On the use of choking as a boundary for fast fluidization

摘要

Fast fluidization is widely regarded as a flow regime between the dilute and dense-phase transport regimes in upward flow of gas-particle suspensions where choking does not occur and the system is insensitive to changes in superficial gas velocity and solids flux. Among the attempts in recent years to predict the boundaries of the fast fluidization regime, the use of the concept of choking appears to be most popular. This paper examines the validity of the use of choking as a boundary for fast fluidization. It is shown that this approach arises from the confusion in the definition of choking. Alternative methods are discussed which would enable better prediction of the boundaries of fast fluidization.