The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
M. C. Hong - One of the best experts on this subject based on the ideXlab platform.
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Radial Flow rapid pressure swing adsorption
Adsorption, 1995Co-Authors: A. S. T. Chiang, M. C. HongAbstract:A new PSA process has been proposed and experimentally verified. This process was operated with a Radial Flow geometry under a cycle time less than 30 seconds. It has been showed that enriched oxygen could be produced when air was fed inward. The same system showed virtually no separation effect if the feed direction was reversed. The change of separation efficiency upon Flow reversal was most significant when small adsorbent particles were employed. A ø 200×75 mm annular packing with 3 µm particles of zeolite 5A was able to produce 60% purity oxygen from air. The effect of Flow direction on system performance confirmed the importance of Flow resistance distribution. In Radial Flow geometry, most of the Flow resistance was located near the center of the disk. The relative small pressure gradient at the feed end enabled a better absorbent utilization during the inward feed step, and a more effective desorption during the vent step. The same principle could be extended to other geometric configurations.
S.l. Dixon - One of the best experts on this subject based on the ideXlab platform.
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Radial-Flow Gas Turbines
Fluid Mechanics and Thermodynamics of Turbomachinery, 2013Co-Authors: S.l. Dixon, C.a. HallAbstract:The chapter discusses the concept of a Radial Flow turbine that is used for producing hydraulic power. It discusses mainly two types of Radial Flow turbines—the inward Flow Radial Flow (IFR) and outward Flow gas turbines. The IFR turbine covers tremendous ranges of power, rates of mass Flow, and rotational speeds, from very large outwards turbines used in hydroelectric power for the generation of hundreds of megawatts down to tiny closed cycle gas turbines for the space power generation of a few kilowatts. The IFR gas turbine continues to be used extensively for powering automotive turbo charges, aircraft auxiliary power units, and expansion units in gas liquefaction. Over a limited range of specific speed, IFR turbines provide efficiency about equal to that of the best axial-Flow turbines. The significant advantages offered by the IFR turbine compared with the axial-Flow turbine are the greater amount of work that can be obtained per stage, the ease of manufacture, and its superior ruggedness. Different types of inward turbines are also discussed in this chapter, along with the optimum design selection of IFR turbines including factors such as nozzle blade row boundary layers, rotor passage boundary layers, disc wind age, and kinetic energy loss at exit.
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Chapter 8 – Radial Flow Gas Turbines
Fluid Mechanics and Thermodynamics of Turbomachinery, 2010Co-Authors: S.l. DixonAbstract:Publisher Summary The chapter discusses the concept of a Radial Flow turbine that is used for producing hydraulic power. It discusses mainly two types of Radial Flow turbines—the inward Flow Radial Flow (IFR) and outward Flow gas turbines. The IFR turbine covers tremendous ranges of power, rates of mass Flow, and rotational speeds, from very large outwards turbines used in hydroelectric power for the generation of hundreds of megawatts down to tiny closed cycle gas turbines for the space power generation of a few kilowatts. The IFR gas turbine continues to be used extensively for powering automotive turbo charges, aircraft auxiliary power units, and expansion units in gas liquefaction. Over a limited range of specific speed, IFR turbines provide efficiency about equal to that of the best axial-Flow turbines. The significant advantages offered by the IFR turbine compared with the axial-Flow turbine are the greater amount of work that can be obtained per stage, the ease of manufacture, and its superior ruggedness. Different types of inward turbines are also discussed in this chapter, along with the optimum design selection of IFR turbines including factors such as nozzle blade row boundary layers, rotor passage boundary layers, disc wind age, and kinetic energy loss at exit.
Gerard Bois - One of the best experts on this subject based on the ideXlab platform.
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Rotating instability in the vaneless diffuser of a Radial Flow pump
Journal of Thermal Science, 2008Co-Authors: Antoine Dazin, Sophie Coudert, Olivier Coutier-delgosha, Patrick Dupont, Guy Caignaert, Gerard BoisAbstract:The paper refers to the behavior of a vaneless diffuser of a Radial Flow pump in partial Flow operating conditions. Some experimental data have been obtained using 2D/2C PIV and unsteady pressure measurements within the diffuser, in various operating conditions. The experimental results at the lower Flow rate are compared with two-dimensional numerical calculations.
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transient behavior of turbomachineries applications to Radial Flow pump startups
Journal of Fluids Engineering-transactions of The Asme, 2007Co-Authors: Antoine Dazin, Guy Caignaert, Gerard BoisAbstract:A theoretical analysis of the fast transients of turbomachineries, based on the study of unsteady and incompressible fluids mechanics equations applied to an impeller, is proposed. It leads to internal torque, internal power, and impeller head of an impeller during transient periods. The equations show that the behavior of a pump impeller is not only depending on the acceleration rate and Flow rate, as it is usually admitted, but also on velocity profiles and their evolution during the transient. Some hypotheses on the Flow in a Radial Flow pump are proposed. They are validated by comparison with the experimental results of a single stage, single volute Radial Flow pump during some fast acceleration periods. The model is also used to analyze the behavior of the pump during a fast startup.
George T. Tsao - One of the best experts on this subject based on the ideXlab platform.
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Multicomponent Radial Flow chromatography
Advances in Biochemical Engineering \ Biotechnology, 2015Co-Authors: Gow-jen Tsai, George T. TsaoAbstract:Radial Flow chromatography (RFC) was introduced into the commercial market in the mid-1980s [1] as an alternative to the conventional axial Flow chromatography (AFC) for preparative- and large-scale applications. Figure 14.1 shows a schematic of an RFC column with inward Radial Flow. Compared to AFC, the RFC geometry in Fig. 14.2 provides a relatively large Flow area and a short Flow path. It allows a higher volumetric Flow rate with a lower bed pressure compared to longer AFC columns. If soft gels or affinity matrix materials are used as separation media, the low-pressure drop of RFC helps prevent bed compression [2, 3]. An experimental case study of the comparison of RFC and AFC was carried out by Saxena and Weil [4] for the separation of ascites using the QAE cellulose packing. They reported that by using a higher Flow rate, the separation time for RFC was one-fourth of that needed for a longer AFC column with the same bed volume. It was claimed that by using RFC instead of AFC, separation productivity can be improved quite significantly [1]. Lay et al. tested and modeled a continuous RFC system for protein separation [5]. Recently, Yan et al. successfully used a commercially available 500-mL RFC column packed with ion-exchange resins to separate antiproliferative polysaccharides from Hypsizigus marmoreus. Numerous other experimental studies have also been reported using RFC columns. Both prepacked and unpacked RFC columns, with a size range from 50 mL to 200 L in bed volume, are commercially available. A comprehensive review was provided by Gu in 2013 [6].
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A theoretical study of multicomponent Radial Flow chromatography
Chemical Engineering Science, 2001Co-Authors: Gow-jen Tsai, George T. TsaoAbstract:A theoretical study of Radial Flow chromatography was carried out based on a general nonlinear multicomponent rate model which considers Radial dispersion. external mass transfer, intraparticle diffusion. and nonlinear multicomponent isotherms. Radial dispersion and mass transfer coefficients were treated as variables which are dependent on the Radial coordinate of the Radial Flow column. The model was solved numerically by using the finite element method and the orthogonal collocation method for the discretization of partial differential equations and Gear's stiff method for the solution of the resulting ordinary differential equation system. Computer simulations were carried out for various multicomponent chromatographic operations. Dispersion and mass transfer effects were investigated. The question of whether Radial dispersion and mass transfer coefficients should be treated as variables was discussed. The difference between inward Flow and outward Flow in Radial Flow chromatography and the comparison between conventional axial Flow chromatography and Radial Flow chromatography were studied. Langmuir isotherms were used in this work.
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Multicomponent affinity Radial Flow chromatography
Separations Technology, 1992Co-Authors: Gow-jen Tsai, George T. TsaoAbstract:Abstract Radial Flow chromatography can provide high volumetric Flow rates with small bed pressures. It is advantageous for use in affinity chromatography in which resolution requirements can be easily achieved because of highly selective biospecific binding. In this work a general multicomponent kinetic rate model has been formulated for the simulation of various aspects of Radial Flow affinity chromatography. The model accounts for Radial dispersion, external mass transfer, intraparticle diffusion, second-order kinetics, and reactions between soluble ligands and the macromolecules in the elution stage of affinity chromatography. The model is solved with an efficient and robust numeric procedure that uses the finite element, the orthogonal collocation, and the Gear's stiff methods. Kinetic effects have been studied and compared with mass transfer effects. The three stages of affinity chromatography—frontal adsorption, wash, and elution—have been simulated. The effects of the concentration and the affinity of the soluble ligands used in the elution stage have been discussed.
Alexander J. White - One of the best experts on this subject based on the ideXlab platform.
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A comparison of Radial-Flow and axial-Flow packed beds for thermal energy storage☆
Applied Energy, 2017Co-Authors: Joshua D. Mctigue, Alexander J. WhiteAbstract:Packed-bed thermal reservoirs are an integral component in a number of electrical energy storage technologies. The present paper concentrates on packed beds where the heat transfer fluid travels along the Radial co-ordinate. The governing energy equations and various mechanisms that cause exergetic losses are discussed. The Radial-Flow packed bed is compared to a dimensionally similar axial-Flow packed bed. This approach provides a fair assessment of the underlying behaviour of the two designs. Multi-objective optimisation allows a wide range of design variables to be considered, and is employed to compare optimal Radial-Flow and axial-Flow stores. Axial-Flow stores that have been segmented into layers are also considered. The results indicate that Radial-Flow stores have a comparable thermodynamic performance, but that the additional volume required for by-pass Flows leads to higher capital costs.
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A comparison of Radial-Flow and axial-Flow packed beds for thermal energy storage
Energy Procedia, 2017Co-Authors: Joshua D. Mctigue, Alexander J. WhiteAbstract:Abstract A thermal energy storage system where heat is transferred to a cylindrical packed bed along the Radial coordinate is described. The governing energy equations and various mechanisms that cause exergetic losses are discussed. The Radial-Flow packed bed is compared to a dimensionally similar axial-Flow packed bed. A multi-objective optimisation of Radial-Flow and axial-Flow stores indicates that Radial-Flow stores have a comparable performance, but that the additional volume required for by-pass Flows leads to higher capital costs.
