Delayed phase inversion in stirred liquid—liquid dispersions

Gilchrist, Alexei; Dyster, Kate N.; Moore, I. P. T.; Nienow, Alvin W.; Carpenter, Keith

doi:10.1016/0009-2509(89)85172-3

Cited by 34 publications

(22 citation statements)

References 7 publications

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“…Thus, using a concentration of chlorobenzene of about 40% by volume, with an impeller placed in it, led initially to a water in oil (w/o) dispersion (second rule of thumb) which after a certain period (the delay time, fd), inverted to o/w (first rule of thumb). Gilchrist et al (1989) also observed that over a quite narrow concentration range, t d varied from zero (instantaneous inversion or one in which a w/o dispersion never formed) to infinity (w/o was always the stable structure). The delay time depended on a variety of fluid dynamic features (agitator speed, baffling, up or downward pumping) and liquid physical properties but could not be predicted a priori.…”

Section: Introductionmentioning

confidence: 86%

“…The understanding of phase inversion is still extremely poor, especially in stirred vessels as pointed out in a recent review by Davies (1992), even though the phenomenon has been studied at intervals for about 40 years (Roger et al, 1956). Relatively recently, Gilchrist et al (1989) proposed that the measurement of the delay time associated with phase inversion might provide a useful way of gaining insight into the dynamics of the process. In their experiments, the system was set up to take advantage of the two rules of thumb; first, the one dis- cussed above and secondly, that the phase in which the impeller is placed will be the continuous one.…”

Section: Introductionmentioning

confidence: 99%

“…The delay time depended on a variety of fluid dynamic features (agitator speed, baffling, up or downward pumping) and liquid physical properties but could not be predicted a priori. Gilchrist et al (1989) used the measurement of conductivity (low values for w/o to high for o/w dispersions) to detect the phase inversion. A typical example of the transient conductivity response is shown in Figure 1.…”

Section: Introductionmentioning

confidence: 99%

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Video technique for measuring dynamics of liquid‐liquid dispersion during phase inversion

et al. 1994

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Section: Introductionmentioning

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Video technique for measuring dynamics of liquid‐liquid dispersion during phase inversion

et al. 1994

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“…Effects of equipment geometry and materials of construction have also been examined (1,7). Effects of equipment geometry and materials of construction have also been examined (1,7).…”

Section: Introductionmentioning

confidence: 99%

Phase Inversion of Liquid–Liquid Dispersions Under Applied Electric Fields

Dong

Tsouris

2001

Journal of Dispersion Science and Technology

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This paper presents experimental studies on the effects of applied electric ®elds on aqueousaorganic liquid±liquid dispersions, using tolueneawater systems with certain physical properties modi®ed by various additives. In general, because of polarization and deformation effects, coalescence of aqueous drops is facilitated by the application of electric ®elds. As a result, with an increase in the applied voltage, the ambivalence regimeÐthe range of the organic volume fraction plotted versus energy input, in which either phase may be continuous or dispersedÐis narrowed and shifted toward higher volume fraction of the organic phase. Effects of physical properties of liquid±liquid dispersions such as aqueous-phase conductivity, organicphase viscosity, aqueous-phase pH, and liquid±liquid interfacial surface tension are reported here. Variation of these physical properties affected the ambivalence regime differently under the conditions with and without an applied electric ®eld. The phase-inversion behavior was studied in the agitation range of 450±1000 rpm for an applied-voltage range of 0±1000 V, using a stirred tank equipped with a Rushton impeller. The effect of electric ®elds on the drop size distribution was also studied for both organic-phase-dispersed and aqueous-phase-dispersed. The drop size distribution of aqueous drops shifted toward larger size while no signi®cant change in the size of organic drops was observed as the ®eld strength increased. The experimental results are qualitatively interpreted based on the electric polarization mechanism and drop-breakageacoalescence arguments.

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“…Comme le diam•tre caractŽristique de la dispersion est liŽ ˆ l'Žnergie apportŽe, il a ŽtŽ choisi, au m•me titre que celle-ci, pour paramŽtrer la fraction critique [14,15,16]. L'inversion est alors dŽfinie comme un Žqui-libre entre la rupture des grosses gouttes engendrŽe par la turbulence, et la coalescence des plus petites gouttes.…”

Section: Introductionunclassified

Etude sur la prédiction de l'inversion de phase

Décarre

Fabre²

1997

Rev. Inst. Fr. Pét.

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En écoulement diphasique eau-huile dans lequel une des phases est dispersée dans l'autre, il peut se produire sous certaine condition d'écoulement une inversion de phase, la phase continue devenant dispersée. Ce phénomène, qui contrôle la nature de la phase mouillant la paroi de la conduite dans laquelle s'écoulent les phases, a des conséquences importantes sur la corrosion et sur la perte de charge. Nous présentons un modèle d'inversion, basé sur une approche thermodynamique, valable pour tous les régimes d'écoulement. Les données expérimentales utilisées pour la validation du modèle sont issues d'une étude bibliographique. En écoule-ment laminaire, cette approche conduit à des résultats similaires à ceux du modèle de Yeh. Pour la plupart des données disponibles, ce modèle prédit bien la fraction critique pour laquelle l'inversion de phase se produit. PHASE INVERSION BEHAVIOR FOR LIQUID-LIQUID DISPERSIONSIn two phase oil-water dispersed flow, a phase inversion may occur whereby the continuous phase becomes dispersed. This phenomenon which controls the nature of the phase in contact with the pipe has a great importance on the corrosion and on the pressure drop. A model for the phase inversion is presented, it is based on a thermodynamic approach, and it is valid for all flow regimes. Experimental data from the litterature are used to validate the model. In laminar flow, this approach gives similar results to those obtained by Yeh. For most data, the model agrees well with the experimental data. ESTUDIO ACERCA DE LA PREDICCIÓN DE LA INVERSIÓN DE FASEEn flujo difásico agua-aceite, en el cual una de las fases se encuentra en dispersión en la otra, puede producirse, en ciertas condiciones de flujo, una inversión en cuyo caso la fase continua pasa al estado de dispersión. Este fenómeno, que controla la naturaleza de la fase humectante de la pared del conducto, dentro del cual fluyen las fases, tiene importantes consecuencias con respecto a la corrosión y a las pérdidas de carga. Se presenta en este artículo un modelo de inversión, fundado en un enfoque termodinámico, valedero para todos los regímenes de flujo. Los datos experimentales utilizados para la validación del modelo proceden de un estudio bibliográfico. En flujo laminar, este enfoque conduce a resultados similares de aquellos del modelo de Yeh. Para la mayor parte de los datos disponibles, este modelo predice correctamente la fracción crítica para la cual se produce la inversión de fase.

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Delayed phase inversion in stirred liquid—liquid dispersions

Cited by 34 publications

References 7 publications

Video technique for measuring dynamics of liquid‐liquid dispersion during phase inversion

Video technique for measuring dynamics of liquid‐liquid dispersion during phase inversion

Phase Inversion of Liquid–Liquid Dispersions Under Applied Electric Fields

Etude sur la prédiction de l'inversion de phase

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