粉体的气体输送过程中,颗粒的荷电包含了粉体速度、浓度及颗粒尺寸等大量信息,阵列式静电传感器是获取这些信息的重要手段,但由于静电传感器灵敏场的非均匀性,流型变化会给测量造成较大的误差。该文基于点电荷思想建立了阵列式静电传感器的三维静电场数学模型,并应用有限元法系统地分析了阵列式静电传感器的结构参数(包括电极的长宽尺寸、屏蔽罩的长度和半径,绝缘管道的厚度等)对传感器灵敏场分布特性的影响。最后结合理论分析和实验,证实了模拟结果的准确性,从而为实现阵列式静电传感器的优化设计提供了理论依据。
In pneumatic conveyed powder flow,the charged particle contains rich information on gas-solid flow,including the velocity,concentration,particle size and so on.The electrodynamic sensor array can be used to get the information.However,due to its inhomogeneity,the different flow patterns may cause measurement error of the particle flow parameters.Based on unity point charge,the mathematic model of the electrodynamic sensor array was established,and the 3 dimensional electrostatic field in the sensing zone of the sensor was solved using finite element method.The effects of structural parameters of the electrodynamic sensor(including dimension of the electrode,the length and radius of the shielding,the thickness of the insulated pipe and so on) were investigated systematically.Theorical analysis and experiments were also performed.The results show that the simulation is accurate,which provides a theoretical basis for the performance improvement and design of the sensor.