Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

Effect of Inter-Particle Interaction on Wear Prediction of a Deep-sea Mining Pump
Tao Guo, Jingzhao Hu, Guojun Hong, Yuren Liu

CCCC National Engineering Research Center of Dredging Technology and Equipment Co. LTD.
Shanghai, China

ABSTRACT

trajectories and impacting velocity of particles in a slurry pump.
Pagalthivarthi, Gupta, Tyagi and Ravi (2011) studied the movement ofsparse particles in the volute of centrifugal pump by using DPM twoway coupling, and qualitatively studied the influence of factors such as
flow rate, rotational speed and volute geometric size on the erosivewear. Zou, Lu and Li (2013) used the Particle Transport Solid Model inthe commercial software ANSYS CFX to solve the two-way coupling
process of lifting manganese nodules in a two-stage deep-sea mining
pump, and obtained pump characteristic curves and the distribution ofparticles in the pump.

Compared with steady tracking of ore particles, the transient tracking ispreferred to predict the wear prediction of deep-sea mine pump. Via
user-defined functions, the particles rebound model in ANSYS Fluent
is corrected so that it can transiently track particles in a moving domain
correctly. Two Euler - Lagrange coupled approaches, one of whichtakes inter-particle interaction into account during Lagrangian tracking
and the other is not, are introduced in the simulation and theirnumerical results are compared. The comparisons show that the interparticle interaction should be taken into account for Lagrangian
tracking of densely distributed particles: the shielding effect makes
particles more disperse in the pump, thereby avoiding the false
concentration of erosive wear on the inner wall.

The relative positions of moving and static blades in pump change
incessantly, which has obvious influence on particle trajectories.
Another E-L coupled approach, CFD coupled with discrete element
method (DEM), is often used in the numerical study of transient
tracking of particles in pumps. Li, Liu and Hu (2019) and Su, Tang, Li,Zhu, Mianowicz, and Balaz (2020) used Fluent coupled EDEM (acommercial DEM software) to calculate the transient motion of coarse
particles in a two-stage deep-sea mining pump. The former studied thepressure and particle distribution on the blade surface of the pump at
different rotational speeds. Another study was carried out in the similar
way by Su, Tang, Li, Zhu, Mianowicz, and Balaz (2020), they studied
the distribution, velocity and trajectories of particles in the impeller anddiffuser. Tang and Kim (2020) used the CFD-DEM coupling code incommercial software STAR-CCM+ to transiently track particles in asingle-channel sewage pump, and studied the influence of particle sizeand particle shape on the flow field and wall contact force. DEM
usually uses Hertz-Mindlin contact model to deal with inter-particle
interaction, which consumes a lot of calculation.

KEY WORDS: Erosive wear; particle tracking; dense discrete phasemodel; deep-sea mining pump

INTRODUCTION
The global clean energy transition has created a huge demand forbattery metals such as Li, Cu, Ni, Mn and Co. Polymetallic nodules,
also known as manganese nodules, are widely distributed on theabyssal plains of the global oceans over a depth range of about 4000 6000 m (Li, Li, Hein, Dong, Wang, Ren, Wu, Li and Chu, 2021). They
are rich in critical and strategic metals, and provide a potential sourceof critical metals for sustaining human development for the foreseeable
future (Hein, Koschinsky and Kuhn, 2020). Although there is no proventechnology or equipment to mine these nodules, slurry pump andvertical pipelines might be the most viable options. The movement ofore particles has a great influence on the flow and the erosive wear on
the inner wall of the pump, that is why particle tracking is an importantbasis for the study of improving the performance or the lifetime of thepump, as it

Like the CFD-DEM coupled approach, DPM can transiently track
particles. By taking into account the inter-particle interaction and theeffect of particle volume fraction on momentum transfer, Fluent
introduced an enhanced approach, dense discrete phase model (DDPM),
to transiently track particles in dense flow, where the volume fractionof particles is high. But the above two approaches are rarely used totransiently track particles in pump, because the rebound modules inFluent has a serious flaw for particle tracing in an incessantly moving
domain. In this study, the flaw is corrected by a user defined function, a
volume fraction dependent drag force model is introduced, and themovement of ore particles in a deep-sea mining pump are transiently

Based on simplified Euler-Lagrange (E-L) coupled approaches, someresearchers solved the motion of sparse particles in slurry pumps byignoring the inter-particle interaction and the transient characteristics ofthe impeller. Using the discrete phase model (DPM) in a commercial
CFD software ANSYS Fluent, Wu (2010) studied the effects of particle
size, blade parameters, rotational speed and other factors on the relative

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