CFD-DEM analysis of internal flow characteristics in multistage deep-sea mining pumps

The potential profits associated with deep-sea mineral deposits have encouraged the development of new mining techniques. In particular, the effectiveness of lift pumps is crucial to the success or failure of these mining operations. In this study, the interior pressure field, turbulence characteristics, and turbulent kinetic energy of deep-sea mining pumps were numerically simulated using the computational fluid dynamics/discrete element method (CFD-DEM). Turbulence in the solid–liquid two-phase flow in deep-sea mining lift pumps was also investigated using CFD-DEM, and the key factors affecting lift and efficiency were obtained. Data exchange among particles and between particles and fluids was fully considered to obtain reliable calculation results. The results show that lift pump operation improves when the speed increases. A real-world hydraulic test was conducted to verify the simulation result. That is, increasing the speed of the lift pump stabilises the flow of particles and fluids and gradually increases the lift and efficiency. The simulation method provides a reliable starting point for developing and optimising subsea lift pumps.