Effect of Particle Factors on the Reflux and Blockage of a Deep-Sea Six-Stage Pump Based on CFD-DEM

The deep-sea six-stage centrifugal pump is an essential power source of the lifting system that conveys slurry containing coarse particles. Emergency failure of the electric system can easily lead to pump blockage because of slurry reflux. The reflux movement of particles in a six-stage pump under emergency power failure is investigated using the verified computation fluid dynamics and discrete element method (CFD-DEM) simulation. The JKR contact model is used to perform particle simulation. Simultaneously, shaped particles are added to realistically simulate the reflux characteristics under deep-sea mining conditions. The effect of particle size, shape, and size distribution in the reflux is investigated. The blockage behavior of the particles during reflux and the blockage mechanism is clarified. Particles with less shape and size below 30 mm are more conducive to safe slurry transportation. The experimental results verify the credibility of the CFD-DEM simulation results. The deep-sea six-stage centrifugal pump is an essential power source of the lifting system. Emergency failure of the electric system can easily lead to pump blockage because of slurry reflux. The reflux movement of particles under emergency power failure is investigated in this manuscript. Particles with less shape and size below 30 mm are more conducive to safe slurry transportation.image