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Dissertations / Theses on the topic 'Centrifugal separation'
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Gerger, Marcus. "Centrifugal Separation of 1-Methylnaphthalene." Thesis, KTH, Skolan för kemivetenskap (CHE), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-206732.
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In this report, modifications and experimental tests with an early stage test rig intended for producing a commercial solution to fractionating pyrolysis oil are described. The idea is to use centrifugal force to separate the formed aerosols from condensible gases with a lower volatility. A stacked disc centrifuge prototype built to work at high temperature was used. The experiment was done with a single component, 1-Methylnaphtalene (1-MN) to evaluate the functionality of the test rig. No separation was achieved, concluding that further work need to be done at different operating parameters with 1-Methylnaphtalene prior to including more components. The reason for the negative separation result is probably due to that the saturation ratio was to low resulting in that no aerosol was formed during the experiments. Further work includes improving the stability of the inlet stream to the centrifuge. Perform more experiments with other process parameters, recommendation is to decreasing the temperature at the inlet to the centrifuge to increase the saturation ratio. It is also suggested that an optical in situ measuring devise is added to the test rig to facilitate operation.
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Svensson, Anders. "Control Strategy in a Centrifugal Separation Process." Thesis, KTH, Reglerteknik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-105154.
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Ett nytt koncept för separering av jäst från öl har tagits fram på Alfa Laval i Tumba. Jästen matas nu ut kontinuerligt istället for att skjutas ut då separatorn har fyllts med för mycket jäst, konceptet gör att man kan spara öl som annars försvinner i samband med skott. För att konceptet skall vara lönsamt måste den utmatade jästen ha tillräckligt hög densitet trots att indensiteten ständigt sjunker, samtidigt som man måste ha bra separering. I det här examensarbetet har en reglerstrategi för denna höghastighets centrifugal separationsprocess utvecklats. Genom experimentella studier av systemet kunde en matematisk modell av separationsprocessen skapas. Modellen användes sedan som grund for en MPC-regulator där densiteten styrdes genom att styra flödena i processen. En implementering av styrningen genomfördes sedan i processlaboratoriet i Tumba. Separeringen antogs vara bra så länge massflödet in var relativt lågt och trycknivåerna var bra. Med MPC-regulatorn gick det att hålla densiteten över en satt gräns i laboratorieexperiment. Det visas också att en ervariabel regulator i det här fallet har fördelar över envariabla. Förutsättningar för att i ett nästa steg även reglera separeringseffektiviteten anses finnas.A new concept for separating yeast from beer has been developed at Alfa Laval in Tumba. The yeast is now continuously fed out from the separator instead of discharged when too much yeast have collected in the separator. The concept makes it possible to save beer which otherwise would have been wasted at discharges. For the concept to be protable, the density of out yeast must be high enough even though the inlet density is steadily declining, and at the same time have good separation eency. In this thesis a control strategy has been developed for this high speed centrifugal separation process. Through experimental studies a mathematical model of the separation process could be made. This model was then used for a MPC-controller where the density was controlled by controlling the ows of the process. An implementation of the control strategy was carried out in the process laboratory in Tumba. The separation was assumed to be good as long as the mass inow was relatively low and the pressure levels were steady. With the MPC-controller it was possible to maintain the density over the set limit in laboratory experiments. It is also shown that a multivariable controller has benets compared to a single variable controller. Controlling the separation efficiency is deemed possible and is the next step.
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Setford, S. J. "Combined bioreaction and separation in centrifugal fields." Thesis, Aston University, 1992. http://publications.aston.ac.uk/9781/.
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The aim of this work has been to investigate the principle of combined centrifugal bioreaction-separation. The production of dextran and fructose by the action of the enzyme dextransucrase on sucrose was employed to elucidate some of the principles of this type of process. Dextran is a valuable pharmaceutical product used mainly as a blood volume expander and blood flow improver whilst fructose is an important dietary product. The development of a single step process capable of the simultaneous biosynthesis of dextran and the separation of the fructose by-product should improve dextran yields whilst reducing capital and processing costs. This thesis shows for the first time that it is possible to conduct successful bioreaction-separations using a rate-zonal centrifugation technique. By layering thin zones of dextrasucrase enzyme onto sucrose gradients and centrifuging, very high molecular weight (MW) dextran-enzyme complexes were formed that rapidly sedimented through the sucrose substrate gradients under the influence of the applied centrifugal field. The low MW fructose by-product sedimented at reduced rates and was thus separated from the enzyme and dextran during the reaction. The MW distribution of dextran recovered from the centrifugal bioreactor was compared with that from a conventional batch bioreactor. The results indicated that the centrifugal bioreactor produced up to 100% more clinical dextran with MWs of between 12 000 and 98 000 at 20% w/w sucrose concentrations than conventional bioreactors. This was due to the removal of acceptor fructose molecules from the sedimenting reaction zone by the action of the centrifugal field. Higher proportions of unwanted lower MW dextran were found in the conventional bioreactor than in the centrifugal bioreactor-separator. The process was studied on a number of alternative centrifugal systems. A zonal rotor fitted with a reorienting gradient core proved most successful for the evaluation of bioreactor performance. Results indicated that viscosity build-up in the reactor must be minimised in order to increase the yields of dextran per unit time and improve product separation.
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Wang, Xuesong. "Numerical and experimental study of centrifugal fluidised bed separation." Thesis, University of Nottingham, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433995.
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Barimani, Mohammad. "Numerical simulation of particle separation in centrifugal air classifiers." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/56718.
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The demand for fine mineral powder in various industries has stimulated creative methods for separating the fine portion of particles from a mixture. Among the many different types of classifiers invented, centrifugal rotor air classifiers are characterized by their capability in producing ultra-fine products with a cut-size as low as 3um.
Classification occurs due to the size-dependence of aerodynamic and inertial forces acting on particles: coarse particles have a higher ratio of centrifugal force to aerodynamic drag than do fine particles, and therefore are preferentially ejected to the classifier perimeter. Therefore, the high speed rotor located inside the classifier is key to classification. Computational fluid dynamics (CFD) is utilized in this study to investigate the motion of calcium carbonate particles in a rotor classifier. The single phase flow in two- and three-dimensional models of the rotor is computed. Two turbulence models, namely K-Omega and RSM, are applied to close the Reynolds-averaged Navier-Stokes equations. Once the single phase flow has been computed the motion of solid particles is simulated using the Discrete Phase Model. This model ignores particle-particle interactions and the influence of the particles on the air flow. The motion of the particles is coupled to a statistical model of the turbulent velocity fluctuations. By tracking hundreds of particles, the efficiency for a variety of hypothetical classifiers is estimated. Though the CFD models, in comparison with experiments, cannot accurately predict the absolute cut-size values, they have proved effective in predicting cut-size shifts as a result of rotor geometry modification or alternative operating conditions. Based on these simulations two new rotors were built and the change in cut-size was predicted within 30% accuracy. Based on the paths of a large number of particles tracked in various operating conditions, regions in the rotor with very high particulate concentrations are identified. We speculate that this elevated concentration makes particle-particle interactions much more important than would be expected based on the feed concentration, which could in turn reduce the acceptance of the smallest particles.Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate
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Stein, Alexander. "Computational analysis of stall and separation control in centrifugal compressors." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/11884.
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Lycon, David Steven. "Flux enhancement and fouling reduction in a centrifugal membrane process." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0021/NQ44796.pdf.
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Surakitbanharn, Yosyong. "The efficient separation of platinum group metals using centrifugal partition chromatography." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/186074.
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Centrifugal Partition Chromatography (CPC) is a multistage liquid-liquid countercurrent distribution technique which utilizes rotating teflon cartridges to hold a liquid phase stationary while the other liquid phase is pumped at a constant flow rate. It has been demonstrated to be a valuable technique for the base line separations of families of metal ions such as the platinum group metals (PGM)--Pt, Pd, Rh and Ir. The separations of these metals as their anionic chloro complexes were achieved using the heptane-water phase pair with a stable and relatively inexpensive extractant trioctylphosphine oxide (TOPO) functioning as a ligand in its neutral form and as a cation in its protonated form. A striking feature of the chromatograms of the complexes and ion pairs were their much poorer efficiencies compared to the efficiency of an organic analyte like 3-picoline under identical distribution rations. The inefficiencies of the PGM separations were also a function of the concentrations of the aqueous and organic phase components. These inefficiencies could be attributed to slow kinetics of the back extraction of the complexes and ion pairs and could be used to derive the mechanisms of these slow chemical kinetic steps. A correlation was established for the Pd(II) system between the CPC inefficiencies and the half lives of the slow reactions measured independently by stopped flow in micelles. This correlation was utilized to derive the rate constants for the back extraction of the TOPO complexes and ion pairs of Pt and Ir. The mechanisms of the extraction reactions were derived using the principle of microscopic reversibility based on the mechanisms of the back extraction reactions. This was then used to obtain estimates for the rate constants for the extraction reactions as well. The PGM were thus separated and their equilibrium and kinetics (extraction and back extraction) completely characterized using CPC. This is a significant development with CPC because such complete equilibrium and kinetic characterizations are hard to achieve with conventional liquid chromatographic techniques.
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Bizard, Arnaud François Marie. "Design of conical centrifugal filters : an analytical approach." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609854.
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Hopmann, Elisabeth Anna [Verfasser]. "Development of a Centrifugal Partition Chromatographic Separation: from Molecule to Process / Elisabeth Anna Hopmann." München : Verlag Dr. Hut, 2013. http://d-nb.info/1035049996/34.
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Cherdieu, Patrick. "Contrôle du décollement dans un diffuseur aubé de turbomachine centrifuge." Thesis, Ecole centrale de Lille, 2013. http://www.theses.fr/2013ECLI0020/document.
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L'amélioration de la performance des turbomachines fonctionnant loin de leur point d'adaptation passe par la maîtrise des phénomènes instationnaires qui se produisent dans ces différents organes. L'étude présentée ici se concentre sur les interactions entre une roue de ventilateur centrifuge et son diffuseur. Elle vise, par des mesures de pression sur les différentes parois du diffuseur, ainsi que par des sondages dans les canaux inter-aubages à analyser finement ces phénomènes instationnaires et notamment les décollements fluctuants apparaissant sur les aubes à sur débit, et à mesurer leur influence sur la performance du diffuseur. Dans un second temps, un dispositif de contrôle passif de ces décollements utilisant des générateurs de vortex est proposé. Plusieurs configurations sont testés et leurs résultats sont comparésThe performance improvement of turbomachinery operating at off-design conditions can be achieved by the understanding of unsteady phenomena which are occuring in its components. The present study is focussing on the interaction between a centrifugal impeller fan and its vaned diffuser. It aims at analysing precisely these unsteady phenomena (and especially the fluctuating separated region identified on the vanes wall) and their consequences on the diffuser performance by three holes probe and unsteady pressure measurements. In a second step, devices for a passive control of the separation are introduced. Several configurations are tested and their results are compared
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Le, Sausse Paul. "Contribution à la modélisation de l’écoulement dans un compresseur centrifuge et développement de critères d’optimisation." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0105.
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Cette thèse est le fruit d’un partenariat entre la société Johnson Controls et l’université Bordeaux1. L’objectif s’inscrit dans le cadre d’un projet de développement de pompe à chaleur innovante et est de développer un compresseur centrifuge à haute compression. Pour ce faire, un modèle numérique a été créé afin de simuler l’écoulement dans ce type de compresseur. Afin de respecter des impératifs industriels, une première géométrie a été établie par modifications itératives de divers paramètres et analyse des performances induites. L’écoulement a ensuite été étudié plus précisément, particulièrement pour mieux comprendre l’apparition des décollements. Enfin, une étude instationnaire de l’écoulement dans le diffuseur a été effectuée. Au delà des phénomènes physiques étudiés et appréhendés au cours de ce processus, c’est avant tout une méthodologie qui valorise ce travailThis thesis is the result of a partnership between the company Johnson Controls and the university Bordeaux1. The objective is part of a project to develop innovative heat pump and involves the design of a high head centrifugal compressor. To do this, a numerical model is created to simulate the flow in this kind of compressor. To observe industriel deadlines, a first geometry was established by iterative changes of various parameters in analysing induced effiencies. The flow was then studied further, especially to better understand the onset of flow separation. Finally, a study of unsteady flow in the diffuser was performed. Beyond the physical phenomena investigated and comprehended during this process, it is firstly a methodology that values this work
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Bizzarri, Didier. "Compact air separation system for space launcher." Doctoral thesis, Universite Libre de Bruxelles, 2008. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210488.
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A compact air separator demonstrator based on centrifugally enhanced distillation has been studied. The full size device is meant to be used on board of a Two Stage To Orbit vehicle launcher. The air separation system must be able to extract oxygen in highly concentrated liquid form (LEA, Liquid Enriched Air) from atmospheric air. The LEA is stored before being used in a subsequent rocket propulsion phase by the second stage of the launcher. Two reference vehicles are defined, one with a subsonic first stage and one with a supersonic first stage. In both cases, oxygen collection is performed during a cruise phase (M 0.7 and M 2.5 respectively). The aim of the project is to demonstrate the feasibility of the air separation system, investigate the separation cycle design, and assess that the separator design selected is suitable for the reference vehicles.The project is described from original base ideas to design, construction, extended testing and analysis of experimental results. Preliminary computations for a realistic layout have been performed and the motivations for the choices made during the process are explained. Test rig design, separator design and technical discussion are provided for a subscale pilot unit. Mass transport parameters and flooding limits have been estimated and experimentally measured. Performance has been assessed and shown to be sufficient for the reference Two Stage To Orbit vehicles. The technology developed is found suitable without further optimization, although some volume and mass reduction would be desirable for the supersonic first stage concept. There are many ways of optimisation that can be further investigated. The aim of this program, however, is not to fully optimize the device, but to demonstrate that a device based on a simple, robust, low-risk design is already suitable for the launch vehicles. On top of that analysis, directions for improvements are suggested and their potentials estimated. A complete assessment of those improvements requires further maturation of the technological concept through further testing and practical implementations.
Directions for future work, general conclusions and a vehicle development roadmap have also been provided.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
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Dehaine, Quentin. "Récupération des Terres Rares (La, Ce, Nd) et métaux rares (Sn, Nb, W) à partir de résidus micacés issus de la production de kaolin." Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0019.
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Les granites à métaux rares ont une faible valeur économique mais sont souvent exploités pour leurs minéraux industriels. L’objectif de ce travail est d’évaluer la potentialité de certains résidus issus de la production de kaolin de St Austell (Angleterre) pour la récupération de métaux critiques (CRMs) comme les Terre Rares légères (LREE), le niobium (Nb), le tungstène (W) et l’étain (Sn) via le développement d’un procédé de récupération des CRMs. L’étude des résidus miniers montre que les CRM sont concentrés dans le résidu micacé avec des teneurs en LREE allant jusqu’à 170 ppm avec 40 à 60% des CRMs distribués dans ce résidu. Un procédé de traitement de ce résidu a été développé incluant des étapes de concentration par gravité et flottation. Les teneurs en LREE permettent la récupération d’environ 60% des LREE avec des teneurs de 1,6 % et 0,5% LREE respectivement dans le concentré de gravité et flottationRare metals granites have always been considered of poor economic value due to their low metal grades but, when altered, they are often exploited for their industrial minerals. This work address the recovery of critical metals (CRMs) including Light Rare Earth Elements (LREE) and rare metals (Sn, Nb, W) from St Austell (UK) kaolin residues though the development of a beneficiation process. Results shows that CRMs are pre-concentrated in the micaceous residue stream with LREE grades of 170 ppm, which account from 40% to 60% of the mass of CRM entering the plant. Analysis of this residue streams shows a high variability of CRM grades and suggest a cut-off grades for some of them. A combined gravity/flotation process have been developed for this residue which allow to recover up to 60% LREE with LREE grade of 1.6 to 0.5% for the gravity and flotation concentrate respectively
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Abtahi, Seyyed Mohammad Hossein. "Synthesis and characterization of metallic nanoparticles with photoactivated surface chemistries." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/78081.
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During recent decades metallic nanoparticles have been found very interesting due to their unique characteristics which make them suitable for different applications. In this research, for the very first time, we tried to perform selective surface photo activation chemistry on the targeted facets of nanoparticles while they are in suspension. This technique enabled us to form desired assemblies of nanoparticles. We focused on elongated shaped gold nanorod due to its unique surface plasmon resonance and probable biomedical applications. In this research we formed a dumbbell shape assembly of nanoparticles in suspension. A probable application for these assemblies can be in vivo imaging. Initially, we reproduced gold nanorods using existing techniques in prior papers and optimized them according to our research needs. A low rpm centrifugal separation technique was developed to efficiently separate synthesized gold nanorods from other shapes. Several characterization techniques were utilized to characterize nanoparticles at each step including UV-absorbance, zeta potential, and dynamic light scattering. Different generations of oligomers were synthesized to be used as gold nanorods coating, and each coating was tested and characterized using appropriate techniques. Our two-step coating replacement method using one of these photocleavable oligomers enabled us to achieve, for the very first time, selective UV photo activation of gold nanorod tips. The photo activated tips were then exposed to oppositely charged gold nanospheres to form dumbbell shape assemblies of gold nanorods and nanospheres. Furthermore, dumbbell shape assembly of nanoparticles was investigated and characterized.Master of Science
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Rand, Peter. "An investigation of the mode of operation of the Knelson concentrator." Thesis, University of Nottingham, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367155.
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Monsen, Gisle Otto Tviberg. "Modeling of a centrifugal separator for dispersed gas-liquid flows." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for energi- og prosessteknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18678.
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Natural gas is a vital component of the worlds’ supply of energy. In Norway all the gas can be found offshore where it needs to processed before transport. A vital part of the processing is gas and liquid separation. Current gas-liquid separators are big and expensive, and the offshore industry is looking for more compact separators. One of the more prominent technologies is the NNNGLseparator developed at NTNU. To further identify its possibilities, a thorough research program has been startedIn this thesis one-dimensional models describing pressure drop and separation performance of the NTNU Natural Gas Liquid Separator (NNGLseparator) for dispersed gas-liquid flows has been studied. Here modeling of separation performance was divided into cyclonic separation and droplet capture by the meshpad, and then combined in sequence. The droplet capture is assumed to occur before cyclonic separation.To analyze the impact of centrifugal force on droplet capture, the force was included in a previous proposed model describing droplet capture by a single fiber in the meshpad. With this as basis, modeling of total droplet capture for the meshpad was analyzed. Through this analysis we proposed an extension on the existing model for the case of the flow not following the rotation of the meshpad. The droplets that are not captured are then separated through cyclonic separation. To model this separation mechanism, a modified time of flight model was developed. The modification includes the mesh porosity, and a - factor describing the droplet’s reduced radial velocity due to the obstructing meshpad.Existing models for pressure drop across fixed porous media were compared to experimental data to identify which model best applies to the meshpad used in the NNGLseparator. How this model performs in describing a rotating porous media was then analyzed for the two scenarios; fully developed flow before mesh entry and developing flow inside a rotating meshpad. Through this analysis an extension to the pressure drop model was proposed, which includes the tangential velocity difference between rotating mesh and gas flow. A previous proposed model for pressure drop across wet mesh pad was reviewed. This led to a discussion on how liquid hold up differs in the NNGLseparator from conventional fixed meshpads. The proposed one-dimensional models were then analyzed through a parametric study of the separator performance in terms of pressure drop and efficiency of droplet separation for different flow conditions and geometries.
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MIGLIAVACCA, SYLVANA C. P. "Calculo dos parametros de separacao de uma centrifuga a contracorrente com variacao axial do fluxo interno." reponame:Repositório Institucional do IPEN, 1991. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10271.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Drogue, Sophie Christine. "La chromatographie liquide-liquide centrifuge : application a la separation de pristinamycines." Paris 6, 1992. http://www.theses.fr/1992PA066459.
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La chromatographie liquide-liquide centrifuge (cllc) ou counter-current chromatography (ccc) est une technique de separation dont le principe est proche de celui de la chromatographie en phase liquide (cpl) si ce n'est que la phase stationnaire solide est remplacee par un liquide. Une des phases d'un systeme de solvants biphasique est donc retenue dans une bobine de tube teflon grace a une force centrifuge, ce qui permet a l'autre phase d'etre pompee continument et d'eluer les solutes selon la valeur de leurs coefficients de partage. La premiere partie fait le point sur la cllc en presentant les differents appareils qui ont ete developpes, de la machine de craig aux appareils performants actuels ainsi que les applications correspondantes. La deuxieme partie, experimentale, concerne l'application de la cllc a la separation d'une famille d'antibiotiques, les pristinamycines. Une premiere etape a consiste a choisir un moyen de detection en ligne adapte a la presence de deux phases liquides non miscibles. Ensuite, a l'aide de la litterature sur les separations d'antibiotiques, un systeme de solvants biphasique offrant une retention de phase stationnaire dans l'appareil, une resolution et une selectivite suffisantes pour la separation des pristinamycines a ete mis au point. Pour debuter la comparaison avec la cpl preparative, les limites d'injection en quantite et en volume ont ete determinees pour des appareils analytique, semi-preparatif et preparatifs. Enfin, grace a un choix judicieux de methode de separation preparative adaptee a la cllc et aux pristinamycines, une comparaison entre la production de pristinamycine iib pure par cllc et par clhp preparative conventionnelle a ete etablie. Ainsi, nous montrons que la productivite et la purete du produit sont similaires avec ces deux techniques, mais le grand avantage de la cllc est son faible cout de fonctionnement
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Pérez, Montero Anna Maria. "Enantioselectivitat de derivats de prolina com a selectors quirals en cromatografia en contracorrent." Doctoral thesis, Universitat de Barcelona, 2012. http://hdl.handle.net/10803/96153.
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En les últimes dècades, el fenomen de l’enantioselectivitat ha adquirit una importància creixent per a la indústria farmacèutica a l’hora del desenvolupament de nous fàrmacs. Això és degut a la observació d’una diferent resposta per part de l’organisme en funció de l’estereoquímica de la molècula exògena administrada, ocasionada per l’elevada estereoselectivitat dels processos fisiològics. Diferents exemples es poden trobar a la literatura a partir del desastre produït pel fàrmac anomenat talidomida, en què es va responsabilitzar la forma S de l’efecte teratogen mentre s’assignà l’acció sedant a la R. Molts altres fàrmacs quirals presenten una dicotomia d’efecte pels enantiòmers. A mode d’exemple l’anestèsic prolocaïna presenta diferències d’activitat entre enantiòmers. En aquest cas la forma de configuració S posseix majoritàriament l’acció anestèsica, mentre que la R és responsable dels efectes tòxics del fàrmac, que pot produir metahemoglobinèmia.
Així, doncs, l’adiministració, i per tant la comercialització de fàrmacs enantiomèricmanet purs, simplifica aspectes farmacològics, farmacocinètics, terapèutics i toxicològics de l’acció dels fàrmacs. Altres avantatges que s’aconsegueixen amb aquest procedir són la disminució de la dosi de fàrmac requerida per a produir l’efecte desitjat i la menor variabilitat interpersonal de l’efecte produït per una determinada dosi.
Degut a la importància de l’administració de fàrmacs enantiomèricament purs, en el present treball s’estudia l’aplicació de la cromatografia en contracorrent (CPC/CCC) en la separació de mescles racèmiques. La CCC/CPC és una variant de la cromatografia líquida, en la què la fase mòbil i la fase estacionària estan formades per dos líquids immiscibles entre sí.
Així, s’han dissenyat i sintetitzat noves entitats quirals derivades de l’aminoàcid L-prolina. Una vegada caracteritzades, s’ha estudiat la seva aplicació en la separació de racèmics, a la vegada que s’ha estudiat el seu mecanisme d’enantioreconeixment per poder establir unes pautes a l’hora de dissenyar nous selectors quirals (SQ).
D’altra banda, la CCC/CPC al tractar-se d’una tècnica que es dona entre dos líquids immiscibles. S’ha estudiat l’aplicació de nous sistemes de dissolvents menys contaminats, com es el cas de l’etoxinonafluorobutà. Així, s’han construït diferents sistemes de dissolvents que contenen el dissolvent fluorat, a l’hora que s’han utilitzat SQs fluorats.Nowdays, the significance of the enantiomèric purity in the chiral active ingredients used in drug manufacture is well recognized. In addition, the strict regulations established by health authorities on the commercialisation of chiral drugs, has led to the requirement for analytical and preparative methods for enantioseparation. Although diverse procedures exist, chromatographic techniques are amongst the most used to resolve mixtures of enantiomers at a preparative level. In the present doctoral thesis we intend to study the enantioselectivity phenomena of L-proline derivatives as chiral selectors in countercurrent chromatography (CCC) using diferent solvent systems. CCC is an effective separation technique base don the differences in partitioning of solutes in a sample between two non-miscible solvents or solutions that constitute the solvent system. Therefore, the mobile and the stationary phases in the chromatographic process are liquids. The absence of a solid support opens a whole range of possibilities to apply alternative elution modes alternatives to the classic one. The exchange between mobile phase and stationary phase during the separation, that CCC only involves the change of a valve position, allows the dual and mutidual mode. Also, the application of ph-zone refining, a kind of displacement chromatography that involve the addition of a displacement agent in the mobile phase, has been evaluated in order to improve the separation of ionizable racemates. Finally, the evaluation of the enantioselectivite capacity of fluorinated solvents and chiral selectors has been tested in CCC and in liquid membranes.
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Wiik, Marianne, and Mikaela Sahlin. "Life Cycle Assessment : Life cycle assessment of a high speed centrifugal separator." Thesis, KTH, Industriell ekologi, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-32798.
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The main objective is to perform a life cycle assessment (LCA) on a hot milk high-speed centrifugal separator (HMRPX 918-HGV-74C, product number 881275 01 01. The purpose of a life cycle assessment (LCA) is to provide a picture of a product’s total environmental impact during its lifecycle. The study is carried out according to ISO 14 040, i.e. all methods, data and assumptions are accounted for in order to make an external review possible. An LCA could provide the basis for an Environmental Product Declaration (EPD). The LCA clearly shows that the main environmental impact of the separator is caused by CIP and electricity used during operation. The major part of the impact from the CIP chemicals is due to the energy needed for their manufacture. Fossil fuels account for most of the impact for both operation and manufacture of chemicals. Therefore customers should be encouraged to use environmentally friendly electricity and chemicals, such as renewable energy sources and sodium hydroxide made with membrane technology. It is also important to use as little as possible of cleaning agents and make sure that waste is treated properly.www.ima.kth.se
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ANDRADE, DELVONEI A. de. "Analise termo hidrodinamica de uma centrifuga a contracorrente." reponame:Repositório Institucional do IPEN, 1999. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10721.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Schwienheer, Christoph Heinrich [Verfasser]. "Advances in centrifugal purification techniques for separating (bio-) chemical compounds / Christoph Heinrich Schwienheer." München : Verlag Dr. Hut, 2016. http://d-nb.info/1122524749/34.
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Benkhedja, Houaria. "Extraction au point de trouble de substances organiques et électrolytes à l'aide de mélangeurs-décanteurs." Phd thesis, Toulouse, INPT, 2015. http://oatao.univ-toulouse.fr/14245/1/BENKHEDJA.pdf.
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Au-dessus d’une certaine température appelée température de trouble (Tc), les solutions aqueuses de la majorité des tensioactifs non ioniques polyéthoxylés se séparent en deux phases liquides en équilibre : la phase diluée et le coacervat. Grâce à la solubilisation micellaire de composés hydrophobes, amphiphiles ou même ioniques et à leur concentration dans le (faible) volume de coacervat, une extraction à deux phases aqueuses (extraction par point de trouble ou par coacervat)peut être réalisée et appliquée à des opérations de dépollution d'effluents industriels ou à la concentration ou encore à la séparation de substances à haute valeur ajoutée. L’extraction par point de trouble (CPE) est une technique relativement simple et écologique pour l'élimination des matières toxiques de l'environnement, qui s’est avérée efficace dans le traitement de divers contaminants (organiques et inorganiques dissous ou dispersés) de l’eau. Une première partie de cette thèse consiste à rappeler quelques notions sur la pollution industrielle des eaux et quelques généralités sur les tensioactifs (TA) et sur l’extraction liquide-liquide. Elle est suivie d’une description des réactifs, du matériel et des méthodes utilisées au cours de ce travail, comme préliminaire à la mise au point d'un procédé d'extraction par coacervat. Quelques propriétés thermodynamiques superficielles (adsorption) et d’association (micellisation) de deux tensioactifs non ioniques industriels (le Simulsol NW342 et le Tergitol 15-S-7) ont été déterminées. Les courbes de démixtion des systèmes binaires (eau/TA) ainsi que l’effet de divers additifs (sel, composés organiques, tensioactifs ioniques) sur le point de trouble sont étudiés. Le diagramme isotherme du système ternaire (eau/TA/ phénol) est tracé. Une application du modèle de Flory-Huggins-Rupert pour la prédiction des courbes de démixtion des tensioactifs non ioniques a été expérimentée. L’extraction à un seul contact, à partir de solutions modèles, utilise des alcools oxo éthoxylés biodégradables (Simulsol NW342 et Tergitol 15-S-7) pour des polluants organiques dissous (phénol, 1-phényléthanol et alcool benzylique) et un mélange de tensioactifs non ionique (Simulsol NW342) et ionique (SDS ou CTAB) pour des polluants métalliques solubles (plomb(II), molybdène(VI)). On cherche le meilleur compromis entre le pourcentage de soluté extrait (E%),la fraction volumique du coacervat (фv), et les pourcentages de soluté et de tensioactif restants dans la phase diluée (Xs,d et XTA, d), en utilisant un plan d'expériences de type Scheffé et un lissage empirique des courbes. Les résultats sont très prometteurs car les pourcentages d’extraction varient de 60 à 95% pour les solutés organiques et de 40 à 85% pour les solutés métalliques, les meilleures performances étant obtenues pour le phénol et le plomb. D’autre part, il est possible, en jouant sur le pH, d’améliorer les séparations et de recycler le tensioactif après désextraction des solutés. Les cinétiques d’extraction, de séparation et de clarification ont été aussi étudiées pour une meilleure compréhension de ces systèmes. Enfin, l’extraction continue du phénol à partir du mélange eau/4%Simulsol NW342/0,2%phénol (mass.) a été testée sur deux appareillages (extracteur centrifuge et mélangeurdécanteur)thermostatés. Dans un procédé multi-étagé à courants croisés sur un mélangeur-décanteur, on arrive à réduire la concentration du phénol à moins de 0,3ppm (concentration limite selon la législation) après six étages.
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Saffari, Yasaman. "Leak Test on High-Speed Separator." Thesis, KTH, Kemiteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-90477.
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High speed separators from Alfa Laval are widely in use for processing flammable and non-flammable liquids. The following work is focusing on the case of non-flammable liquid as the process liquid in case the working area around the equipment may contain quantities of explosive gases. As stated by Alfa Laval documentation, the major risk is leaking of the explosive atmosphere into the separator from the surrounding environment which may result in producing zone 1 or zone 2 of hazardous area classification. Zone 1: Area in which an explosive gas-air mixture is likely to occur for short periods in normal operation.1 Zone 2: Area in which an explosive gas-air mixture is not likely to occur, and if it occurs it will only exist for a very short time due to an abnormal condition.1 According to Alfa Laval design package, there is a need of continuous inert gas injection into the separator during the process in order to reduce the oxygen concentration and keep it in the safe level (inert gas purging) and this policy is aimed to meet the requirements of ATEX-directive 94/9/EC/2003. The objective of the current thesis is a wish to have a better understanding of the potential risks, evaluating them and try to find ways to ease the process. The outcome can be useful to make a basic instruction for further tests and simplifications as well. The separator GTN 50 is selected and hydrogen (1% concentration) is used to simulate the explosive atmosphere. The result of the tests indicates that the cooling down stage after normal operation is the only period in which hydrogen will leak into the separator, frame top part and it should be cleaned up before the next start up. A number of recommendations -Ventilation to the fresh air, Water discharges, Pressurized air injectionare also being tested and discussed. Ventilation to the fresh air and injection of pressurized air seem to be applicable A Standard Testing Flow chart is suggested and calculation on real case is considered. A number of additional ideas are also included in the last section.
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Gardner, Nicola Jane. "The development of a high efficiency centrifugal separator for gas/liquid mixtures at high pressure." Thesis, University of Liverpool, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337168.
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Bell, George Ross Arana. "Analysis and Development of a Decanter Centrifuge: Power consumption analysis, development of a composite bowl, and feed accelerator analysis." Thesis, University of Canterbury. Mechanical Engineering, 2013. http://hdl.handle.net/10092/8678.
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This project was concerned with the analysis and development of a decanter centrifuge. The aim of the project was to increase the understanding of the operation of the machine, and identify and implement methods of improving the performance.
A comprehensive breakdown of the power consumption of a GTech-Bellmor 1456 Centrifuge Decanter was completed. There are four components of the power consumption in a decanter centrifuge: friction during product transport, viscous and kinetic losses during feed acceleration, inefficiencies in power transmission components, and aerodynamic losses, known as windage. A mathematical model was developed to predict the power, torque, and axial force required by product transport. A relationship for the power consumed during feed acceleration was derived from first principles. The power transmission losses are comprised of inefficiencies in the motors, belt drives, gearbox, bearings, and seals; each of these was quantified. The windage has two components: the surface drag on the bowl as it rotates in an annular space and the pressure drag on external protrusions. The windage was predicted empirically and computationally. Methods that were identified for improving the decanter centrifuge were: reduce the mass of bowl and scroll, improve wear resistance, reduce the coefficient of friction of the bowl wall and scroll faces, optimise scroll geometry, redesign the feed accelerator to increase acceleration efficiency, implement control of the bowl speed, differential speed, and pool depth, and recess the bolt heads on the bowl and cover the third phase ports.
An analysis of several worn centrifuges revealed that the majority of the wear occurs on the scroll, bowl wall, accelerator, and solids discharge ports. An experiment was developed to recreate the wear conditions inside a centrifuge. A high pressure abrasive film was forced between materials moving relative to each other. Similar results were observed for acetel, UHMWPE, and 316 stainless steel when using a pin-on-disk wear test rig. A new composite bowl was developed for two main reasons, weight reduction, and improved wear and friction characteristics. The full design process was applied to the bowl and several concepts were generated for a new scroll. The design of the bowl included conceptual design, material selection, material testing, constructing scale models, and the manufacture of a full-size bowl for a GTech-Bellmor 1456 Centrifuge Decanter. The potential for using composite materials in decanter centrifuges was demonstrated. The manufacturing method developed during this project was novel and produced parts suitable for use in high-speed rotating machinery.
The feed accelerator analysis consisted of three components: theoretical, experimental, and computational analysis. Three feed acceleration mechanisms were identified: viscous dissipation, impulse force, and mass flow induced velocity. An experimental method was developed to examine decanter centrifuge feed accelerator designs. The method allowed for the measurement of efficiency and high-speed photography of the flow between the accelerator and the rotating pool. The order of best to worst performing of the six tested designs was Modified Disk, Disk, Plate, Conical, Drum, and Esbjerg. The feed accelerator was modelled using ANSYS-CFX 14.5 and compared to the experimental results. There was excellent agreement between the flow in the annular space observed using high-speed photography and the paths predicted using the computational model. A parametric study of the Drum and Disk feed accelerator designs was undertaken using the computational model. It was found that increasing the surface area of the port faces of the Drum accelerator and increasing the discharge angle and discharge radius for the Disk accelerator improved the performance.
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MIGLIAVACCA, SYLVANA C. P. "Modelagem do comportamento separativo de ultracentrifugas via rede neural." reponame:Repositório Institucional do IPEN, 1999. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10729.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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CRUS, MARIA U. de L. "Modelagem dos parâmetros separativos de ultracentrífugas para enriquecimento de urânio através de modelos de redes neurais híbridas." reponame:Repositório Institucional do IPEN, 2005. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11258.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
30
Aspinwall, Jacob Raleigh. "Design of an Improved Moisture Separator in a Turbocharger System for Fuel Cells." Thesis, Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4976.
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Moisture recovery is important in the operation of many fuel cell systems, especially proton exchange membrane (PEM) fuel cells. The exhaust of a PEM fuel cell is a moderate temperature, pressurized humid air stream. A system that recovers liquid water condensate from the pressurized humid exhaust stream of a PEM fuel cell would markedly increase the effectiveness of such a system. The recovered water could be used to hydrate the fuel cell membrane, and it could supply a hydrocarbon reformer used for generating hydrogen.
This project investigated and documented moisture recovery from the simulated humid exhaust stream of a 25 kW fuel cell with an improved axial flow separator. An axial flow centrifugal separator design was chosen as the best candidate due to its high efficiency and low pressure drop and a prototype was designed and constructed. The separator was then integrated into an experimental test system. First, the stream was simulated by heating compressed air and then humidifying it with superheated steam. Then, after expanding through the turbine section of an automotive turbocharger, the humid stream was passed through the moisture separator where liquid water condensate was removed from the flow. Results are presented for varying turbine inlet conditions at three separate separation lengths. It is shown that the separation efficiency for the improved design was 40% higher and the pressure drop was only 1/3 that of the conventional separator.
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BENMERZOUKA, ABDERRAHIM. "Etude de la configuration diphasique annulaire dans un dispositif tournant. Application au probleme de la separation centrifuge liquide-gaz." Nantes, 1989. http://www.theses.fr/1989NANT2046.
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Ce travail porte sur l'etude de la separation centrifuge des ecoulements diphasiques ascendants liquide-gaz a proportion volumique variable, en geometrie annulaire verticale, appliquee au probleme du prelevement de la phase liquide separee. Dans une premiere partie, nous proposons une analyse parametrique relative aux phenomenes physiques de l'ecoulement monophasique tournant dans une conduire annulaire. Un modele mathematique decouple est alors propose, il conduit d'une part a la determination de la position de l'interface et d'autre part a la prediction de l'evolution des profils de vitesses axiales dans la phase liquide separee en fonction du rapport des debits volumiques liquide-gaz (turbulent-laminaire). En seconde partie, des essais experimentaux donnent le comportement global des profils de vitesses axiales qui presentent une zone de survitesse quasiment affine a proximite de la paroi exterieure; cette propriete conduit a proposer une correlation liant le maximum de la vitesse dans cette zone et le nombre de rossby, qui rend compte de la distorsion des profils par les forces centrifuges. La version du modele propose, donne alors une approche significative de la realite experimentale pour l'ensemble des conditions d'essai, sous la forme de deux versions de l'utilisation de la correlation utilisant le nombre de rossby: la premiere pour predire l'ecoulement dans la zone de paroi exterieure, la seconde pour predire l'ecoulement dans la zone interfaciale
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ANDRADE, MONICA de C. V. "Aplicacao de redes neurais para deteccao de erros grosseiros em dados de processo de separacao de isotopos de uranio por ultracentrifugacao." reponame:Repositório Institucional do IPEN, 2004. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11158.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
33
Morandin, Marcelo Luiz. "Modelagem de um filme liquido sob a ação combinada dos campos centrifugo e gravitacional de forças : hidrociclones." [s.n.], 1999. http://repositorio.unicamp.br/jspui/handle/REPOSIP/264026.
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Orientador: Eugenio Spano RosaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: O estudo desenvolvido têm como tema central separadores cic1ônicos gás-líquido. Mais precisamente, procura-se caracterizar experimentalmente e desenvolver um modelo que possa prever o comportamento do escoamento de líquido que se desenvolve na forma de um filme de espessura reduzida sob a ação combinada dos campos centrífugo e gravitacional de forças, sendo esta uma das principais características dos separadores ciclônicos. Para tal, utiliza-se de duas técnicas experimentais para determinação direta da espessura média do filme de líquido: sonda de condutância e ultra-som. Por meio de visualização o ângulo que o filme faz com a horizontal também é determinado experimentalmente. Uma combinação destas variáveis experimentais permite uma determinação indireta das componentes axial e tangencial da velocidade média local do filme. Um modelo é desenvolvido a partir das equações de camada limite na forma integral tomada em termos médios num sistema cilíndrico de coordenadas e sob a hipótese de escoamento axisimétrico. São realizadas comparações entre as técnicas experimentais empregadas e os dados utilizados para validar o modelo proposto
Abstract: The work is applied to the gas-liquid separator field and focus on the hydrodynamics aspects of the developing liquid film under the action of centrifugal and gravitational force fields. The main objective is to characterize experimentally the liquid film and develop a model capable to predict the average film quantities. Toward this objective two experimental techniques are employed to measure the average film thickness distribution: a conductive probe and ultrasound. AIso, using flow visualization the angle of the film with respect to the horizontal is determined. Using these two experimentally variable and the mass flow rate, the axial and tangentiallocal average film velocity is indirectly achieved. The flow modei developed is based on the integral form of the boundary layer equations in a cylindrical coordinate system and assuming axis-symmetric flow. A direct comparison between the film thickness experimental techniques is drawn as well as the model validation is conducted against the experimental data
Mestrado
Fenomenos de Transporte
Mestre em Engenharia Mecânica
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Kroll-Rabotin, Jean-Sébastien. "Analyse physique et modélisation de la séparation centrifuge de particules ultrafines en film fluant : application au séparateur industriel Falcon." Thesis, Toulouse, INPT, 2010. http://www.theses.fr/2010INPT0077/document.
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Les concentrateurs Falcon permettent de séparer des particules en fonction de leur densité. Leur capacité à traiter des débits de suspension importants rend leur utilisation courante dans les procédés miniers. Dans les gammes de tailles ultrafines (entre 1 et 100 μm), leur coupure devient à la fois granulométrique et densimétrique. Ce travail a porté sur la compréhension de leur physique et de ses limites. Une analyse de leurs mécanismes de séparation a abouti à une loi d’échelle analytique, validée expérimentalement. Des investigations plus complètes appliquées aux suspensions ultrafines ont été réalisées numériquement. Finalement un critère physique liant la gamme de taille à séparer aux densités des différentes fractions a été explicité et appliqué à la valorisation de sédiments finsEnhanced gravity separators are widely used in minerals beneficiation, as their superior gravity field enables them to separate particles within narrow classes of density and size. This study aims to shed light on the Falcon concentrator’s ability to separate particles with size and density ranges lower than usual, 1 to 100 micrometers and 1.2 to 3.0 s.g. respectively. Differential particle settling being identified as the prevailing separation mechanism under such conditions, this study couples a theoretical and numerical approach with targeted experiments to build a predictive Falcon separation model that embeds phenomenological fluid and particle flow analysis. Based on this model, physical limitations were identified and quantified through explicit relations between operating parameters, and particle size and density ranges. Falcon’s efficiency to beneficiate dredged sediments was characterized in this way
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Sajner, Pavel. "Hydrodynamická separace sedimentu vodního toku." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228371.
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The dissertation deals with clogging of reservoirs and ponds by redundant sediments which penetrate water system by erosion. It describes methods of extracting pond sediments. It contains measurement of dewatering of sediments on hydrocyclone and design of laboratory hydrocyclone and filter unit. In the conclusion there is design of technology of dewatering sediments which were extracted by wet method by drainage excavator. Numerical simulation of flowing in hydrocyclones is simulated in the CFX programme and dewatering technology is simulated in the CHEMCAD programme.
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Fojtíková, Radka. "Vznik mikrosuspenze perikinetickou a ortokinetickou koagulací." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2008. http://www.nusl.cz/ntk/nusl-216203.
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This diploma thesis is focused on study of physico-chemical influences on model surface-water treatment which contain humic compounds. From those factors were monitored especially the dose of destabilizing reagent, pH value, temperature, velocity gradient of mixing and time of its duration. As destabilizing reagents were used Al2(SO4)3 .18H2O a Fe2(SO4)3 . 9H2O.
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Roche, Timothy Edward. "An investigation of centrifugal blood-cell separation." Thesis, 2001. http://library1.njit.edu/etd/fromwebvoyage.cfm?id=njit-etd2001-082.
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Thesis (Ph. D.)--New Jersey Institute of Technology, Dept. of Chemical Engineering, Chemistry and Environmental Science, 2001.Includes bibliographical references. Also available via the World Wide Web.
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Branger, Arturo I. "Separation of fractionally crystallized milk fat by centrifugal methods." 1993. http://catalog.hathitrust.org/api/volumes/oclc/32483480.html.
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Thesis (M.S.)--University of Wisconsin--Madison, 1993.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 113-119).
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Yang, Jyun-Ren, and 楊竣任. "The Branch Design on Cell Separation Using Centrifugal Force." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/6qtj87.
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碩士國立虎尾科技大學
機械與機電工程研究所
102
The purpose of cell separation is to make a difference cell type,the function help biomedical treatment get best data analysis,and save the costs.This study apply the way of centrifugal force to drive bio-chip,and get cell separation.The simulation is using COMSOL software of Laminar Flow Module and Paticle Tracking Module. To result the speed and geometric design influent each other.The design of sheath flow is important,it impacts good efficiency cell separation.The experiment of MEMS process produce bio-chip, the material is using PDMS make biocompatible well.The verification of experiment and simulation is to get the best design parameters
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Chen, Xuan-fu, and 陳宣甫. "Development of Microfluidic Centrifugal Platform for Plasma Separation and Sample Preparation." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/26zdnm.
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碩士國立虎尾科技大學
自動化工程研究所
102
In performing blood tests for clinical diagnosis purposes, it is first necessary to separate the plasma from the whole human blood. However, traditional methods for separating and preparing plasma are labor intensive and time consuming. Accordingly, the present study proposes a simple lab-on-CD device in which the plasma is first separated from the whole human blood, then divided into two samples of equal volume, and finally decanted into a detection chamber for analysis purposes. The optimal geometry parameters of the Y-shaped microchannel used to divide the plasma sample are determined by means of computational fluid dynamics (CFD) simulations. The performance of the proposed device is then evaluated using blood samples with hematrocrit concentrations ranging from 6~48%. The results show that given a CD rotation speed of 1800 rpm for a blood sample with a hematocrit concentration of 6%, a separation efficiency of 96% can be achieved within 5~6 s. Moreover, the two plasma samples collected from the left and right branches of the optimized Y-shaped splitter network differ in volume by no more than 0.5 nL. Finally, it is shown that the volume of plasma decanted into the detection chamber can be precisely controlled through an appropriate manipulation of the disk rotation speed. The second objective of this work is to design a microfluidic platform for the separation of plasma from whole human blood and the subsequent mixing of the plasma with a prothrombin time reagent. The results show that mixing efficiency of more than 97% can be obtained within 5 s given a CD rotation speed of 3400 rpm.
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Li, Bo-Shiun, and 李柏勳. "Development of Centrifugal Platform for Rapid Separation and Mixing of Blood Plasma." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/5jrxd7.
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碩士國立虎尾科技大學
自動化工程研究所
101
This paper presents a new lab-on-CD microstructure capable of directly separating plasma from the whole blood into different reservoirs and performing plasma mixing functions. We propose a CD microfluidic platform, including a microchannel network consisting of a plasma separation microchannel network and a mixer microchannel network. As the disk rotates, the centrifugal force causes the separation of blood cells and plasma because of their different densities. The blood cells enter a collection chamber, while the plasma flows to the downstream mixer microchannel network. Numerical simulations are performed to investigate the flow characteristics and mixing performance of three CD microfluidic mixers. The results show that given an appropriate specification of the microchannel geometry and a CD rotation speed of 2000 rpm, 95% separation efficiency is achieved within 5-6 s for diluted blood with a hematocrit of 6%, and a mixing efficiency of more than 96.4% can be obtained within 5 s at an angular frequency of 2200 rpm.
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Chen, Yu-An, and 陳昱安. "Centrifugal Filter Device for Micro-particles Separation and Rare Tumor Cell Detection." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/79636562812328505172.
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碩士國立清華大學
奈米工程與微系統研究所
102
In this study, a centrifugal multilayer filter device is applied for particles and Circulating Tumor Cells (CTCs) separation. In recent years, many researches emphasize separating microparticles by using microfluid chips. Size-based separation is the most straightforward and common approach for microfluid based separation. However, the main disadvantage of size-based filtration encountered is clogging. The reason is that the concentration of particle sample is too high and the clogging will lead to reducing separation efficiency. In this study, a multilayer concentric filter device with different pore sizes combined with changing Revolution(s) Per Minute(RPM) instantly to generate cross-flow and reduce the phenomenon of particles clogging. We use the centrifugal filter device to separate microparticles and further apply this concept to CTCs detection. Tumor cells can be bounded by specific antibody coated with PS beads. The antibody has the ability to bind specific antigen on tumor cells .The conjugated size of CTCs and PS bead will become larger depending on how many tumor cells and PS beads bounded. The results show a significant clogging reducing with particle separation and the rare targeted tumor cells mixed with blood cells in the ratio of 1:1,000,000 are successful demonstrated. The centrifugal filter device was fabricated using photolithography and soft-lithography techniques. It is fabricated by regular PDMS modeling process. The advantages of biocompatible, low cost, disposable, and transparent of PDMS make , it fulfill with the requirements of useful microfluidic biochips. The centrifugal filter device and centrifuge used in this research are portable.
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Hsu, Wen-Haw, and 徐文浩. "Electric-force and Centrifugal-force interacted CD Player-Like Microelectrophoresis Biomedical Separation System." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/92928551960092108761.
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碩士國立中興大學
精密工程研究所
91
The goal of this thesis is to develop a versatile CD-like multi-channel electrophoresis based biomedical separation system that is driven by the interactive forces between the centrifugal force and the electric field force. At the first stage, both the CNC based micro machining and the semi-conductor fabrication processes are adopted to build a new thin-membrane type micro electrophoresis chip. Easy to fabricate and low cost are its main advantages. Secondly, the proposed CD-like multi-channel electrophoresis based biomedical separation system is developed. The centrifugal force control of this system is realized through the velocity control of a DC servo motor, while the electric field is governed through the concentric-circle conducting wires that can be tuned to provide different voltages. Experimental results demonstrate that the EOF (Electro-Osmotic Flow) effect can be effectively handled when the electric force and centrifugal force are in the opposite direction. Benefits from this are the electrophoresis separation time can be extended and the channel length can be reduced; therefore, a more effective separation result can be obtained. Moreover, other advantages such as low-calorific capacity, low-chemistry reaction, and no variation on the ion concentration during processes make this biomedical separation system more usful.
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Pharoah, Jon George. "Fluid dynamics and mass transport in rotating channels with application to Centrifugal Membrane Separation." Thesis, 2002. https://dspace.library.uvic.ca//handle/1828/10215.
Full textAbstract:
Centrifugal membrane and density separation (CMS) is a novel technology proposed for treatment of waste water and industrial process streams. This cross flow filtration process combines the energy recovery inherent to centrifugal reverse osmosis (CRO) with the potential alleviation of membrane fouling and concentration polarization due to the favourable effects of centrifugal and Coriolis accelerations.
This dissertation presents a computational study of CMS undertaken to understand the basic hydrodynamics and mass transfer of the processes and to provide insight for the design of CMS devices. Two distinct membrane models were developed, the porous wall model (PWM) and the source term model (STM), and incorporated into Computational Fluid Dynamics (CFD) codes which solve the full Navier-Stokes equations coupled to a scalar transport equation which accounts for dissolved species. These models are used to simulate two and three dimensional laminar flows in both non-rotating and rotating reverse osmosis membrane cartridges and to predict permeate fluxes.
Plate and frame geometries are first examined and it is determined that CMS benefits most from channels with streamwise directions directed radially. It is also shown that the benefits of CMS can be attributed largely to the secondary flows and mixing associated with Coriolis acceleration, and the PWM and the STM are found to perform similarly in the case of reverse osmosis. Next, the STM is used to perform a parametric study of the flow and mass transfer in rectangular and square rotating channels. It is shown that while normal rotation is preferable to spanwise rotation, relatively small deviations from the spanwise orientation are adequate to achieve most of the normal rotation performance, and that differences between the two orientations are minimal in the case of square channels. Also, the flow characteristics are again shown to correlate well with the magnitude of the Coriolis acceleration.
Flows in triangular and circular channels are also considered, and are shown to perform similarly to rectangular channels. These channel orientations have application in hollow fiber membrane modules and potentially in spiral wound membrane modules.
Finally, the flow and mass transfer in channels with periodic streamwise obstacles are considered. Such obstacles are related to feed spacers used in spiral wound membrane elements and impact considerably on the flow characteristics and mass transfer performance. Flow obstacles are shown to increase mass transfer performance in all cases, with alternating surface mounted performing best. A preliminary investigation is undertaken into rotating flows with periodic obstacles, and the flow fields are shown to depend strongly on the blockage ratio and on the Rossby number. In most cases, it is found that mass transfer performance does not necessarily correlate with either wall shear stress or the local flow field.
Several general conclusions regarding CMS can be drawn from this work. It is preferable to operate a CMS devices at low flow rates, which is contrary to conventional wisdom in membrane separation. Secondly, the mixing induced by channel rotation is both more effective and more efficient than the mixing induced by the feed spacers considered here. Finally, the magnitude of the Coriolis acceleration is the dominant parameter in determining CMS performance. This means that a CMS device can either operate at relatively low rotational speeds with flow in the radial direction, or at higher speeds but lower angles of inclination with respect to the rotational axis.Graduate
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Wang, Bo-Sen, and 王柏森. "Separations of Active Compounds in Mulberry Leaves Using Centrifugal Partition Chromatography." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/23pkkh.
Full textAbstract:
碩士國立交通大學
應用化學系碩博士班
101
Separations of active compounds, including Chlorogenic acid, Isoquercitrin, Astragalin, Quercetin 3-(6-malonylglucoside) and Kaempferol 3-(6-malonylglucoside) in mulberry leaves, were carried out using centrifugal partition chromatography (CPC) in this study. These five components in the crude extract by 60% (v/v) ethanol were first identified using HPLC-MS. After pre-extractions using ethyl acetate and water, we used solvent systems, (methyl t-butyl ether /acetone/H2O =6：4：10、7：3：10、8：2：10) and (methyl t-butyl ether /acetone/ H2O = 6：4：10、7：3：10、8：2：10) added with 0.6% (v/v) formic acid, four solvent systmes (methyl t-butyl ether /acetone/H2O/EA =7：3：10：2) , (methyl t-butyl ether /acetone/ H2O/EA = 7：3：10：2) added with 0.6% (v/v) formic acid, to separate sample extracts. The descending elution mode was applied, i.e. the lower aqueous layer was used as the mobile phase, and the upper organic layer as the stationary phase. Under 900 rpm, the volume of the stationary phase retained was 188 mL in the separation cells of a total volume 240 mL; stationary-phase retention ratio was 78%. The CPC effluent monitored using an on-line UV/Vis detector was fraction-collected every 3 mL, and the fractions were further analyzed using HPLC . The purities were 70.2%, 97.3%, 97.2%, 69.1% and 69.6% for Chlorogenic acid, Isoquercitrin, Astragalin, Quercetin 3-(6-malonylglucoside) and Kaempferol 3-(6-malonylglucoside), respectively, under the optimized separation.
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Chiang, Yu-Hong, and 姜淯紘. "The Flowfield Analyse of Centrifugal Separator for Clarification Bio-diesel Fuel." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/83308819814510485163.
Full textAbstract:
碩士國防大學理工學院
機械工程碩士班
97
The main purpose of the thesis is to simulate and analyze the flow in a centrifugal separator using CFD. FLUENT has been used to predict the flow of clarifying bio-diesel in the centrifugal separator (disc centrifuge). For the separation of liquid-liquid two phases flow, Eulerian method was used to solve the concentration equation And, Lagrangian method was employed for the separating of liquid-solid two phases flow and chasing the trajectories of the particles in the flow. Eulerian-Lagrangian method has also been used to predict the clarification of the three phases (liquid-liquid-solid) bio-diesel flow in the disc centrifuge. Combined with the Design of Experiments (based on the Taguchi Method) the optimal design of the disc centrifuge has been obtained. For the liquid-liquid separation the optimal angle of disk is 45° and for the liquid-solid separation the optimal angle of disk is 60°. On bio-diesel clarifying, the optimal angle of disk is 45° for the liquid-liquid separation when disk gap is 4mm and rotating speed is 6000rpm and the input flowing rate is 4 t/h. For liquid-solid separation, the optimal angle of disk is 60°, when disk gap is 4mm, rotating speed is 8000rpm, and the input flowing rate of import is 4 t/h.
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Chen, Ling-Yi, and 陳伶宜. "Preparative Separations of Five Active Compounds in Mulberry Leaves Using Centrifugal Partition Chromatography." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/86619337585462044663.
Full textAbstract:
碩士國立交通大學
應用化學研究所
98
Active components in mulberry leaves are found effective in reducing the total cholesterol concentration in human blood, thus are able to help prevent atherosclerotic lesion. Preparative separations of five active compounds, including Chlorogenic acid, Isoquercitrin, Astragalin, Quercetin 3-(6-malonylglucoside) and Kaempferol 3-(6-malonylglucoside) in mulberry leaves, were carried out using centrifugal partition chromatography (CPC) in this study. CPC is a technique of liquid-liquid chromatography which needs no solid-state support for the stationary phase. Accordingly, permanent adsorption of analytic molecules can be avoided during elution. In addition, the stationary phase volume in the separation column can be very large compared with the packed column. These two properties make the technique very suitable for preparative separations of biomolecules and natural products. These five components in the crude extract by 60% (v/v) ethanol were first identified using ESI-MS. After pre-extractions using ethyl acetate and water, we used two solvent systems, i.e. methyl t-butyl ether (MTBE) / acetone / H2O = 6:4:10 and MTBE / acetone / H2O = 6:4:10 added with 0.6% (v/v) formic acid, to separate sample extracts. The descending elution mode was applied, i.e. the lower aqueous layer was used as the mobile phase, and the upper organic layer as the stationary phase. Under 900 rpm, the volume of the stationary phase retained was 187 mL in the separation cells of a total volume 220 mL. The CPC effluent monitored using an on-line UV/Vis detector was fraction-collected every 3 mL, and the fractions were further analyzed using HPLC and NMR. The purities and recoveries were 98% (59.2 mg)、94% (95.7 mg)、97% (56.7 mg)、93.5% (28.0 mg)、92.5% (23.0 mg), for Chlorogenic acid, Isoquercitrin, Astragalin, Quercetin 3-(6-malonylglucoside) and Kaempferol 3-(6-malonylglucoside), respectively, obtained from a 20-g dry mulberry leaf sample.
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黃詩軒. "Preparative Separations of Two Flavonoids in Onion by Centrifugal Partition Chromatography Using a Three-phase Solvent System." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/77034271549059352944.
Full textAbstract:
碩士國立交通大學
應用化學系碩博士班
99
We developed a preparative separation of two active compounds,quercetin-3,4-di-O-glucoside (Q3,4G) and quercetin-4-O-glucoside(Q4G), from onion using centrifugal partition chromatography (CPC)with a three-phase solvent system. The crude extract was obtained using a 60% (v/v) ethanol aqueous solution. The three-solvent system was composed of hexane / methyl tert-butyl ether / acetonitrile / water = 2:2:3:3 (v/v). The stationary-phase retention ratio was 82% (including 21% middle phase and 79% lower phase) in a 240-ml column under 1000 rpm rotation speed. Theseparation column was first filled with the lower phase and the middle phase was pumped into the column. After the equilibrium was reached, the upper phase was delivered until the second equilibrium was attained. We then injected the sample solution and eluted the column with the upper phase under the ascending mode for 30 min. The elution was then switched using the middle phase for 50 min. Finally, the elution was completed using the lower phase for 120 min under the descending mode. The collected fractions were analyzed using electrospray ionization mass spectrometry (ESI-Mass). The purities and recoveries, estimated using a HPLC, were 90% (0.33 mg) and 92% (0.12 mg) for quercetin-3,4-di-O-glucoside and quercetin-4-O-glucoside, starting from a 0.26 g onion crude extract.