利用电容层析成像法测量气力输送中的煤粉流量

采用电容层析成像技术(ECT),对常温下气力输送的固体(如煤粉)浓度、速度和质量流量进行了测试研究.为克服电容传感器敏感场的不均匀对成像造成的影响,实验系统中利用旋风分离作用将固体颗粒集中在近壁面区域,传感器电极布置在分离器直管上.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得出质量流量.测量结果与称重法测试结果吻合,证明电容层析成像法可获得可靠的测量结果.

Measurement of Flow Rate of Pulverized Coal in Pneumatic Conveying Using Electrical Capacitance Tomography

Experimental studies have been carried out on the measurement of the concentration,velocity and mass flow rate of the solid(such as the pulverized coal) in a pneumatic conveying pipeline under normal temperature by use of electrical capacitance tomography(ECT).In order to compensate the inhomogeneity of the sensor sensitivity,a cyclone was used in the experimental system to collect the solid particles to the neighborhood of the wall.The sensors were placed in the straight part of the separator.The concentration was measured by a single layer capacitance,while the velocity was measured by a double-layer capacitance. Mass flow rate was determined from the solid velocity measured and the volumetric fraction.The measured results agree with the results by weighing method,which confirms the reliability of this method.