顶喷流化床加湿-干燥过程微波层析成像测量  

Measurement of the Wetting and Drying Processes in a Top Spray Fluidized Bed By Microwave Tomography

作　　者：车汉桥 梁士国 叶佳敏[1] 王海刚[1,2] CHE Han-Qiao;LIANG Shi-Guo;YE Jia-Min;WANG Hai-Gang(Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China;University of Chinese Academy of Sciences, Beijing 100049, China)

机构地区：[1]中国科学院工程热物理研究所,北京100190 [2]中国科学院大学,北京100049

出　　处：《工程热物理学报》2018年第5期1004-1010,共7页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.61320106004;No.61771455)

摘　　要：流化床反应器进行药物颗粒混合、制粒和干燥工序中,颗粒含水率通常会在大范围(1%～25%)内变化。为优化生产过程,避免故障发生,需要对流化床内湿颗粒流动进行实时监测。微波层析成像(Microwave Tomography,MWT)技术具有较宽的工作频段,适用于高介电常数和高电导率介质的测量。本文利用16个天线微波层析成像传感器对顶喷流化床加湿-干燥过程进行层析成像测量,得到了不同实验条件下颗粒含水率变化曲线和截面颗粒分布图像。实验结果显示,通过对平均介电常数-颗粒含水率关系的标定,可以准确地在线测量颗粒含水率。同时,微波成像揭示了被测截面颗粒分布特征。在此基础上,结合流化床内压差数据对加湿-干燥过程中颗粒流态变化进行了深入讨论,本研究表明,微波层析成像技术应用于流化床过程监控和关键参数提取具有广泛的前景。In fluidized bed mixing, granulation and drying processes, the moisture content of particles can change within a large range（1%～25%）. To improve the efficiency of granulation processes and avoid faults, it is important to develop a tool that enable the monitoring of the wet particle flow. Microwave tomography（MWT） has a wide range of operational frequency, and it is applicable to measure solids concentration with high permittivity or conductivity. This paper introduces the measurement of wetting and drying processes in a top spray fluidized bed using a MWT sensor with 16 antennas. The solids moisture and images of solids distribution are obtained from the measurement data. It is shown that the solids moisture can be accurately measured using the calibration data between mean permittivity and solids moisture of off-line samples. The solids distribution in the cross-sectional area are revealed by the MWT images. Based on the MWT image and the pressure data, the gas-solid flow regimes are further investigated in the wetting and drying process. Experiment results show that microwave tomography is a promising technique for the measurement of fluidized bed with high moisture content particles.

关 键 词：流化床 微波层析成像 含水率测量 

分 类 号：TM934.2[电气工程—电力电子与电力传动]