A new correlation for minimum spouting velocity for conical spouted beds operating with high density particles

Abstract

Hydrodynamics of conical spouted beds operating with high density particles was studied by means of measuring the minimum spouting velocity and analysis of pressure signals in time and frequency domains. Three different types of particles, zirconia (dp = 1 mm; ρp = 6050 kg/m3), zirconia toughened alumina (ρp = 3700 kg/m3; dp = 1, 2 and 2.4 mm) and glass beads (ρp = 2460 kg/m3, dp = 1 and 2 mm) were used in the experiments. Experiments were performed in three small scale (γ = 30°, 45° and 60°) and two large scale (γ = 31° and 66°) beds at different gas inlet diameters and static bed heights. It was found by the analysis of pressure signals that the pressure drop in the stable spouting bed increases with increasing bed size, static bed height, gas inlet diameter and density of particles, and decreasing particle size and cone angle. The minimum spouting velocity increases with increasing particle size, cone angle, static bed height and density of particles, and decreasing bed size and gas inlet diameter. Power spectral density of the pressure signals also revealed significant influence of the above mentioned parameters on the hydrodynamics of conical spouted beds. Based on the results of the experiments, a new correlation is proposed for prediction of the minimum spouting velocity in conical spouted beds operating within the density range of 2460–6050 kg/m3 particles. The average relative error and correlation coefficient of the proposed correlation was found to be 10.55% and 0.95, respectively, which shows the potential of the proposed correlation for prediction of the minimum spouting velocity in conical spouted beds with high density particles.