Effect of interaction of particles with different sizes on particle kinetics in multi-sized slurry transport by pipeline

Abstract

Three types of slurries (two single-sized glass-bead slurries 0.44 mm and 0.125 mm in diameter and a multi-sized mixture containing the two sizes in equal fraction by mass) transported by a 54.9-mm-diameter horizontal pipe are modeled using a steady three-dimensional hydrodynamic multiphase model based on the kinetic theory of granular flow. The effect of interaction of particles with different sizes on particle kinetics—such as particle concentration distribution, velocity distribution, granular pressure distribution, wall shear stress distribution, flow regime, and their change trends—are investigated for particles of different sizes for varying efflux solid concentration and flow conditions in a multi-sized slurry by comparing it with those in single-sized slurries under the same conditions. The results reveal the different transport properties and regularly changing trend of equal-sized particles in multi-sized and single-sized slurries under the same conditions with varying solid concentrations and flow velocities. Additionally, a lubrication layer forms from fine particles near the bottom of a multi-sized slurry, which is a key factor affecting the performance of coarse particles especially at low flow velocity, and changes the coarse particles' flow regime from saltation to a sliding bed, thereby reducing the collision energy consumption and pressure drop. The solid-concentration distribution in the simulation results agrees with published experimental data.