The onset velocity of a liquid–solid circulating fluidized bed

摘要: Abstract The critical transition velocity, Ucr, previously defined by Liang et al. [W.-G. Liang, S.-L. Zhang, J.-X. Zhu, Y. Jin, Z.-Q. Yu and Z.-W. Wang, Flow characteristics of the liquid–solid circulating fluidized bed, Powder Technol., 90 (1997) 95–102.] to demarcate conventional fluidization regimes, was found vary with total solids inventory feeding system. In this work, an onset velocity for regime, Ucf, is proposed give lowest Ucr value provide a convenient demarcation that independent system geometry. This liquid obtained measuring time required empty all particles in batch operated bed under different velocities. method can be used wide range involves less influence operating conditions such as Compared newly more intrinsic parameter, only dependent on particle properties. Based experimental results work other published results, properties equipment setup also discussed.