Particle Distribution and Motion in Six-Stage Centrifugal Pump by Means of Slurry Experiment and CFD-DEM Simulation

Abstract

Six-stage centrifugal pumps are used in deep-sea mining lifting systems and are required to convey slurry containing coarse particles. A six-stage centrifugal pump suitable for operation in a natural mining system was manufactured. High-flow and full-scaled slurry conveying experiments at a 5% and 9% volume concentration of particles was carried out at a large modified test site with artificial nodules. CFD-DEM simulations were carried out to obtain slurry transport characteristic curves, particle transport and distribution characteristics, where the simulation method was validated by the experiment data. A clarified two-stage pump can be used instead of a multi-stage pump for simplified simulation calculations with acceptable accuracy. Local agglomeration of particles caused by backflow was found at the outlet of the diffuser, and such agglomeration decreased with increasing flow rates. It was found that particles are transported non-uniformly, particles transport in diffusers in strands. Particles are transported in a pulse-like mode within the pump, with the latter stage showing similar particle characteristics to those transported in the previous pump stage.

The Development History and Latest Progress of Deep-Sea Polymetallic Nodule Mining Technology

“…The result achieved from the assessment was a maximum walking speed greater than 1 m/s and a maximum nodule harvesting capacity of 41 kg/h. The test lifting pump was assessed for its performance in the transport of clean water and mineral slurry [73,74]. The main results of the slurry transport performance evaluation are presented as follows: the maximum particle size of artificial nodules d = 20 mm, the working flow Q w = 468.3 m 3 /h, the volume fraction of polymetallic nodules C V = 10%, the head H = 97.14 mH 2 O, and the productivity of wet polymetallic nodules W = 49.35 t/h.…”

“…However, it has to achieve the high demand for the winch load and the speed required for the production capacity necessary for commercial extraction, and anti-twisting measures for the cables have yet to be tested and verified. On the other hand, in the sea trials in South Korea and China, the track self-mining collector showed good mobility and a high-precision path control performance [37,38,45], and the multi-stage centrifugal pump and hydraulic pipeline transport scheme also achieved good research results [24,73]. Therefore, the "centrifugal pump and hydraulic pipe lifting + self-propelled tracked nodule collector" system will be the mainstream technical scheme of the deep-sea polymetallic nodule mining system for a period of time in the future.…”

Study on Fiber Clogging Mechanism in Sewage Pump Based on CFD–DEM Simulation

“…The results showed that the instantaneous wear rates of the impeller, volute, and wear plate in the pump changed periodically with the rotation of the impeller. Deng et al [21] obtained the transport characteristic curve, particle transport characteristics, and distribution characteristics of slurry in a six-stage centrifugal pump by CFD-DEM simulation. The simulation method was verified by experimental data.…”

Numerical Analysis of Single-Particle Motion Using CFD-DEM in Varying-Curvature Elbows

“…Furthermore, Hu et al [18] applied the coupled CFD-DEM simulations to clarify the solid-liquid two-phase flow in twostage centrifugal pumps for different particle sizes with constant particle concentrations. Deng et al [19] investigated the hydrodynamic (and coarse) kinetic behavior of the particles in the pump for slurry transfer using the coupled CFD-DEM simulation. The group determined the slurry transport characteristic curves as well as the particle transport and distribution characteristics of six-stage centrifugal pumps.…”