A pseudo-fluid representation of vertical liquid-coarse solids flow

The pseudo-fluid concept has been applied for the prediction of the pres- sure gradient and voidage in vertical liquid-coarse solids flow. Treating the flowing mixture as a single homogenous fluid, the correlation for the friction coefficient of the suspension-wall was developed, as was the correlation between the true voidage and the apparent (volumetric) voidage in the transport tube. Experiments were per- formed using water and spherical glass particles 1.20, 1.94 and 2.98 mm in diameter in a transport tube of 24 mm in diameter. The loading ratio (Gp/Gf) was varied be- tween 0.05 and 1.05 and the fluid superficial velocity was between 0.4 Ut and 4.95 U t where U t represents the single particle terminal velocity. The voidage ranged from 0.648 to 0.951 for these ratios. Experimental data for the pressure gradient and voidage from the literature agree well with the proposed correlations.