中文摘要：

基于图像采集与处理方法实验研究了液-液循环流化制冰床的流化特性,发现颗粒的聚团、分散、粘连和聚并4个典型流化特征,获得了颗粒的沿程粒径分布,基于弗劳德准则数Fr揭示了颗粒流化特征与液-液循环流化床流化状态的相关性,讨论了流化床散式流化状态的参数区域。结果表明,颗粒的流化特征和沿程粒径分布随液-液循环流化床高度、运行参数及参数组合的变化而发生改变;距液-液循环流化床底部0.50 m高度内首先发生颗粒的聚团流化,受颗粒相变程度影响,进而在流化床0.50 m高度以上形成颗粒的聚并、粘连和分散流化,但颗粒聚并形成更大颗粒的现象不可避免;液-液循环流化床的流化状态由弗劳德准则数判别,并与颗粒的流化特征相对应,其理想的流化状态——散式流化主要发生在分散液体流量较小、循环液体流速和温度较低的区域。

英文摘要：

Fluidization characteristics of drops or ice particles in liquid-liquid circulating fluidized bed（LLCFB） for fluid ice production were experimentally studied by means of image gathering and processing.Four typical fluidization characteristics were defined;they were the diffuseness,convergence,adhesion and coalescence of particles.Particles size distributions along the height of LLCFB were obtained.The relativity was revealed between particles fluidization characteristics and fluidization states of LLCFB based on Froude number,Fr and the range of operating parameters combination was discussed which could achieve particulate fluidization states of LLCFB.The results show that the variations of particles fluidization characteristics and sizes distributions are presented by the effect of the height,operating parameters and their combination.The particles diffuseness firstly happened at the bottom of LLCFB,0.50 m,under the influence of particles phase change which further led to the convergence,adhesion and coalescence of particles at the other heights,but the phenomena that larger particles formed due to the coalescence of particles must occur.Fluidization states were estimated by Fr calculation and directly affected by particles fluidization characteristics,its perfect fluidization states and particulate fluidization were mainly appeared at some range of operating parameters,such as smaller volume flow-rate of dispersive liquid and lower velocities and temperature of cycle liquid coolant.