利用电容层析成像测量稀疏气固两相流动

采用电容层析成像技术(ECT)，对常温下稀疏气力输送的固体浓度、速度和质量流量进行了测试研究。浓度分布采用单层电容传感器，速度分布采用双层电容传感器得出相关信号。由测得的速度及体积分数通过计算可以得出质量流量。为克服电容传感器敏感场的不均匀性对成像造成的影响，实验系统中装置了一旋风分离装置，通过旋风分离作用将固体颗粒主要集中在壁面区域，传感器电极布置在分离器直管上。通过对截面体积分数分布、平均值以及波动特性的分析证明了这种测试方法的可行性及可靠性。相关测量结果与称重法测试结果吻合良好，证明这种方法可获得可靠的测量结果。

Measurement of Thin Gas-solids Flow Using Electrical Capacitance Tomography

Experimental studies are carried out on the subtle mass flow measurement in a pneumatic conveying pipeline using electrical capacitance tomography. The mass flow rate is determined from two parameters, namely the solids velocity and the volumetric concentration. The former is measured by cross-correlating the capacitance fluctuations caused by the conveyed solids, and the latter by the image reconstruction method. The two parameters are then combined to give the solids mass flow rate. A cyclone is employed in this system where the sensors are placed in order to compensate the inhomogeneity of the sensor sensitivity. The distribution of void fraction in radial direction, the average void fraction and the wavy characteristics are analyzed. The feasibility and reliability of the method are verified by the experimental results.