O presente trabalho apresenta um estudo associado à separação de gás para escoamento gás-líquido em um duto anular inclinado. Esse tipo de escoamento e geometria são encontrados em separadores de gás do tipo shroud invertido na indústria de petróleo quando utilizadas técnicas de bombeamento para a exploração de poços. A presença de gás livre a montante da bomba é uma das maiores limitações dos sistemas de bombeamento, por acarretar cavitação e falhas dinâmicas nos equipamentos. O presente estudo tem por objetivo garantir a separação total de gás livre a montante da bomba através da proposição de um separador do tipo shroud invertido em tubulação inclinada para aplicação na exploração de petróleo em poços direcionais. Um estudo experimental com ar e água como fluidos de trabalho a pressão quase atmosférica foi desenvolvido visando a compreensão da fenomenologia do separador shroud invertido. Foram observados escoamentos em duto anular do tipo: bifásico gás-líquido ascendente, monofásico em canal livre e bifásico gás-líquido descendente devido ao fenômeno de aeração; foram coletados também dados de eficiência de separação em função do ângulo de inclinação, vazão do líquido e queda de pressão entre o shroud e a saída do tubo de produção. Encontrou-se uma variável de extrema importância no fenômeno de separação até agora não reportada na literatura: o nível do anular interno do shroud (NAI). Um modelo fenomenológico que prevê a separação total do gás foi desenvolvido a partir da interpretação dos fenômenos físicos observados experimentalmente. Uma correlação inédita para a modelagem do fenômeno de dissipação de energia cinética turbulenta vinculado à separação do gás é proposta. O modelo foi validado qualitativamente com dados da literatura e ajustado com os dados coletados neste trabalho, mostrando boa concordância. / This paper presents a study associated with gas separation in an inclined gas-liquid annular-duct flow. This type of flow and geometry are found in shroud-inverted gas separators applied to petroleum industries when using pumping technique for oil production. High void fraction at the pump suction of is one of the most important limitations of the SCP technique, causing cavitation and dynamics failures in the equipment. The present study aims to provide a solution for the total gas separation through the use of an innovative inclined inverted-shroud separator for directional wells. An experimental study, where air and water at near atmospheric pressure constituted the working fluids, was carried out to understand the phenomenology of the inclined inverted-shroud separator. Different annular-duct flows were observed: upward gas-liquid flow, single-phase open channel flow, downward gas-liquid flow due to the phenomenon of aeration; also new data of separation efficiency were collected as a function of inclination angle, liquid flow rate and pressure drop between the shroud and production pipe outlet. One of the most significant findings is that the liquid level of the inner annular channel (NAI) of the shroud is a very important variable in the phenomenon of separation; so far this was not reported in the literature. Based on the observations, a phenomenological model that predicts total gas separation is proposed. A new correlation for the modeling of the dissipation of turbulent kinetic energy associated with the gas separation is presented. The model was qualitatively compared with available data from the literature and quantitatively adjusted against the new experimental data obtained in this work, and the agreement was quite good.

O escoamento líquido-líquido, em especial o escoamento óleo-água, vem atraindo a atenção de pesquisadores devido à alta demanda pelo combustível fóssil no atual cenário petrolífero mundial e nacional. Os desafios tecnológicos colocados pelas descobertas de reservas de óleos pesados e altamente viscosos consideram, em especial, a preocupação por minimizar as perdas energéticas nas linhas. Emulsões inversas ou dispersões óleo-em-água, na qual o óleo se encontra disperso de maneira uniforme em água, caracteriza-se pela baixa viscosidade aparente, tornando-se um tipo de emulsão desejável em algumas etapas do transporte de petróleo. Esses fatos tornam essencial o estudo deste tipo de padrão para o dimensionamento e operação ótima de dutos de produção de petróleo. Contudo, não existe ainda um número abrangente de trabalhos sobre padrão disperso líquido-líquido, ao comparar com escoamento em fases separadas. Trabalhos sobre dispersões têm reportado redução de atrito sem a adição de substâncias químicas em regime turbulento. No entanto, não há ainda um entendimento satisfatório do fenômeno. Na maioria dos trabalhos, sendo quase todos realizados com óleos leves e pouco viscosos, a redução é reportada em dispersões água-em-óleo, com escassos trabalhos reportando o fenômeno em dispersões óleo-em-água. A pesquisa realizada tratou do estudo experimental e teórico de dispersões óleo-em-água em tubulações. O escoamento foi caracterizado a partir da obtenção de dados de holdup, gradiente de pressão por fricção, distribuição das fases e padrão de escoamento. Uma teoria foi proposta para explicar a redução de atrito detectada neste trabalho, baseada na existência de um filme fino de água que escoa em contato com a parede do tubo, a baixos números de Reynolds, evitando o contato direto do núcleo turbulento (mistura bifásica) com a parede do tubo. O referido filme líquido foi detectado e quantificado utilizando-se técnica visual. Além disso, um modelo dinâmico baseado na teoria de lubrificação hidrodinâmica foi desenvolvido como tentativa de explicar a formação do filme líquido parietal no escoamento turbulento de dispersões óleo-água. / Liquid-liquid flow, especially oil-water flow, has attracted the attention of researchers due to the high demand for petroleum in the current global scenario. The discovery of reserves of heavy and highly viscous oils creates new challenges which are mainly concerned with reducing the significant pressure drop in pipes. Inverse emulsion or oil-in-water dispersions in which the oil is dispersed in water is characterized by its low effective viscosity, making it a desirable type of emulsion in some steps of oil production. These facts make the study of dispersed liquid-liquid flow essential for the design and optimal operation of oil pipelines. However, the studies on such flow pattern are scanty in comparison to those on separate flows, as stratified and annular flow patterns. Drag reduction in oil-water turbulent flow without the addition of any chemical substance has been reported in some studies. This phenomenon has received increasing attention in recent years, because there is not a satisfactory understanding of its dynamics yet. Most studies, almost all using light oils, report drag reduction in dispersion of water-in-oil, with few studies reporting the phenomenon in oil-in-water dispersions. This research comprises an experimental and theoretical study on oil-in-water dispersions in pipes. Pressure gradient, holdup, phase distribution and flow patterns data were obtained to characterize the two-phase flow. A theory was proposed to explain the drag reduction detected in this work, based on the existence of a thin water film flowing in contact with the pipe wall at low Reynolds numbers, avoiding contact between the turbulent core (mixture) and the pipe wall. The liquid film was detected and quantified using visual technique. In addition, a dynamic model based on the hydrodynamic lubrication theory was developed as an attempt to explain the formation of the liquid film.

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

L’extrapolation des réacteurs catalytiques nécessite l’acquisition des données cinétiques sur des réacteurs à petite échelle dans les conditions opératoires industrielles. Le critère de dimensionnement utilisé lors de la réduction d’échelle est la conservation de la vitesse volumique horaire, ce qui conduit à des vitesses de circulation très faibles dans les réacteurs pilotes à lit-fixe. A ces vitesses, les flux de transfert de matière externes peuvent devenir limitant par rapport au flux de réaction. Dans ce contexte, une nouvelle géométrie de réacteur a été imaginée pour intensifier les transferts de matière et chaleur et pour augmenter les vitesses de circulation des fluides : le réacteur "filaire". Il s’agit d’un réacteur dont le diamètre est égal ou proche de celui des grains de catalyseur et avec un ratio longueur sur diamètre très élevé. Le principal objectif de cette thèse est de caractériser ce réacteur en termes d’hydrodynamique et de transferts de matière externes pour définir ses limites d’utilisation. En écoulement diphasique, ce réacteur est relativement piston et la rétention liquide est élevée, ce qui permet d'assurer un mouillage total du catalyseur. En ce qui concerne les vitesses des transferts de matière externe, celles-ci sont proches de celles d'un réacteur agité avec panier et sont supérieures à celles caractéristiques d'un réacteur pilote à lit-fixe conventionnel. Cette observation est liée à l’augmentation des vitesses locales du liquide et à la présence d'un écoulement du type Taylor modifié. En conclusion, le réacteur "filaire" constitue une alternative efficace aux réacteurs pilotes à lit-fixe pour l’étude de catalyseurs mis en forme. / Small size fixed-bed reactors are a common choice for testing industrial supported catalyst under industrial operating conditions. The most common criterion for reactor’s scale-down is based on the conservation of the liquid hourly space velocity which leads to a very low fluid flow velocity at the laboratory scale. Under these conditions, the external mass transfer flux can become the limiting step of the process. In this context, a new reactor geometry was proposed to intensify mass and heat transfers and to increase fluid flow velocities: the single pellet string reactor. This reactor is composed of a tube with an internal diameter close to that of the catalyst particles and with a high length over diameter ratio. The main goal of this thesis is to characterise the hydrodynamic and external mass transfer performances of this new reactor in order to define its application domain. In two-phase gas-liquid flow, the reactor flow is plug flow and the liquid hold-up values are high, which insures a complete wetting of the catalyst particles. The mass transfer coefficients were quantified and the measured rates are much higher than those observed in conventional pilot fixed-bed reactors, which can be explained by the increased local liquid velocities and by the modified Taylor flow regime. Catalytic tests with a very fast model reaction revealed that the external mass transfer performances of the single pellet string reactor are close to those measured in a stirred tank reactor equipped with a catalytic basket. In conclusion, the single pellet string reactor represents a new and efficient alternative to fixed-bed pilot reactors to study shaped catalysts.

Kraft recovery boiler smelt is shattered into small droplets by an impinging steam jet to prevent smelt-water explosions in the dissolving tank. Inadequate shattering increases the likelihood of dissolving tank explosions. While industry has not dedicated much effort to smelt shattering, the safety implications require smelt shattering to be studied in detail. An experimental set-up was constructed to simulate the shattering operation using a water-glycerine solution and air instead of smelt and steam respectively. The objective was to examine how physical properties and flow characteristics affect shattering. It was found that increasing shatter jet velocity greatly reduced droplet mean diameter. Increasing the liquid flow rate greatly increased droplet size, as expected. Shattering was not significantly affected by viscosity, unless a weak shatter jet was used on a highly viscous fluid. Increasing the proximity of the shatter jet nozzle decreased droplet size.

Seit mehr als einem Jahrhundert ist ein wachsendes wissenschaftliches Interesse an Tropfen und den Vorgängen bei deren Aufprall auf die verschiedensten Substrate zu verzeichnen, wohl auch durch die Fotografien von Worthington (1908) ausgelöst. Inzwischen wurden viele Erkenntnisse durch große Fortschritte bei der experimentellen Untersuchung (z.B. mittels Hochgeschwindigkeitsaufnahmen) und durch theoretische und computergestützte Untersuchung (z.B. durch skalenfreie und numerische Modellierung) gewonnen. Trotzdem bleibt durch die Vielfältigkeit und Komplexität der Phänomene während des Tropfenaufpralls sowie wegen der ständig erweiterten Anwendungsbereiche dieses Forschungsgebiet hochaktuell. Insbesondere sehr kleine und gleichzeitig sehr schnelle Tropfen (Tropfendurchmesser 10µm bis 100µm, Tropfengeschwindigkeit 10m/s bis 100m/s) kommen in vielen modernen Anwendungen vor (z.B. Verbrennungsmotoren, Tintenstrahldrucker, Reinigung von Oberflächen). In diesem wichtigen, aber für Untersuchungen schwer zugänglichen Parameterbereich gibt es immer noch offene Fragen. Die vorliegende Arbeit beschäftigt sich daher mit diesen schnellen Mikrotropfen in Bezug auf ihre Herstellung und den Aufprallvorgang auf ein festes, trockenes oder benetztes Substrat. Zunächst wird eine Methode zur Erzeugung eines Hochgeschwindigkeitssprays realisiert, welche auf dem durch Ultraschall gesteuerten Plateau-Rayleigh-Zerfall eines Flüssigkeitsstrahls beruht. Sie ermöglicht es, sowohl Tropfengröße als auch –geschwindigkeit präzise und mit hoher Reproduzierbarkeit über den gesamten oben angegebenen Parameterbereich einzustellen. Durch gezielte Manipulation eines Einzeltropfens durch elektrische Felder wird anschließend der Tropfenaufprall auf Substrate unterschiedlicher Benetzbarkeit mit sehr hoher zeitlicher Auflösung (ca. 100 Mio. Bilder pro Sekunde) bei gleichzeitig hoher räumlicher Auflösung (< 1µm) untersucht. Es zeigt sich, dass bekannte Modelle für langsamere und größere Tropfen im Millimeterbereich auch für schnelle Mikrotropfen Gültigkeit behalten. Somit ist bei gleichen dimensionslosen Kennzahlen (z.B. Reynolds-Zahl, Weber-Zahl, Ohnesorge-Zahl) eine skalenfreie Beschreibung des Tropfenaufpralls möglich. Schließlich wird die Methode zur Tropfenerzeugung auf einen für Anwendungen in der Reinigung relevanten Fall übertragen. Hierbei geht es um den Tropfenaufprall auf ein von einem Flüssigkeitsfilm überströmten Substrat. Es werden die während des Auftreffvorgangs auftretenden Geschwindigkeiten in der sich bildenden radialen Strömung in Abhängigkeit von verschiedenen Prozessparametern bestimmt. Aus den Ergebnissen lassen sich Aussagen über die zu erwartende Reinigungswirkung durch derartige Tropfen und den Einfluss der Prozessparameter treffen.

Kraft recovery boiler smelt is shattered into small droplets by an impinging steam jet to prevent smelt-water explosions in the dissolving tank. Inadequate shattering increases the likelihood of dissolving tank explosions. While industry has not dedicated much effort to smelt shattering, the safety implications require smelt shattering to be studied in detail. An experimental set-up was constructed to simulate the shattering operation using a water-glycerine solution and air instead of smelt and steam respectively. The objective was to examine how physical properties and flow characteristics affect shattering. It was found that increasing shatter jet velocity greatly reduced droplet mean diameter. Increasing the liquid flow rate greatly increased droplet size, as expected. Shattering was not significantly affected by viscosity, unless a weak shatter jet was used on a highly viscous fluid. Increasing the proximity of the shatter jet nozzle decreased droplet size.

This diploma thesis describes a JSD600 unit intended for mathematical processing, measuring and data recording. The JSD600 unit is highly intended for industrial measuring of water steam energy delivery.First part of the work focuses on basics of the JSD600 unit detailing and describing main structures and principles for relevant data storing.Next part summarizes some basic facts and knowledge from the area of industrial liquid flow, energy measuring and describes water steam states. All these points within this range are needed for dilemma understanding.Last task deals with complete list of communication datagrams, which have been used for communication with JSD600 unit, including a main packet of structure descriptions.The second part of this dissertation brings the unit setup application description including some implementation details of the most interesting parts.