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Relevant bibliographies by topics / Gas-liquid-solid flows

Academic literature on the topic 'Gas-liquid-solid flows'

Author: Grafiati

Published: 6 September 2023

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Journal articles on the topic "Gas-liquid-solid flows"

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KAWASAKI, Koji, and Keji NAKATSUJI. "NUMERICAL EXPERIMENT OF GAS-LIQUID PHASE AND SOLID-GAS-LIQUID PHASE FLOWS." PROCEEDINGS OF HYDRAULIC ENGINEERING 46 (2002): 1049–54. http://dx.doi.org/10.2208/prohe.46.1049.

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Douek, R. S., G. F. Hewitt, and A. G. Livingston. "Hydrodynamics of vertical co-current gas-liquid-solid flows." Chemical Engineering Science 52, no. 23 (December 1997): 4357–72. http://dx.doi.org/10.1016/s0009-2509(97)00182-6.

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KITAHARA, Hiroyuki, and Kunio YOSHIDA. "Flow Patterns for Gas-Liquid and Gas-Liquid-Solid Flows in a Vertical Pipe." JAPANESE JOURNAL OF MULTIPHASE FLOW 3, no. 2 (1989): 145–54. http://dx.doi.org/10.3811/jjmf.3.145.

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Lee, Y. J., and J. H. Kim. "A Review of Holography Applications in Multiphase Flow Visualization Study." Journal of Fluids Engineering 108, no. 3 (September 1, 1986): 279–88. http://dx.doi.org/10.1115/1.3242575.

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Holographic techniques are used in many fields of science and engineering including flow observation. The purpose of this paper is to review applications of holography to multiphase flow study with emphasis on gas-solid and gas-liquid two-phase flows. The application of holography to multiphase flow has been actively explored in the areas of particle sizing in particulate flows and nuclei population measurements in cavitation study. It is also recognized that holography holds great potential as a means of visualizing dynamic situations inherent in multiphase flows. This potential has been demonstrated by holographic flow visualization studies of coal combustion processes in gas-solid flows, gas-liquid two-phase critical flow measurements, and flashing flows in a nozzle. More effective and refined holographic techniques as well as efficient image processing methods are very much in need to facilitate and enhance the understanding of complex physical phenomena occurring in multiphase flows.

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Sassi, Paolo, Youssef Stiriba, Julia Lobera, Virginia Palero, and Jordi Pallarès. "Experimental Analysis of Gas–Liquid–Solid Three-Phase Flows in Horizontal Pipelines." Flow, Turbulence and Combustion 105, no. 4 (May 9, 2020): 1035–54. http://dx.doi.org/10.1007/s10494-020-00141-1.

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AbstractThe dynamics of three-phase flows involves phenomena of high complexity whose characterization is of great interest for different sectors of the worldwide industry. In order to move forward in the fundamental knowledge of the behavior of three-phase flows, new experimental data has been obtained in a facility specially designed for flow visualization and for measuring key parameters. These are (1) the flow regime, (2) the superficial velocities or rates of the individual phases; and (3) the frictional pressure loss. Flow visualization and pressure measurements are performed for two and three-phase flows in horizontal 30 mm inner diameter and 4.5 m long transparent acrylic pipes. A total of 134 flow conditions are analyzed and presented, including plug and slug flows in air–water two-phase flows and air–water-polypropylene (pellets) three-phase flows. For two-phase flows the transition from plug to slug flow agrees with the flow regime maps available in the literature. However, for three phase flows, a progressive displacement towards higher gas superficial velocities is found as the solid concentration is increased. The performance of a modified Lockhart–Martinelli correlation is tested for predicting frictional pressure gradient of three-phase flows with solid particles less dense than the liquid.

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Silapov, Begench, and Iulian Nistor. "MOVEMENT OF TWO-PHASE GAS-LIQUID FLOW IN HORIZONTAL AND INCLINED PIPES." Romanian Journal of Petroleum & Gas Technology 4 (75), no. 1 (2023): 61–72. http://dx.doi.org/10.51865/jpgt.2023.01.06.

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"Two-phase flows are found in almost all areas of technology. For example, tubular evaporators, boiling water reactors, boiler blowdown systems, heaters, boilers, gas lift pumps, oil and geothermal wells, oil and gas pipelines, refrigerators, process pipelines, and condensers. Two-phase flows are classified as mixtures. According to the composition of the mixture are divided: (a) for single-component (or one-component) - vapor-liquid flows; (b) multicomponent - gas-liquid flows. One-component mixtures consist of the same substance in different states of aggregation. This can be not only vapor-liquid, but also a mixture of liquid or vapor with a solid phase, a water-ice mixture, or a vapor flow with ice particles, for example, in sublimation installations. Multicomponent mixtures are a combination of substances of different physical nature. These include not only gas-liquid flows, but also, for example, mixtures of air and sand, water and oil. The paper presents the main attention is paid to the movement of two-phase flows in the pipeline."

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Rampure, Mohan R., Vivek V. Buwa, and Vivek V. Ranade. "Modelling of Gas-Liquid/Gas-Liquid-Solid Flows in Bubble Columns: Experiments and CFD Simulations." Canadian Journal of Chemical Engineering 81, no. 3-4 (May 19, 2008): 692–706. http://dx.doi.org/10.1002/cjce.5450810348.

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Baltussen, M. W., L. J. H. Seelen, J. A. M. Kuipers, and N. G. Deen. "Direct Numerical Simulations of gas–liquid–solid three phase flows." Chemical Engineering Science 100 (August 2013): 293–99. http://dx.doi.org/10.1016/j.ces.2013.02.052.

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Hosokawa, Shigeo, and Akio Tomiyama. "Turbulence modification in gas–liquid and solid–liquid dispersed two-phase pipe flows." International Journal of Heat and Fluid Flow 25, no. 3 (June 2004): 489–98. http://dx.doi.org/10.1016/j.ijheatfluidflow.2004.02.001.

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Hegab, A. M., S. A. Gutub, and A. Balabel. "A Developed Numerical Method for Turbulent Unsteady Fluid Flow in Two-Phase Systems with Moving Interface." International Journal of Computational Methods 14, no. 06 (August 2017): 1750063. http://dx.doi.org/10.1142/s0219876217500633.

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This paper presents the development of an accurate and robust numerical modeling of instability of an interface separating two-phase system, such as liquid–gas and/or solid–gas systems. The instability of the interface can be refereed to the buoyancy and capillary effects in liquid–gas system. The governing unsteady Navier–Stokes along with the stress balance and kinematic conditions at the interface are solved separately in each fluid using the finite-volume approach for the liquid–gas system and the Hamilton–Jacobi equation for the solid–gas phase. The developed numerical model represents the surface and the body forces as boundary value conditions on the interface. The adapted approaches enable accurate modeling of fluid flows driven by either body or surface forces. The moving interface is tracked and captured using the level set function that initially defined for both fluids in the computational domain. To asses the developed numerical model and its versatility, a selection of different unsteady test cases including oscillation of a capillary wave, sloshing in a rectangular tank, the broken-dam problem involving different density fluids, simulation of air/water flow, and finally the moving interface between the solid and gas phases of solid rocket propellant combustion were examined. The latter case model allowed for the complete coupling between the gas-phase physics, the condensed-phase physics, and the unsteady nonuniform regression of either liquid or the propellant solid surfaces. The propagation of the unsteady nonplanar regression surface is described, using the Essentially-Non-Oscillatory (ENO) scheme with the aid of the level set strategy. The computational results demonstrate a remarkable capability of the developed numerical model to predict the dynamical characteristics of the liquid–gas and solid–gas flows, which is of great importance in many civilian and military industrial and engineering applications.

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Dissertations / Theses on the topic "Gas-liquid-solid flows"

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Cai, Xuan [Verfasser], and B. [Akademischer Betreuer] Frohnapfel. "Interface-Resolving Simulations of Gas-Liquid Two-Phase Flows in Solid Structures of Different Wettability / Xuan Cai ; Betreuer: B. Frohnapfel." Karlsruhe : KIT-Bibliothek, 2016. http://d-nb.info/1126036811/34.

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Liu, Yefei [Verfasser], Kai-Olaf [Akademischer Betreuer] Hinrichsen, and Ville R. I. [Akademischer Betreuer] Kaila. "Two-fluid modeling of gas-solid and gas-liquid flows: Solver development and application / Yefei Liu. Gutachter: Kai-Olaf Hinrichsen ; Ville R. I. Kaila. Betreuer: Kai-Olaf Hinrichsen." München : Universitätsbibliothek der TU München, 2014. http://d-nb.info/1059477254/34.

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Bogner, Simon [Verfasser], Ulrich [Gutachter] Rüde, Manfred [Gutachter] Krafczyk, and Jens [Gutachter] Harting. "Direct Numerical Simulation of Liquid-Gas-Solid Flows Based on the Lattice Boltzmann Method / Simon Bogner ; Gutachter: Ulrich Rüde, Manfred Krafczyk, Jens Harting." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2017. http://d-nb.info/1139171534/34.

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Sassi, Arobba Paolo Juan. "Experimental analysis of multiphase flows. Design and setup of an experimental facility." Doctoral thesis, Universitat Rovira i Virgili, 2021. http://hdl.handle.net/10803/671990.

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Una millor comprensió dels complexos fenòmens que regeixen la dinàmica del fluxos tri-fàsics així com un increment en la capacitat predictiva de la seva dinàmica, són crucials en el disseny i construcció de sistemes fluidics d'interès per a una àmplia gama d'indústries. Aquest treball de recerca presenta el disseny i muntatge de LESLIE, un circuit tancat de baixa pressió destinat a la recerca en la dinàmica de fluxos bifàsics i trifàsics a través de canonades i els seus accessoris. LESLIE està pensat per obtenir mesures de paràmetres clau i caracteritzar fluxos multifàsics amb fases gasoses, líquides i sòlides, tant en canonades horitzontals com verticals. Presentem aquí noves dades experimentals per a règims intermitents en fluxos bifàsics i trifàsics en configuració horitzontal amb aire, aigua i partícules de polipropilè amb mides d'entre 1 i 2 mil·límetres. Visualitzacions del flux, mesures de pressió i fracció de buit s'han obtingut per a diferents condicions d'operació. En aquest treball investiguem l'impacte de la presència de partícules sòlides sobre la caiguda de pressió, el règim de flux i la freqüència del "slug". A més, l'anàlisi del comportament de fluxos bifàsics anulars mitjançant tècniques de processat d'imatges ha permès obtenir resultats sobre la distribució de mida de gotes.
La dinámica de los flujos trifásicos se rige por fenómenos de alta complejidad, tanto conceptual como matemática. Una mejor comprensión así como un incremento en la capacidad de predicción de su dinámica, son cruciales para el diseño y construcción de instalaciones de interés para una amplia gama de industrias. Este trabajo de investigación presenta el diseño y montaje de LESLIE, un circuito cerrado de baja presión destinado a la investigación experimental de la dinámica de flujos bifásicos y trifásicos a través de tuberías y sus accesorios. LESLIE está pensado para obtener medidas de parámetros clave y caracterizar flujos multifásicos con fases gaseosas, líquidas y sólidas, tanto en tuberías horizontales como verticales.Presentamos aquí nuevos datos experimentales para regímenes intermitentes en flujos bifásicos y trifásicos en configuración horizontal usando aire, agua y partículas de polipropileno con tamaños de entre 1 y 2 milímetros. Visualizaciones del flujo, medidas de presión y fracción de vacío se han obtenido para diferentes condiciones de operación de flujos intermitentes. En este trabajo investigamos el impacto de la presencia de partículas sólidas sobre la caída de presión, el régimen de flujo y la frecuencia del "slug". Además, el análisis del comportamiento de flujos bifásicos anulares mediante técnicas de procesado de imágenes ha permitido obtener resultados sobre la distribución de tamaño de partícula, las cuales también se presentan en este trabajo.
The dynamics of three-phase flows involve phenomena of high complexity, whose understanding and an enhanced prediction capacity of fluid dynamics in multiphase flow systems is crucial for the design and construction of facilities meant for a wide range of industries. This research work presents the design and set up of LESLIE, a low pressure multiphase flow loop for the experimental analysis of two and three-phase flows through pipelines and their accessories. It is designed to measure key parameters, so as to characterise the behaviour of multiphase flows involving gas, liquid and solid phases both in horizontal and vertical pipelines. New experimental data is presented in this study for intermittent two and three-phase flows in horizontal pipelines involving air, water and polypropylene pellets of sizes ranging between 1 and 2 millimetres. Flow visualization, pressure and void fraction measurements were performed and are explored in this work for the case of intermittent flows for a variety of settings. The influence of solid particles over the frictional pressure drop, flow regime and slug frequency is reported in this work. Furthermore, the analysis of the dynamics of annular two-phase flows by means of image processing techniques has allowed obtaining droplet size distributions, which are also presented in this study.

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Dong, Xuefeng Materials Science &amp Engineering Faculty of Science UNSW. "Modelling of gas-powder-liquid-solid multiphase flow in a blast furnace." Awarded by:University of New South Wales. School of Materials Science and Engineering, 2004. http://handle.unsw.edu.au/1959.4/20808.

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The ironmaking blast furnace (BF) is a complex reaction vessel involving counter-, coand/ or cross-current flows of gas, powder, liquid, and solids. However, the interactions of these multiphase flows have not been completely understood. The objective of this thesis is to develop a suitable model to simulate the powder flow and accumulation in packed beds and then extend it to numerically investigate the multiphase flow in the furnace. Gas-powder flow in a slot type packed bed has been experimentally studied in order to understand the flow and accumulation behaviour of powder in systems like an ironmaking blast furnace. A variety of variables including gas flowrate, powder flowrate and packing properties have been taken into consideration. It is found that a clear and stable accumulation region can form in the low gas-powder velocity zone at the bottom of the bed. The accumulation region is stable and shows strong hysteresis. The distribution of softening-melting layers in the blast furnace known as the cohesive zone (CZ) is modelled by inserting solid blocks into the bed. The results indicate that the inverse-V cohesive zone shape leads to low powder accumulation within the CZ and at the corner of the bed. A mathematical model is proposed to describe gas-powder flow in a bed packed with particles. The model is the same as the two fluid model developed on the basis of the space-averaged theorem in terms of the governing equations but extended to consider the interactions between gas, powder and packed particles, as well as the static and dynamic holdups of powder. In particular, a method is proposed to determine the boundary between dynamic and stagnant zones with respect to powder phase, i.e. the profile of the powder accumulation zone. The validity of numerical modelling is examined by comparing the predicted and measured distributions of powder flow and accumulation under various flow conditions. With high PCI rate operations, a large quantity of unburned coal/char fines flow together with the gas into the blast furnace. Under some operating conditions, the holdup of fines results in deterioration of furnace permeability and lower production efficiency. Therefore, the proposed model is applied to simulate the powder (unburnt coal/char) flow and accumulation inside the blast furnace when operating with different cohesive zone (CZ) shapes. The results indicate that powder is likely to accumulate at the lower part of W-shaped CZs and the upper part of V- and inverse V-shaped CZs. In addition, for the same CZ shape, a thick cohesive layer can lead to a large pressure drop while the resistance of narrow cohesive layers to gas-powder flow is found to be relatively small. Gas-powder flow in moving beds of solid particles has been numerically investigated, under conditions related to the ironmaking blast furnace and high rate pulverized coal injection. A new correlation, which is formulated to describe static powder holdup in a moving packed bed, is incorporated into the previous mathematical model and applied to a description of gas-powder flow in a blast furnace. Compared with the results of fixed beds, the results show that the solids descent due to the consumption of ore, coke and unburnt char in various regions, together with the non-uniform structural distribution, significantly affects powder flow and accumulation in a blast furnace. Finally, liquid flow is simulated through force balance approach and numerical results are compared with the different liquid inlet distribution under the iron-making blast furnace conditions with gas flow. The results show that the effect of inlet distribution on liquid flow is significant in the upper part of coke region in BF and possible loading and dry zone can be numerically identified. Then, this part of work is incorporated to the developed gas-powder-solid modelling system to investigate the influence of liquid phase on other phases flow in the blast furnace although heat transfer and chemistry are not considered in the model.

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Cui, Zhe. "Hydrodynamics in a bubble column at elevated pressures and turbulence energy distribution in bubbling gas-liquid and gas-liquid-solid flow systems." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1109956144.

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Thesis (Ph. D.)--Ohio State University, 2005.
Title from first page of PDF file. Document formatted into pages; contains xxiii, 187 p.; also includes graphics Includes bibliographical references (p. 179-187). Available online via OhioLINK's ETD Center

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Rapisarda, Andrea. "Hydrodynamic characterization of two/three phase flow regimes in stirred tank." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019.

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Questo progetto di ricerca riguarda i processi di miscelazione in sistemi multifase meccanicamente agitati(regime turbolento). I sistemi studiati sono: gas-liquido, solido-liquido e gas-solido-liquido. Lo scopo è quello di analizzare il movimento delle particelle solide all'interno di un recipiente agitato, calcolandone la velocità(n) alle quali si è ottenuto lo stato di estrazione delle particelle(nJD), della completa dispersione(nCD) e del loading(nloading), attraverso l'uso di due diversi valori di diametro delle particelle. Le misure sono state effettuate utilizzando due giranti su un albero e condotte con 6 diverse portate di gas e (da 3 a 6) concentrazioni X di particelle solide. La presente ricerca dimostra che i valori di nloading non dipendono dalla concentrazione X di particelle nel sistema con acqua come fase liquida per entrambi i diametri di particelle dp, nel sistema con 0.4 Kmol/m3 di NaCl per dp1 e nel sistema con 0.8 Kmol/m3 di NaCl per dp2. Nei sistemi con acqua e 0.4 Kmol/m3 di NaCl come fase liquida, i valori di nCD aumentano con l'aumento della concenrtrazione di particelle. I valori di nJD aumentano significamente con l'aumento della concentrazione solida, per entrambi i diametri di particelle nel sistema a coalescenza(con acqua) e non coalescenza con concentrazione di elettrolita 0.8 Kmol/m3 di NaCl. La stessa dipendenza di nJD=f(X) è osservata per 0.4 Kmol/m3 di NaCl per dp2. Per l'intera gamma di concentrazioni solide X, per lo stesso valore ddel diametro delle particelle, si ottengono valori inferiori di velocità di nloading, nCD, nJD per la configurazione delle giranti CD6-PBT.

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Liedtke, Anne-Kathrin. "Study of a new gas-liquid-solid three phase contact mode at millimetric scale : catalytic reactors using “slurry Taylor” flow." Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10137/document.

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Des réacteurs avec solide en suspension (« slurry »), très répandu dans l'industrie chimique, du laboratoire à la production, offrent des bonnes capacités en transfert de matière et de chaleur. Leur flexibilité facilite le changement de la phase solide et permet une régénération en continue des catalyseurs en cas de désactivation. Cependant, ils présentent un fort rétro-mélange, et donc un désavantage pour des réactions ayant des enjeux de sélectivité et/ou de conversion poussées. L'écoulement segmenté dit de Taylor est souvent mis en œuvre dans les réacteurs micro-structurés (RMS), grâce à ses propriétés intéressantes (capacités de transfert, écoulement, piston). Cependant, l'utilisation des solides catalytiques dans ces RMS est le plus souvent résolue par immobilisation du catalyseur nuisant la flexibilité. L'écoulement « slurry Taylor » (EST) qui utilise les recirculations internes dans les segments liquides pour transporter des particules en poudre, peut potentiellement répondre à cet enjeu. L'objet de cette étude est la conception et la caractérisation de ce nouveau mode de contact gaz-liquide-solide (G-L-S) dans des tubes millimétriques horizontaux et verticaux. Des études hydrodynamiques ont révélé différents régimes d'écoulement dépendant de la vitesse et de l'orientation de l'écoulement. Pour étudier le transfert de matière L-S, une résine échangeuse d'ion a été utilisée et une première corrélation pour le nombre de Sherwood est proposée
Slurry reactors, widely encountered in chemical industry (laboratory scale up to manufactaring), offer good mass and heat transfer capacities and their high flexibility ensures the simple changeover of solid phases enables a continuous online fresh catalyst feed for fast deactivating catalysts. However slurry reactors promote a high degree of backmixing which can be a drawback for reactions with selectivity issues or when very high conversions are required. In microreaction technology, Taylor flow is often employed providing excellent heat and mass transfer and almost ideal plug flow behavior. Solid handing in these small structures is often resolved by immobilizing the solid catalyst which impinges on the flexibility. One possible solution to combine beneficial properties of Taylor flow with the operational flexibility of conventional slurry reactors is a “slurry Taylor” flow (STF) where catalyst particles are suspended and kept in motion by the internal circulations present in the liquid slugs. The focus of this work is the design and characterization of this innovative gas-liquid-solid contactor. Particles were transported in millimetric horizontal and vertical tubing without the risk of clogging. Hydrodynamic studies revealed different flow patterns depending mainly on velocity and flow orientation. Ion exchange resin particles were used to study the liquid-solid mass transfer and first correlation for the Sherwood number in STF is proposed

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Serres, Marion. "Étude hydrodynamique d'un écoulement gaz-liquide dans un milieu poreux confiné." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEN018/document.

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Cette thèse se focalise sur les écoulements gaz-liquide dans un milieu poreux, problématique rencontrée dans des domaines variés allant de la physique fondamentale à la chimie appliquée. Nous avons caractérisé expérimentalement les régimes hydrodynamiques dans deux géométries différentes : un canal millifluidique (écoulement quasi-1D) et une cellule de Hele-Shaw (écoulement quasi-2D). L’originalité de ce travail est d’analyser l’effet du milieu poreux (lits de billes polydisperses ou mousses solides à cellules ouvertes), du confinement (1D/2D) et de la gravité en couplant des approches locales et globales développées dans les communautés de physique expérimentale et de génie chimique. D’une part, une analyse globale a permis de quantifier les pertes de charge [1] et, basée sur le transport d’un traceur fluorescent, les distributions de temps de séjour [2] et le transfert gaz-liquide dans l’expérience 1D ; d’autre part, une analyse locale de la fraction liquide et l’évolution spatio-temporelle de son contenu fréquentiel ont permis de mettre en évidence deux régimes hydrodynamiques dans le canal millifluidique [3-5] : un régime pseudo-Taylor, où les caractéristiques de l’écoulement périodique amont sont conservées, et un régime modulé, pour lequel l’écoulement se désorganise à l’entrée du milieu poreux. Un modèle phénoménologique basé sur la propagation des bulles dans le milieu est proposé, et rend compte de l’existence de ces deux régimes [4,5]. Enfin, ces deux analyses sont couplées pour étudier les écoulements dans la cellule de Hele-Shaw, et une analyse dimensionnelle de l’effet du confinement et de la gravité sur les écoulements gaz-liquide dans un milieu poreux est proposée.Références –[1] M. Serres, R. Philippe & V. Vidal, to be submitted to Geophys. Res. Lett. (2017). [2] M. Serres, D. Schweich, R. Philippe & V. Vidal, to be submitted to Chem. Eng. Sci. (2017).[3] M. Serres, R. Philippe & V. Vidal, Compte-rendus de la 19e Rencontre du Non-Linéaire, Eds. E. Falcon, M. Lefranc, F. Pétrélis & C.-T. Pham, Non-Linéaire Publications, 109-114 (2016).[4] M. Serres, M.-L. Zanota, R. Philippe & V. Vidal, Int. J. Multiphase Flow 85, 157-163 (2016).[5] M. Serres, T. Maison, R. Philippe & V. Vidal, to be submitted to Int. J. Multiphase Flow (2017)
This thesis focuses on gas-liquid flow in porous media, a common problem encountered in various domains from fundamental physics to applied chemical engineering. We have characterized the hydrodynamic regimes based on two different experimental devices geometry: a millichannel (1D flow) and a Hele-Shaw cell (2D flow). The originality of this work is to analyze the influence of the porous medium (monodisperse micro-packed beds or open cell solid foams), confinement (1D/2D) and gravity by coupling global and local analysis from either chemical engineering or fundamental physics community. On the one hand, a global analysis made it possible to quantify pressure drops, residence time distributions (RTD) based on fluorescent dye transport and gas-liquid mass transfer on the 1D device. On the other hand, a local analysis of the liquid fraction and the spatio-temporal evolution of its frequency pointed out the existence of two hydrodynamic regimes: a Taylor-like regime in which the characteristics of the periodic flow upstream are conserved in the porous medium and a modulated regime characterized by the flow disorganization at the porous medium entrance. A phenomenological model is developed based on bubbles propagation inside the medium and reproduces well both regimes. These two analyses are finally coupled to study multiphase flows inside the Hele-Shaw cell. The effects of gravity and confinement are discussed

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Braga, Maria. "Étude des phénomènes de transfert et de l'hydrodynamique dans des réacteurs agités à panier catalytique." Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10011/document.

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Parmi les différents outils de laboratoire, les réacteurs agités triphasiques à panier catalytique sont souvent utilisés pour l'acquisition de données cinétiques avec des catalyseurs mis en forme. Malgré sa large utilisation, très peu d'auteurs se sont intéressés à la caractérisation de l'hydrodynamique et des transferts de matière de ces outils. Or, dans les cas de réactions rapides, des limitations hydrodynamiques et/ou au transfert peuvent conduire à des difficultés à discriminer les catalyseurs ou à obtenir des paramètres cinétiques. L'objectif de cette étude était de connaître le domaine d'applicabilité de ces outils et présenter des pistes d'optimisation. Une méthodologie de caractérisation qui couple une étude hydrodynamique et une étude de transfert de matière a été mise en place. L'étude hydrodynamique a permis d'établir une cartographie des régimes d'écoulement gaz/liquide selon les conditions opératoires et les configurations géométriques. Cette étude a permis d'expliquer les résultats obtenus au niveau du transfert de matière, notamment, l'influence de la présence du panier et des bulles de gaz. Dans la configuration actuelle, cet outil semble être limité par le transfert liquide/solide. Ainsi, avec ce système, des études cinétiques pour des réactions avec une constante cinétique cin k pouvant aller jusqu'à 0,02 s-1 pourront être réalisées. Au-delà, l'outil sera inadapté. Pour améliorer cet outil de test, il faut optimiser le réacteur en modifiant le design du panier et de la turbine, et le diamètre de la cuve de manière à maximiser la vitesse radiale à travers du milieu poreux. Il faut aussi éviter la présence d'un régime de contournement du panier par le liquide
Stationary catalytic basket stirred reactors are often used among the various three-phase laboratory reactors for primary screening of commercial shaped catalysts. Until today, hydrodynamics and mass transfer studies concerning the impact of the presence of the basket in the flow are scarce which can be an obstacle to catalyst screening mainly in the case of fast reactions. The aim of this study is to know the range of applicability of these devices and optimize them if necessary. A characterization methodology that couples hydrodynamics and mass transfer was developed. The hydrodynamic studies allowed establishing a flow regime map of the gas/liquid flow for different reactor designs and operational conditions. This study has allowed as well understanding the influence of the basket and gas bubbles on gas/liquid and solid/liquid mass transfer. For the studied reactor, the liquid/solid mass transfer is the limiting phenomena. This system can however be used for catalyst screening for reaction rate constants smaller than 0.02 s-1. For faster reactions, these devices must be improved by changing the design of basket and impeller and the tank diameter. The optimized configuration should improve de radial flow through the porous medium and avoid the flow bypassing around the basket

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Book chapters on the topic "Gas-liquid-solid flows"

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Bourloutski, E., and M. Sommerfeld. "Euler/Lagrange Calculations of Gas-Liquid-Solid-Flows in Bubble Columns with Phase Interaction." In Bubbly Flows, 243–59. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-642-18540-3_19.

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Valentine, Brian G. "Multiphase Flow Phenomena (Gas/Solid and Gas/Liquid Systems)." In Mechanical Engineering Series, 77–95. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-68578-2_3.

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Pandit, Aniruddha. "Multiphase Phenomena and Design of Gas-Solid-Liquid Stirred Tanks." In Handbook of Multiphase Flow Science and Technology, 1–41. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-4585-86-6_50-1.

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Cavalli, Stella, Rafael F. Alves, Carlos L. Bassani, Eduardo Nunes dos Santos, Marco da Silva, Moises A. Marcelino Neto, Amadeu K. Sum, and Rigoberto E. M. Morales. "Experimental Analysis of Three-Phase Solid-Liquid-Gas Slug Flow with Hydrate-Like Particles." In Lecture Notes in Mechanical Engineering, 267–73. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-93456-9_24.

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Yonemoto, Yukihiro, and Tomoaki Kunugi. "Multi-scale Multiphase Flow Gas–Liquid–Solid Interfacial Equation Based on Thermodynamic and Mathematical Approach." In The Surface Wettability Effect on Phase Change, 317–41. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-82992-6_11.

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Hou, Rong Guo, Chuan Zhen Huang, Jun Wang, Hong Tao Zhu, and Yan Xia Feng. "Simulation of Gas-Solid-Liquid Three-Phase Flow Inside and Outside the Abrasive Water Jet Nozzle." In Materials Science Forum, 833–36. Stafa: Trans Tech Publications Ltd., 2006. http://dx.doi.org/10.4028/0-87849-421-9.833.

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Hou, Rong Guo, Chuan Zhen Huang, Li Li, Zong Wei Niu, and Zhi Yong Li. "Simulation of the Gas-Liquid-Solid Three-Phase Flow Velocity Field Outside the Abrasive Water Jet(AWJ) Rectangle Nozzle and Ellipse Nozzle." In Advances in Grinding and Abrasive Technology XIV, 470–73. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-459-6.470.

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Abiev, Rufat. "Analysis of Hydrodynamics and Mass Transfer of Gas-Liquid and Liquid-Liquid Taylor Flows in Microchannels." In Process Analysis, Design, and Intensification in Microfluidics and Chemical Engineering, 1–49. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-7138-4.ch001.

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Analysis of hydrodynamics and mass transfer Taylor flows in micro channels of both gas-liquid and liquid-liquid systems on the basis of classical theoretical approach with some simplifying assumptions was performed. Results of theoretical analysis for description of hydrodynamic parameters and mass transfer characteristics were confirmed by comparison with the author's own and available in literature experimental data. It was shown that the main parameters of two-phase Taylor flows could be quite precisely described theoretically: mean bubble/droplet velocity, liquid film thickness, real gas holdup (which is always smaller than so-called dynamic holdup), pressure drop. Peculiarities of liquid-liquid flows compared to gas-liquid Taylor flows in capillaries are discussed. Wettability effect on hydrodynamics was examined. Tools of mass transfer intensification of gas-liquid and liquid-liquid Taylor flow in micro channels are analyzed. Three-layer model for heat and mass transfer has been proposed and implemented for the case of solid-liquid mass transfer for gas-liquid Taylor flows; optimal process conditions for this process are found theoretically and discussed from physical point of view.

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Yabe, Takashi, Youichi Ogata, and Takao Kawai. "Simulation of Structure-Fluid Interaction by Universal Solver CIP for Solid, Liquid and Gas in Cartesian Grid." In Numerical Simulations of Incompressible Flows, 340–49. WORLD SCIENTIFIC, 2003. http://dx.doi.org/10.1142/9789812796837_0020.

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"Flow of Gas, Liquid and Solid." In Blast Furnace Phenomena and Modelling, 297–413. Dordrecht: Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-009-3431-3_4.

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Conference papers on the topic "Gas-liquid-solid flows"

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Zhang, Xinyu, and Goodarz Ahmadi. "Particle Effects on Gas-Liquid-Solid Flows." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-65695.

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A numerical simulation is carried out to study the role of particles in gas-liquid-solid flows in bubble columns. An Eulerian-Lagrangian model is used and the liquid flow is modeled using a volume-averaged system of governing equations, while motions of bubbles and particles are evaluated using Lagrangian trajectory analysis. It is assumed that the bubbles remain spherical. The interactions between bubble-liquid and particle-liquid are included in the study. The discrete phase equations include drag, lift, buoyancy, and virtual mass forces. Particle-particle interactions and bubble-bubble interactions are accounted for by the hard sphere model approach. The bubble coalescence is also included in the model. Neutrally buoyant particles are used in the study. A parcel approach is used and a parcel represents a certain number of particles of same size, velocity, and other properties. Variation of particle loading is modeled by changing the corresponding number of particles in every parcel. In a previous work, the predicted results were compared with the experimental data, and good agreement was obtained. The transient flow characteristics of the three-phase flow are studied and the effects of particle loading on flow characteristics are discussed. The simulations show that the transient characteristics of the three-phase flow in a column are dominated by time-dependent vortices. The particle loading can affect the characteristics of the three-phase flows and flows with high particle loading evolve faster.

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Liu, Xijie, Yap Yit Fatt, and Sami Ainane. "CFD Modeling of Erosion in Gas-Solid and Liquid-Solid Flows." In RDPETRO 2018: Research and Development Petroleum Conference and Exhibition, Abu Dhabi, UAE, 9-10 May 2018. American Association of Petroleum Geologists, Society of Exploration Geophysicists, European Association of Geoscientists and Engineers, and Society of Petroleum Engineers, 2018. http://dx.doi.org/10.1190/rdp2018-41921364.1.

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Hosokawa, Shigeo, and Akio Tomiyama. "TURBULENCE MODIFICATION IN GAS-LIQUID AND SOLID-LIQUID DISPERSED TWO-PHASE PIPE FLOWS." In Third Symposium on Turbulence and Shear Flow Phenomena. Connecticut: Begellhouse, 2003. http://dx.doi.org/10.1615/tsfp3.330.

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Zhang, Xinyu, and Goodarz Ahmadi. "Roles of Neutrally Buoyant Particles in Gas-Liquid-Solid Flows." In ASME 2012 Fluids Engineering Division Summer Meeting collocated with the ASME 2012 Heat Transfer Summer Conference and the ASME 2012 10th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/fedsm2012-72038.

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A CFD study is carried out to investigate the roles of neutrally buoyant particles in gas-liquid-solid flows in bubble columns. An Eulerian-Lagrangian model is used and the liquid flow is modeled using a volume-averaged system of governing equations, while motions of bubbles and particles are evaluated using Lagrangian trajectory analysis. Bubbles are assumed to remain spherical. Bubble-liquid interaction and particle-liquid interaction are included in the study. The drag, lift, buoyancy, and virtual mass forces are included in the discrete phase equations. Particle-particle interactions and bubble-bubble interactions are accounted for by a hard sphere model. The bubble coalescence is also included in the analysis. Neutrally buoyant particles are used in the study. The predicted results were compared with the experimental data in a previous work, and good agreement was obtained. The transient flow characteristics of a gas-liquid-solid three-phase flow and a gas-liquid two-phase flow are studied and the roles of neutrally buoyant particles are discussed. The simulations show that the transient characteristics of the flows in a bubble column are dominated by time-dependent vortices. The presence of particles can affect the characteristics of the flows and flows with particles evolve faster.

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Ahmadi, Goodarz, and Xinyu Zhang. "Three-Phase Liquid-Gas-Solid Flows in a Bubble Column." In ASME 2005 Fluids Engineering Division Summer Meeting. ASMEDC, 2005. http://dx.doi.org/10.1115/fedsm2005-77071.

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An Eulerian-Lagrangian computational model for simulations of gas-liquid-solid flows in three-phase slurry reactors is developed. In this approach, the liquid flow is modeled using a volume-averaged system of governing equations, whereas motions of bubbles and particles are evaluated by Lagrangian trajectory analysis procedure. It is assumed that the bubbles remain spherical and their shape variations are neglected. The two-way interactions between bubble-liquid and particle-liquid are included in the analysis. The discrete phase equations include drag, lift, buoyancy, and virtual mass forces. Particle-particle interactions and bubble-bubble interactions are accounted for by the hard sphere model approach. The bubble coalescence is also included in the model. The predicted results are compared with the experimental data, and good agreement is obtained. The transient flow characteristics of the three-phase flow are studied and the effects of bubble size on variation of flow characteristics are discussed. The simulations show that the transient characteristics of the three-phase flow in a column are dominated by time-dependent staggered vortices. The bubble plume moves along the S-shape path and exhibits an oscillatory behavior. While particles are mainly located outside the vortices, some bubbles and particles are retained in the vortices. Bubble upward velocities are much larger than both liquid and particle velocities. In the lower part of the column, particle upward velocities are slightly smaller than the liquid velocities, while in the upper part of the column, particle upward velocities are slightly larger. The bubble size significantly affects the characteristics of the three-phase flows and flows with larger bubbles appear to evolve faster.

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Zhang, Xinyu, and Goodarz Ahmadi. "Effects of Neutrally Buoyant Particles on Gas-Liquid-Solid Flows." In ASME 2013 Fluids Engineering Division Summer Meeting. ASME, 2013. http://dx.doi.org/10.1115/fedsm2013-16299.

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Sedrez, Thiana A., and Siamack A. Shirazi. "The Effect of Phase Interaction Forces and Particle Rotation on Solid Particle Erosion in Liquid-Solid and Liquid-Gas-Solid Flows." In ASME 2022 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/fedsm2022-86755.

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Abstract Forces acting on both gas and particle phases and the interaction between them and the liquid phase in liquid-gas-solid flow are examined via Computational Fluid Dynamics (CFD) and the results are compared with experimental data. A simplified methodology to simulate multiphase flow is proposed using the Eulerian-Eulerian-Lagrangian approach. The proposed modeling approach for the liquid-gas interaction forces and particle rotation is compared with experimental erosion data for two elbows in series. For the experiments, a 50.8 mm inner diameter pipe vertical facility with water, air, and sand particles is used to collect wall thickness loss data in two elbows in series: one elbow vertical to horizontal and another horizontal to vertical downward. The particle rotation forces in these highly rotational flows with liquid-solid flows are considered in this investigation. In addition, interphase forces between liquid and gas for dispersed-bubble flow, such as drag, surface tension, turbulent dispersion, turbulence interaction, virtual mass, and wall lubrication, were investigated. Lastly, the simulated effect of the forces on fluid velocity, particle velocity, and erosion rates are presented and discussed. The results show that rotation of particles and Magnus lift force do not significantly impact particle trajectory for liquid-solid flows. However, the Magnus lift force exerts an increase in erosion in both elbows. Overall, for liquid-gas-solid flow, interphase forces separately do not significantly impact erosion (presenting on average 24% higher erosion than experimental data). The greater change is observed when drag, virtual mass, wall lubrication, and surface tension are applied together, increasing erosion considerably (83% higher than experimental data).

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Musavian, S. M., and A. F. Najafi. "Numerical Simulations of Gas-Liquid-Solid Flows in a Hydrocyclone Separator." In ASME/JSME 2007 5th Joint Fluids Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/fedsm2007-37374.

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The flow behavior in hydrocyclones is quite complex. The Computational Fluid Dynamics (CFD) method was used to simulate the flow fields inside a hydrocyclone in order to improve its separation efficiency. In the computational fluid dynamics study of hydrocyclones, the air-core dimension is a key to predicting the mass split between the underflow and overflow. In turn, the mass split influences the prediction of the size classification curve. Three models, the k–e model, the Reynolds stress model without considering air core and Reynolds stress turbulence model with VOF multiphase model for simulating aircore, were compared for the predictions of velocity, axial and tangential velocity distributions and separation proportion. The RSM with aircore simulation model, since it produces some detailed features of the turbulence and multi phase, is clearly closer in predicting the experimental data than the other two.

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Sakaguchi, Tadashi, H. Minagawa, K. Sahara, and T. Saibe. "ESTIMATION OF VOLUMETRIC FRACTIONS OF EACH PHASE IN GAS-LIQUID-SOLID THREE-PHASE SLUG FLOW IN VERTICAL PIPES." In Dynamics of Two-Phase Flows. Connecticut: Begellhouse, 2023. http://dx.doi.org/10.1615/0-8493-9925-4.40.

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Zhang, Xinyu, and Goodarz Ahmadi. "Effects of Particle Density on Gas-Liquid-Solid Flows in Bubble Columns." In ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-21082.

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A numerical simulation is performed to study the effects of particle density on gas-liquid-solid flows in bubble columns. An Eulerian-Lagrangian model is used where the liquid flow is modeled by a volume-averaged system of governing equations and motions of particles and bubbles are modeled by Lagrangian trajectory method. Interactions between particle-particle, bubble-bubble, bubble-liquid and particle-liquid are included in the study. The drag, lift, buoyancy, and virtual mass forces are evaluated for the particles and bubbles. Particle-particle and bubble-bubble interactions are accounted for by a hard sphere model. The bubble coalescence is also included in this study. The predicted results were compared with the experimental data in a previous work, and satisfied agreement was obtained. Particles with various density are used in different cases. A parcel method is used to account for particle load. The effects of particle density on gas-liquid-solid three-phase flows are discussed based on the comparison of the transient flow characteristics of these gas-liquid-solid three-phase flows. The simulations show that large particle density may result in weak phase mixing in gas-liquid-solid three-phase flows in bubble columns.

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Reports on the topic "Gas-liquid-solid flows"

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Liu, D., and T. de Bruin. New technology for fluid dynamic measurements in gas-liquid-solid three-phase flow reactors. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1991. http://dx.doi.org/10.4095/304508.

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Svedeman. L51729 Gas Scrubber Performance Evaluation - Measurement Methods. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), April 1995. http://dx.doi.org/10.55274/r0010420.

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Scrubbers and separators are used in natural gas pipelines to remove solid and liquid materials from the gas stream. Failure to remove the entrained materials from the gas can result in equipment damage, increased pressure drop due to liquid accumulation, flow measurement errors, and corrosion. The performance of separators is rarely tested after a separator is installed because there is a lack of test instrumentation and it is difficult to conduct tests at the high pressures. The only indicators of poor separator performance are recurring problems in downstream equipment or the detection of accumulated materials in downstream piping. Instrumentation is needed that can verify separator performance when the unit is installed and to periodically monitor separator performance. The report documents results of instrument tests. The objectives of the instrument evaluations were to verify that the instruments could be used to measure particles penetrating a separator, to provide a comparative evaluation of the instruments, and to identify any measurement problems that could be encountered in field testing. One important result was that the separator minimum removable drop size increased as the operating pressure increased. This trend is not generally known, since there is a lack of test results for pressures above atmospheric pressure. The separator performance test results are documented in this report. Two different particle measuring instruments were evaluated for documenting separator performance. The two instruments were the video imaging system with automatic image analysis and the laser-based phase Doppler particle measuring system. The instruments were evaluated in laboratory tests that were conducted on a commercially available vane-type separator. The objectives of the instrument evaluations were to verify that the instruments could be used to measure particles penetrating a separator, to provide a comparative evaluation of the two instruments, and to identify any measurement problems that could be encountered in field testing. The video imaging system has a number of attractive attributes, but it was not able to measure the small diameter drops at the separator exit. The primary limitation was that the optical system could not clearly image the small drops (in the range from 5 to 30 um). The phase Doppler particle measuring system was capable of measuring all of the parameters needed to document the separator performance. Based on the instrument evaluations, future efforts on developing measurement methods for documenting separator performance should focus on adapting the phase Doppler system to field testing.

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Snyder, Victor A., Dani Or, Amos Hadas, and S. Assouline. Characterization of Post-Tillage Soil Fragmentation and Rejoining Affecting Soil Pore Space Evolution and Transport Properties. United States Department of Agriculture, April 2002. http://dx.doi.org/10.32747/2002.7580670.bard.

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Tillage modifies soil structure, altering conditions for plant growth and transport processes through the soil. However, the resulting loose structure is unstable and susceptible to collapse due to aggregate fragmentation during wetting and drying cycles, and coalescense of moist aggregates by internal capillary forces and external compactive stresses. Presently, limited understanding of these complex processes often leads to consideration of the soil plow layer as a static porous medium. With the purpose of filling some of this knowledge gap, the objectives of this Project were to: 1) Identify and quantify the major factors causing breakdown of primary soil fragments produced by tillage into smaller secondary fragments; 2) Identify and quantify the. physical processes involved in the coalescence of primary and secondary fragments and surfaces of weakness; 3) Measure temporal changes in pore-size distributions and hydraulic properties of reconstructed aggregate beds as a function of specified initial conditions and wetting/drying events; and 4) Construct a process-based model of post-tillage changes in soil structural and hydraulic properties of the plow layer and validate it against field experiments. A dynamic theory of capillary-driven plastic deformation of adjoining aggregates was developed, where instantaneous rate of change in geometry of aggregates and inter-aggregate pores was related to current geometry of the solid-gas-liquid system and measured soil rheological functions. The theory and supporting data showed that consolidation of aggregate beds is largely an event-driven process, restricted to a fairly narrow range of soil water contents where capillary suction is great enough to generate coalescence but where soil mechanical strength is still low enough to allow plastic deforn1ation of aggregates. The theory was also used to explain effects of transient external loading on compaction of aggregate beds. A stochastic forInalism was developed for modeling soil pore space evolution, based on the Fokker Planck equation (FPE). Analytical solutions for the FPE were developed, with parameters which can be measured empirically or related to the mechanistic aggregate deformation model. Pre-existing results from field experiments were used to illustrate how the FPE formalism can be applied to field data. Fragmentation of soil clods after tillage was observed to be an event-driven (as opposed to continuous) process that occurred only during wetting, and only as clods approached the saturation point. The major mechanism of fragmentation of large aggregates seemed to be differential soil swelling behind the wetting front. Aggregate "explosion" due to air entrapment seemed limited to small aggregates wetted simultaneously over their entire surface. Breakdown of large aggregates from 11 clay soils during successive wetting and drying cycles produced fragment size distributions which differed primarily by a scale factor l (essentially equivalent to the Van Bavel mean weight diameter), so that evolution of fragment size distributions could be modeled in terms of changes in l. For a given number of wetting and drying cycles, l decreased systematically with increasing plasticity index. When air-dry soil clods were slightly weakened by a single wetting event, and then allowed to "age" for six weeks at constant high water content, drop-shatter resistance in aged relative to non-aged clods was found to increase in proportion to plasticity index. This seemed consistent with the rheological model, which predicts faster plastic coalescence around small voids and sharp cracks (with resulting soil strengthening) in soils with low resistance to plastic yield and flow. A new theory of crack growth in "idealized" elastoplastic materials was formulated, with potential application to soil fracture phenomena. The theory was preliminarily (and successfully) tested using carbon steel, a ductile material which closely approximates ideal elastoplastic behavior, and for which the necessary fracture data existed in the literature.

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Lahav, Ori, Albert Heber, and David Broday. Elimination of emissions of ammonia and hydrogen sulfide from confined animal and feeding operations (CAFO) using an adsorption/liquid-redox process with biological regeneration. United States Department of Agriculture, March 2008. http://dx.doi.org/10.32747/2008.7695589.bard.

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The project was originally aimed at investigating and developing new efficient methods for cost effective removal of ammonia (NH₃) and hydrogen sulfide (H₂S) from Concentrated Animal Feeding Operations (CAFO), in particular broiler and laying houses (NH₃) and hog houses (H₂S). In both cases, the principal idea was to design and operate a dedicated air collection system that would be used for the treatment of the gases, and that would work independently from the general ventilation system. The advantages envisaged: (1) if collected at a point close to the source of generation, pollutants would arrive at the treatment system at higher concentrations; (2) the air in the vicinity of the animals would be cleaner, a fact that would promote animal growth rates; and (3) collection efficiency would be improved and adverse environmental impact reduced. For practical reasons, the project was divided in two: one effort concentrated on NH₃₍g₎ removal from chicken houses and another on H₂S₍g₎ removal from hog houses. NH₃₍g₎ removal: a novel approach was developed to reduce ammonia emissions from CAFOs in general, and poultry houses in particular. Air sucked by the dedicated air capturing system from close to the litter was shown to have NH₃₍g₎ concentrations an order of magnitude higher than at the vents of the ventilation system. The NH₃₍g₎ rich waste air was conveyed to an acidic (0<pH<~5) bubble column reactor where NH₃ was converted to NH₄⁺. The reactor operated in batch mode, starting at pH 0 and was switched to a new acidic absorption solution just before NH₃₍g₎ breakthrough occurred, at pH ~5. Experiments with a wide range of NH₃₍g₎ concentrations showed that the absorption efficiency was practically 100% throughout the process as long as the face velocity was below 4 cm/s. The potential advantages of the method include high absorption efficiency, lower NH₃₍g₎ concentrations in the vicinity of the birds, generation of a valuable product and the separation between the ventilation and ammonia treatment systems. A small scale pilot operation conducted for 5 weeks in a broiler house showed the approach to be technically feasible. H₂S₍g₎ removal: The main goal of this part was to develop a specific treatment process for minimizing H₂S₍g₎ emissions from hog houses. The proposed process consists of three units: In the 1ˢᵗ H₂S₍g₎ is absorbed into an acidic (pH<2) ferric iron solution and oxidized by Fe(III) to S⁰ in a bubble column reactor. In parallel, Fe(III) is reduced to Fe(II). In the 2ⁿᵈ unit Fe(II) is bio-oxidized back to Fe(III) by Acidithiobacillus ferrooxidans (AF).In the 3ʳᵈ unit S⁰ is separated from solution in a gravity settler. The work focused on three sub-processes: the kinetics of H₂S absorption into a ferric solution at low pH, the kinetics of Fe²⁺ oxidation by AF and the factors that affect ferric iron precipitation (a main obstacle for a continuous operation of the process) under the operational conditions. H₂S removal efficiency was found higher at a higher Fe(III) concentration and also higher for higher H₂S₍g₎ concentrations and lower flow rates of the treated air. The rate limiting step of the H₂S reactive absorption was found to be the chemical reaction rather than the transition from gas to liquid phase. H₂S₍g₎ removal efficiency of >95% was recorded with Fe(III) concentration of 9 g/L using typical AFO air compositions. The 2ⁿᵈ part of the work focused on kinetics of Fe(II) oxidation by AF. A new lab technique was developed for determining the kinetic equation and kinetic parameters (KS, Kₚ and mₘₐₓ) for the bacteria. The 3ʳᵈ part focused on iron oxide precipitation under the operational conditions. It was found that at lower pH (1.5) jarosite accumulation is slower and that the performance of the AF at this pH was sufficient for successive operation of the proposed process at the H₂S fluxes predicted from AFOs. A laboratory-scale test was carried out at Purdue University on the use of the integrated system for simultaneous hydrogen sulfide removal from a H₂S bubble column filled with ferric sulfate solution and biological regeneration of ferric ions in a packed column immobilized with enriched AFbacteria. Results demonstrated the technical feasibility of the integrated system for H₂S removal and simultaneous biological regeneration of Fe(III) for potential continuous treatment of H₂S released from CAFO. NH₃ and H₂S gradient measurements at egg layer and swine barns were conducted in winter and summer at Purdue. Results showed high potential to concentrate NH₃ and H₂S in hog buildings, and NH₃ in layer houses. H₂S emissions from layer houses were too low for a significant gradient. An NH₃ capturing system was designed and tested in a 100-chicken broiler room. Five bell-type collecting devices were installed over the litter to collect NH₃ emissions. While the air extraction system moved only 10% of the total room ventilation airflow rate, the fraction of total ammonia removed was 18%, because of the higher concentration air taken from near the litter. The system demonstrated the potential to reduce emissions from broiler facilities and to concentrate the NH₃ effluent for use in an emission control system. In summary, the project laid a solid foundation for the implementation of both processes, and also resulted in a significant scientific contribution related to AF kinetic studies and ferrous analytical measurements.

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