针-弧面式高压放电电流特性实验研究

Experimental Study on Current Characteristics of Needle-cambered High Voltage Discharge

为了提高高压静电分选效率以寻求能产生最佳电场的放电针密度,通过改变外加电压与放电针密度,研究了辊筒弧面电流分布规律。采用自制的针-弧面式高压放电装置,针与弧面间距d设为47 mm,制作了5种不同针密度的放电针,使放电针对1/4的辊筒弧面进行放电。结果表明:在一定范围内,随着针密度的增加,辊筒弧面电流增加;针密度达到一定值后,随着针密度的增加,辊筒弧面电流又开始减小,26针时辊筒弧面电流最大;针-弧面式放电空间中,放电针垂直于弧面处的辊筒弧面电流最大并向两侧递减且呈Gauss分布,电场有效区间是以针垂直于弧面位置为对称轴且左右各23°的区域;利用电场理论和MATLAB对电场的模拟解释了针密度对辊筒弧面电流分布的影响。

In order to seek the best density of discharge needles to generate electric field that improves the efficiency of high voltage electrostatic separation, we investigated the current distribution on the roller＇s cambered surface by varying the needle density and the corona voltage using a homemade needle-cambered surface high-voltage discharge device. In the tests, tips of discharge needles were 47 mm away from the roller surface, and five different needle densities were used for the discharges between the needles and a quarter of the roller surface. The results show that current on the roller sur- face increases with increasing needle density before the density reaches a value of 26, then it decreases. The simulation of current indicates that, within the discharge area, current follows the Gaussian distribution, and its peak appears at the point where the needles are perpendicular to the surface. The area with the perpendicular line of this point to the roller surface as its symmetric axis, expanding 23° to both sides, is the available area for electrostatic separation. We also explained the effect of current density on the roller surface＇s current distribution by electric field theory and electric field simulation.