Research for the method of removing solid impurity from liquefied plastic waste using electrostatic force

在塑料废物的回收系统中，塑料液化似乎是最合适的方法。然而，为了获得高质量的再生，必须从这种液化塑料中去除金属颗粒或碳化物质等外来物质。本研究的目的是寻求一种利用静电力去除的方法。由于有必要了解液化塑料中固体颗粒运动的基本特征，我们通过使用硅油和球形导电颗粒来模拟该系统。检查直径为1至2毫米的碳和钢颗粒。用视频显微镜观察颗粒的运动并记录在录像带上。将直流电场作用于浸入硅油中的平行平板电极系统。放置在下电极上的粒子被电场带电荷，因此作用在粒子上的力就变成了库仑力和重力的总和。更多e.当库仑力超过重力时，粒子向上电极上升。颗粒起升时的阈值电压与理论值吻合。当外加电压高于阈值时，粒子呈现上下运动。观察到的有趣现象是，在电荷转移过程中，粒子经常被保持在电极上。对碳粒子来说，向上和向下运动的速度几乎相等。虽然钢颗粒向上运动的速度比向下运动的速度慢，但随着外加电压的增加，它们的运动距离越来越近。粒子停留在电极上的时间偏差很大。施加的电压越大，电极上的颗粒保持时间越短。放电电流在粒子接触电极时突然产生，并逐渐减小。通过对放电电流脉冲进行积分得到粒子的电荷量随外加电压的增加而增加。此外，观察到不同的运动模式，粒子向上和向下运动，在电极边缘呈现弯曲轨迹。这有可能通过改变电场的结构来控制粒子的运动。研究将在这些实验的基础上进一步阐明粒子运动与电场组态之间的关系。少

In a recycling system of plastic waste, liquefaction of plastics seems the most suitable method. However, the foreign substances, such as metal particles or carbonized material, must be removed from such liquefied plastics in order to get high quality reproduction. The purpose of this research is to seek a removing method by means of electrostatic force. Since it is necessary to know the fundamental characteristics of a solid particle motion within liquefied plastics, we have simulated this system by using silicone oil and a spherical conductive particle. Carbon and steel particles of 1 to 2 mm diameter are examined. The motion of the particle was observed and record in video tape with video microscope. The DC electric field is applied to a parallel plate electrode system which is immersed in silicone oil.The particle placed on the lower electrode is charged by the electric field, so that the force acting on the particle becomes the sum of the Coulombic force and the gravitational forc … More e. When the Coulombic force overcomes the gravitational force, the particle rises toward the upper electrode. The threshold voltage when the particle starts lifting agreed with the theoretical value. When the applied voltage is above the threshold the particle shows up-and-down motion. Interesting phenomenon observed is that the particle is often held on the electrode during the charge transferring. For carbon particles the velocities of upward and downward motion are almost equivalent. Although the velocity of upward motion for steel particle is slower than downward, they are getting closer with increase of the applied voltage. The elapsed time of a particle held on the electrode deviates extensively. The larger voltage is applied, the shorter the particle holding time on the electrode becomes.The discharge current arises abruptly when the particle contacts the electrode and decreases gradually. The charge amount of a particle, which is obtained by integrating the discharge current pulse, increases with the applied voltage. Furthermore, different motion pattern was observed, that the particle moves up and down showing curved trajectory at the edge of electrodes. This has the potentiality to control the particle motion by changing the configuration of electric field. The research will continue to clarify the relation between the particle motion and the electric field configuration on the base of the knowledge gained in these experiments. Less