Abstract: The flow characteristics of FCC particles were studied in a fast fluidized bed reactor with 300 mm diameter. Flow behaviors of gas and solids in the system were measured by pressure cyclic detecting and optical fiber measuring instruments, respectively. The effects of operating conditions on catalyst concentration, particles velocity, screening distribution along the bed axle and radial direction were examined. The experimental results show that when the superficial gas velocity is enhanced in 2.0~2.6 m/s, the catalyst flux is increased to 60~160 kg/(m2×s) and the axial distribution of catalyst concentration can be maintained in 50~650 kg/m3. The radial distribution of catalyst concentration is lower in the central region and higher near the wall. In the axial direction, the radial local catalyst concentration gradually decreases in the particle accelerating region and tends to smooth in the fully developed region. The radial local catalyst concentration decreases with superficial gas velocity increasing or catalyst flux decreasing, radial homogenization is improved. And catalyst concentration appears to be close at the non-dimensional radial position r/R<0.7. The radial distribution of particle velocity is the parabola structure with higher particle velocity in the central region and lower near the wall. The radial local particle velocity increases with superficial gas velocity increasing or catalyst flux decreasing.

Key words: fast fluidized bed, particles velocity, screening distribution, experimental study

摘要： 采用压力巡检仪和光纤测量仪，对直径300 mm的快速流化床反应器内气固两相流动特性进行了研究，考察了操作条件对快速床轴、径向催化剂颗粒浓度、颗粒速度、筛分分布等的影响. 结果表明，当操作气速提高到2.0~2.6 m/s，相应的催化剂循环强度在60~160 kg/(m2×s)，床层密度可保持在50~650 kg/m3；催化剂颗粒浓度在径向上呈中心低、边壁高的不均匀分布，轴向上各径向位置在颗粒加速区逐渐降低、在充分发展区趋于稳定、随表观气速增大或催化剂循环强度减小而减小，且径向均匀性变好，在r/R<0.7的中心区域趋于一致；颗粒速度在径向上呈中心高、边壁低的抛物线形分布，且随操作气速增大或催化剂循环强度增大而更加明显.

关键词: 快速流化床, 颗粒速度, 筛分分布, 实验研究