Application Of Magnetically Driven Rotating Sliding Arc Discharge Plasma In Air Purification

Plasma discharge can generate ultraviolet rays,a strong electric field and strong,active particles,which can effectively inactivate bacteria and affect air purification.The magnetic-driven rotating sliding arc discharge plasma has the features of a simple device,high discharge efficiency,high concentration of active particles,and large discharge area,which is very suitable for the application requirements in the air purification field.In this paper,a magnetically driven rotating sliding arc discharge plasma generator with a coaxial structure is designed,and its discharge characteristics are investigated under different power supply parameters.Combined with the COMSOL simulation tool,the electromagnetic field variation under different conditions was analyzed,and the sterilization effect of magnetic rotary arc discharge plasma has experimented.In a modulation cycle,the magnetic-driven rotary sliding arc discharge process can be divided into three stages: arc initiation,sliding and extinguishing.After the power is turned on,the air discharges at high voltage,forming an arc between the cathode and anode.The arc slides in the discharge channel under the action of the magnetic field to stabilize the discharge,and the arc is extinguished when the applied voltage ends.The voltage range for stable discharge of this device is between 6.5 k V-7.0 k V.When the voltage is too low,only discharge filaments are generated around the anode,and an arc cannot be formed between the cathode and the anode,and when the voltage is too high,a strong discharge arc is generated,and the arc cannot be formed to slide.When the pulse modulation power supply duty cycle is small,it cannot form a stable sliding arc.As the duty cycle increases,the arc sliding distance gradually increases.When the duty cycle exceeds 70%,the arc can be in the conductive channel stable sliding.In this paper,COMSOL Multisim is used to simulate the electromagnetic field of the discharge device,establish the physical model of the magnetically driven rotating sliding arc discharge,and study the effect of the magnetic ring on the electromagnetic field and the effect of the power supply parameters on the electric field strength.The simulation results show that the electric field intensity in the discharge channel is significantly higher when the magnetic ring is present,and the electromagnetic field distribution is more uniform.By changing the power supply parameters,it is found that the electric field intensity increases with the increase of power supply voltage and pulse modulation duty cycle.This article conducts magnetic-driven rotating sliding arc discharge plasma sterilization experiments on Lactobacillus fermentum.The experimental results showed that the sterilization rate reached more than 99% after 25 s of sterilization.The sterilization effect was enhanced with the increased duty cycle of power supply pulse modulation.The best sterilization effect was achieved when the power supply voltage was 6.6 k V.Ozone is an essential factor for sterilization.In this paper,the ozone concentration in the plasma was tested,and the results showed that the ozone concentration showed an overall increasing trend with the increase of the power supply voltage and pulse modulation duty cycle.Finally,based on research on magnetically driven rotating sliding arc discharge plasma,a small-sized plasma generator is designed for air purification,and the purification equipment’s circuit principle and structural components are analyzed.