Global Flow Structure in a Square Gas-Solid Fluidized Bed

Turbulent fluidization is a flow regime between bubbling fluidization and fast fluidization. The influence of static bed heights and axial locations on transition velocity was studied from bubbling fluidization 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. Experiment results show that the transition velocities increase with decreasing location of observation or increasing 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 in the whole bed. Based on those, the prediction model is built that the average solids concentrations of bed cross-section are used to reflect the variation of gas-solid interaction along the bed height. The new prediction correlation by fitting parameters of experimental data is in well agreement with experiment results