Abstract: The fluidization characteristics of quartz sand and FCC catalyst particles in 6 microscale fluidized beds with inner diameters of 4.3, 5.5, 10.5, 15.5, 20.5 and 25.5 mm were investigated. The influences of bed diameter (Dt), static bed height (Hs), particles and gas properties on the pressure drop and minimum fluidization velocity (umf) were examined. The results show that the theoretical pressure drops of microscale fluidized beds deviated from the experimental values under different particles and gas properties. The pressure drop correlations for large size fluidized beds failed to compute microscale fluidized beds. umf increased with decreasing Dt. When the ratio of Hs to Dt ranged from 1 to 3, umf was expressed by linear relationship with Hs, while the slope of equation of umf versus Hs decreased with the increase of Dt. Dt/dp and Hs/dp were defined as dimensionless variables, a new equation was developed to predict umf under the present experimental conditions.

Key words: microscale fluidized bed, minimum fluidization velocity, static bed height, bed diameter, pressure drop

摘要： 在内径4.3, 5.5, 10.5, 15.5, 20.5和25.5 mm的6个气固微小流化床中，考察了石英砂和不同粒径的催化裂化催化剂的流化特性. 研究了流化床尺寸、颗粒及流化介质物性对微小流化床床层压降及最小流化速度的影响. 结果表明，不同颗粒及流化介质的微小流化床床层压降实验值均小于计算值. 传统的压降关联式不能直接用于微小流化床. 其最小流化速度随床径减小呈指数增大，在高径比1:1~3:1范围内，最小流化速度随料高增大近似呈线性增大，其增大速度随床径增大而变缓. 基于实验数据得出了微小流化床最小流化速度的关联式.

关键词: 微小流化床, 最小流化速度, 料高, 床径, 床层压降