Prediction Model of Transition Velocity from Bubbling to Turbulent Fluidization in a Square Gas-Solid Fluidized Bed

The relationship between transition velocity and static bed heights as well as axial levels were studied from bubbling to turbulent fluidization in a 368 mm×368 mm square fluidized bed, based on the pressure gradient fluctuation by measurement differential pressures transducer of FCC. The results show that the transition velocities increase with decreasing the location of observation or increasing the static bed heights. And the transition of regime from bubbling fluidization to turbulent fluidization is a process gradually happened from the upper to the lower bed section and is not instantaneous behavior concurrence simultaneity in the entire bed. Based on this, the prediction model is built that the introduction of the average particle concentration of bed cross-section is used to reflect the variation of gas-solid interaction along the bed height, and a new prediction correlation by simulating parameters of experimental data, which is in good agreement with experiment results.