Particle anti-accumulation design at impeller suction of deep-sea mining pump and evaluation by CFD-DEM simulation

Abstract

deep-sea mining pumps work in the mining lifting system, transport slurry containing coarse particles. The impeller suction was the most dangerous place to clog in slurry transportation, because of its highest concentration over the whole pump. The axially mounted splitter plates were proposed to improve the convey condition in the impeller suction, numerical pump models with three lengths (50, 100, 150 mm) of splitter plates were established. The improvement comparison of particle transport characteristics and hydraulic performance of the deep-sea mining pump was evaluated by CFD-DEM simulation. Through the analysis and comparison of the particle distribution, concentration fluctuations, flow field, head loss and inlet velocity, etc. The 100 mm splitter plates were considered to be the best scheme among the three. 100 mm splitter plates boosted the hydraulic head between the pump inlet and the outlet of the first stage pump by 4.08% under rated condition, reduced the local slurry increasing concentration from 27.44% to 5.93%, reduced the slurry concentration fluctuation amplitude from 12.72% to 6.78%, shielded the reverse flows between adjacent runners, limited and corrected most of the pre-rotation flow, solved the particle accumulation problem in impeller suction area, improved the safety of deep-sea mining pump.