Minimum spouting velocity of flat-base spouted fluid bed

Abstract

Experiments were performed on spout characteristics of a cylindrical spout-fluidized bed (I.D.=10cm) with different static heights and two materials (Al2O3 and high density polyethylene). Results of minimum spouting velocity obtained in this study were compared with reported correlations for both spouted and spout-fluidized beds. Considerable discrepancies were found between the values obtained using different model equations as well as with respect to experimental results. Based on the Mathur–Gishler correlation, a new correlation is proposed for calculating the minimum spouting velocity that introduces the ratio U/Umf. It was found that the minimum spouting velocity decreases with increasing fluidizing gas velocity (U/Umf). The pressure drop at the point of minimum spouting velocity is also correlated using this dimensionless group and is presented in this work. This investigation demonstrates that the use of correlations reported in the literature that focus primarily on conical bottom spouted beds are not applicable to flat-bottom spouted and spout-fluidized beds.