Measurement and Analysis of multiple distribution of tribo-charge for a mixture of particles in gas-solids pipe flow

本文对气固两相管流中颗粒的摩擦荷电进行了理论和实验研究。提出了一种基于粒子碰撞壁面引起的电荷转移的粒子带电模型，该模型考虑了粒子与壁面碰撞次数、粒子初始电荷和碰撞带电因子三个概率密度函数。这些函数分别影响静电电荷分布，因此可以从电荷分布确定颗粒带电的关键参数。为了验证该模型，建立了一个测量粒子电荷分布的系统，并利用带正电粒子和带负电粒子进行了相关实验。结果表明，实验结果与理论计算结果吻合较好，通过对实验数据确定的关键参数值的分析，定量评价了颗粒荷电状态。此外，双极电荷分布进行了测量，使用粉末的混合物，表明在稀相传输系统中的电荷分布可以解释由每个粉末的电荷分布的线性加和性。还发现，颗粒电荷可以通过由不同材料制成的管道的布置来控制。本研究构建了颗粒荷电分析与控制系统。

The tribo-charging of particles in gas-solids pipe flow has been studied both theoretically and experimentally. A model for the particle charging has been presented, which is based on the charge transfer caused by particle impact on the wall surface and takes into account three probability density functions, i.e. (i) the number of collisions of a particle with the wall, (ii) initial particle charge, and (iii) the impact charging factor characterizing the transferred charge. These functions individually affect the electrostatic charge distribution, and hence key parameters on the particle electrification can be determined from the charge distribution. To verify the model, a system for measuring particle charge distribution has been constructed and the relevant experiments have been carried out using positively charged particles and negatively charged particles. It was found that the experimental results were in agreement with the theoretical ones, and by analyzing the values of the key parameters determined from the experimental data, the states of the particle charging were evaluated quantitatively. Furthermore, bipolar charge distributions were measured using a mixture of powders, showing that the charge distributions in a dilute phase transport system could be explained by the linear additivity of the charge distribution of each powder. It was also found that the particle charge can be controlled by the arrangement of the pipes made of different materials. In the present research, the system to analyze and control the particle charging was constructed.