Simulation Of Liquid-solid Two-phase Flow With Coarse Particles In Pipes

Mineral resources are distributed on the sea floor several kilometers deep inoceans. It is widely known that the most practical way of lifting the minerals from thesea floor is to use the hydraulic lifting technique. This is also one of the maintechnology areas in our country's deep-sea mining technology development. Thehydraulic lifting technique for minerals is basically a liquid-solid two-phase flow withcoarse particles. Its mechanism is very complicated, involving many factors in itsphysical models. According to the basics of the liquid-solid two-phase flow, this paperstudies on the motions of coarse particles in hydraulic lifting pipes. It providesguidelines for the engineering design and optimization of hydraulic lifting system andit is significant to the development of solid-liquid two-phase fluid transmissiontechnology.In this paper, a simplified physical model was established based on theexperiment of CRIMM. A Fortran77 program was made using Euler-Lagrangemethod to predict the particle tracks in vertical pipe, bend pipe, as well as verticalpipe with horizontal vibration. The program can show the particle tracks through flowvisualizations, helping people to understand particle movement. Based on the resultsof the computation, a concept of lifting efficiency was proposed to study the optimallifting speed of the liquid phase, as well as the minimum liquid lifting speed neededfor certain solid phase conditions.Besides, empirical formulae about drag coefficient and Reynolds number weresuggested by fitting the dimensionless data form the experiment of CRIMM. It isuseful for the pressure loss calculation in solid-liquid two-phase flow with coarseparticles.