Scale-up of liquid-liquid phase mixing vessel.

Abstract

The scale-up effect of mixing vessels on the drop size of a liquid-liquid dispersion is discussed and correlative equations to estimate drop sizes in breakup and coalescence regions are proposed. It is shown that (n3d2D)(4Npln) is applicable as a scale-up standard and that the average energy dissipation rate, the Webernumberin the mixing vessel or the agitational Reynolds numberis not a satisfying scale-up standard. It is also shownthat the effect of volumefraction of dispersed phase on drop size is affected by the scale-up ratio; that is, the scale-up ratio is expected to have a smaller effect on drop size as the fraction of dispersed phase increases.

Steady‐state drop‐size distributions in high holup fraction dispersion systems

“…Another assumption made in the original model derivation by Narsimhan et al (1979) was a negligible effect of E on A. A general expression of the energy input per unit mass, E, for baffled and unbaffled systems is given by (Shuichi, 1958;Nishikawa et al, 1987): where P, E , N * , D,, D,, H , and K denote the power input (g.cm/s2), the average power input/unit mass (cm2/s3)), the impeller speed (s-I), the impeller and tank diameters (cm), the tank height (cm), and the power number (dimensionless), respectively.…”

Extraction in a single-stage mixer-settler

“…Scaleup of the Contactor. As for the scaleup of a liquid-liquid mixing vessel, Nishikawa et al (1987) recommended the use of the variable (4NP/ir)(n3cPD). This variable coincides with the average energy dissipation rate per unit mass of liquid in the mixing vessel when the vessel scale is fixed, and the dispersed phase fraction is kept constant.…”

“…Eckert et al (1985) reported that the impeller tip speed (nd) can have the controlling effect in drop formation. Nishikawa et al (1987) added that in such a case the impeller-to-vessel diameter ratio should also be taken into account.…”

Mean drop size correlations and population balance models for liquid—liquid dispersion

“…The proportional relation has been applied by most researchers to develop semiempirical d 32 correlations. The work to investigate the relation between d 32 and d max has been extended for different conditions where values of constant C at different conditions range between 0.38 and 0.70 as summarized by Zhou and Kresta (1997) . However, the authors did not support the linear proportional relation between d 32 and d max .…”