Hydrodynamics of three-phase fluidization of homogeneous ternary mixture in a conical conduit — Experimental and statistical analysis

Abstract

Hydrodynamics of conical fluidized bed differ from that of columnar beds by the fact that a velocity gradient exists along the axial direction of the bed. The gas–liquid–solid fluidized bed has emerged in recent years as one of the most promising devices for three-phase operations. Such a device is of considerable industrial importance as evident from its wide applications in chemical, refining, petrochemical, biochemical processing, pharmaceutical and food industries. To explore this, a series of experiments have been carried out for homogeneous well-mixed ternary mixtures of dolomite of varying compositions in a three-phase conical fluidized bed. The hydrodynamic characteristics determined included the bed pressure drop, bed fluctuation and bed expansion ratios. The single and combined effects of operating parameters such as superficial gas velocity, superficial liquid velocity, initial static bed height, average particle size and cone angle on the responses have been analyzed using response surface methodology (RSM). A 25 full factorial central composite experimental design has been employed. Analysis of variance (ANOVA) showed a high coefficient of determination value and satisfactory prediction second-order regression models have been derived. Experimental values of bed pressure drop, bed fluctuation and bed expansion ratios have been found to agree well with the developed correlations.