Effect of Particle Density on the Reflux Performance in a Lifting Pump

抄録

To investigate the impact of particle density on the reflux performance of the lifting pump, a CFD-DEM coupling approach was employed to simulate pump reflux behavior using spherical particles with different densities (1.25 g/cm³, 1.5 g/cm³, 1.8 g/cm³). The effects of particle density on the reflux performance were analyzed and compared. The results demonstrate that, as particle density increases, the particle velocity within the two-stage pump decreases. The accumulation of particles extends toward the impeller and the flow channels of the guide vanes. This accumulation is more pronounced in the secondary pump than in the first stage pump. Additionally, the total number of particle collisions increases, with particle-particle collisions becoming the dominant form. The ratio of particle-particle collisions to the total number of collisions rises, particularly in the secondary pump, where collisions at the secondary guide vanes happen with much greater frequency. The particle pass rate decreases with higher particle densities, with the highest pass rate of 57.17% observed at 1.25 g/cm³. Furthermore, after the reflux process, the total number of particles within the pump increases with higher particle densities. The accumulation in the secondary pump exceeds that in the first stage pump. Overall, the performance of the lifting pump in terms of reflux declines as the density of particles rises.