Drop Size Distribution in a Standard Twin-Impeller Batch Mixer at High Dispersed-Phase Volume Fraction

2009 ◽  
Vol 32 (8) ◽  
pp. 1203-1210 ◽  
Author(s):  
A. EL-Hamouz
Keyword(s):  
Size Distribution ◽  
Drop Size ◽  
Volume Fraction ◽  
Drop Size Distribution ◽  
Dispersed Phase ◽  
Phase Volume ◽  
Phase Volume Fraction ◽  
Batch Mixer

Prediction of Frictional Pressure Gradient in Horizontal Oil/Water Dispersion Flow

SPE Journal ◽  
2010 ◽  
Vol 16 (01) ◽  
pp. 148-154 ◽  
Author(s):  
Jany Carolina Vielma ◽  
Ovadia Shoham ◽  
Ram S. Mohan ◽  
Luis E. Gomez
Keyword(s):  
Pressure Gradient ◽  
Volume Fraction ◽  
Average Error ◽  
Dispersed Phase ◽  
Phase Volume ◽  
Water Dispersion ◽  
Phase Volume Fraction ◽  
Law Of The Wall ◽  
Oil Water ◽  
The Law

Summary A novel model has been developed for the prediction of frictional pressure gradient in unstable turbulent oil/water dispersion flow in horizontal pipes. This model uses the friction-factor approach, based on the law of the wall, to predict the pressure gradient. Modification of both the von Karman coefficient κ' and the parameter B' have been carried out in the law of the wall to include the effect of the dispersed phase—namely, the dispersed-phase volume fraction and the characteristic-droplet-size diameters. The developed model applies to both dilute and dense flows, covering the entire range of water cuts. Model predictions have been compared with a comprehensive experimental database collected from literature, resulting in an absolute average error of 9.6%. Also, the comparisons demonstrate that the developed model properly represents the physical phenomena exhibited in unstable turbulent oil/water dispersions. These include drag reduction, increase in frictional pressure gradient with increasing dispersed-phase volume fraction, and the peak in the frictional pressure gradient at the oil/water phase-inversion region.

scholarly journals The Influence of Internal Intermittency, Large Scale Inhomogeneity, and Impeller Type on Drop Size Distribution in Turbulent Liquid-Liquid Dispersions

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 340 ◽  
Author(s):  
Wioletta Podgórska
Keyword(s):  
Size Distribution ◽  
Large Scale ◽  
Drop Size ◽  
High Efficiency ◽  
High Viscosity ◽  
Drop Size Distribution ◽  
Dispersed Phase ◽  
Power Number ◽  
Scale Inhomogeneity ◽  
Impeller Type

The influence of the impeller type on drop size distribution (DSD) in turbulent liquid-liquid dispersion is considered in this paper. The effects of the application of two impellers, high power number, high shear impeller (six blade Rushton turbine, RT) and three blade low power number, and a high efficiency impeller (HE3) are compared. Large-scale and fine-scale inhomogeneity are taken into account. The flow field and the properties of the turbulence (energy dissipation rate and integral scale of turbulence) in the agitated vessel are determined using the k-ε model. The intermittency of turbulence is taken into account in droplet breakage and coalescence models by using multifractal formalism. The solution of the population balance equation for lean dispersions (when the only breakage takes place) with a dispersed phase of low viscosity (pure system or system containing surfactant), as well as high viscosity, show that at the same power input per unit mass HE3 impeller produces much smaller droplets. In the case of fast coalescence (low dispersed phase viscosity, no surfactant), the model predicts similar droplets generated by both impellers. In the case of a dispersed phase of high viscosity, when the mobility of the drop surface is reduced, HE3 produces slightly smaller droplets.

Numerical simulation of a concentrated emulsion in shear flow

1996 ◽  
Vol 321 ◽  
pp. 395-419 ◽  
Author(s):  
M. Loewenberg ◽  
E. J. Hinch
Keyword(s):  
Shear Flow ◽  
Volume Fraction ◽  
Flow Direction ◽  
Continuous Phase ◽  
Boundary Integral ◽  
Dispersed Phase ◽  
Phase Volume ◽  
Phase Volume Fraction ◽  
Rigid Particles ◽  
Concentrated Emulsion

A three-dimensional computer simulation of a concentrated emulsion in shear flow has been developed for low-Reynolds-number finite-capillary-number conditions. Numerical results have been obtained using an efficient boundary integral formulation with periodic boundary conditions and up to twelve drops in each periodically replicated unit cell. Calculations have been performed over a range of capillary numbers where drop deformation is significant up to the value where drop breakup is imminent. Results have been obtained for dispersed-phase volume fractions up to 30% and dispersed- to continuous-phase viscosity ratios in the range of 0 to 5. The results reveal a complex rheology with pronounced shear thinning and large normal stresses that is associated with an anisotropic microstructure that results from the alignment of deformed drops in the flow direction. The viscosity of an emulsion is only a moderately increasing function of the dispersed-phase volume fraction, in contrast to suspensions of rigid particles or undeformed drops. Unlike rigid particles, deformable drops do not form large clusters.

Drop size distribution in a batch mixer under breakage conditions

2002 ◽  
Vol 63 (1) ◽  
pp. 65-74 ◽  
Author(s):  
M.C Ruiz ◽  
P Lermanda ◽  
R Padilla
Keyword(s):  
Size Distribution ◽  
Drop Size ◽  
Drop Size Distribution ◽  
Batch Mixer
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