采用电容层析成像技术直接对稀疏气力输送的固体浓度进行测量是困难的。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流浓缩装置,传感器电极布置在浓缩器直管上,对常温下稀疏气力输送的固体浓度进行了测试研究。通过对截面积体积分数分布、平均值以及浓波动特性的分析证明这种测试方法是可行的。通过调节浓缩器顶部的抽吸风量对断面径向浓度分布及平均体积分数进行分析研究,研究结果表明少量的抽吸会对成像有益,但抽吸量太大会扰乱流场而与引入旋流浓缩装置的目的相违背。
It is difficult to measure the concentration of solids in subtle gas-solids flow directly using electrical capacitance tomography (ECT).A cyclone is employed in the experimental system where the sensors are placed in order to compensate the inhomogeneity of the sensor sensitivity.Experimental studies are carried out on the subtle mass flow measurement in a pneumatic conveying pipeline.The distribution of volume concentration in radial direction,the average volume concentration and the fluctuating characteristics are analyzed.The experimental results show this method is workable by means of the online metering system.The distribution of solids in the cross section and the diversification of volume concentration in radial direction are analyzed by changing the suction amount in the top of the cyclone.The experimental results show that a little amount is favorable to the tompography,but too much amount will disturb the cyclone field.