内循环微型流化床流动特性

发布时间：2018-06-19 17:14

本文选题：微型流化床 + 内循环　；参考：《化工学报》2017年10期

【摘要】：针对开发适用于化学气相沉积反应动力学研究的微型流化床反应分析仪的应用需求,研究了外径为30 mm的内循环微型流化床中气固流动特性,具体考察了中心射流管伸入高度、内导流管直径和颗粒装载量对实现固体物料内循环的最小操作气速和导流管与环隙区间窜气的影响。结果表明,随着射流管伸入高度的增大,实现颗粒内循环流动的最小操作气速变大;存在最优的导流管直径(20 mm),使得实现颗粒环流的最小操作气速较小;增大颗粒装载量有利于降低颗粒内循环的最小操作气速。通过检测示踪气体在环隙区内的质谱信号,发现在所考察的参数范围内,反应器底部不存在导流管区向环隙区的窜气;在反应器上部,由于颗粒对气体的夹带,环隙区上部总能检测到示踪气体,且窜气特性随操作气速的增大而增强。研究结果可为设计适用于化学气相沉积反应的内循环微型流化床反应器提供参考。
[Abstract]:In order to develop a micro fluidized bed reaction analyzer suitable for the study of chemical vapor deposition reaction kinetics, the gas-solid flow characteristics in an inner circulating micro fluidized bed with an external diameter of 30 mm were studied, and the height of the central jet tube was investigated in detail. The influence of the diameter of the inner diversion tube and the amount of particle loading on the minimum operating gas velocity and the gas channeling between the tube and the annular space for realizing the internal circulation of solid material. The results show that the minimum operating gas velocity increases with the increase of the inlet height of the jet tube, and the minimum operating gas velocity of the particle circulation is smaller because of the existence of an optimal diameter of 20 mm of the diversion tube. The increase of particle loading is beneficial to reduce the minimum operating gas velocity of the particle internal circulation. By detecting the mass spectrum signals of tracer gas in the annular gap region, it is found that there is no gas channeling from the diversion tube area to the annulus region at the bottom of the reactor in the range of parameters investigated, and in the upper part of the reactor, because of the entrainment of the particles to the gas, Tracer gas can always be detected in the upper part of the annulus, and the gas channeling characteristics increase with the increase of the operating gas velocity. The results can be used as a reference for the design of a micro fluidized bed reactor with internal circulation for chemical vapor deposition reaction.
【作者单位】：中国科学院过程工程研究所多相复杂系统国家重点实验室;
【基金】：国家重点研发计划项目(2016YFF0102600) 中国科学院“百人计划”项目(Y224051398)~~
【分类号】：TQ051.13

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