HYDROCYCLONEs have been used as an operational tool to separate liquids from solids in different industries for more than 50 years. Considering the importance of this issue, many experimental and numerical attempts have been made to estimate the performance of this tool regarding the resulting pressure drop and the separation efficiency (particles separation limit diameter). Most of the numerical studies for simulating the fluid flow pattern inside HYDROCYCLONEs have been conducted using the ‘’Fluent’’ commercial software. The other alternative for this evaluation is the application of CFD in COMSOL Multiphysics. This work is mainly focused on studying the effect of entering tangent velocity and also determining the flow pattern by CFD simulation in the powerful COMSOL Multiphysics software. Thereafter, correlations proposed by a number of authors are compared with experimental data to evaluate their performances. Among them, the correlations suggested by Barth and Koch-Lich showed acceptable accordance with reference data and thus were chosen for sensitivity analysis. Based on the results, three geometrical parameters of the HYDROCYCLONE body have considerable effects on the separation efficiency. The findings revealed that decreasing the outlet diameter and the inlet width result in increasing the efficiency of HYDROCYCLONE while enlarging the body diameter has negative effects on it. Furthermore, the cyclone efficiency is enhanced as the density difference between fluid and solid and the input velocity becomes larger.

HYDROCYCLONEs are used for removing suspended solids such as silt and sand from water. In this study، all the factors involved in the performance of HYDROCYCLONEs were initially identified and listed before they were optimized using the Taguchi experiment design method. It was the objective of the present study to optimize the efficiency of HYDROCYCLONEs in removing sand from water. For this purpose، 18 HYDROCYCLONEs were designed and constructed to test all the variables affecting their performance including HYDROCYCLONE inlet، overflow، apex، and body diameters as well as cylindrical، total، and vortex finder heights. Minimum (20 mg/l) and maximum (100 mg/l) concentrations of total suspended solids (sand) in the samples from the water wells in Mashhad city along with the observed particle distribution were used in the optimization. Statistical analysis of the results showed that the ratio of the inlet and overflow diameters to that of the HYDROCYCLONE was 0. 225 and that the ratio of the apex diameter to that of the HYDROCYCLONE was 0. 15. Also، the ratios of the cylindrical and vortex finder heights to the total height of the HYDROCYCLONE were 0. 12 and 0. 08، respectively. Under optimum conditions، sand removal efficiency varied from 95. 9% to 98. 4% in different experiments. This is while a value of 97. 2± 1. 1% was obtained as the result of three tests in the HYDROCYCLONE optimized in this experiment. Comparison of the mass removal efficiencies predicted by the Taguchi method and the values measured in the optimal HYDROCYCLONE tests showed that both sets of data were very close and substantially high. Moreover، it was found that the geometric elements obtained in this study were generally in the range of minimum and maximum ratios proposed for HYDROCYCLONEs used in mining. These ratios may، therefore، be recommended for use in the construction of real-scale HYDROCYCLONEs for sand removal from water.

HYDROCYCLONEs are the most efficient used classifiers in the grinding circuits. HYDROCYCLONEs are normally modeled and simulated using empirical models. These models can only be used within the range of the experimental data from which the model parameters have been derived. Computational fluid dynamics (CFD) is a powerful tool in simulating fluid flow in HYDROCYCLONEs. This research work deals with 3D simulation and modeling of fluid flow in a single phase HYDROCYCLONE using CFD. The main simulation steps include preparing the geometry, meshing it, defining the properties of the materials involved, and setting the boundary layer and conditions. The experimenal data measured in a laboratory HYDROCYCLONE were used for validation of the model. The simulation results indicated that the tangential velocity increased traversing towards the core, before decreasing at the interface with the air core. The liquid axial velocity inside the HYDROCYCLONE varied from-1. 59 m/s to 6. 52 m/s. The axial velocity is a result of two swirling flows, the inner upward flowing inside the air core and the outer downward flowing near the cyclone wall. The liquid axial velocity inside the HYDROCYCLONE varied from-5. 58 m/s to 5. 46 m/s. The LES model showed the least error on predicting the velocity profiles, the air core dimensions (7. 8%), the pressure drop (7. 52%) and the mass split ratio to overflow (0. 18%). The effect of various geometric (spigot diameter, vortex diameter and cone angle) and process (feed flow rate) parameters on tangential velocity of the fluid was investigated.

Dewatering and water recycling operations in mineral concentration processes lead to not only cost-effective water use, but also less waste disposal to the environment. In this study, optimization of dewatering process in Zareshouran gold processing plant is carried out using HYDROCYCLONE containing circuit. For this purpose, 12 experiments using 4 spigots with 2, 3, 6, 9 mm diameter, and in 3 operation state of spray discharge, transition state and rope discharge have been conducted. Dewatering capability of HYDROCYCLONE is evaluated based on solid weight percent and solid recovery of underflow stream. The results indicate that in the same operation state, increase in spigot diameter leads to an increase in solid recovery and a decrease in solid weight percent of underflow stream. On the other hand, as the operation state tends to rope discharge solid weight percent and solid recovery of underflow increases simultaneously. Therefore, it can be stated that spray discharge pattern has a higher dewatering capability. Using a spigot with 6mm diameter in the operation state of spray discharge, solid recovery and solid weight percent reaches 75 and 61%, respectively. In this condition, if HYDROCYCLONE is considered as the first step of dewatering process, 75% of the feed solid content can be directly transferred to tailings dam at a lower cost. On the other hand, the overflow stream carries only 25% of feed solid content. If pressure filter present in current dewatering system are considered as the second step of dewatering process, their feed slurry will be reduced by 75%. This means an overall increase in dewatering system capacity by HYDROCYCLONE.

Forming the air-core, is the one of flow properties in HYDROCYCLONE. The swirling flow causes a cylindrical low pressure area at the axis of HYDROCYCLONE which is constant throughout the entire length of the HYDROCYCLONE. Air-core affects the separation efficiency. In this study, low pressure areas were used to predict air-core diameter. Computational Fluid Dynamics (CFD) method was used to determine the pressure distribution inside of HYDROCYCLONE. Three models including: the renormalization group k-e model, the Reynolds stress model, and the large-eddy simulation model, were compared for the prediction of aircore dimension. Air-core diameter was evaluated by using three planes, one on cylindrical part and two on conical section. Results show that, the RSM turbulence model is more accurate than two other models.

In this work CFD simulation of water-coke HYDROCYCLONE has been considered and influence of effective parameters have been investigated. The RSM turbulence model, mixture multiphase approach Schiller Naumann drag model have been used. The results are in good agreement with empirical data from industrial HYDROCYCLONE in Jam Petrochemical Company. The simulation results show that with enhancement of entrance particle size the separation efficiency increases. Moreover, three different turbulence models (RNG K-ε, Realizable k-ε and RSM) applied in this work and results show that the RSM is the best approach in terms of accuracy. Moreover, changes in mass flow rate in inlet show that increasing the flow rate can increase the efficiency. Additionally, the number of inlets has been examined in this study. The results show that the two inlets design can produce the better results compared to single inlet one.

In this work, a Colman-Thew HYDROCYCLONE type has been simulated utilizing CFD method. In order to take into account the turbulent and multi-phase flow RSM approach and Eulerian-Eulerian model has been applied, respectively. Moreover, for verification obtained results, a comparison between results and reported experimental data are drawn in term of HYDROCYCLONE separation efficiency and split ratio. These results show 9% and 7% average errors for separation efficiency and split ratio respectively. Furthermore, the results show that by decreasing the length of the cylindrical section of HYDROCYCLONE from h=1.5D to h=0.29D, efficiency and overall efficiency incrase 20% and conic shape instaed of cylindrical section, improves the HYDROCYCLONE performance 10%.

COMSIM has been developed in Excel spreadsheet to simulate industrial grinding circuits that consist of ball mills and HYDROCYCLONE. In this software Population Balance Model (PBM) has been used for simulating ball mill performance. In this model, the required parameters are mean Retention Time Distribution (RTD) of particles inside the ball mill, selection function and breakage function. Also, for simulating HYDROCYCLONE performance two empirical models, Plitt and Nageswararao models have been used. These two models predict performance based on HYDROCYCLONE geometry and inlet pulp characterisation.This package allows simulation of circuits consist any layout configuration of ball mills and HYDROCYCLONEs. Data obtained from the simulator are compared with measured data from the plant. This reliable performance of the simulation software. Easy handling of input and output, validation of input data, multiple displays of various flows and graphical representation of the results constitute the characteristics of this user friendly similuator.

HYDROCYCLONE is the most effective classification unit in mineral processing practices. This device is very sensitive to the operational parameters. Due to the short residence time of material in the HYDROCYCLONE, its monitoring has a great effect on the circuit performance. Two criteria are normally used to evaluate the cyclone performance, namely, cut size and water recovery to underflow. In this research, first, underflow discharge angle was measured using image processing technique. Then, statistical method was used to evaluate the effect of operational parameters on the underflow discharge angle. Empirical models were fitted to the data, relating the underflow angle to the variables. It was shown that this method can be used to control, the HYDROCYCLONE performance.

In this work, a Colman-Thew HYDROCYCLONE type has been simulated by CFD method for asphaltene separation from heavy crude oil. In CFD simulations, the Reynolds Stress Turbulence Model (RSM) and mixture model for multiphase simulation have been used and thirty micron is considered for diameter of asphaltene particles. The CFD simulation results have been compared with the experimental data. The CFD model can predict the HYDROCYCLONE efficiency with ten percent average error. Effect of inlet flow rate, diameter of asphaltene particles, viscosity of continuous phase and HYDROCYCLONE split ratio as operating conditions have been studied by CFD simulation. The results show that the performance of HYDROCYCLONE could be improved with increasing of inlet flow rate and decreasing of continuous phase viscosity. Also 133% improvement on overall efficiency is observed with increasing the diameter of asphaltene particles to 50 micron. Changing the split ratio has the dual effect on performance of HYDROCYCLONE. With increasing the split ratio, the overall efficiency of HYDROCYCLONE is increased but the overflow (product) is reduced, so the optimization is needed.