Hydrodynamic characteristics of jet‐spouted beds

Jet‐spouted beds characterised by high velocity gas jets (above 1.7 U msl ), and shallow bed depths H 0 of around 2 D 1 were investigated on laboratory scale beds and industrial scale beds and the results obtained thereof are correlated and presented in this work. Compared with the classical spouted beds, important differences in bed structure, solid movements and basic hydrodynamic characteristics were observed. The minimum spouting velocity, bed voidage and pressure drop during stabilized spouting are described in terms of dimensionless equations. Bed expansion was used as the basis for the classification of different jet‐spouting regimes (incoherent spouting, fast spouting, pneumatic conveying) and changes in the slope of the bed expansion curve are correlated with regime changes. This classification could be useful in the optimization of industrial scale jet‐spouted beds. A typically applicable regime of fast spouting was identified.