等离子体射流雾滴的荷电特性研究

Property of Plasma Charge Spray

为了从理论上探讨等离子体荷电过程出现的瞬时不稳定和突变现象,在高压电场下用网状目标法测量雾滴群体电流,用荷质比评价雾滴的荷电效果,试验研究了电晕产生的等离子体射流喷雾荷电过程。电极间气体电离过程的伏安特性分析、荷电过程的电学模型理论分析和试验结果表明:等离子体荷电喷雾产生的突变现象是极间气体电离,阻抗变化,从而引起极间电压降低,电流(荷质比)增大,是等离子荷电过程的固有特性;等离子体荷电喷雾雾滴的荷质比与荷电电压间存在线性关系,其荷电效果受电极的结构形式和尺寸、极间气体介质的厚度、雾化液体的介电性能及喷头和喷雾参数等因素的影响;安全高效的荷电电压要高于起晕电压,宜为15-20 kV。

The experiment on the jet spray droplet charge is launched in which the net target method is used to measure the current of droplet group, the charge-quality ratio is used to evaluate the charge result of droplets The plasma jet droplet charge arising from the corona is studied. Through analyzing the voltage-ampere property in the inter-electrode gas ionization, an electrical model in the charge process is established so as to gain a theoretical insight into the momentary instability and the sudden change in the process of plasma charge The theoretical analysis and the experimental result indicates that the sudden change in the plasma charge spray is due to the inter-deetrode gas ionization and the impedance change, the interdeetrode voltage decreases as the current （ charge-quality ration） increases which is a natural property of the plasma charge process. Moreover, it is found that the charge-quality ratio of the plasma charge droplet spray is linear with the charge voltage and the charge result is affected by the structure and the size of the deetrode, the thickness of the inter-electrode gas medium, the didectric property of atomized liquid, the nozzle and the spray parameters, etc The safe and effident charge voltage is higher than the corona inception voltage and is between 15-20 kV.