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A semi-industrial scale hydrocyclone with a 250 mm internal diameter was used to concentrate medium-grade celestine ore (75%–85% celestine) from the Montevive deposit of Granada (Spain) using a dense ferrosilicon (FeSi) medium. For this purpose, a Box–Behnken factorial design (BBD) was carried out, with the response variable being the Sr concentration measured by X-ray fluorescence (XRF), as well as the concentration of celestine measured by X-ray diffraction (XRD) of the mineral collected from the under (sunk) stream of the hydrocyclone. The experimental factors to be optimised were the density of the medium in the mixing tank (water, FeSi, and feed mineral) varying from 2.7 to 2.9 kg/L, the hydrocyclone inlet pressure from 0.8 to 1.2 bar, and the hydrocyclone inclination (from 15° to 25° from the horizontal). The range of densities of the dense medium to be tested was determined from previous sink–float experiments using medium-grade ore, in which the distribution of mineral phases with different particle size fractions was determined. To evaluate the separation behaviour, the following parameters were considered: the enrichment ratio (E), the tailings discarding ratio (R), and the mineral processing recovery (ε). From the factorial design and the response surface, the optimum parameters maximising celestine concentration in the under stream (78%), were determined. These optimised parameters were: a density of 2.75 kg/L for the dense medium, an inlet pressure of 1.05 bar, and a hydrocyclone inclination varying from 18° to 20°. Under these conditions, a 94% recovery of celestine (68% Sr) can be achieved. These results show that medium-grade celestine ore, accumulated in mine tailings dumps, can be effectively concentrated using DMS hydrocyclones and that the operating parameters can be optimised using a factorial experiment design. This study can contribute to reducing overexploitation of strategic mineral resources, avoiding blasting and environmentally damaging clearing, by applying a simple and sustainable technique.

The object of research is the process of dewatering oil emulsions by using a hydrocyclone with forced flow rotation taking into account rheological properties. The problem solved in the work is related to production, primary preparation and transportation of oils. The process of oil extraction is accompanied by saturation of the product with water, salts, mechanical particles and light fractions, which requires primary preparation of oil through multi-stage, sometimes long-term, low-productivity processing in order to separate the above-mentioned components. The water content of some deposits, especially marine deposits, is 80%, which makes the process of oil dehydration particularly important for preparing oil for transportation. Among the known methods of dewatering oil emulsions, such as settling, heat treatment, chemical treatment, electrodehydration and centrifugation, the last one allows to significantly influence the separation processes. The essence of the centrifugation process, consists in increasing the rotational speed of the particles of the dispersed phase by replacing the natural force of gravity with a more powerful centrifugal force. The density of water and mechanical impurities is higher than the density of oil, and particles under the action of centrifugal force are pressed against the wall and, coagulating, are removed through the flow separator. In the course of the work, the main regularities of the process were determinedcentrifugation, namely the rate of sedimentation of the water fraction from the rheological parameters of the emulsion and the kinematic characteristics of the hydrocyclone with forced rotation of the flow. It was established that the dependence of the volume of the water fraction of the oil emulsion is a power function of the second order, and the rate is linear. The settling of a water particle has a linear dependence on the size of the particle. Speed The set speed of settling of water particles of an oil emulsion allows you to calculate the length of the turbine depending on the required performance, speed of rotation and rheological properties. The developed theoretical provisions of the process of dewatering oil emulsions by using a hydrocyclone with forced rotation of the flow, taking into account the rheological properties, allow designing machines of this type for various conditions of oil production.

This study performed the numerical simulation of the vortex finder (VF) diameter and depth effects on the separation performance of the hydrocyclone-type devices for multiphase fluid separation, namely the static pressure, pressure drop, split ratio, short-circuit flow, velocity field, and classification accuracy. The static pressure, pressure drop, and split ratio were found to be negatively related to the VF diameter. As the VF diameter increased from 0.26D 2 to 0.56D 2 , the maximum static pressure dropped from 94483.56 to 26067.86 Pa, and the pressure drop was reduced from 93336.50 to 26408.69 Pa. Meanwhile, the steepness index increased with the VF diameter in a particular range. The results strongly indicated that an increased VF diameter led to reduced energy consumption and improved separation accuracy of the hydrocyclone, decreasing the tangential velocity, increasing the short-circuit flow, and disrupting the symmetry of the locus of zero vertical velocity (LZVV). The effects of the VF depth on the separation performance were as follows: with increasing VF depth, short-circuit flow and split ratio decreased, the steepness index increased within a specific range, and the symmetry of the LZVV gradually improved. This implies that increased VF depths can help enhance the separation performance of the hydrocyclone but excessively large VF depths would deteriorate it. [Display omitted] • The accuracy of the mathematical model used in the paper was verified. • Effects of the vortex finder diameter on the classification performance were studied. • Effects of the vortex finder depth on the separation performance were studied. • Separation efficiency of the hydrocyclone was analyzed. [ABSTRACT FROM AUTHOR]

Copyright of Chemical Engineering (China) / Huaxue Gongcheng is the property of Hualu Engineering Science & Technology Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aimed to develop a hydrocyclone with a spiral guide feeding body structure to improve classification efficiency and classification accuracy. The spiral guide feeding body structure could pre-arrange the particles before they entered into the separation chamber, thus avoiding the turbulence of the flow field and effectively improving the separation efficiency and separation accuracy. The flow field features and separation performance of a hydrocyclone were studied using the response surface method to obtain the prediction model of separation efficiency and cut-size and the interaction law between influencing factors and the optimal combination of parameters under multiple response indicators. The industrial application showed that the classification efficiency was improved by 4.56% over the conventional feeding body structure. This indicated that the hydrocyclone with a spiral guide feeding body structure had potential industrial application value and certain advantages in improving the separation performance. [ABSTRACT FROM AUTHOR]

Hydrocyclones are devices used in numerous areas of the chemical, food, and mineral industries to separate fine particles. A hydrocyclone with a diameter of d50 mm was modeled using the commercial Simcenter STAR-CCM+13 computational fluid dynamics (CFD) simulation package. The numerical methods confirmed the results of the different parameters, such as the properties of the volume fraction, based on CFD simulations. Reynolds Stress Model (RSM) and the combined technique of volume of fluid (VOF) and discrete element model (DEM) for water and air models were selected to evaluate semi-implicit pressure-linked equations and combine the momentum with continuity laws to obtain derivatives of the pressure. The targeted particle sizes were in a range of 8–100 microns for a dewatering application. The depth of the vortex finder was varied to 20 mm, 30 mm, and 35 mm to observe the effects of pressure drop and separation efficiency. The split water ratio increased toward a 50% split of overflow and underflow rates as the length of the vortex finder increased. It results in better particle separation when there is a high injection rate at the inlet. The tangential and axial velocities increased as the vortex finder length increased. As the depth of the vortex finder length increased, the time for particle re-entrainment into the underflow stream increased, and the separation efficiency improved. [ABSTRACT FROM AUTHOR]

This study demonstrates the use of hydrocyclone as a thickener to precipitate sulfate ions from wastewater. Simulated wastewater containing different concentrations of sodium sulfate (100–400 mg L−1) dissolved in distilled water was prepared. Lime was added as the precipitating agent. Different flow rates of the feed (3–11 L min−1) were used for two split ratios (0.1, 0.9). The results showed that increasing inlet flow rate, initial concentration, and split ratio enhanced the separation by concentrating sulfate ions in the underflow. Design Of Experiments was performed to determine the most effective factor on the response (underflow concentration) and to assign the optimum operating conditions. The effect was in the order: inlet flow rate, initial concentration, and split ratio. The quadratics of the factors also affected the separation in the order (inlet flow rate)2, (inlet flow rate) × (split ratio), (inlet flow rate) × (initial concentration). The optimum (maximum) value of the underflow concentration of sulfate ions was 856.538 mg L−1 at the optimum operating conditions (11 L min−1 inlet flow rate, 400 mg L−1 initial concentration, and 0.9 split ratio). The experimental value at the optimum operating conditions was 932 mg L−1 including 8% error. The process was applied on a real wastewater taken from a tile factory. The results confirmed the experimental results in that the pollutant was concentrated in the underflow. It was concluded that using hydrocyclone as a thickener was feasible to separate sulfate ions from wastewater. Also, the separation using hydrocyclone could be integrated with another technique such as electrocoagulation or ion exchange to recover sulfur as an attempt toward sustainable development requisites. [ABSTRACT FROM AUTHOR]

Hydrocyclone with guide vanes is one type of swirl flow launching device without energy input. For researching the flow characteristics of that hydrocyclone, the flow distribution of the sections and their variation along the flow were studied using numerical simulation and physical experiment. In addition, the flow field was convenient to be divided into three-dimensional velocities: axial velocity, circumferential velocity, radial velocity and the static pressure. The result showed that the water flow had obvious diversion by the effect of guide vanes. The axial velocity varied into the distribution of higher values emerging away from the pipe wall and the surfaces of guide vanes, and the value was higher on downstream surfaces than upstream surfaces of the guide vanes. The radial velocity's direction pointed at the axis of pipe on upstream surfaces, and pointed at the pipe wall on the downstream surfaces of the guide vanes; the influenced range was larger in sections along the flow. The circumferential velocity increased along the flow, closing the distorted guide vanes; the value of that velocity was larger closer to the guide vanes, especially the downstream surfaces of the guide vanes. The static pressure decreased along the flow, and the value was larger on the upstream surfaces than the downstream surfaces of the guide vanes. The results can provide some theory references to improve the construction of the hydrocyclone. [ABSTRACT FROM AUTHOR]

Taper angle is an important factor for characterizing a hyrocyclone's separation performance. Appropriate setting of the taper angle can contribute to particle grading and separation performance of the hydrocyclone. Through numerical analysis, this study investigated the flow fields and separation performances of the hydrocyclones with different taper angles in depth. Moreover, the numerical simulation results were compared with experimental data of the conventional hydrocyclone for accuracy validation. The results showed that the tangential velocity, axial velocity, and the diameter of air core increased with the increasing taper angle. At a too large or a too small taper angle, the inner flow field would become unstable, thereby leading to the increasing number of dislocated particles and reducing the particle separation precision. For the hydrocyclone with a diameter of 75 mm, the separation precision of fine particles can be remarkably enhanced by setting the taper angle of 15°, accompanied with the improvement of product quality. The present data can provide the related enterprises with favorable guidance and a theoretical foundation for further designing the taper angle of novel hydrocyclones. [ABSTRACT FROM AUTHOR]

In determining the reasons for the quality loss of coal concentrates, the influence of the ferric oxide content on the heavy to medium enrichment of coal in hydrocyclones is studied. Excessive content of ferric oxide increases the basicity index Iba of the ash and impairs the quality of the industrial concentrates. This excess of ferric oxide may be attributed to regulation of the enrichment in hydrocyclones with a magnetite suspension, which is a mechanical mixture of water and magnetite concentrate (which, in turn, is a mixture of ferrous and ferric oxides, FeO·Fe2O3). [ABSTRACT FROM AUTHOR]

Overflow pipes are important components of hydrocyclones. The overflow products can carry huge amounts of residual energy when being discharged. In order to take full advantage of the residual energy and enhance hydrocyclone separation performance, this research designed a novel hydrocyclone by adding static mixing units with spiral elements in the overflow pipe. This study performed numerical simulations to investigate the effects of the install position of the spiral structure on the separation performance and inner flow field of the hydrocyclone. It can be concluded that both tangential velocity and pressure are first enhanced and then reduced by the elevation of the spiral structure. When the spiral structure is installed 30 mm away from the overflow pipe bottom, because of the hindrance of spiral elements, the discharge of coarse particles with the overflow are fully decreased and the quality of overflow products are enhanced. [ABSTRACT FROM AUTHOR]

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

There are many factors that affect the separation performance of the hydrocyclone, including the structure of the feed body, but the mechanism of influence of the internal flow field of the hydrocyclone on the Axial Velocity Wave Zone (AVWZ) is not yet clear. Based on the numerical test method, this paper analyzes the influence of the feed body structure on the internal flow field and the particle distribution characteristics of the AVWZ and its internal relationship with its separation performance. The results show that the influence mechanism of the structural parameters of the inlet structure on its separation performance is extremely complex, but all of them are reflected in the AVWZ's characteristics, including the flow field characteristics, spatial distribution characteristics, and internal particle distribution. The changes on the inlet diameter will also influence the flow field, centrifugal strength, turbulence strength, and particle distribution, while the inlet aspect ratio is altered largely by changing the settling distance of particles. Finally, effects of inlet structure on the separation performance of the hydrocyclone can be explained from the AVWZ, which provides the basis for designing the inlet structure to improve separation performance. [ABSTRACT FROM AUTHOR]

Inlet head, as the multi-phase flow transport channel, imposes significant effects on the separation performance of a hydrocyclone. Ultra-fine powder is an inevitable product in the mining processing industry and sets extremely high requirements on product quality. Because of favorable water-carrying capability, fine particles can be hardly separated in a conventional feeding body. In order to satisfy the separation requirements of fine particles, this study designed a vorticose involute-line diversion inlet head that can effectively enhance the separation precision of fine particles and improve the product quality. Meanwhile, this study selected four hydrocyclones with different feeding structures for comparative analysis, and explored the isobaric pressure, velocity field, air core, and separation performance of the hydrocyclones through numerical simulation. The numerical analysis results showed that the effective pressure range in the novel hydrocyclone expands and the energy loss drops. The air core diameter is the lowest, the separation space of fine particles is the greatest, and the separation time is the longest, which can achieve a more thorough separation with the highest cutting capability and separation precision of fine particles. Finally, after an optimum design, the separation performance achieves the optimal at a wrap angle of 180°. [ABSTRACT FROM AUTHOR]

Copyright of Misr Journal of Agricultural Engineering is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim in this study was to determine how surging modifies the dynamic behaviour of the cyclonic flow in a hydrocyclone using computational fluid and granular dynamics models. The Volume-of-Fluid model was used to model the air-core formation. Fluid–particle, particle–particle, and particle–wall interactions were modelled using an unsteady two-way coupled Discrete Element Method. Turbulence was modelled using both the Reynold's Stress Model and the Large Eddy Simulation. The model predictions indicate that the phenomenon of surging modifies the dynamics of the cyclonic flow in hydrocyclones and subsequently impacts separation. The results reveal that the primary cyclonic separation mechanisms break down during surging and result in air-core suppression. The flow and primary separation mechanism in the core of the hydrocyclone is driven by the pressure drop and the flow and primary separation mechanism near the wall is primarily driven by the gravitational and centrifugal force-induced momentum. However, surging causes a breakdown in this mechanism by swapping this primary flow and separation behaviour, where the pressure drop becomes the primary driver of the flow near the walls and gravitational and centrifugal force-induced momentum primarily drives the flow in the core of the hydrocyclone. [ABSTRACT FROM AUTHOR]

In order to clarify the influence of feed rate on a hydrocyclone flow field, numerical simulation was employed to model the influence of feed rate on the pressure field, velocity field, air column, turbulent kinetic energy, and split ratio. The results revealed that static pressure, tangential velocity, and radial velocity increased with an increase in the feed rate. When the feed rate at the inlet increases from 1 m/s to 5 m/s, the static pressure increases from 5.49 kPa to 182.78 kPa, tangential velocity increases from 1.97 m/s to 11.16 m/s, and radial velocity increases from 0.20 m/s to 1.16 m/s demonstrating that a high feed rate facilitated the strengthening separation of the flow field. Meanwhile, with the increase in the feed rate, the split ratio of the hydrocyclone decreased, indicating that the concentration effect of the hydrocyclone improved. Additionally, the formation time of the air column was reduced, and the flow field became more stable. Nevertheless, the axial velocity and the turbulent kinetic energy also increased with the increase in the feed rate, and the increase in the axial velocity reduced the residence time of the material in the hydrocyclone, which was not conducive to the improvement of separation accuracy. In addition, the increase in turbulent kinetic energy led to an increase in energy consumption, which was not conducive to the improvement of the comprehensive performance of the hydrocyclone. Therefore, choosing an appropriate feed rate is of great significance to the regulation of the flow field and the improvement of hydrocyclone separation performance. [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Mineral Processing Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• It is the first study comparing the performances of centrifugal classifiers. • Comprehensive lab test works were conducted at different operating and design conditions. • The assessments focused on overall and mineral-based performances. • Air classification was found to be more efficient. • Thorough economic investigations should be made as a complementary study. The research aimed at comparing the performances of two common centrifugal type classifiers, air classifier and hydrocyclone, operated dry and wet respectively. The reason for starting the study is the possible shifting to dry processing in the future as the water has limited availability. Such comprehensive research has not been undertaken in the literature although individual assessments were completed. Within the scope, copper ore, gold ore and magnetite-calcite blends were chosen as these applications are common globally. The research commenced with the experimental tests via laboratory scale air classifier and hydrocyclone. Afterwards, size analyses and component measurements (via XRF, MLA, fire assay) were undertaken. The data was initially used in mass balancing of the experimental data to adjust the flow rates alongside with assays then Tromp curves were plotted to determine cut size, sharpness of cut, bypass parameters. Comparison of the two classifiers were completed for the same overflow target sizes. Throughout the assessments, the magnitudes of the Tromp curve parameters for the overall classification and component-based results were compared. As a result, air classifier may be alternative to hydrocyclone classification since less bypass, higher sharpness values were obtained. This study provides insights on choosing the dry or wet classification. [ABSTRACT FROM AUTHOR]

• A hydrocyclone was used for dynamic adsorption of methylene blue solution. • The adsorption and separation of adsorbent was integrated in hydrocyclone. • A model for predicting the removal efficiency of methylene blue is developed. To address the issues of low adsorption efficiency of activated carbon in dyeing wastewater treatment, a dynamic adsorption process using activated carbon for wastewater treatment was proposed. A hydrocyclone was used as the carrier, and the adsorbent separation process was integrated into the same single device. Methylene blue (MB) was used to simulate printing and dyeing wastewater. The effects of initial concentration of MB solution, ratio of activated carbon quality to wastewater flow, and adsorption temperature on the adsorption efficiency were investigated. The results showed that the optimal adsorption efficiency of MB by activated carbon was 95.2 % when the initial concentration of MB solution was 12 mg/L, the ratio of activated carbon quality to wastewater flow was 0.5 mg/mL, and the adsorption temperature of MB solution was 44.5 °C. In addition, compared with the water bath oscillation method, the removal efficiency of MB was increased by 731 % under the same adsorption conditions. The research shows that it is feasible to treat printing and dyeing wastewater by using a hydrocyclone to enhance activated carbon adsorption. The research aims to provide a practical basis for future optimization of the structure and operation parameters of hydrocyclone and to reveal their wide application prospects. [Display omitted] [ABSTRACT FROM AUTHOR]

Previous hydrocyclone optimizations often overlooked crucial objectives interactions, thereby weakening the overall system performance. This study presents a framework that integrates meta-heuristic algorithms with preference-informed decision-making to simultaneously optimize key performance objectives. Meta-heuristics identify comprehensive Pareto-optimal sets, while preference-informed decision-making evaluates each solution's overall separation performance according to specific separation preferences. Supported by computational fluid dynamics, the study quantifies the trade-off between optimal overall separation performance and pressure drop, enabling the attainment of optimal overall separation performance at any pressure drop within the Pareto-optimal set. Among the evaluated algorithms, the strength Pareto evolutionary algorithm 2 (SPEA2) stands out for its exceptional diversity and convergence. With this framework, the study circumvents excessive compromises on neglected but crucial objectives, especially highlighting the significant adverse effects of overlooking water split or cut size. Overall, this study provides an integrated approach for developing energy-efficient hydrocyclones that maximize overall separation performance tailored to specific separation requirements. [Display omitted] • Optimizing four objectives mitigates the loss in overall performance compared to two. • SPEA2 generates a more well-distributed Pareto optimal set than other algorithms. • Both preferred separation performance objectives and overall performance improve. • A moderate preference for the weighting ratio of water split enhances the cut size. [ABSTRACT FROM AUTHOR]

A pilot hydrocyclone plant was used to concentrate medium-grade celestine ore (67% celestine) from the Montevive deposit in Granada (Spain) by using a dense media concentration (DMS) process. To optimize the concentration process, several types of heavy minerals (coarse, fine C40 ferrosilicon and/or magnetite) were used to prepare a dense media with a constant density of 3.0 kg/L. Then, the dense media (loaded with run-of-mine celestine mineral) was fed into the hydrocyclone system. The mineral was then separated into two streams, the first containing the mineral fractions that float (over stream) and the second containing fractions that sink (under stream) in the dense media. Next, the heavy minerals (ferrosilicon and/or magnetite) were recovered from the dense media using magnetic separation. The celestine mineral recovered from each stream was divided into two fractions with particles size above or below 250 μm to study the effect of the mineral particle size on the separation process. Their mineral composition was quantified by X-ray diffraction (XRD) using the Rietveld method. The celestine is preferentially concentrated in the under stream in the mineral fraction with particles larger than 250 μm (up to 90% celestine). The optimum results (highest % of celestine) were obtained after desliming and using the ferrosilicon C40 medium, which has the smallest particle size (

Natural gas hydrate is a promising substitute energy resource for the future. Currently, the inefficient sand control technology impedes the commercialization of Natural gas hydrate. The main challenge lies in breaking the consolidation of Natural gas hydrate and sands, and then separating micrometer-sized sands from the drilling fluid. In this paper, we present a technology based on hydroscyclone that effectively breaks the consolidations and removes sand. We used polypropylene powders and silica sands as substitutes for the hydrates and sands, and we added cement to replicate the consolidation. Inside the hydrocyclone, the material particles receive a strong shear force from the 3-dimension rotating swirling flow field generated by the device, as well as a centrifugal force produced by their own rotation and revolution. With the high-speed camera, we observed the effect of these forces breaking the consolidation and separating sands. It was further noted that the proportion of residual polypropylene powders in the recovered materials were between 0.46% and 1.05% after the materials were processed by the hydrocyclone. The low residual content of polypropylene powders demonstrated the success of hydrocyclone technology in breaking the consolidation and effectively addressing the problem of sand control in the extraction of Natural gas hydrate and sands.

The paper studies the possibility of assessing the separation of mineral raw materials, taking into account the rheology of the mineral slurry. The ores of the Mayskoye deposit were chosen as the object of the study, characterized by a thin impregnation of the valuable component – gold in the host minerals, which determines the use of fine and ultrafine milling. This fact is essential because the presence of a fine grade seriously affects the rheology of the mineral slurry used in subsequent mineral processing stages. This predetermines the necessity to take into account rheological parameters. The research performed provides the development of a methodology for assessing the separation of minerals in the hydrocyclone based on the interpretation of numerical and mathematical modeling data. using the object-oriented programming language Python, a program for calculating empirical coefficients of the rheological equation, theoretically describing the dynamics of internal transformations of the mineral slurry, was developed. Taking into account the process parameters of the laboratory unit with hydrocyclone and ore properties, three concentrations of solids in the mineral slurry were selected, conditionally corresponding to the minimum, average and maximum values. Rheological equations successively composed for three concentrations, i.e., 400, 500, and 700 g/l, made it possible to calculate the critical shear rates corresponding to the maximum dispersion of the mineral slurry in the hydrocyclone flow. Subsequent numerical simulation using Ansys Fluent software, as well as statistical evaluation of the shear rates at different levels of solids content showed that the shear rate profile in the cross-section of the hydrocyclone corresponding to the maximum dispersion of the mineral slurry is obtained at the content of 400 g/l.

A rectangular inlet generally exceeds a circular inlet in separation performance. However, there still lacks detailed information that can appropriately determine the height-to-width ratio of the rectangular inlet. For this reason, this study investigated the effect of the height-to-width ratio of the rectangular inlet on the separation performance of hydrocyclone with a diameter of 75 mm through numerical analysis. The numerical results fitted well with the experimental data and thus validated the effectiveness of the present method. The appropriate height-to-width ratio was determined by overall analyzing the pressure field, the velocity field, the air column, the turbulence field in the hydrocyclone and the separation efficiency. Based on the present research results, as the height-to-width ratio increased, both the pressure drop and tangential velocity first increased and then decreased, while the turbulence energy first decreased and then increased. At a height-to-width ratio of 3, the short-circuit flow rate and the turbulence energy were lowest and the separation precision was highest, suggesting favorable product quality. Conclusively, for the hydrocyclone with a diameter of 75 mm, the optimal height-to-width ratio of the rectangular inlet should be within the range of 3~4. This finding can provide insightful foundation for designing a reasonable inlet. [ABSTRACT FROM AUTHOR]

The intake of natural water or waste water from a depth exceeding the suction height of centrifugal pumps is mainly carried out due to additional water supply at the suction of the pump. However, this process becomes more complicated if it is necessary to purify water from mechanical impurities. The purpose of the presented work is to consider this issue based on the development and study of the parameters of an ejector water intake treatment plant equipped with a pressure-vacuum hydrocyclone. The main contribution of the ongoing research is the establishment of the technological parameters of the installation, and their features in the pressure-vacuum mode of operation, in contrast to the known pressure and vacuum hydrocyclones separately. In terms of methodology, the main parameters of the developed installation were established during the testing of its prototype on a specially built stand using well-known regulatory guidelines in the hydraulic research system. As a result of the study, the nature of the change in pressure inside a cylindrical–conical hydrocyclone, with established design dimensions and the patterns of formation of vacuum and pressure-vacuum modes depending on the initial parameters, was revealed. The data obtained to determine the effect of technological parameters of ejection and the characteristics of the supplied water with impurities on the operating mode of the hydrocyclone confirm the efficiency of water intake and purification. A rational mode of joint operation of the elements of a closed system is achieved at the maximum value of the installation efficiency and ensuring low specific energy consumption per 1 m3 of treated water. [ABSTRACT FROM AUTHOR]

Solid phase is an important component of drilling fluid, but when drilling fluid with high solid content is injected to well bottom, it leads to decrease in rate of penetration (ROP) and waste of drilling energy. Therefore, it is an economic method to add solid control equipment near bit to achieve solid removal of bottom-hole drilling fluid. Based on hydrocyclone separation technology, this paper presents a new near-bit hydrocyclone (NBHC) installed with guide vanes for downhole solid–liquid separation. Structure and separation mechanism of NBHC are introduced. This tool can separate part of solids contained in drilling fluid into wellbore annulus in advance, especially plugging particles. In this way, the solid content of drilling fluid flowing into bit will reduce, thereby the bit rock-breaking environment will improve and ROP increase. Firstly, the Euler multiphase flow model is adopted to simulate the NBHC for Φ311.2 mm wellbore. The results indicate that NBHC has a strong ability of drilling fluid solid separation, and the mass separation efficiency reaches 79.30%. Then, the effects of nozzles diameter, mud flow rate, solid volume fraction and solid size on the separation efficiency and pressure drop of NBHC are studied by simulation. Results show that the separation efficiency is positively correlated with nozzles diameter and solid size, negatively correlated with solid volume fraction, but not significantly correlated with inlet mass flow rate. It is proved that appropriate structural parameters help to further improve the working performance of NBHC, and it is an effective way to increase the ROP indirectly. [ABSTRACT FROM AUTHOR]

The monodisperse pseudo-boehmite (PB) is an essential raw material for the preparation of the hydrogenation catalyst carrier, γ-Al 2 O 3 , which is of great significance for the efficient conversion of heavy crude oil and the development of the residue hydrotreating technology. The introduction of hydrocyclone has been proved to better improve the grade efficiency of PB particles. However, in the actual production process, it is found that the change of slurry viscosity will have a serious impact on particle size control and centrifugal classification of PB particles. Therefore, in this paper, based on the computational fluid dynamics (CFD), the internal flow field characteristics of the hydrocyclone and the effect of continuous phase viscosity on particle classification efficiency were systematically studied. The results demonstrated that hydrocyclone not only participated in particles classification, but also indirectly promoted particle growth. Satisfied classification efficiency was obtained in practical industrial applications by adopting the optimized condition parameter (Na 2 CO 3 concentration of slurry 5 wt%). The average PB particles size increased from 12.9 µm to 40.3 µm, and the corresponding separation efficiency was improved to 74.9%. The obtained results can provide a feasible reference and theoretical basis for optimization of continuous-carbonization preparation process of PB particles. [Display omitted] • The effect of slurry viscosity on PB centrifugal classification was numerically simulated. • Efficient classification and rapid growth of PB particles were achieved in hydrocyclone. • The average PB particles size was increased to 40.3 µm by slurry viscosity control. • The separation efficiency of PB particles was improved to 74.9% in the industrial pilot test. • Fish-hood effect of PB particles classification in hydrocyclone was discussed. [ABSTRACT FROM AUTHOR]

An industrial water injection hydrocyclone was adopted in the Taixi coal preparation plant to overcome the shortcoming of fine particle entrainment in the underflow and improve the grading efficiency. Parameter optimization of the hydrocyclone was critical prior to putting it into production. A particle swarm optimization optimized support vector machine (PSO-SVM) model based on uniformly designed experiments was built. It was satisfactory in accuracy as the average of the absolute of relative error was 1.73% for the training dataset, and the relative error of the test dataset was 8.43%. The trends of grading efficiency versus underflow port diameter, inlet pressure and water injection pressure were analyzed, respectively. It was found that the maximum efficiency was obtained when underflow port diameter was 50 mm, inlet pressure was 0.25MPa and water injection pressure was 0.04 MPa. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Railway Science & Engineering is the property of Journal of Railway Science & Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Microplastics have been identified as a potentially emerging threat to water environment and human health. Therefore, there is a pressing demand for effective strategies to remove microplastics from water. Hydrocyclone offers a rapid separation and low energy consumption alternative but require reduction of microparticle entrainment by short flow, which limits the effectiveness for small density differentials and ultralow concentrations separation. We proposed an enhanced mini-hydrocyclone with overflow microchannels (0.72 mm width) based on the active control of short flow in hydrocyclone for microplastic removal from water. The overflow microchannels effectively redirect the particles that would typically be entrained by the short flow, leading to higher separation efficiency. Simulation results show overflow microchannels effectively reduced short flow to 0.7 %, a reduction of up to 94 % compared to conventional hydrocyclones. The hydrocyclone with overflow microchannel demonstrated a removal efficiency exceeding 98 % for 8 μm plastic microbeads at ultralow concentrations (10 ppm), which is a 33.7 % improvement over conventional hydrocyclone. Compared with other methods (e.g., filtration, adsorption, coagulation) for microplastic removal, this work achieves rapid separation capability and long period operation, highlighting hydrocyclone as a promising approach for microplastic removal in industry-scale water treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Microplastics have attracted considerable attention as emerging contaminants that threaten water bodies. The removal of microplastics from a mini-hydrocyclone, enhanced by air flotation, was studied numerically. The three-phase flow was modeled using the Eulerian-Eulerian model coupled with interphase interactions. The characteristics of the flow field and distribution of microplastics and microbubbles were discussed, and the mechanism of cyclonic air flotation separation was analyzed. It was found that injecting microbubbles accelerated the axial migration of microplastics and moved the enriched area upward toward the overflow. The coalescence rate of the bubbles near the axis was higher than their breakage rate, which led to the formation of an air core. The length and diameter of the air core increased with the inlet gas holdup. When the air core size closely matched the overflow, the constrained flow channel prevented the discharge of microplastics. The optimal air holdup must be determined to ensure the efficiency of the cyclonic air flotation process. The sizes of the microbubbles used for cyclonic air flotation should be comparable to those of the separated microplastics. The upper cone angle significantly promoted the migration of microplastics to the axis. This study was conducted to purify microplastic-containing wastewater using an environmentally friendly and energy-efficient technique and to provide a theoretical basis and practical reference for applying microplastic separation technology in water., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Abstract Polymer flooding technology is widely used to enhance the oil recovery, but it increases the viscosity of the produced liquid, making the subsequent water treatment more challenging. Application of polymers impacts separation performance of hydrocyclone, which is an important equipment of produced liquid preseparation and sewage treatment in oil fields. In this work, the effect of polymer solution concentrations on the separation performance of hydrocyclone was studied by using sensitivity analysis. The sensitivity was calculated by numerical simulation, and the influence of polymer concentration on velocity field, pressure field, oil volume fraction, and separation efficiency of hydrocyclone was evaluated. The prototype was processed according to the similarity principle of fluid mechanics, and the relevant laboratory tests were carried out to verify the accuracy of simulation results. Within the tested range (100‐1000 mg/L), the increase of polymer solution concentrations caused adverse impacts on the velocity field, pressure field, and oil volume fraction of the hydrocyclone. When the concentrations of polymer solution reached 800 mg/L, the separation efficiency was reduced to less than 60%. The sensitivity sequence obtained by calculation is as follows: underflow outlet pressure drop > overflow outlet pressure drop > axial velocity > radial velocity > tangential velocity > pressure drop ratio. The change of pressure drop at underflow and overflow outlets was the primary cause for poor separation performance of hydrocyclone. The work can be used to guide the design and application of hydrocyclone for efficient treatment of polymer‐containing treatment liquid.

Liquid rheology affects the separation performance of hydrocyclones. Sewage entering a de-foulant hydrocyclone with a reflux ejector (DFHRE) exhibits different rheological properties based on the source. In this study, particle image velocimetry is used to investigate the effect of liquid rheology on the overflow–suck–underflow effect of the DFHRE. Results show that the effects of the rheological properties, liquid concentration, and inlet velocity on the flow field are primarily reflected inside the locus of the zero vertical velocity at the cone section of the DFHRE. In addition, the overflow–suck–underflow effect becomes less prominent as the apparent viscosity increases. An increase in glycerin (Newtonian) concentration increases the total pressure drop, unlike an increase in polyacrylamide aqueous solution (PAM, non-Newtonian). Increasing the inlet velocity can enhance the overflow–suck–underflow effect in PAM owing to the lower drag force. This implies that the DFHRE can achieve an overflow–suck–underflow effect on fluids with a lower drag force and enhance the separation performance. [ABSTRACT FROM AUTHOR]

The performance of multiphase flow processes is often determined by the distribution of phases inside the equipment. However, controllers in the field are typically implemented based on flow variables, which are simpler to measure, but indirectly connected to performance (e.g., pressure). Tomography has been used in the study of the distribution of phases of multiphase flows for decades, but only recently, the temporal resolution of the technique was sufficient for real-time reconstructions of the flow. Due to the strong connection between the performance and distribution of phases, it is expected that the introduction of tomography to the real-time control of multiphase flows will lead to substantial improvements in the system performance in relation to the current controllers in the field. This paper uses a gas–liquid inline swirl separator to analyze the possibilities and limitations of tomography-based real-time control of multiphase flow processes. Experiments were performed in the separator using a wire-mesh sensor (WMS) and a high-speed camera to show that multiphase flows have two components in their dynamics: one intrinsic to its nonlinear physics, occurring independent of external process disturbances, and one due to process disturbances (e.g., changes in the flow rates of the installation). Moreover, it is shown that the intrinsic dynamics propagate from upstream to inside the separator and can be used in predictive and feedforward control strategies. In addition to the WMS experiments, a proportional–integral feedback controller based on electrical resistance tomography (ERT) was implemented in the separator, with successful results in relation to the control of the distribution of phases and impact on the performance of the process: the capture of gas was increased from 76% to 93% of the total gas with the tomography-based controller. The results obtained with the inline swirl separator are extended in the perspective of the tomography-based control of quasi-1D multiphase flows. [ABSTRACT FROM AUTHOR]

Hydrocyclone is a very simple and cost-effective way to separate inhomogeneous fluid-solid mixtures. It is important to ensure adequate separation efficiency during their operation. Many researchers have worked to identify the factors that influence separation. Geometry has been identified as one of the most important influencing factors. This article summarises the results of this research in order to provide a comprehensive picture of the importance and impact of each geometric element. [ABSTRACT FROM AUTHOR]

Copyright of Mining & Metallurgy (10057854) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Science Technology & Industry is the property of Chinese Society of Technology Economics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tapered segment, the main separation region in a hydrocyclone, is mainly used to cut off the short-circuit flow. Generally, a single straight-line tapered segment is set in a conventional hydrocyclone, the effects of multi-curved-line combination-type tapered segment on the flow field in the hydrocyclone and the related separation performance have been poorly investigated. In this study, five different types of hydrocyclones with different tapered-segment structures (straight line, parabolic curve, hyperbolic curve, the combination of parabolic curve and straight line and the combination of hyperbolic curve and straight line), denoted as Type A, Type B, Type C, Type D and Type E hydrocyclones, respectively) were selected for numerical analysis. The simulation data were compared with classical experimental values by Hsieh et al. to validate the accuracy. Moreover, the changes of pressure fields, velocity fields, air columns, turbulence intensities and separation efficiencies in five different hydrocyclones were investigated in depth. The results showed that both the pressure drop and the tangential velocities of Type C and Type E hydrocyclones were higher than that of Type A hydrocyclone, while the pressure drop of Type B and Type D hydrocyclones was lower than that of Type A hydrocyclone. Under a higher pressure, fine particles moved toward the center more easily, thereby leading to the decreasing number of dislocated particles. Compared with conventional straight-line tapered segment, the combination-type tapered segment exhibited smaller axial velocity, which prolonged the retention time of particles in the hydrocyclone and contributed to full particle separation. The turbulence intensity can be weakened by changing the tapered-segment structure. The turbulence intensity in Type D hydrocyclone was lowest among the five hydrocyclones. In addition, the separation performance of hydrocyclones can also be enhanced by changing the structural form of the tapered segment. Type B hydrocyclone was featured by favorable separation performance and Type D hydrocyclone exhibited a small cutting size. [ABSTRACT FROM AUTHOR]

Most cold-climate biological nutrient removal facilities experience poor settling mixed liquor during winter, resulting in treatment capacity throughput limitations. The Metro Wastewater Reclamation District in Denver, Colorado, operated two full-scale secondary treatment trains to compare the existing biological nutrient removal configuration (Control) to one that was modified to operate with an anaerobic selector and with hydrocyclone selective wasting (Test) to induce granulation. Results from this evaluation showed that the Test achieved significantly better settling behaviour than the Control. The difference in the mean diluted SVI30 between the Test and Control were statistically significant (P < 0.05), with values of 77 ± 17 and 135 ± 25 mL/g observed for the Test and Control respectively. These settling results were accompanied by differences in the particle size distribution, with notably higher settling velocities commensurate with increasing particle size. The degree of granulation observed in the Test train was between 32 and 56% of the mass greater than ≥250 μm in particle size whereas 16% of the mixed liquor in the Control was ≥250 μm over the entire study period. The improved settling behaviour of the Test configuration may translate into an increase of secondary treatment capacity during winter by 32%. HIGHLIGHTS Inducing granulation in a full-scale continuous flow activated sludge system was possible with the application of both biological and physical selection pressures.; Observations in this study could translate to a cost effective intensification solution versus traditional expansion for WRRFs evaluating capacity needs.;

ABSTRACT Technologies associated with the use of a membrane bioreactor (MBR) is becoming one of the dynamically developing directions in the wastewater disposal system. However, a certain part of the used design of membrane units are exposed to mechanical contamination, which significantly impairs their performance. This is especially noticeable when working at wastewater treatment plants, where the required degree of preliminary cleaning from solid mechanical particles and suspended solids is not provided. The purpose of the work is to improve the process of post-treatment of urban wastewater and protect the membrane element of the installation from clogging with coarse impurities and wear, with an overestimated concentration of suspended solids. The essence of the improved membrane technology of wastewater treatment consists in the preliminary capture of heavy and suspended particles with a size of more than 0.03 microns in a hydrocyclone, followed by water treatment in a chamber of a membrane bioreactor of modern design. The operating conditions of the membranes were determined by the operating modes and parameters of the bioreactor, in particular, by the degree of formation of colloidal compounds in it, which adversely affect the permeability. The density of the initial water varied within 1.059 - 1.078 g / cm³, and the content of solid particles was up to 0.3 mm. activated sludge was filtered under vacuum on a Buchner funnel through a thin layer of cotton wool and gauze. During the tests, the indicators for capturing suspended solids were 5.0 - 9.0 mg / dm³, while, when working without a hydrocyclone, they were equal to 27 - 30 mg / dm³. The maximum performance of the hydrocyclone is provided at an inlet pressure of 225-300 kPa, and the pressure loss in the hydrocyclone chamber is 7.9 - 9.0 kPa.. It has been established that additional preparation of waste water for the post-treatment process using a hydrocyclone increases the cleaning capacity of membrane elements by reducing the load of accumulation of coarse impurities on the membrane surface.

Production of chemical pulp is accompanied by various impurities in addition to the cellulose fibres produced. The impurities are mainly due to lignin fragments and wood resin components in the wood. The possibility of removing impurities such as fines and extractives at the early production stages by hydrocyclone fractionation was investigated.A sample of unbleached eucalyptus chemical pulp was fractionated using a hydrocyclone at feed consistencies of 0.1% to 1.0% and mass reject rates of 5% to 41%. Fractionation efficiency was assessed by measuring changes in consistency, Canadian Standard Freeness, fibre morphology, and extractives (wood resin) in the fibres.It was found that fractionating at consistencies of 0.6 - 1.0% at mass reject rates of 5 – 20% produced acceptable fractionation, with simultaneous removal of extractives associated with fibre fines.Fractionation of unbleached chemical pulps under these conditions could produce chemical pulps with enhanced bleaching and further processing properties.

• Health state assessment and remaining useful life prognostic of hydrocyclone • Augmenting degradation sequences by fusing mechanism modeling and TimeGAN learning • A unified framework for constructing and clustering degradation health indicators • Quantifying prediction uncertainty of remaining useful life of equipment Deploying health state (HS) assessment and remaining useful life (RUL) prognostic on the industrial equipment can effectively avoid shutdown and reduce productivity losses. This paper proposes a temporal self-clustering (TSC) and time-series generative adversarial network (TimeGAN) based uncertainty-aware health prognostic algorithm for the hydrocyclone, a critical machine in the mineral processing. To label the HS of degradation data, an autoencoder based TSC algorithm is proposed. It integrates the extraction and clustering of health indicators into a unified framework, so that the correlation information between feature extraction and clustering can be captured for cluster analysis. A Benders decomposition based optimization approach is designed to synthetically optimize network weights and clustering centers, thereby extracting and labeling data features more reasonably. For quantifying prediction uncertainty, an uncertainty-aware prognostic algorithm is proposed to predict the RUL distribution, and the uncertainty can be quantified as the standard deviation (Std) of the distribution. Furthermore, a mechanism and TimeGAN fusion temporal sequence generation algorithm is proposed to augment the degradation process sequences of the equipment. Verification experiments using the actual data show that the proposed algorithm can effectively evaluate the HS of the equipment and provide a sensible and convincing RUL prediction. [ABSTRACT FROM AUTHOR]