Immiscible fluid mixing

Briscoe B J, Lawrence CJ, Mietus WGP. A review of immiscible fluid mixing. Adv Colloid Interface Sci 1999 81(1) 1-17. 

The process of liquid-liquid extraction, which includes the mixing of two immiscible fluids (emulsification) and separation of two immiscible fluids from the emulsion (settling), is applied in industry in one of the following three forms ... 

This paper is divided into two main, interconnected parts—breakup and coalescence of immiscible fluids, and aggregation and fragmentation of solids in viscous liquids—preceded by a brief introduction to mixing, this being focused primarily on stretching and self-similarity. 

The treatment of mixing of immiscible fluids starts with a description of breakup and coalescence in homogeneous flows. Classical concepts are briefly reviewed and special attention is given to recent advances—satellite formation and self-similarity. A general model, capable of handling breakup and coalescence while taking into account stretching distributions and satellite formation, is described. 

Grace, H. P., Dispersion phenomena in high viscosity immiscible fluid systems and application of static mixers as dispersion devices in such systems. 3rd Eng. Found. Conf. Mixing, Andover, N. H. Republished in Chem. Eng. Commun. 14, 225-227 (1982). 

In addition to water, NAPLs, such as petroleum, oils, tars, and biological fluids, are often present in the subsurface. When more than one fluid is present, there is a need to describe how well they mix, referred to as their miscibility. Water and vegetable oil are immiscible fluids. Many of the NAPLs are immiscible with water and will occur as separate fluid bodies, droplets, zones, etc. in the subsurface environment. 

The double-pipe mixer was designed and so far only used for contacting and reacting immiscible fluids [134], The respective flow-pattern maps were derived and annular and slug flows as well as complete spread of the inner-tube fluid were identified as distinct regimes. Since in this chapter only miscible liquids are concerned, no protocol and no results are given for the mixer below. H owever, the device is mentioned, since it could in principle be used also for mixing miscible fluids. 

Fluid-flow phenomena The mixing of one fluid in another, immiscible fluid by convection and molecular diffusion during flow through capillary spaces or porous media. 

Fig. 7.24 Breakup of a droplet of 1 mm diameter in simple shear flow of Newtonian fluids with viscosity ratio of 0.14, just above the critical capillary number. [Reprinted by permission from H. E.H. Meijer and J. M. H. Janssen, Mixing of Immiscible Fluids, in Mixing and Compounding of Polymers, I. Manas-Zloczower and Z. Tadmor, Eds., Hanser, Munich (1994).]...

Tubular flow reactors (TFR) deviate from the idealized PFR, since the applied pressure drop creates with viscous fluids a laminar shear flow field. As discussed in Section 7.1, shear flow leads to mixing. This is shown schematically in Fig. 11.9(a) and 11.9(b). In the former, we show laminar distributive mixing whereby a thin disk of a miscible reactive component is deformed and distributed (somewhat) over the volume whereas, in the latter we show laminar dispersive mixing whereby a thin disk of immiscible fluid, subsequent to being deformed and stretched, breaks up into droplets. In either case, diffusion mixing is superimposed on convective distributive mixing. Figure 11.9(c) shows schematically the... 

Condensation of mixed vapors of immiscible fluids can be treated in the same manner as outlined in Example 7.25. 

Boryczko K, Dzwinel W, Yuen D (2000) Mixing and droplets coalescenee in immiscible fluid 3-D dissipative particle dynamics model, UMSl 2000/142. Minneapolis University of Minnesota Supercomputing Institute... 

More than 70 years elapsed between the first report of aqueous two-phase systems (11) and their subsequent applications to biochemical systems (12). In the last ten years in particular, there have been several innovative applications of aqueous two-phase systems (13). Aqueous two-phase systems consist of two immiscible fluids in a bulk water solvent. In such systems, the percentage of water in both phases is high, i.e. between 75 and 95%. As a consequence, the surface tension between the two immiscible phases may be as low as 0.1 dyne/cm so that a gentle mixing is sufficient to produce and maintain an emulsion (14). 

The formation of a hydrosol which sets to a true hydrogel in a short time is the basis for an important recent advance in the art of catalyst manufacture on a large scale. The gelation time of a silica-alumina hydrosol is a function of several variables (pH, concentration, degree of mixing of reagents, and temperature), the control of which permits a uniform dispersion of the hydrosol into an immiscible fluid, such as oil,... 

The middle phase of ternary amphiphilic systems is quite intriguing because it is difficult to understand how the addition of a small amount of amphiphile to two immiscible fluids like oil and water can cause them to mix, producing a single isotropic phase. It is even more difficult to fashion a theory that can describe what the structure of this phase might be. 

We will define a dispersed system as a fluid consisting of one or more internal phases, suspended in a liquid (aqueous or organic), external phase. In this sense, we may distinguish suspensions, which consist of one or more solid phases suspended in a liquid, and emulsions, which are one or more liquid pha.ses. dispersed in an immiscible liquid. Mixed solids and liquid suspended phases may also be pre.sent, as is the case of many food and cosmetic product,s. 

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