants. Finally, cavitation jets and ultrasonic cavitation further treat the wastewater, ultimately achieving degradation. This system utilizes the synergistic effect of hydraulic cavitation and Fenton oxidation to improve degradation efficiency and effectively reduce treatment time. However, the system has disadvantages such as complex equipment, high investment costs, and the need for a continuous supply of Fenton reagent, which may lead to additional operating costs and environmental impacts, especially the corrosive sludge generated during the Fenton reaction.

[0004] The utility model patent "An Underwater Pulsed Discharge Plasma Device for Treating Organic Wastewater" (Publication No.: CN212982539 U) proposes an underwater pulsed discharge plasma technology for effectively degrading pollutants in organic wastewater. Its working principle involves introducing organic wastewater into the device using plasma discharge technology. The wastewater flows through holes in the cathode plate and enters multiple electric field regions, promoting the electric field effect. Simultaneously, the device introduces air through a ventilation channel, providing oxygen atoms for the oxidation reaction, thereby generating strong oxidants such as hydroxyl radicals and hydrogen peroxide, promoting the degradation of organic wastewater. However, the active substances such as hydroxyl radicals and hydrogen peroxide have short lifespans, thus being consumed quickly, leading to energy waste and affecting the degradation efficiency of organic wastewater and the energy utilization rate in the treatment process. This limits the efficiency and sustainability of this technology in practical applications.

[0005] The invention patent "A System and Method for Hydrodynamic Cavitation-Coordinated Plasma Degradation of Organic Wastewater" (Publication No.: CN119118415 A) proposes a system and method for hydrodynamic cavitation-coordinated plasma degradation of organic wastewater. In this system, wastewater is aerated to generate microbubbles before entering a plasma rotating cavitation reactor. The rotor rotation generates cavitation, releasing hydroxyl radicals. The wastewater then enters the plasma discharge chamber through a downjet cavitation channel, where fan-shaped electrodes discharge to generate ozone and hydroxyl radicals, further degrading organic matter. The wastewater circulates between the cavitation reaction chamber and the discharge chamber, enhancing the degradation effect, and the pump flow rate is adjusted in real time according to the pollutant removal rate. Although this device combines hydrodynamic cavitation and plasma discharge, the particle trajectory in the plasma discharge chamber is relatively simple, resulting in a low contact frequency between oxidized substances and pollutants, leading to a waste of oxidized substances. Therefore, the performance of this system has room for further improvement.

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

[0007] 1. Low level of integration. The plasma discharge device and the hydraulic cavitation device are set up 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 level of integration of the organic wastewater degradation device.

[0008] 2. The short lifespan of reactive substances such as ozone and hydroxyl radicals prevents the device from effectively utilizing them. Individually generated reactive substances must travel a certain distance to enter the cavitation unit, leading to their degradation and low utilization rate. Furthermore, the low frequency of contact between reactive substances and the substances to be degraded further affects the degradation effect of organic wastewater, and the degradation efficiency still needs improvement.

[0009] 3. Low utilization rate of active ingredients. Before the fluid enters the cavitation zone, the movement of active ingredients mainly relies on water pumps and a parallel magnetic field in one direction, resulting in a single trajectory and insufficient contact frequency with pollutants. Furthermore, the short contact time leads to incomplete reaction processes, affecting overall reaction efficiency. Summary of the Invention

[0010] To address the aforementioned technical problems, this invention provides a hydraulic cavitation wastewater degradation system based on magnetic field-enhanced plasma discharge (MFPD), offering a novel technical solution for the efficient degradation of organic wastewater. This invention integrates plasma discharge technology, hydraulic cavitation technology, and magnetic field enhancement technology. It designs a MFPD-enhanced plasma discharge hydraulic cavitation reactor, incorporating an aeration device to generate micron-sized bubbles in the organic wastewater. A pump then pumps the microbubble-rich organic wastewater into the organic wastewater inlet on the side of the MFPD-enhanced plasma discharge hydraulic cavitation reactor. The MFPD utilizes a medium to block the generation of ozone, hydroxyl radicals, and other active substances during the discharge, which, combined with the hydraulic cavitation technology, enhances the degradation of organic wastewater, thus improving the degradation effect. An external rotating magnetic field is incorporated, making the trajectories of the ionized particles more complex, increasing the frequency of collisions between particles and pollutants, and extending the contact time for a more complete reaction. The hemispherical cavitation rotor has upper and lower rows of teeth with opposite inclination angles, generating shear force on the fluid during rotation, increasing the frequency of cavitation bubble generation and collapse, thereby improving the degradation efficiency of organic wastewater.

[0011] The technical solution adopted in this invention is as follows:

[0012] On one hand, the present invention provides a hydraulic cavitation wastewater degradation system based on magnetic field-enhanced plasma discharge, comprising 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 drive device; the cavitation generator includes a cavitation reaction chamber, on which an excitation coil for enhancing the magnetic field is disposed, the excitation coil being powered by a rotating magnetic field power supply; the cavitation generator includes a lower end cover, with an organic wastewater inlet on one side and an organic wastewater outlet on the other side; the gas-liquid mixing and conveying device is connected to the organic wastewater inlet via a water pump; the wastewater outlet is connected to the organic wastewater outlet via an overflow valve;

[0013] The cavitation reaction chamber is internally equipped with a plasma discharge chamber and a cavitation reaction chamber, which are connected by multiple organic waste liquid channels. The outer wall of the plasma discharge chamber is provided with a fan-shaped electrode, which is fixed in a slot on the outer wall of the plasma discharge chamber. A rotatable hemispherical cavitation rotor is provided inside the cavitation reaction chamber, and the power drive device is driven by the hemispherical cavitation rotor. The hemispherical cavitation rotor is provided with an upper row of teeth and a lower row of teeth.

[0014] In one embodiment of the present invention, the power drive device includes a hemispherical cavitation rotor motor, which is fixed on a motor bracket. The motor bracket is fixed on an inclined bracket, which is fixedly connected to an upper flange on the cavitation reaction chamber via an inclined bracket flange. The output end of the hemispherical cavitation rotor motor is connected to a hemispherical cavitation rotor main shaft via 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. The hemispherical cavitation rotor has a threaded hole along its axial centerline, and the hemispherical cavitation rotor main shaft is connected to the hemispherical cavitation rotor... The cavitation rotor is fixedly connected by threaded holes; the wastewater stored in the gas-liquid mixing and conveying device is aerated to generate a gas-liquid two-phase solution with microbubbles, and the water pump transports the gas-liquid two-phase solution from the organic wastewater inlet to the plasma discharge chamber. The hemispherical cavitation rotor motor drives the hemispherical cavitation rotor to rotate through a coupling and the main shaft of the hemispherical cavitation rotor. During the rotation of the hemispherical cavitation rotor, the pressure of the fluid increases when it passes through the upper and lower rows of teeth, and decreases when it passes through the grooves between adjacent rows of teeth. At the same time, the rows of teeth of the hemispherical cavitation rotor generate shear force by changing the flow direction and speed of the fluid to further increase the cavitation efficiency.

[0015] In one embodiment of the present invention, the upper row of teeth rotates to the left and the lower row of teeth rotates to the right. When the hemispherical cavitation rotor rotates at high speed, the flow direction and speed of the fluid change. The fluid is squeezed at the junction of the upper and lower rows of teeth to increase the fluid pressure. When the fluid flows into the groove between adjacent rows of teeth, the pressure is released, thereby realizing the cavitation reaction.

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

[0017] In one embodiment of the present invention, the fan-shaped electrodes are distributed in a circumferential manner on the outer wall of the plasma discharge cavity. A layer of fan-shaped electrodes is installed on one side of the outer wall of the plasma discharge cavity as a positive electrode, and a layer of fan-shaped electrodes is installed on one side of the inner wall of the plasma discharge cavity as a negative electrode. The fan-shaped electrodes are connected to a high-voltage power supply through wires. By applying voltage between the two electrodes, a dielectric barrier is formed to block the plasma discharge phenomenon, so as to generate ozone and hydroxyl radicals in water.

[0018] In one 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 connected to the plasma discharge chamber through a channel between the lower end cover flange and the lower flange. The plasma discharge chamber is connected to the cavitation reaction chamber through an organic waste liquid channel.

[0019] In one embodiment of the present invention, the inclination angle of the upper and lower rows of teeth of the hemispherical cavitation rotor is 30° with the axial angle of the hemispherical cavitation rotor. The hemispherical cavitation rotor is installed at an angle 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 carried into the top of the cavitation reaction chamber along with the teeth of the hemispherical cavitation rotor. When the organic waste liquid flows into the cavitation reaction chamber, it flows through the cavitation reaction area again to achieve repeated cavitation.

[0020] In one 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 disposed on the cavitation reaction cavity, so that the rotating magnetic field is distributed circumferentially along the cavitation reaction cavity. In the plane, its rotating magnetic field strength is expressed as:

[0021] (1)

[0022] In the formula, For frequency, For the magnitude of the rotating magnetic field, for directional magnetic field components for Magnetic field components in the direction;

[0023] Assuming the parallel magnetic field is along the cylindrical coordinate system Directional distribution, size is In Cartesian coordinates, it is represented as:

[0024] (2)

[0025] In the formula,

[0026] The total magnetic field is:

[0027] (3)

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

[0029] (4)

[0030] in, The Lorentz force experienced by a charged particle, For particle charge, For particle velocity, The magnetic field strength;

[0031] According to Newton's second law:

[0032] (5)

[0033] in, For particle mass;

[0034] Decompose velocity and magnetic field into , , Quantity:

[0035] (6)

[0036] (7)

[0037] The components of the Lorentz force are:

[0038] (8)

[0039] After unfolding, we get:

[0040] (9)

[0041] Therefore, the equation of motion is:

[0042] (10).

[0043] In one embodiment of the present invention, the magnetic field generator further includes an MCU main control element, an amplifier circuit and a MOS transistor; the MCU main control element controls the on and off of the MOS transistor through the amplifier circuit to precisely control the current intensity, frequency and phase of the excitation coil (31) and generate a rotating magnetic field with adjustable intensity and controllable direction; the rotating magnetic field and the electrostatic field generated by the fan-shaped electrode (53) in the plasma discharge cavity (52) form a composite electromagnetic field, so that the charged particles present a three-dimensional spiral motion trajectory, and increase the probability of collision between particles and pollutants.

[0044] On the other hand, the present invention provides a method for degrading hydrodynamic cavitation wastewater based on magnetic field-enhanced plasma discharge, employing the aforementioned hydrodynamic cavitation wastewater degradation system based on magnetic field-enhanced plasma discharge, the method comprising:

[0045] Step 1: Open the organic wastewater inlet and outlet, and turn on the water pump so that the organic wastewater in the gas-liquid mixed state in the gas-liquid mixing and conveying device enters the organic wastewater inlet at a certain flow rate through the water pump.

[0046] Step 2: Connect the high-voltage power supply to discharge the fan-shaped electrode, forming a dielectric barrier plasma discharge, which generates ozone and hydroxyl radicals in the water. Both are strong oxidants that can effectively degrade organic pollutants in wastewater.

[0047] 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 effect, enhances the degradation effect of oxidizing substances generated by the discharge, and improves the wastewater treatment efficiency.

[0048] Step 4: 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. The degraded wastewater is discharged through the organic waste liquid outlet.

[0049] Step 5: Detect the pollutant removal rate of the liquid flowing out of the organic wastewater outlet and adjust the water pump flow rate in real time to achieve efficient degradation of organic wastewater.

[0050] The beneficial effects of this invention are as follows:

[0051] (1) This technology integrates plasma discharge technology and hydraulic cavitation technology, using dielectric barrier plasma (DBD) to generate low-temperature plasma rich in ozone, free radicals, electrons, and excited-state molecules in organic wastewater. 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 organic pollutants in the wastewater, and significantly improving the utilization rate of active substances. This synergistic effect not only enables more thorough degradation of organic matter but also effectively shortens the degradation time and reduces energy consumption.

[0052] (2) The hemispherical cavitation rotor is designed with upper and lower rows of teeth with different rotation directions, which enhances the shear force of wastewater in the cavitation zone and promotes the generation and collapse of bubbles. In addition, the tooth groove design with opposite inclination angles improves the flow pattern of wastewater and accelerates the circulation of wastewater between the cavitation zone and the discharge zone, thereby strengthening the cavitation effect and ionization effect, improving the gas-liquid mass transfer efficiency, and further enhancing the degradation effect of organic wastewater.

[0053] (3) An excitation coil is installed outside the cavitation reaction shell and 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 electrodes, causing the plasma movement trajectory in the fluid in the plasma discharge chamber to be a complex spiral motion. Since the magnetic field generated by the excitation coil is rotating, the axis and radius of the spiral will change periodically when it interacts with the parallel magnetic field generated by the electrodes, which increases the frequency of particle contact with pollutants and effectively increases the wastewater degradation efficiency. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 A schematic diagram of the structure of a hydraulic cavitation wastewater degradation system based on magnetic field enhanced plasma discharge provided in an embodiment of the present invention.

[0056] Figure 2 This is a cross-sectional view of the plasma cavitation reactor provided in an embodiment of the present invention.

[0057] Figure 3 This is a schematic diagram of the cavitation reaction chamber provided in an embodiment of the present invention.

[0058] Figure 4 This is a schematic diagram of the structure of the lower end cap provided in an embodiment of the present invention.

[0059] Figure 5 This is a schematic diagram of the hemispherical cavitation rotor provided in an embodiment of the present invention.

[0060] Figure 6 A circuit diagram of a rotating magnetic field provided in an embodiment of the present invention.

[0061] Figure 7 A flowchart of a hydrocavitation wastewater degradation method based on magnetic field-enhanced plasma discharge, provided for an embodiment of the present invention.

[0062] The components in the diagram are labeled 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 toothed section; 413. Lower toothed section; 42. Cavitation reaction chamber; 43. Cavitation reaction chamber body; 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 generator; 51. Slip ring; 52. Plasma discharge chamber; 53. Sector electrode; 54. Organic waste liquid channel; 6. Power drive 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 Implementation

[0063] 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 may be used alone or in combination with other aspects, unless explicitly stated that combination is not permitted. In particular, any feature considered preferred or advantageous may be used in combination with other preferred or advantageous features.

[0064] The terms "first" and "second" used in this invention are only used to distinguish different components with the same name and do not indicate their order or primary / secondary relationship.

[0065] Furthermore, when a component is described as being "on" another component, it means that the component can be placed directly on the component or indirectly through one or more intermediate components. Similarly, if a component is described as being "connected" to another component, it can be directly connected or indirectly connected through one or more intermediate components.

[0066] The directional terms "upper," "lower," "top," "bottom," "front," "rear," "inner," and "outer" used in this invention are for descriptive convenience only and do not indicate or limit the actual direction or operation of the device. Therefore, these directional terms should not be construed as limiting the scope of protection of this invention.

[0067] like Figures 1 to 5As shown, this invention provides a hydrodynamic 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 generator 5, and a power drive device 6. The cavitation generator 4 includes a cavitation reaction chamber 43 and a lower end cover 44. An excitation coil 31 for enhancing the magnetic field is provided on the cavitation reaction chamber 43, and the excitation coil 31 is powered by a rotating magnetic field power supply. An organic wastewater inlet 441 is provided on one side of the lower end cover 44, and an organic wastewater outlet 442 is provided on the other side. The gas-liquid mixing and conveying device 1 is connected to 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 is aerated to generate a gas-liquid two-phase solution with microbubbles. The water pump pumps the gas-liquid two-phase solution to the magnetic field enhanced plasma cavitation reactor. The magnetic field enhanced plasma cavitation reactor ionizes, cavitates and degrades the gas-liquid two-phase solution.

[0068] like Figure 2 and Figure 4 As 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 generator 5 includes a slip ring 51, a plasma discharge chamber 52, a sector electrode 53, and a liquid channel 54. The power drive 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... The motor is bolted to the motor bracket 62, which is bolted to the inclined bracket 65. The inclined bracket 65 is bolted to the upper flange 431 on the cavitation reaction chamber 43 via the inclined bracket flange 66. The output end of the hemispherical cavitation rotor motor 61 is connected to the hemispherical cavitation rotor main shaft 64 via the coupling 63. The cavitation reaction chamber 43 provides support and fixation for the internal components of the entire magnetic field enhanced plasma cavitation reactor. The cavitation reaction chamber 43 contains a plasma discharge chamber 52, a fan-shaped electrode 53, and the cavitation reaction chamber 42.

[0069] like Figure 2 and Figure 5As shown, in some embodiments, a hemispherical cavitation rotor 41 is provided inside the cavitation reaction chamber 42. The hemispherical cavitation rotor 41 has a threaded hole 411 at its center and upper teeth 412 and lower teeth 413 on its edge. The upper teeth 412 are rotated to the left and the lower teeth 413 are rotated to the right. 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.

[0070] Preferably, the rotational speed of the hemispherical cavitation rotor 41 is set to 1800 r / min, the inclination angle of the upper row of teeth 412 and the lower row of teeth 413 is 15°, and the hemispherical cavitation rotor 41 is installed with its axial angle of 30° relative to the cavitation reaction chamber 43.

[0071] like Figure 2 and Figure 3 As 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, and 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 through 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 rotation directions, some of the organic waste liquid will flow to the top of the cavitation reaction chamber 42 with the rotation of the hemispherical cavitation rotor 41 and undergo the cavitation process again. The other part of the organic waste liquid will flow to the organic waste liquid outlet 442 through the pipe set at the bottom of the cavitation reaction chamber 43. Within the cavitation reaction chamber 42, the upper row of teeth 412 and the lower row of teeth 413 of the hemispherical cavitation rotor 41 form narrow flow channels between themselves and the inner wall of the cavitation reaction chamber 42, while the grooves between adjacent rows of teeth form wide flow channels between themselves and the inner wall of the cavitation reaction chamber 42. When the organic waste liquid flows through the narrow flow channels, the flow velocity increases significantly, and the pressure decreases accordingly; while in the wide flow channels, the flow velocity decreases, and the pressure increases accordingly. Furthermore, because the upper row of teeth 412 and the lower row of teeth 413 rotate in opposite directions, the hemispherical cavitation rotor 41 applies a shear force to the organic waste liquid during rotation. This shear force accelerates fluid flow, reduces local pressure, promotes the formation of cavitation bubbles, and enhances the energy released during bubble collapse. Simultaneously, the shear force also increases the frequency of bubble generation and collapse, thereby further enhancing the efficiency of the cavitation reaction.

[0072] like Figure 3As shown, in some examples, an excitation coil 31 is provided on the cavitation reaction chamber 43, which is powered by a rotating magnetic field power supply; the sector-shaped electrode 53 ionizes the organic waste liquid in the plasma discharge chamber 52. The rotating magnetic field generated by the excitation coil 31 works synergistically with the hydraulic 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, and simultaneously optimizing the liquid flow characteristics through the magnetohydrodynamic effect (MHD effect), improving the uniformity of the cavitation effect. In addition, the rotating magnetic field works synergistically with the plasma discharge: the magnetic field guides the charged particles generated by the plasma discharge to move along a spiral trajectory, and due to the rotational characteristics of the magnetic field, the particle trajectory exhibits complex three-dimensional characteristics, with the axis and radius of the spiral trajectory dynamically changing with the rotation of the magnetic field. This complex motion significantly increases the probability of particle collision, thereby promoting the full reaction between active substances and organic waste and improving reaction efficiency.

[0073] like Figure 2 , Figure 3 and Figure 4 As shown, in some embodiments, the cavitation reaction chamber 43 is provided with a plasma discharge chamber 52, a fan-shaped electrode 53, and the cavitation reaction chamber 42; the lower end cover 44 is provided with an organic wastewater outlet 442 communicating with the cavitation reaction chamber 42, and the plasma discharge chamber 52 is communicated with the organic wastewater inlet 441; the cavitation reaction chamber 43 includes an upper flange 431 connecting the inclined support 65 and a lower flange 432 connecting the lower end cover 44, the upper end of the lower end cover 44 is provided with a lower end cover flange 443, the lower end cover flange 443 is connected to the lower flange 432, the organic wastewater inlet 441 is communicated with the plasma discharge chamber 52 through the channel between the lower end cover flange 443 and the lower flange 432, and the plasma discharge chamber 52 is communicated with the cavitation reaction chamber 42 through the organic waste liquid channel 54.

[0074] like Figure 1 , Figure 2 and Figure 4 As shown, organic wastewater containing microbubbles enters the plasma discharge chamber 52 through the organic wastewater inlet 441. In the plasma discharge chamber 52, it is discharged through the fan-shaped electrode 53. Under the action of the rotating magnetic field, the ions rotate, increasing the contact frequency between the oxidizing substances and the organic wastewater. It then enters the cavitation reaction chamber 42 through the liquid channel 54. During the rotation of the hemispherical cavitation rotor 41, the upper row of teeth 412 and the lower row of teeth 413 form a cavitation region between the rotor 41 and the inner wall of the cavitation reaction chamber 42.

[0075] Within the cavitation reaction chamber 42, the high-speed flow and cavitation bubbles generated by the rotation of the hemispherical cavitation rotor 41 lead to extremely high temperatures and pressures in the liquid. The cavitation bubbles interact with the active oxidizing substances generated by the dielectric barrier discharge, while the shock waves released by the collapsed cavitation bubbles further promote the decomposition of organic matter, thereby significantly improving the degradation efficiency.

[0076] Furthermore, the plasma discharge cavity 52 is provided with dielectric barrier layers on both sides and is equipped with sector-shaped electrodes 53. Each sector-shaped electrode 53 has a height of 50 mm, a thickness of 2 mm, and an included angle of 59° between its two sides. In the cavitation reaction cavity 43, the six sector-shaped electrodes 53 are evenly distributed circumferentially to ensure the uniformity and efficiency of plasma discharge.

[0077] A fan-shaped electrode 53 is installed on one side of the outer wall of the plasma discharge cavity 52 as a positive electrode, and a fan-shaped electrode 53 is installed on one side of the inner wall of the plasma discharge cavity 52 as a negative electrode. The slip ring 51 and the fan-shaped electrode 53 are connected to a high-voltage power supply through wires. By applying a sufficiently high voltage between the outer electrode, the inner electrode, and the hemispherical cavitation rotor 41, a dielectric barrier is formed to block the plasma discharge phenomenon, thereby generating active substances such as ozone and hydroxyl radicals in water. Preferably, the plasma discharge cavity 52 is made of quartz glass or a material with a relative permittivity greater than 3.8, and the wall thickness of the plasma discharge cavity 52 is 3 mm.

[0078] like Figure 3 and Figure 6 As shown, the rotating magnetic field generator 3 includes a power supply for the rotating magnetic field and an excitation coil 31, which is mounted on the cavitation reaction chamber 43. Figure 6For example, Q1 to Q6 are six MOSFETs, controlling the on / off state of each circuit. To the left of the MOSFETs is an amplifier circuit, which controls the on / off state of the MOSFETs via the MCU's main control components. a, b, and c are three coils. When Q1 and Q4 are on, coils a and b are connected; when Q1 and Q6 are on, coils a and c are connected; when Q3 and Q2 are on, coils b and a are connected; when Q3 and Q6 are on, coils b and c are connected; when Q5 and Q2 are on, coils c and a are connected; when Q5 and Q4 are on, coils c and b are connected. When current flows in coil a, the direction of the magnetic field is determined by the direction of the current. Assuming the current direction is from top to bottom, 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. There is a dead zone during each switching operation to prevent short circuits caused by direct connection between the upper and lower MOSFETs, which could damage components in the circuit. When a rotating magnetic field is generated, its state changes over time, and its strength can be expressed as:

[0079] (1)

[0080] In the formula, For frequency, For the magnitude of the rotating magnetic field, for directional magnetic field components for The magnetic field component in the direction.

[0081] Assuming the parallel magnetic field is along the cylindrical coordinate system Directional distribution, size is In the Cartesian coordinate system, it can be represented as:

[0082] (2)

[0083] In the formula,

[0084] The total magnetic field is:

[0085] (3)

[0086] The motion of charged particles (such as ozone ions, superoxide anions, and free radicals) in a magnetic field is determined by the Lorentz force:

[0087] (4)

[0088] in, The Lorentz force experienced by a charged particle, For particle charge, For particle velocity, denoted as , where is the magnetic field strength.

[0089] According to Newton's second law:

[0090] (5)

[0091] in, The mass is the particle mass.

[0092] Decompose velocity and magnetic field into , , Quantity:

[0093] (6)

[0094] (7)

[0095] The components of the Lorentz force are:

[0096] (8)

[0097] After unfolding, we get:

[0098] (9)

[0099] Therefore, the equation of motion is:

[0100] (10)

[0101] In addition, such as Figure 7 As shown, the present invention also provides a method for degrading hydrocavitation wastewater based on magnetic field-enhanced plasma discharge, employing the above-mentioned hydrocavitation wastewater degradation system based on magnetic field-enhanced plasma discharge, comprising the following steps:

[0102] Step 1: Open the organic wastewater inlet 441 and the organic wastewater outlet 442, and turn on the water pump so that the organic wastewater in the gas-liquid mixing and conveying device 1 in the gas-liquid mixed state enters the organic wastewater inlet 441 at a certain flow rate through the water pump.

[0103] Step 2: Connect the high-voltage power supply to discharge the sector electrode 53, forming a dielectric barrier plasma discharge, which generates ozone and hydroxyl radicals in the water. Both are strong oxidants that can effectively degrade organic pollutants in wastewater.

[0104] Step 3: Start the rotating magnetic field power supply to generate a rotating magnetic field through the excitation coil 31. The rotating magnetic field promotes the movement of molecules and ions in the wastewater through the magnetic effect, thereby enhancing the degradation effect of oxidizing substances (such as ozone and hydroxyl radicals) generated by the discharge and improving the wastewater treatment efficiency.

[0105] Step 4: 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 area. The high-speed rotating hemispherical cavitation rotor 41 causes the organic wastewater to degrade in the cavitation area. The degraded wastewater is discharged through the organic waste liquid outlet 442.

[0106] Step 5: Detect the pollutant removal rate of the liquid flowing out of the organic wastewater outlet 442, and adjust the water pump flow rate in real time to achieve efficient degradation of organic wastewater.

[0107] Although the present invention has been described in detail through the above embodiments, those skilled in the art can still make appropriate modifications to the technical solutions in these embodiments or make equivalent substitutions for certain technical features according to actual needs. However, these modifications, substitutions, or improvements must not deviate from the core ideas and basic principles of the present invention, and they still fall within the protection scope of the present invention. Therefore, any adjustments and optimizations made based on the spirit and purpose of the present invention should be considered as covered by the present invention.

Claims

1. A hydraulic cavitation wastewater degradation system based on magnetic field-enhanced plasma discharge, characterized in that, The device 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 generator (5), and a power drive device (6). The cavitation generator (4) includes a cavitation reaction chamber (43), on which an excitation coil (31) for enhancing the magnetic field is provided. The excitation coil (31) is powered by a rotating magnetic field power supply. The cavitation generator (4) includes a lower end cover (44), on which an organic wastewater inlet (441) is provided on one side and an organic waste liquid outlet (442) is provided on the other side. The gas-liquid mixing and conveying device (1) is connected to the organic wastewater inlet (441) via a water pump. The wastewater outlet (2) is connected to the organic waste liquid outlet (442) via an overflow valve. The cavitation reaction chamber (43) is provided with a plasma discharge chamber (52) and a cavitation reaction chamber (42) inside. The plasma discharge chamber (52) and the cavitation reaction chamber (42) are connected by multiple organic waste liquid channels (54). The outer wall of the plasma discharge chamber (52) is provided with a fan-shaped electrode (53), which is fixed in a slot provided on the outer wall of the plasma discharge chamber (52). The cavitation reaction chamber (42) is provided with a rotatable hemispherical cavitation rotor (41). The power drive device (6) is driven and connected to the hemispherical cavitation rotor (41). The hemispherical cavitation rotor (41) is provided with an upper row of teeth (412) and a lower row of teeth (413). The power drive device (6) includes a hemispherical cavitation rotor motor (61), which 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 the upper flange (431) on the cavitation reaction chamber (43) via 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) via a coupling (63). A slip ring (51) is provided on the hemispherical cavitation rotor main shaft (64). A high-voltage power supply provides power to the hemispherical cavitation rotor (41) through the slip ring (51). The hemispherical cavitation rotor (41) has a threaded hole (411) along its axial centerline. The hemispherical cavitation rotor main shaft (61) is connected to the upper flange (431) on the cavitation reaction chamber (43). 4) Fixedly connected to the threaded hole (411) in the hemispherical cavitation rotor (41); the wastewater stored in the gas-liquid mixing and conveying device (1) generates a gas-liquid two-phase solution with microbubbles through the aeration device, and the water pump transports the gas-liquid two-phase solution from the organic wastewater inlet (441) to the plasma discharge chamber (52). 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 it passes through the upper row of teeth (412) and the lower row of teeth (413), and the pressure decreases when it passes through the groove between adjacent rows of teeth. At the same time, the rows of teeth of the hemispherical cavitation rotor (41) generate shear force by changing the flow direction and speed of the fluid, so as to further increase the cavitation efficiency. The upper row of teeth (412) rotates to the left, and the lower row of teeth (413) rotates to the right. When the hemispherical cavitation rotor (41) rotates at high speed, the flow direction and speed of the fluid change. The fluid is squeezed at the junction of the upper row of teeth (412) and the lower row of teeth (413) to increase the fluid pressure. When the fluid flows into the groove between adjacent rows of teeth, the pressure is released, thereby realizing the cavitation reaction. The fan-shaped electrodes (53) are distributed around the outer wall of the plasma discharge cavity (52). A layer of fan-shaped electrodes (53) is installed on one side of the outer wall of the plasma discharge cavity (52) as a positive electrode, and a layer of fan-shaped electrodes (53) is installed on one side of the inner wall of the plasma discharge cavity (52) as a negative electrode. The fan-shaped electrodes (53) are connected to a high-voltage power supply through wires. By applying voltage between the two electrodes, a dielectric barrier is formed to block the plasma discharge phenomenon, so as to generate ozone and hydroxyl radicals in water. The cavitation reaction chamber (43) includes an upper flange (431) connected to the inclined support (65) and a lower flange (432) connected to the lower end cover (44). The lower end cover (44) is provided with a lower end cover flange (443) at its upper end. The lower end cover flange (443) is connected to the lower flange (432). The organic wastewater inlet (441) is connected to the plasma discharge chamber (52) through the channel between the lower end cover flange (443) and the lower flange (432). The plasma discharge chamber (52) is connected to the cavitation reaction chamber (42) through the organic waste liquid channel (54). The angle between the upper row of teeth (412) and the lower row of teeth (413) of the hemispherical cavitation rotor (41) and the axial direction of the hemispherical cavitation rotor (41) is 30°. The hemispherical cavitation rotor (41) is installed at an angle so that during the rotation of the hemispherical cavitation rotor (41), part of the organic waste liquid at the bottom of the cavitation reaction chamber (42) is carried into the top of the cavitation reaction chamber (42) along with the teeth of the hemispherical cavitation rotor (41). When the organic waste liquid flows to the cavitation reaction chamber (42), it flows through the cavitation reaction area again to achieve repeated cavitation.

2. The hydraulic cavitation wastewater degradation system based on magnetic field-enhanced plasma discharge according to claim 1, characterized in that, The plasma discharge cavity (52) is made of quartz glass or a material with a relative permittivity greater than 3.8.

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