Separation dispersion and

Flooding-point. Because the flooding-point is no longer synonymous with that for spray towers, equations 13.34 and 13.35 predict only the upper transition point. Dell and Pratt 30 1 adopted a semi-empirical approach for the flooding-point by consideration of the forces acting on the separate dispersed and continuous phase channels which form when coalescence sets in just below the flooding-point. The following expression correlates data to within 20 per cent ... 

The theory of fractional polarity can be used to separate dispersion and polar interaction terms from contact angle data. Combining Young s equation (Eq. (1)) and the equation for the work of adhesion (Eq. (7)) gives. 

Knowles P J and Meath W J 1987 A separable method for the calculation of dispersion and induction... 

Coalescence and Phase Separation. Coalescence between adjacent drops and between drops and contactor internals is important for two reasons. It usually plays a part, in combination with breakup, in determining the equiHbrium drop si2e in a dispersion, and it can therefore affect holdup and flooding in a countercurrent extraction column. Secondly, it is an essential step in the disengagement of the phases and the control of entrainment after extraction has been completed. 

When two or more molecular species involved in a separation are both adsorbed, selectivity effects become important because of interaction between the 2eobte and the adsorbate molecule. These interaction energies include dispersion and short-range repulsion energies (( ) and ( )j ), polarization energy (( )p), and components attributed to electrostatic interactions. 

The process of flushing typically consists of the foUowing sequence phase transfer separation of aqueous phase vacuum dehydration of water trapped in the dispersed phase dispersion of the pigment in the oil phase by continued appHcation of shear thinning the heavy mass by addition of one or more vehicles to reduce the viscosity of dispersion and standardization of the finished dispersion to adjust the color and rheological properties to match the quaHty to the previously estabHshed standard. 

Efforts have also been made to overcome compHcated processes. Methods to reduce the number of steps or to use new starting materials have been studied extensively. l-Amino-2-chloro-4-hydroxyanthraquinone (the intermediate for disperse red dyes) conventionally requires four steps from anthraquinone and four separation (filtration and drying) operations. In recent years an improved process has been proposed that involves three reactions and only two separation operations starting from chloroben2ene (Fig. 2). 

Dispersed-Solids Leacbing Equipment for leaching fine solids by dispersion and separation includes batch tanks agitated by rotating impellers or by air and a variety of continuous devices. 

In a packed column the HETP depends on the particle diameter and is not related to the column radius. As a result, an expression for the optimum particle diameter is independently derived, and then the column radius determined from the extracolumn dispersion. This is not true for the open tubular column, as the HETP is determined by the column radius. It follows that a converse procedure must be employed. Firstly the optimum column radius is determined and then the maximum extra-column dispersion that the column can tolerate calculated. Thus, with open tubular columns, the chromatographic system, in particular the detector dispersion and the maximum sample volume, is dictated by the column design which, in turn, is governed by the nature of the separation. 

The effects of confinement due to matrix species on the PMF between colloids is very well seen in Fig. 1(c). At a small matrix density, only the solvent effects contribute to the formation of the PMF. At a higher matrix density, the solvent preserves its role in modulating the PMF however, there appears another scale. The PMF also becomes modulated by matrix species additional repulsive maxima and attractive minima develop, reflecting configurations of colloids separated by one or two matrix particles or by a matrix particle covered by the solvent layer. It seems very difficult to simulate models of this sort. However, previous experience accumulated in the studies of bulk dispersions and validity of the PY closure results gives us confidence that the results presented are at least qualitatively correct. 

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