In this article, droplet size and its distribution along a pulsed liquid–liquid extraction column, is studied where SiO2 nanoparticles with concentrations of 0.01, 0.05 and 0.1 vol.% and different hydrophobicities are applied to the dispersed phase. Using ultrasonication, nanoparticles were dispersed in kerosene as the base fluid. Nanofluids' stability was ensured using a UV–vis spectrophotometer. Some 22,000 droplets were measured by photographic technique and results were compared with systems containing no‐nanoparticles (Water–Acetic acid–Kerosene). Addition of nanoparticles changed the droplet shape from ellipsoidal to spherical. Also, there was a marked influence on droplet breakage and droplet coalescence at 0.01 vol.%, and 0.05 vol.% or higher volume fractions, respectively. © 2012 Canadian Society for Chemical Engineering

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A rotating disc contactor with inner diameter of 91 mm and 21 compartments was used to investigate local and average static hold-ups in the column. Three chemical systems, including distilled water as stagnant continuous phase and toluene, kerosene, and butyl acetate as dispersed phase, in case of no mass transfer, were applied. Different parameters consisting of drop size and static hold-up were measured experimentally under various operating conditions, and two dimensionless correlations for estimation of local static hold-up as a function of average mother drop size, physical properties, rotor speed, and stage number were proposed in two cases: (1) immovable and (2) rotating rotor discs. Furthermore, two dimensionless correlations were presented to estimate average static hold-up as a function of average mother drop size, physical properties, rotor speed, and number of stages in the column in the two aforementioned conditions. Un contacteur de disque rotatif avec un diamètre interne de 91 mm et 21 compartiments aété utilisé pourétudier les retenues statiques locales et moyennes dans la colonne. Trois systèmes chimiques, y compris de l'eau distillée comme phase continue stagnante et du toluène, du kérosène et de l'acétate de butyle comme phase dispersée, en cas d'aucun transfert de masse, ontété utilisés. Différents paramètres composés de la dimension des gouttes et la retenue statique ontété mesurés de façon expérimentale selon diverses conditions de fonctionnement et deux corrélations adimensionnelles pour l'estimation de la retenue statique locale comme fonction de la dimension de la goutte mère moyenne, des propriétés physiques, du régime rotor et du nombre d'étapes ontété proposées dans deux cas: (1) disques du rotor fixes et (2) rotatifs. De plus, deux corrélations adimensionnelles ontété présentées pour estimer la retenue statique moyenne comme fonction de la dimension de la goutte mère moyenne, des propriétés physiques, du régime rotor et du nombre d'étapes dans la colonne dans les deux conditions mentionnées précédemment.

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Five different nanofluids have been prepared by use of two‐step procedure, in which SiO2 nanoparticles with different volume fractions and hydrophobicities have been dispersed in butyl acetate as base fluid by applying ultrasonication method. Three different methods have been used to evaluate the nanofluids' stability: conventional sedimentation method, particle size analyser and UV‐Vis spectrophotometric. As a quite novel research, these nanofluids were applied to a Rotary Disc Contactor with 91 mm diameter and 12 rotating discs to investigate breakage probability and the first critical rotor speed. The effects of nanoparticles' volume fraction and hydrophobicity, as well as rotor speed, mother drop size and continuous phase height on the breakage phenomenon have been studied. © 2011 Canadian Society for Chemical Engineering

A rotary disc contactor with 9.1 cm inner diameter and 28 compartments has been used to investigate the effect of continuous phase height on the first and second critical rotor speeds, as well as breakage probability by using 12 different chemical systems, in case of mass transfer and no mass transfer. Three modified correlations have been proposed to predict the first and second critical rotor speeds as well as break up probability by considering physical properties, drop size, and continuous phase height. Furthermore, estimated results of the proposed correlations were compared to the randomly selected literature data.Un contacteurà disque rotatif de diamètre intérieur de 9,1cm et 28 compartiments aété utilisé pourétudier l'effet de la hauteur de phase continue sur la première et seconde vitesses critiques de rotor ainsi que sur la probabilité de défaillance mécanique en utilisant douze systèmes chimiques différents, en cas de transfert de masse et sans transfert de masse. Trois corrélations modifiées ontété proposées pour prédire les première et seconde vitesses critiques de rotor ainsi que la probabilité de défaillance mécanique en tenant compte des propriétés physiques, de la taille des gouttes et de la hauteur de phase continue. De plus, les résultats estimés ontété comparésà la littérature sélectionnée de façon aléatoire.Keywords: rotary disc contactor, drop breakage probability, the first critical rotor speed, the second critical rotor speed

This paper presents a study of a D-STATCOM (Distribution Static Compensator) used for mitigating voltage sag. The basic idea of the voltage sag mitigation, using a D-STATCOM is to dynamically inject a current of desired amplitude, frequency and phase into the grid line. The proposed method extracts the active and reactive parts of the positive-and negative-sequence component for generating reference values of current that need to be injected into the point of connection D-STATCOM in order to compensate the voltage errors. The proposed method offers structural simplicity and less calculation complexity. Simulation results indicate that this method is effective and D-STATCOM has good performance to mitigate the voltage sag.