A Preliminary Research On The Corona Characteristics Of Gas-solid Mixture In Non-uniform Electric Field

Recently, the discharge in a two-phase mixture has been applied in many fields, and it has wide application prospect in environmental treatments. The research on the discharge in a two-phase mixture is helpful to know the physical mechanism in the discharge process and the effect of the solid parameters on discharge, and accelerates the application of discharge technique.In this article the phenomena and mechanism of corona discharge in gas is summarized, and the corona characteristics of the gas-solid mixture in non-uniform electric field are researched by experiments. The effect of the volume ratio and permittivity on corona onset voltage of mixture is studied, and the corona characteristic of gas-solid mixture and gas is compared as well.Experimental result indicates that: 1) In DC or AC voltage, the corona onset voltage of gas-solid mixture decreases when the volume ratio increases. 2) In DC voltage, if the gas-solid mixture has a low volume ratio, the negative corona onset voltage is lower than the positive corona onset voltage, but if the gas-solid has a high volume ratio, the negative corona onset voltage exceeds the positive corona onset voltage. The critical value of volume ratio should be researched in next experiments. 3) In DC voltage, the positive corona onset voltage of gas-solid mixture consisted of higher permittivity material is lower than that consisted of lower permittivity material, but in the case of negative polarity, the converse is true. 4) In AC voltage, the corona onset voltage of the gas-solid mixture consisted of higher permittivity material is higher than that consisted of lower permittivity material. But the difference of the values is not so distinct as that in DC voltage. 5) In DC voltage, the negative corona onset voltage of gas-solid mixture is higher than that of air, but the positive corona onset voltage of gas-solid mixture appears different characteristics when compared with the corona onset voltage of gas. In the case of positive polarity, if the gas-solid mixture has a low volume ratio, the corona onset voltage of gas-solid mixture is higher than that of air. When the volume ratio gets great enough, the corona onset voltage of gas-solid mixture is higher than that of the air when the gap interval is shorter than a critical value, but when the gap interval exceeds the critical value, the corona onset voltage of gas-solid mixture is lower than that of the air.