The Experts below are selected from a list of 66135 Experts worldwide ranked by ideXlab platform
Hideto Yoshida - One of the best experts on this subject based on the ideXlab platform.
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design of novel hydrocyclone for improving fine Particle Separation using computational fluid dynamics
Chemical Engineering Science, 2013Co-Authors: Kuoje Hwang, Yawe Hwang, Hideto YoshidaAbstract:Abstract Several novel hydrocyclones are designed to improve fine Particle Separation using computational fluid dynamics. The effects of inlet size, number of inlets and top-plate types on the Particle Separation efficiency and cut-size sharpness are discussed based on the same feed flow rates. The fluid and Particle flows are simulated using a segregated, steady-state, 3-dimensional implicit numerical solver supplied by FLUENT software. The governing equations are coupled using the SIMPLE algorithm, while the Reynolds stress model is employed for the hydrocyclone turbulent model due to its' anisotropic nature. Particle trajectories are simulated based on a Lagrangian frame considering the continuous phase interactions. The simulated Particle Separation efficiencies approximately agree with the available experimental data. The results show that increasing the inlet number and narrowing the inlet width are effective ways to improve the Particle Separation efficiency due to the increase in fluid velocity in the cylindrical parts of hydrocyclone. A cone-shaped top-plate reduces the fine Particle circulation area near the outer surface of overflow conduit, significantly improving the Separation efficiency of fine Particles. However, increasing the cone angle has a contrary effect because of the decrease in Particle residence time. Although installing an extra guide-channel from the inlet may also improve the fine Particle Separation efficiency, it is not effective for Particle classification because of reduced Particle cut-size sharpness.
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effect of apex cone shape and local fluid flow control method on fine Particle classification of gas cyclone
Chemical Engineering Science, 2013Co-Authors: Hideto YoshidaAbstract:Abstract The purpose of this report is to study the effects of apex cone shape and local fluid flow control method on Particle Separation performance of gas-cyclones. New type of dry cyclone with the movable apex cone which is covered with special shaped ring indicated cut size movement from 2 to 40 μm. By use of the apex cone at the inlet of dust box, it is possible to decrease the fluid velocity component in the dust box and to reduce the re-entrainment of Particles from the dust box. The cut size indicated the minimum value for the specific height of the apex cone. The optimum apex cone height was found for each inlet velocity. It is found that the optimum apex cone angle is 70 deg. The minimum 50% cut size was obtained by use of this apex cone angle. From the flow visualization method by use of soap foam, the upward flow and downward flow coexisted on the surface of this special apex cone. The clear interface between upward flow and downward flow was detected on the apex cone angle of 70 deg. The effect of secondary flow injection method on Particle Separation was also examined. It is found that Particle collection efficiency increased with an increased secondary flow rate and number of secondary flow injection in the upper cylindrical part of the cyclone. The new optimum injection method was proposed in this study. The Particle Separation performance and flow visualization results qualitatively supported the 3-dimensional CFD simulation based on the direct method.
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improvement of Particle Separation efficiency by installing conical top plate in hydrocyclone
Powder Technology, 2012Co-Authors: Kuoje Hwang, Hideto Yoshida, Yawe Hwang, Kazuha ShigemoriAbstract:Abstract The improvement of Particle Separation efficiency in a 20-mm hydrocyclone by installing a conical top-plate is studied. The effects of top-plate cone angle on the fluid velocity distributions and Particle trajectories are discussed using computational fluid dynamics. Conical top-plate installation could effectively reduce the low velocity regions near the outer vortex finder surface. Increasing the cone angle will decrease the cross-sectional area of downward flow in the upper cylindrical part, decrease the circulation flow and therefore increase the tangential velocity and centrifugal effect near the hydrocyclone wall. Particle trajectories are simulated based on a Lagrangian frame by considering the interactions with continuous phase once the fluid velocity distributions are known. Quicker Particle collection is induced into the underflow by installing a conical top-plate. However, too quick downward flow may increase the possibility of Particle entraining into the secondary vortex in the conical part under a given underflow ratio. The calculated values of Particle Separation efficiency are compared with the available experimental data to verify numerical method accuracy. The simulated results agree fairly well with the experimental data. It can be concluded that installing a conical top-plate is beneficial for improving Particle Separation efficiency. The optimum cone angle design is 30°.
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effect of apex cone shape on fine Particle classification of gas cyclone
Powder Technology, 2010Co-Authors: Hideto Yoshida, Kunihiro Fukui, Yusuke Nishimura, Tetsuya YamamotoAbstract:Abstract The purpose of this paper is to study the effects of apex cone shape on Particle Separation performance of gas-cyclones by experiment and CFD studies. It is found that the optimum apex cone angle is 70°. The minimum 50% cut size was obtained by use of this special apex cone. From the flow visualization method by use of soap foam, the upward flow and downward flow coexisted on the surface of this special apex cone. The clear interface between upward flow and downward flow was detected on the apex cone angle of 70°. The effect of the apex cone angle on Particle Separation performance decreases under high inlet velocity conditions, because most Particles are moving in the area away from the apex cone. The Particle Separation performance and flow visualization results qualitatively supported the 3-dimensional CFD simulation based on the direct method.
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Particle Separation performance by use of electrical hydro cyclone
Separation and Purification Technology, 2006Co-Authors: Hideto Yoshida, Kunihiro Fukui, Wongsarivej Pratarn, Wiwut TanthapanichakoonAbstract:Abstract A special electrical hydro-cyclone is developed and tested. In the underflow collection box of the hydro-cyclone, it has a central metal rod electrode and a cylindrical metal wall between which the desired DC electrical potential or no potential is applied. Effect of central rod diameter and length on Separation cut size was examined. The aqueous suspensions of silica Particles with a median diameter of 754 nm were tested using a 20 mm-diameter hydro-cyclone without underflow. It was found that the zeta potential of Particles increased proportionally with the value of pH. The electrical potential exhibits a stronger effect when the suspension indicates high pH value. The cut size decreases with the increase of initial pH values. This result is due to the increased negative zeta potential under high pH condition and negatively charged Particles are easily collected by electrostatic force. The cut size decreases with the increase of electrode diameter. The cut size becomes smallest under high pH, large electrode diameter and long electrode length conditions. For the negatively charged Particles, the center electrode should be negative polarity and outer cylindrical wall should be positive. By use of the electrostatic force, the cut size decreases about 9.2% smaller compared to the standard case without electrostatic force.
Xiangchun Xuan - One of the best experts on this subject based on the ideXlab platform.
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charge based Separation of Particles and cells with similar sizes via the wall induced electrical lift
Electrophoresis, 2017Co-Authors: Cory Thomas, Xinyu Lu, Andrew Todd, Yash Raval, Tzuenrong J Tzeng, Yongxin Song, Junsheng Wang, Dongqing Li, Xiangchun XuanAbstract:The Separation of Particles and cells in a uniform mixture has been extensively studied as a necessity in many chemical and biomedical engineering and research fields. This work demonstrates a continuous charge-based Separation of fluorescent and plain spherical polystyrene Particles with comparable sizes in a ψ-shaped microchannel via the wall-induced electrical lift. The effects of both the direct current electric field in the main-branch and the electric field ratio in between the inlet branches for sheath fluid and Particle mixture are investigated on this electrokinetic Particle Separation. A Lagrangian tracking method based theoretical model is also developed to understand the Particle transport in the microchannel and simulate the parametric effects on Particle Separation. Moreover, the demonstrated charge-based Separation is applied to a mixture of yeast cells and polystyrene Particles with similar sizes. Good Separation efficiency and purity are achieved for both the cells and the Particles.
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elasto inertial pinched flow fractionation for continuous shape based Particle Separation
Analytical Chemistry, 2015Co-Authors: Xiangchun XuanAbstract:Shape is an important passive marker in label-free Particle and cell Separation for chemical, biomedical, and environmental applications. We demonstrate herein a continuous-flow shape-based Separation of spherical and peanut-shaped rigid Particles of equal volume (or equivalent spherical diameter) via elasto-inertial pinched flow fractionation (eiPFF). This microfluidic technique exploits the shape dependence of the flow-induced elasto-inertial lift (and hence the cross-stream migration) in viscoelastic fluids to increase the displacement of a sheath flow-focused Particle mixture for a high-purity Separation. The parametric effects on this shape-based Particle Separation via eiPFF are systematically investigated in terms of five dimensionless numbers. It is found that the Separation is strongly affected by the flow rate, fluid elasticity, and channel aspect ratio. Interestingly, the elasto-inertial deflection of the peanut Particles can be either greater or smaller than that of equally volumed spherical Particles. This phenomenon is speculated to correlate with the rotational effects of peanut Particles.
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continuous microfluidic Particle Separation via elasto inertial pinched flow fractionation
Analytical Chemistry, 2015Co-Authors: Xiangchun XuanAbstract:Many of the fluids encountered in chemical and biomedical applications exhibit non-Newtonian behavior. However, the majority of current Particle Separation methods have been demonstrated in Newtonian fluids only. This work presents an experimental study of continuous Particle Separation in viscoelastic solutions via a combined action of elastic and inertial lift forces, which we term elasto-inertial pinched flow fractionation (eiPFF). The parametric effects on eiPFF are systematically investigated in terms of dimensionless numbers. It is found that eiPFF offers much higher Particle throughput and Separation resolution than the traditional steric effects-based PFF. Moreover, eiPFF works most efficiently when the Reynolds number, Re, is of order 1 and hence fills perfectly into the gap of our recently proposed inertia-enhanced PFF (iPFF) technique (Anal. Chem. 2015, 87, 4560−4565) that favors Re of the order 10 or more. However, the Particle Separation via eiPFF does not increase monotonically with the elas...
German Drazer - One of the best experts on this subject based on the ideXlab platform.
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electrokinetically driven deterministic lateral displacement for Particle Separation in microfluidic devices
Microfluidics and Nanofluidics, 2015Co-Authors: Srinivas Hanasoge, Raghavendra Devendra, F J Diez, German DrazerAbstract:An electrokinetically driven deterministic lateral displacement device is proposed for the continuous, two-dimensional fractionation of suspensions in microfluidic platforms. The suspended species are driven through an array of regularly spaced cylindrical posts by applying an electric field across the device. We explore the entire range of orientations of the driving field with respect to the array of obstacles and show that, at specific forcing angles, Particles of different size migrate in different directions, thus enabling continuous, two-dimensional Separation. We discuss a number of features observed in the motion of the Particles, including directional locking and sharp transitions between migration angles upon variations in the direction of the force, that are advantageous for high-resolution two-dimensional Separation. A simple model based on individual Particle–obstacle interactions accurately describes the migration angle of the Particles depending on the orientation of the driving field and can be used to reconfigure the electric field depending on the composition of the samples.
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electrokinetically driven deterministic lateral displacement for Particle Separation in microfluidic devices
arXiv: Fluid Dynamics, 2014Co-Authors: Srinivas Hanasoge, Raghavendra Devendra, Javier F Diez, German DrazerAbstract:An electrokinetically-driven deterministic lateral displacement (e-DLD) device is proposed for the continuous, two-dimensional fractionation of suspensions in microfluidic platforms. The suspended species are driven through an array of regularly spaced cylindrical posts by applying an electric field across the device. We explore the entire range of orientations of the driving field with respect to the array of obstacles and show that, at specific forcing-angles, Particles of different size migrate in different directions, thus enabling continuous, two-dimensional Separation. We discuss a number of features observed in the kinetics of the Particles, including directional locking and sharp transitions between migration angles upon variations in the direction of the force, that are advantageous for high-resolution two-dimensional Separation. A simple model based on individual Particle-obstacle interactions accurately describes the migration angle of the Particles depending on the orientation of the driving field, and can be used to re-configure driving field depending on the composition of the samples.
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gravity driven deterministic lateral displacement for Particle Separation in microfluidic devices
Analytical Chemistry, 2012Co-Authors: Raghavendra Devendra, German DrazerAbstract:We investigate the two-dimensional continuous size-based Separation of suspended Particles in gravity-driven deterministic lateral displacement (g-DLD) devices. The suspended Particles are driven through a periodic array of cylindrical obstacles under the action of gravity. We perform experiments covering the entire range of forcing orientations with respect to the array of obstacles and identify specific forcing angles that would lead to vector Separation, in which different Particles migrate, on an average, in different directions. A simple model, based on the lateral displacement induced on the trajectory of a Particle by irreversible Particle–obstacle interactions, accurately predicts the dependence of the migration angle on the forcing direction. The results provide design guidance for the development of g-DLD devices. We observe directional locking, which strongly depends on the size of the Particle and suggests that relatively small forcing angles are well suited for size-fractionation purposes. We...
Kuoje Hwang - One of the best experts on this subject based on the ideXlab platform.
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design of novel hydrocyclone for improving fine Particle Separation using computational fluid dynamics
Chemical Engineering Science, 2013Co-Authors: Kuoje Hwang, Yawe Hwang, Hideto YoshidaAbstract:Abstract Several novel hydrocyclones are designed to improve fine Particle Separation using computational fluid dynamics. The effects of inlet size, number of inlets and top-plate types on the Particle Separation efficiency and cut-size sharpness are discussed based on the same feed flow rates. The fluid and Particle flows are simulated using a segregated, steady-state, 3-dimensional implicit numerical solver supplied by FLUENT software. The governing equations are coupled using the SIMPLE algorithm, while the Reynolds stress model is employed for the hydrocyclone turbulent model due to its' anisotropic nature. Particle trajectories are simulated based on a Lagrangian frame considering the continuous phase interactions. The simulated Particle Separation efficiencies approximately agree with the available experimental data. The results show that increasing the inlet number and narrowing the inlet width are effective ways to improve the Particle Separation efficiency due to the increase in fluid velocity in the cylindrical parts of hydrocyclone. A cone-shaped top-plate reduces the fine Particle circulation area near the outer surface of overflow conduit, significantly improving the Separation efficiency of fine Particles. However, increasing the cone angle has a contrary effect because of the decrease in Particle residence time. Although installing an extra guide-channel from the inlet may also improve the fine Particle Separation efficiency, it is not effective for Particle classification because of reduced Particle cut-size sharpness.
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improvement of Particle Separation efficiency by installing conical top plate in hydrocyclone
Powder Technology, 2012Co-Authors: Kuoje Hwang, Hideto Yoshida, Yawe Hwang, Kazuha ShigemoriAbstract:Abstract The improvement of Particle Separation efficiency in a 20-mm hydrocyclone by installing a conical top-plate is studied. The effects of top-plate cone angle on the fluid velocity distributions and Particle trajectories are discussed using computational fluid dynamics. Conical top-plate installation could effectively reduce the low velocity regions near the outer vortex finder surface. Increasing the cone angle will decrease the cross-sectional area of downward flow in the upper cylindrical part, decrease the circulation flow and therefore increase the tangential velocity and centrifugal effect near the hydrocyclone wall. Particle trajectories are simulated based on a Lagrangian frame by considering the interactions with continuous phase once the fluid velocity distributions are known. Quicker Particle collection is induced into the underflow by installing a conical top-plate. However, too quick downward flow may increase the possibility of Particle entraining into the secondary vortex in the conical part under a given underflow ratio. The calculated values of Particle Separation efficiency are compared with the available experimental data to verify numerical method accuracy. The simulated results agree fairly well with the experimental data. It can be concluded that installing a conical top-plate is beneficial for improving Particle Separation efficiency. The optimum cone angle design is 30°.
Raghavendra Devendra - One of the best experts on this subject based on the ideXlab platform.
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electrokinetically driven deterministic lateral displacement for Particle Separation in microfluidic devices
Microfluidics and Nanofluidics, 2015Co-Authors: Srinivas Hanasoge, Raghavendra Devendra, F J Diez, German DrazerAbstract:An electrokinetically driven deterministic lateral displacement device is proposed for the continuous, two-dimensional fractionation of suspensions in microfluidic platforms. The suspended species are driven through an array of regularly spaced cylindrical posts by applying an electric field across the device. We explore the entire range of orientations of the driving field with respect to the array of obstacles and show that, at specific forcing angles, Particles of different size migrate in different directions, thus enabling continuous, two-dimensional Separation. We discuss a number of features observed in the motion of the Particles, including directional locking and sharp transitions between migration angles upon variations in the direction of the force, that are advantageous for high-resolution two-dimensional Separation. A simple model based on individual Particle–obstacle interactions accurately describes the migration angle of the Particles depending on the orientation of the driving field and can be used to reconfigure the electric field depending on the composition of the samples.
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electrokinetically driven deterministic lateral displacement for Particle Separation in microfluidic devices
arXiv: Fluid Dynamics, 2014Co-Authors: Srinivas Hanasoge, Raghavendra Devendra, Javier F Diez, German DrazerAbstract:An electrokinetically-driven deterministic lateral displacement (e-DLD) device is proposed for the continuous, two-dimensional fractionation of suspensions in microfluidic platforms. The suspended species are driven through an array of regularly spaced cylindrical posts by applying an electric field across the device. We explore the entire range of orientations of the driving field with respect to the array of obstacles and show that, at specific forcing-angles, Particles of different size migrate in different directions, thus enabling continuous, two-dimensional Separation. We discuss a number of features observed in the kinetics of the Particles, including directional locking and sharp transitions between migration angles upon variations in the direction of the force, that are advantageous for high-resolution two-dimensional Separation. A simple model based on individual Particle-obstacle interactions accurately describes the migration angle of the Particles depending on the orientation of the driving field, and can be used to re-configure driving field depending on the composition of the samples.
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gravity driven deterministic lateral displacement for Particle Separation in microfluidic devices
Analytical Chemistry, 2012Co-Authors: Raghavendra Devendra, German DrazerAbstract:We investigate the two-dimensional continuous size-based Separation of suspended Particles in gravity-driven deterministic lateral displacement (g-DLD) devices. The suspended Particles are driven through a periodic array of cylindrical obstacles under the action of gravity. We perform experiments covering the entire range of forcing orientations with respect to the array of obstacles and identify specific forcing angles that would lead to vector Separation, in which different Particles migrate, on an average, in different directions. A simple model, based on the lateral displacement induced on the trajectory of a Particle by irreversible Particle–obstacle interactions, accurately predicts the dependence of the migration angle on the forcing direction. The results provide design guidance for the development of g-DLD devices. We observe directional locking, which strongly depends on the size of the Particle and suggests that relatively small forcing angles are well suited for size-fractionation purposes. We...
