Effect of the Volume Concentration of Binary Mixed Particles on the Flow and Wear Characteristics of Centrifugal Pumps

Solid–liquid two-phase centrifugal pumps are important fluid transport components in production and life. Most of the studies about the influence of solid-phase parameters on fluid transport mostly focus on single-component solid particles. In this work, two kinds of glass beads with particle sizes of 2 mm and 0.4 mm were used to study the effect of the binary mixed particle volume concentration on the internal flow and wear characteristics of a centrifugal pump. The flow distribution of the binary mixed particles in a centrifugal pump and the interactions between the particles and flow components at different volume concentrations (Cv = 5%, Cv = 7.5%, Cv = 10%, Cv = 12.5%, Cv = 15%) were studied using a Computational Fluid Dynamics-Discrete Element Method (CFD-DEM). The research results show that with the increase in particle volume concentration, the head and efficiency of the pump decrease. Additionally, the distributions of the particles with different concentrations in the impeller flow passage were obtained. Moreover, the coupling force of the flow field acting on the particles decreases with the increase in particle concentration and the time it takes to convey small particles decreases with the increase in concentration, while that of large particles decreases first and then increases. Furthermore, the contact force between the particles and the blade changes periodically with time, and the wear of the centrifugal pump is mainly concentrated on the pressure surface of the blade and the wall of the volute outlet side; the wear rate increases as the particle concentration increases.