Simulation and Experimental Study of Degradation of Polymetallic Nodules in Deep-Sea Multi-Stage Lifting Motor Pump

Abstract

The impeller blades will continually strike the slurry mixture inside the pump, causing deterioration and a change in particle size. In this study, the degradation of mineral particles under various cycle times, rotational speeds, and flow rates is analyzed. The microscopic parameters of polymetallic nodules are calibrated by EDEM, and the transport of polymetallic nodules in the deep-sea lifting electric pump is simulated based on the coupled CFD-DEM solution of solid–liquid two-phase flow. The findings demonstrate that: the number of cycles through the pump has the greatest impact on particle degradation, and the number of fine particles significantly increases after the particles are impacted by the six-stage lifting electric pump several times; the higher the flow rate in the lifting electric pump, the faster the particles are dragged by the fluid, and the more easily the particles degrade; the faster the impeller speed of the lifting electric pump.