Three phase flow of gasndashcoal slurry mixtures in vertical tubes

The pressure drop and liquid and slurry phase holdups of a cocurrent flow of gasNdashoil and gasNdashcoalNdashoil slurry mixture in cylindrical columns (1.85 and 2.85 cm-ID) were investigated. The effect of viscosity (43.1-315 cp) was determined using solutions of two different mineral oils and of four different concentrations of coalNdashoil mixtures. The liquid and slurry holdups increased with liquid flowrate and liquid viscosity and decreased with gas flow rate. For solid concentrations in the range 0-35 wt% with the size of coal employed (0.07-0.16 mm) the slurry behaved like a homogeneous Newtonian fluid. The data for frictional pressure drop and phase holdups were correlated in terms of the ratio of fluid velocity, and the Reynolds and Weber numbers of the liquid and slurry phases.