The multiphase flow models were used to predict pressure drop and segregation of particles flowing in a vertical pipe. To compare calculations with data, it was necessary to assume an effective particle size based on a coefficient of restitution and on inlet void fractions. Different partifle size distributions with equal average particle size generate distinctly different pressure drops and segregations. Contribution of solid interaction force is very important in accounting for the segregation of the particles in a vertical pipe.
All models gave a reasonable prediction of the design parameters. The pressure drops predicted by the models agreed well with both high- and low-pressure experiments.