The flow dynamics of binary particle mixtures in the fluidized bed needs to be monitored in order to optimize the related industrial processes. In this paper, electrostatic sensing and high-speed imaging are applied to measure the velocities of polyethylene and sand particles in the binary particle mixtures in fluidization. Experimental studies were conducted on a lab-scale cold circulating fluidized bed. Correlation function between electrostatic signals from upstream and downstream electrodes placed along the riser shows two peaks that represent transit times for the two types of particles. To verify the above results, high-speed imaging was adopted to capture the flow images of particle mixtures. Particle Image Velocimetry and Particle Tracking Velocimetry algorithms were utilized to process the resulted images in order to measure the velocities of polyethylene and sand particles. The reasons for two-peak correlation functions are illustrated based on the frequency spectrums of the mono-solid-phase electrostatic signals and the velocity difference between polyethylene and sand particles. Finally, comparisons on the velocities obtained from electrostatic sensing and high-speed imaging demonstrate the electrostatic sensor can roughly estimate the particle velocity of binary particle mixtures in the near wall region of the circulating fluidized bed.

中文翻译：

---

结合使用静电感应和高速成像技术测量循环流化床提升管中二元混合物的粒子速度

为了优化相关的工业过程，需要监测二元颗粒混合物在流化床中的流动动力学。在本文中，静电感应和高速成像技术被用于测量流化过程中二元颗粒混合物中聚乙烯和沙颗粒的速度。实验研究是在实验室规模的冷循环流化床上进行的。沿立管放置的上游电极和下游电极的静电信号之间的相关函数显示出两个峰值，表示两种类型粒子的传输时间。为了验证上述结果，采用高速成像来捕获颗粒混合物的流动图像。粒子图像测速和粒子跟踪测速算法用于处理所得图像，以测量聚乙烯和沙粒的速度。基于单固相静电信号的频谱以及聚乙烯与沙粒之间的速度差，说明了出现两峰相关函数的原因。最后，通过静电感应和高速成像获得的速度比较表明，静电感应器可以粗略估计循环流化床近壁区域中二元颗粒混合物的颗粒速度。基于单固相静电信号的频谱以及聚乙烯与沙粒之间的速度差，说明了出现两峰相关函数的原因。最后，通过静电感应和高速成像获得的速度比较表明，静电感应器可以粗略估计循环流化床近壁区域中二元颗粒混合物的颗粒速度。基于单固相静电信号的频谱以及聚乙烯与沙粒之间的速度差，说明了出现两峰相关函数的原因。最后，通过静电感应和高速成像获得的速度比较表明，静电感应器可以粗略估计循环流化床近壁区域中二元颗粒混合物的颗粒速度。