Predicting transport velocities

The minimum transport velocity is defined as the minimum gas velocity required for the vertical, dilute phase transport of particles. Literature data for this characteristic gas velocity are correlated in terms of particle properties. Then, it is shown that the same type of correlation holds for transport velocities governing transition toward fast fluidization. The similarity of these equations suggests that coarse particles can be carried over only in the fast fluidization regime. On the contrary, in a limited range of gas velocities, finer solids can be transported with different flow regimes, depending upon solids feed rate to the column. In that case, the solids feed rate governs transition to fast fluidization.