Synthesis of CFD and Monte-Carlo simulations for improved design and operation of Dense Medium Cyclones

摘要

Accurate resolution of the complex flow features within a Dense Medium Cyclone used in coal beneficiation contributes not only to the design of cyclones of greater separation efficiency but also the optimization of operational process parameters. A three step approach to numerical simulation of flow within such a cyclone, starting with the approximate and simpler Reynolds stress model, transiting to the more complex and accurate Large Eddy Simulation after a certain level of maturity, and then activating a multi-phase model after flow stabilization in the suction core, is developed. A systematic approach based on Monte-Carlo simulations is then synthesized, relating the distribution of particle misplacements stochastically to the distribution of simulated flow and particle conditions like turbulence, size, density, etc. The relationship of misplacements via these particle conditions to the antecedent feed coal conditions is established. Every significant step in the evolution of this approach is validated against experiment or production data and also verified for all necessary conditions of simulation accuracy like grid effects, air-core features, outflow split, misplacement distribution across the size-density matrix and separation efficiency. Thus a coupled Computational Fluid Dynamics and Monte-Carlo simulations approach is synthesized for application to improved design and operation of a Dense Media Cyclone.