Papers by Keyword: Hydrocyclone

Abstract: The growing concern with the environment has driven the development of new technologies for the treatment of produced water. In this context, the filtering hydrocyclone appears as an interesting alternative for the treatment of these waters contaminated with oil from the petroleum industry. This research addresses the flow of fluids inside a hydrocyclone equipped with a porous wall (membrane) containing two tangential inlets and two concentric outlets, with the aim of study the impact of the formation of the polarization layer by concentration on the oily water separation process using CFD. Concentration fields and transmembrane pressure, concentration, and permeate flux profiles are presented and analyzed. The results show that the proposed filtering cyclonic separator concentrates the oil in the central region of the equipment, however, for high oil concentrations; the core expands and approaches the porous wall. Furthermore, the increase in the oil volume fraction causes a decline in the permeate flux, and an increase in feed velocity causes a decrease in the polarization layer.

Abstract: The separation of fine coal can be improved by pre-desliming, which was significantly enhanced when fine coal was processed using a Falcon concentrator, and <45-μm coal slime was removed. Ultrafine classification tests using Krebs classification cyclone with annular rinse water showed that the increase in feeding concentration negatively affected the efficiency of classification while increasing the classification size because the settling was hindered by the high underflow concentrations. The optimization experiments with response indicators of classification efficiency based on orthogonal design using Design-Expert software indicated that the optimal classification efficiency reached 91.32% with a feeding pressure of 0.03 MPa, a rinse water pressure of 0.02 MPa, and a feeding concentration of 12.5%. Meanwhile, the classification size was 49.99 μm, which agreed well with the predicted value.

Abstract: Mining is a relevant economic activity in many countries. In the treatment of ores, water is an indispensable input. For classification of minerals, the mineral industry uses the hydrocyclone process, where water is used as the medium for transporting dispersed ore particles, that are separated from the liquid by centrifugal force inside anequipmentnamed hydrocyclone.The constant advance of computers processing power, the evolution in the techniques and numerical methods, allow to simulate with great precision complex physical problems of fluid dynamics such as flow in hydrocyclones.In this sense, this work aims to analyze the performance of a concentrating hydrocyclone in the separation of ore and water by CFD. In the fluid dynamics simulation, the Eulerian-Lagrangian approach and the Ansys Fluent software were used. Results of pressure, velocity, and volumetric fraction fields of theinvolved phases are presented and evaluated. From the analysis of the results, it was observed that increasing the flow mixture velocity at the entrance of the equipment tends to increase the separation performance of the hydrocyclone.

Abstract: Hydrocyclones are equipment that offer various advantages and have been the subject of studying for many researches related to separation processes of gas-solid, solid-liquid, and liquid-liquid mixtures. The purpose of this work is to study the oil-water separation process in a hydrocyclone by Computational Fluid Dynamics (CFD). Results of the pressure, velocity and volume fraction fields inside the device are presented and analyzed. It was possible to conclude that the proposed mathematical model was able to predict separation performance and the three-dimensional behavior of the phases flow analyzed (water/oil) in the hydrocyclone.

Abstract: In the photovoltaic industry a total of 100,000 tons of silicon is lost as waste per year. This waste is originating from several cropping and sawing steps of the high purity silicon blocks and ingots during the solar cell wafer production, resulting in a silicon containing suspension. Among different approaches to recycle the silicon from this waste is the utilization of hydrocyclones, which can be used to separate or classify particles by weight and size. In this work the use of a hydrocyclone was evaluated to upgrade the silicon fraction from a typical sawing waste. A potential field of use for the recycled silicon particles might be as anode material for next generation lithium ion batteries.

Abstract: Many studies of hydrocyclones have confirmed that increasing the feed-flow rate results in a higher separation efficiency. The purpose of this study was to investigate the separation efficiency for a 100 mm solid–liquid hydrocyclone with 1 and 2 wt% solid concentrations at feed-flow rates of 2, 3, 4, 5 and 6 m³/hr. The solid concentration and particle size distribution were analysed using drying–weighing and a particle-size analyser (Mastersizer 2000), respectively. The experimental results indicated that an increase in feed-flow rate from 2 to 4 m³/hr produced decreased separation efficiency. However, when the feed-flow rates increased from 4 to 6 m³/hr, the separation efficiency increased. Furthermore, the higher the feed-flow rate, the smaller the cut size. A novel separation efficiency equation in terms of the concentration ratio and flow ratio is also proposed.

Abstract: A hydrocyclone is a device used widely in various industries, especially for separation of solids from liquids. Many factors affect the separation efficiency of a hydrocyclone. In this research, the main objectives were a study of the conical length that affected the separation efficiency and proposal of a regression model of Stk₅₀Eu for a hydrocyclone. First, research was performed on the separation efficiency using a 40-mm hydrocyclone. The effects of conical lengths of 200, 240 and 280 mm were investigated. The tested suspension was a mixture of silica and water. The silica particles have an average size of 9–10 μm at a solid concentration of 0.5% w/v. The feed-flow rate of 1 m³/hr was operated with the constant flow ratio of 0.1. From the experimental result, it was found that the shorter conical length obtained the higher separation efficiency. For a conical length of 200 mm, the cylindrical length of 60 mm and the vortex finder length of 40 mm showed the best separation efficiency, up to 84.06%. Second, a regression model of Stk₅₀Eu of the hydrocyclone was established. In this work, data obtained from a total of 75 experiments in the first part and from earlier research were used to form the relationship between the dimensions of the hydrocyclone and Stk₅₀Eu. The calculated Stk₅₀Eu can successfully be used to predict experimental Stk₅₀Eu.

Abstract: In industrial applications, it is very common to use multiple hydrocyclones in parallel to improve the separation. This equipment employs the centrifugal field to promote solid-liquid or liquid-liquid separation. In cases where there is interest in recovering the liquid phase by removing the maximum amount of dispersed phase (waste), such as in oil well drilling units and in water treatment systems, the employment of a hydrocyclone able to promote both the recovering liquid and the concentration of suspension is viable. This paper presents a comparison between two hydrocyclones considered concentrators, called H13 and HCOT3. The results obtained showed that both separators have a satisfactory capacity to concentrate aqueous suspensions, with the underflow-to-throughput ratio equivalent. The Euler number of HCOT3 hydrocyclone was 19% lower than that obtained for the H13 hydrocyclone. Moreover, the results showed that the HCOT3 has a total efficiency of separation 34% greater compared to H13.

Abstract: Hydrocyclones are equipment typically used in solid-liquid separation. Such equipment can be used with the purpose of classifying particles or concentrating suspensions. In this context, a new filtering hydrocyclone was conceived through Surface Response and Differential Evolution Algorithm techniques in order to optimize the Euler’s number. Based on this optimized geometry, the aim of the present paper was to verify the influence of the underflow diameter on the overall separation process at 147 kPa on the same optimized hydrocyclone geometry, but without the filtration effect, by performing laboratory experiments and CFD simulations using the commercial software Fluent®. The results showed that the use of the smallest underflow diameter increased up to 44% (v/v) the concentration of the underflow stream, compared to the suspension initially fed, with an Euler’s number of 862. Despite a small decrease (14%) in the total efficiency and an increase from 12.01 to 16.05 of the reduced cut size diameter, compared to the underflow diameter originally used in the optimization procedure, the benefits of recovering liquid by reducing the underflow diameter outweigh these disadvantages.

Abstract: Kaolin is a white clay, formed by hydrated aluminum silicates, which has several industrial applications. Since it is associated to impurities and presents considerable contents of contaminant elements that interfere in its performance and in its applications, kaolin must pass through a beneficiation process in order to meet the market's demands. The purpose of this work is to study the use of a hydrocyclone in the beneficiation of primary kaolins from Província Pegmatítica da Borborema. The samples were characterized by cation-exchange capacity (CEC), granulometric analysis by laser diffraction (GA), chemical composition by X-ray fluorescence (EDX), X-ray diffraction (DRX), differential thermal analysis (DTA) and thermogravimetric analysis (TG). The purification process did not show good results for kaolin in ABNT 200 mesh in the attempt to obtain colloidal kaolin. On the other hand, it presented very promising results for the beneficiation of raw kaolin, proving the feasibility of the application of this technology to the granulometric classification of this mineral, being an alternative route for the processes adopted in the regional kaolin beneficiation plants, which use washing and sieving.