Abstract Fluidized bed dryers have been widely applied to dry raw materials or final products due to the advantages of good mixing efficiency and high heat and mass transfer rate. In order to control and optimize the drying process of fluidized bed dryers, it is necessary to develop reliable methods to measure the moisture content of solid particles in the bed. Because of the advantages of non-intrusiveness, simple structure and high sensitivity, an electrostatic sensor array has been developed to monitor the drying process. Experimental investigations were conducted on a lab-scale fluidized bed dryer. The moisture content during the drying process was measured using the sampled particles as reference. It is found that the fluctuation of the electrostatic signals can reflect the change in moisture content. However, the relationship between the fluctuation of the electrostatic signal and the moisture content depends on the air velocity in the dryer. To eliminate the velocity effect on moisture content measurement, a model between the moisture content and the root-mean-square magnitude of the electrostatic signal is established. The effectiveness of the model is validated using experimental results under a range of conditions. The findings indicate that the electrostatic sensor array can measure the moisture content in the bed with a maximum error of ± 15%.

中文翻译：

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使用静电传感器阵列测量流化床干燥器中的水分含量

摘要 流化床干燥机由于具有混合效率好、传热传质速率高等优点，被广泛应用于干燥原料或最终产品。为了控制和优化流化床干燥机的干燥过程，有必要开发可靠的方法来测量床中固体颗粒的水分含量。由于具有非侵入性、结构简单和灵敏度高等优点，开发了一种静电传感器阵列来监测干燥过程。实验研究是在实验室规模的流化床干燥器上进行的。干燥过程中的水分含量以采样颗粒为参考进行测量。发现静电信号的波动可以反映水分含量的变化。然而，静电信号的波动与水分含量之间的关系取决于干燥器中的风速。为了消除速度对水分含量测量的影响，建立了水分含量与静电信号均方根幅度之间的模型。使用一系列条件下的实验结果验证了模型的有效性。结果表明，静电传感器阵列可以测量床中的水分含量，最大误差为±15%。使用一系列条件下的实验结果验证了模型的有效性。结果表明，静电传感器阵列可以测量床中的水分含量，最大误差为±15%。使用一系列条件下的实验结果验证了模型的有效性。结果表明，静电传感器阵列可以测量床中的水分含量，最大误差为±15%。