Download or read book Hydrodynamique des colonnes bulles fonctionnant co courant de gaz et de liquide written by and published by . This book was released on 2000 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'étude réalisée met en évidence l'effet d'un garnissage spécifique en inox sur l'hydrodynamique des colonnes à bulle fonctionnant à co-courant ascendant de gaz et de liquide. Dans une première partie, les paramètres - clés de l'hydrodynamique, à savoir la rétention de gaz, le régime d'écoulement, le diamètre des bulles, la vitesse de glissement du gaz et le coefficient de dispersion axiale du liquide, ont été déterminés en absence du garnissage, et ce pour deux diamètres de colonnes différents (15 et 20 cm) et deux types de distributeur de gaz (membrane et plaque percée). Une approche adimensionnelle permettant de décrire le mélange axial de la phase liquide a été établie. L'application de cette approche sur des données de la littérature donne des résultats satisfaisants. Dans la deuxième partie, les mesures ont été réalisées sur les mêmes colonnes à bulles en présence du garnissage. Les résultats obtenus ont montré que ce type de garnissage affecte la distribution radiale de la rétention de gaz et la taille de bulles, donc le régime d'écoulement. Le diamètre de Sauter obtenu, notamment avec la plaque percée, a considérablement diminué en présence du garnissage. Etant fortement conditionnées par le comportement hydrodynamique de la phase gaz, les valeurs du mélange axial de la phase liquide ont diminué en présence du garnissage. L'introduction du garnissage spécifique en inox modifie l'hydrodynamique des colonnes à bulles en homogénéisant les populations de bulles orientant ainsi le mélange de la phase liquide vers un écoulement de type piston.
Download or read book Hydrodynamique des colonnes garnissage avec coulements de gaz et de liquide co courant et contre courant written by Jean-Claude Charpentier (chemicus.) and published by . This book was released on 1968 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrodynamique des colonnes garnissage avec coulements de gaz et de liquide co courant et contre courant written by Jean-Claude Charpentier and published by . This book was released on 1968 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Le travail que nous présentons sur les colonnes à garnissages porte plus particulièrement sur les aspects statique et dynamique de la texture du liquide et sur la mécanique des écoulements diphasés à co-courant vers le bas. Toutefois une étude complète de ces grandeurs est impossible sans avoir présenté au préalable les propriétés hydrodynamiques des écoulements monophasés de gaz, ruissellant de liquide et diphasés de gaz et de liquide à co-courant et contre-courant. C'est ce que nous ferons très succintement au chapitre I après avoir décrit le poste et les conditions expérimentales de mesure. Le chapitre II porte sur la rétention du liquide et introduit un nouveau modèle représentatif de sa texture sous forme de films, de filets et de gouttes. Au chapitre III, on présente une étude sur la distribution axiale des temps de séjour des élements du liquide faite en commun avec un autre chercheur de notre groupe, M. Van Swaaij dont le travail a porté plus généralement sur le mélangeage axial et radial du liquide et du gaz dans les colonnes à garnissage. Au chapitre IV on trouvera dans le cas particulier de l'écoulement ruisselant du liquide une application dynamique de l'aspect statique des textutres ; on détermine en effet les vitesses et les débits du liquide qui s'écoulent sous forme de films, de filets et de gouttes et on compare les résultats avec ceux des mesures de distribution des temps de séjour. Le chapitre V porte sur l'hydrodynamique des écoulements diphasés à co-courant vers le bas et sur l'application des formules de la littérature au cas des colonnes arrosées.
Download or read book Hydrodynamique des colonnes garnissage avec coulements de gaz et de liquide co courant et contre courant written by Jean-Claude Charpentier and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analyse de stabilit et simulation num rique des colonnes bulles written by Elisabeth Léon-Becerril and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: L'objectif de la thèse est la simulation numérique de l'hydrodynamique et du mélange en colonnes à bulles. En régime homogène, les bulles de gaz montent uniformément; en augmentant le débit de gaz, le régime devient hétérogène avec la présence de "grosses" structures. Ces structures ont un caractère instationnaire et contribuent au mélange. Il s'agit donc de simuler ces structures. La première partie explique l'apparition des "grosses" structures à partir d'une analyse de stabilité d'une colonne à bulles. Un régime d'écoulement permanent et établi est perturbé. L'analyse détermine dans quelles conditions la perturbation s'amplifie. Notre approche permet d'unifier des travaux antérieurs et d'expliquer les différences entre les modèles. Le rôle prépondérant de la déformation des bulles est intégré à l'analyse de stabilité. L'analyse est validée à partir de mesures de la vitesse du gaz et la vitesse de propagation des ondes, à différentes vitesses de liquide. L'analyse de stabilité permet aussi de déterminer la transition entre régimes d'écoulement en colonne à bulles et en conduite. La deuxième partie est consacrée à la simulation numérique. Des simulations ont été menées dans un système parallélépipédique, fermé au liquide, avec une injection de gaz ponctuelle. La prédiction de "grosses" structures en présence d'un panache gazeux est validée avec les travaux de Sokolichin & Eigenberger (1994). Nous retrouvons le rôle déterminant de la modélisation de la masse ajoutée. Nous avons simulé une colonne à bulle de section rectangulaire, fermée au liquide avec une injection de gaz uniforme, en testant différentes options de modélisation de la traînée et de la masse ajoutée. A ces simulations de l'hydrodynamique ont été couplés des traçages effectués sur une hydrodynamique instationnaire qui démontrent le rôle essentiel des "grosses" structures sur le mélange dans une colonne à bulles.
Download or read book Hydrodynamique locale et globale d une colonne bulles en conditions industrielles written by Hélène Chaumat and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effet des caract ristiques physiques des mat riaux sur l hydrodynamique et le transfert de mati re des lits fixes fonctionnant co courant ascendant de gaz et de liquide written by and published by . This book was released on 2005 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Airlift Bioreactors written by M. Y. Chisti and published by Springer. This book was released on 1989-02-28 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Faecal Sludge Management written by Linda Strande and published by IWA Publishing. This book was released on 2014-08-15 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is estimated that literally billions of residents in urban and peri-urban areas of Africa, Asia, and Latin America are served by onsite sanitation systems (e.g. various types of latrines and septic tanks). Until recently, the management of faecal sludge from these onsite systems has been grossly neglected, partially as a result of them being considered temporary solutions until sewer-based systems could be implemented. However, the perception of onsite or decentralized sanitation technologies for urban areas is gradually changing, and is increasingly being considered as long-term, sustainable options in urban areas, especially in low- and middle-income countries that lack sewer infrastructures. This is the first book dedicated to faecal sludge management. It compiles the current state of knowledge of the rapidly evolving field of faecal sludge management, and presents an integrated approach that includes technology, management, and planning based on Sandecs 20 years of experience in the field. Faecal Sludge Management: Systems Approach for Implementation and Operation addresses the organization of the entire faecal sludge management service chain, from the collection and transport of sludge, and the current state of knowledge of treatment options, to the final end use or disposal of treated sludge. The book also presents important factors to consider when evaluating and upscaling new treatment technology options. The book is designed for undergraduate and graduate students, and engineers and practitioners in the field who have some basic knowledge of environmental and/or wastewater engineering.
Download or read book Bubble Column Reactions written by Wolf-Dieter Deckwer and published by John Wiley & Sons. This book was released on 1992-04-08 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: This technology, though used for many years, has shown great vitality recently and is still in a state of flux. Provides an account of developments up to the present and also an orderly evaluation of literature already published on the subject. Considerable space is devoted to bubble column reactor performance predictions based on mathematical models and the importance of each is explained with practical examples.
Download or read book Gas cooled Nuclear Reactors written by France. Commissariat à l'énergie atomique and published by . This book was released on 2006 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book From Microphysics to Macrophysics written by Roger Balian and published by Springer Science & Business Media. This book was released on 2007-06-26 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt: This popular, often cited text returns in a softcover edition to provide a thorough introduction to statistical physics and thermodynamics, and to exhibit the universal chain of ideas leading from the laws of microphysics to the macroscopic behaviour of matter. A wide range of applications illustrates the concepts, and many exercises reinforce understanding. Volume II applies statistical methods to systems governed by quantum effects, in particular to solid state physics, explaining properties due to the crystal structure or to the lattice excitations or to the electrons. The last chapters are devoted to non-equilibrium processes and to kinetic equations, with many applications included.
Download or read book Management of Complications in Ophthalmic Plastic Surgery written by David B. Soll and published by . This book was released on 1976 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Four Laws That Drive the Universe written by Peter Atkins and published by OUP Oxford. This book was released on 2007-09-06 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: The laws of thermodynamics drive everything that happens in the universe. From the sudden expansion of a cloud of gas to the cooling of hot metal, and from the unfurling of a leaf to the course of life itself - everything is directed and constrained by four simple laws. They establish fundamental concepts such as temperature and heat, and reveal the arrow of time and even the nature of energy itself. Peter Atkins' powerful and compelling introduction explains what the laws are and how they work, using accessible language and virtually no mathematics. Guiding the reader from the Zeroth Law to the Third Law, he introduces the fascinating concept of entropy, and how it not only explains why your desk tends to get messier, but also how its unstoppable rise constitutes the engine of the universe.
Download or read book Multiphase Catalytic Reactors written by Zeynep Ilsen Önsan and published by John Wiley & Sons. This book was released on 2016-06-09 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a holistic approach to multiphase catalytic reactors from their modeling and design to their applications in industrial manufacturing of chemicals Covers theoretical aspects and examples of fixed-bed, fluidized-bed, trickle-bed, slurry, monolith and microchannel reactors Includes chapters covering experimental techniques and practical guidelines for lab-scale testing of multiphase reactors Includes mathematical content focused on design equations and empirical relationships characterizing different multiphase reactor types together with an assortment of computational tools Involves detailed coverage of multiphase reactor applications such as Fischer-Tropsch synthesis, fuel processing for fuel cells, hydrotreating of oil fractions and biofuels processing
Download or read book How to Design Wastewater Systems for Local Conditions in Developing Countries written by David M. Robbins and published by IWA Publishing. This book was released on 2014-03-15 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a practical handbook providing a step-by-step approach to the techniques used for characterizing wastewater sources and investigating sites where collection, treatment and reuse/disposal technologies will be installed. It is intended to help enable local implementation of on-site and decentralized wastewater management system (DWMS)for wide scale use in development settings. How to Design Wastewater Systems for Local Conditions in Developing Countries helps local service providers and regulatory officials make informed decisions through the use of tools, checklists and case studies. It includes a link to a web based community of on-site and decentralized wastewater professionals, which contains related tools and case studies. This handbook serves as a reference for training classes, certification programs, and higher education programs in civil and sanitary engineering. There is an increasing interest on the part of local government officials and private sector service providers to implement wastewater treatment systems to solve sanitation problems. The model presented in this handbook promotes activities that first generate data related to source and site conditions that represent critical inputs, and then applies this information to the technology selection process. Matching the most appropriate technologies to the specific needs of the wastewater project is the key that leads to long term sustainability. How to Design Wastewater Systems for Local Conditions in Developing Countries is an invaluable resource for public sector decision makers and private sector service providers in developing countries. It is also a useful text for students at engineering colleges in developing countries interested in taking a class that teaches the methods of decentralized wastewater management system (DWMS) development.
Download or read book Philostratus written by Philostratus (the Athenian) and published by . This book was released on 1912 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
