CFD simulation and experimental validation studies on hydrocyclone (original) (raw)
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Advances in Mechanical Engineering, 2010
Effectiveness and efficiency of hydro-cyclone separators are highly dependent on their geometrical parameters and flow characteristics. Performance of the hydro-cyclone can, therefore, be improved by modifying the geometrical parameters or flow characteristics. The mining and chemical industries are faced with problems of separating ore-rich stones from the nonore-rich stones. Due to this problem a certain amount of precious metals is lost to the dumping sites. Plant managers try to solve these problems by stockpiling what could be useless stones, so that they can be reprocessed in the future. Reprocessing is not a sustainable approach, because the reprocessed material would give lower yield as compared to the production costs. Particulate separation in a hydro-cyclone has been investigated in this paper, by using computational fluid dynamics. The paper investigated the influence of various flow and geometric parameters on particulate separation. Optimal parameters for efficient sep...
A Review of CFD Modelling for Performance Predictions of Hydrocyclone
"A critical assessment is presented for the existing numerical models used for the performance prediction of hydrocyclones. As the present discussion indicates, the flow inside a hydrocyclone is quite complex and there have been numerous numerical studies on the flows and the particle motions in hydrocyclone, with a wide range of turbulence and multiphase models tested. Two-equation k-epsilon and RNG k-epsilon models flow velocities with empirical modifications were led to poor results, especially the tangential components in comparison with experimental measurements. Most of the recent studies have utilized the Reynolds stress models (RSM) with different degrees of complexity in the pressure-strain correlation. These RSM studies showed good agreements with velocity measurements. Unfortunately, the velocity profiles were not validated in most of the RSM cases where multiphase particle tracking were applied. Finally, large eddy simulation (LES) is the most advanced turbulence model applied in recent hydrocyclone numeric studies. Besides the additional information on precising the air core correctly, LES provides an additional accuracy in predicting the velocity profiles or the grade efficiency in comparison to the RSM. The multiphase models have been successfully applied in a hydrocyclone to model the Lagranizian motions of spherical particles. Eulerian-Eulerian model have been used to account for the particles effect on the fluid viscosity. Simplified Eulerian model (mixture) model predictions for solid transportation in cyclone were well predicted. Further, the inclusion of modified slip velocity calculation in the Mixture model improves the efficiency predictions close to the experimental data at low feed solid loadings. In future studies, the focus should be to model the three-dimensional flow in a hydrocyclone using at least the Reynolds stress model/LES. The particle tracking should at least include the effects of the turbulence on the particles. All these developed models will only applicable to low feed solid concentration levels. Since most of these models neglect the particle-particle interactions, a more comprehensive numerical method of modified Mixture model is applied for simulating solids flow in hydrocyclones for high feed solids concentration. Explicit models for accounting hindered settling and turbulent diffusion investigated for high feed solid concentrations in industrial cyclones are encouraging." Keywords: hydrocyclone; multi-phase modelling; computational fluid dynamics; classification; turbulence; viscosity
Scientific Mining Journal, 2022
In this paper, an effective method for the classification process simulation in 75mm hydrocyclone is considered. The simulation results and computational time are compared using Reynolds stress model (RSM) and different large eddy simulation (LES) subgrid-scale models as turbulence models. The Lagrangian discrete phase model (DPM) is used to simulate the classification process of particles. As the experimental result for comparison of simulation results, Hsieh's experimental data are used. When the different LES subgrid-scale models are used, the solution converges stably by various solution convergence methods without increasing the grid numbers or reducing the size of time steps than RSM model. As a result, it is confirmed that when an appropriate simulation method is applied with the LES-WMLES S-Omega model, more accurate axial water flow velocity distribution and particle classification simulation results can be obtained at a computational cost similar to that of using the RSM model. By drawing the partition curve, it is possible to select a hydrocyclone with low bypassing of fine particles and high classification efficiency.
Eleventh International Conference on CFD in th e Minerals and Process Industries, 2016
Common applications of hydrocyclone include classification, thickening, de-sliming and de-gritting. In all the operations cyclone separators usually operate under high solid loading conditions. Computational Fluid Dynamic (CFD) models developed so far are unable to predict the behaviour at high percentage of solids. Therefore, present paper aimed to develop CFD model corrected with suitable rheological model, particle drag and lift forces to account particle fluid interactions at high volume fractions. Turbulence is resolved using large eddy simulation. Drag is corrected with solids loading; rheology is modelled using Newtonian model corrected with fines. CFD predicted two-phase water split and air-core data is validated against Electrical Resistance Tomography (ERT) and High Speed Video camera (HSV) measured data. The influence of feed solids on the air core size also investigated. Multiphase simulations ran with 0-50% feed solid loadings are analyzed and validated in terms of cut size and efficiency. Modified CFD model is able to predict the data with reasonable accuracy. Turbulent dispersion index is also calculated to quantify the dispersion effect on the particles. Additional validation in terms of cut size in 250 mm Krebs cyclone (Devullapalli, 1997) is also provided in comparison with discrete phase model and pure mixture model.
Numerical simulation of industrial hydrocyclones performance: Role of turbulence modelling
Separation and Purification Technology, 2017
Flow in industrial hydrocyclones is always turbulent, selection of suitable turbulence model is key for accurate predictions. This paper aims to find the appropriate turbulence model for the hydrodynamic predictions in industrial hydrocyclones. Two-phase and multiphase simulations are conducted in various size industrial hydrocyclones using volume of fluid and modified mixture models coupled with Reynolds Stress Model (RSM), Detached Eddy Simulation and Large Eddy Simulation (LES) turbulence models. Assessment of turbulence model effect on two phase flow field is made with respect to air-core, flow split, mean and turbulent velocities. The simulated flow field in 75 and 250 mm hydrocyclones is validated against literature based Laser Doppler Velocimetry, in-house high speed video and Electrical Resistance Tomography measurements. Mean density segregation contours and radial density profiles variation at different axial positions in a 350 mm dense medium cyclone is compared against Gamma Ray Tomography data. Turbulent intensity profiles are compared to display the turbulence levels. Further turbulence effect on the particles in various size hydrocyclones is analyzed by dispersion index formulation. Multiphase flow predictions in 75 and 250 mm hydrocyclones with RSM and LES models are compared against classical experimental classification performance in terms of cut size and sharpness of separation.
The new approach to the hydrocyclone modeling using computational fluid dynamics (CFD) simulation
This paper presents the simulation of solid particles selection in a hydrocyclone. The Fluent CFD (Computational Fluid Dynamics) software has been used for the simulation. For water flow simulation, within the hydrocyclone, the k-ε turbulent flow model has been used. This allows calculating the velocity, pressure and turbulence field in the hydrocyclone. The Fluent software enables simulation of the solid particles flow within the flowing liquid. Solid particles of different sizes, flowing in this hydrocyclone have been simulated. Finally the selectivity curves, as a basic characteristic of the hydrocyclone, were calculated. The obtained results give real perspective for utilization of the CFD simulations as the basic stage in industrial hydrocyclones design practice.
Mining of Mineral Deposits, 2021
Purpose. Although the hydrocyclone separator has many advantages, it still has some limitations which decrease its separation efficiency in many mineral processing applications because of fine particles which are miss separated to the coarse product in the underflow. Water injection in the conical part of the cyclone was recently implemented to solve this problem. The water injection mechanism and the way in which the injected water affects the separation are still not clear and need to be more investigated. Methods. New design of water injection hydrocyclone was tried using a modified conical part with a water injection range consist of five equal distance injection openings open directly on the periphery of the cone part. Findings. This study presents a mechanical mathematical model that simulates the water injection to give a clear indication of the injection mechanism impact on the classification process. It could also predict the dependence of the basic characteristics of the c...