densities.

$2-8.$ Design of Settler and Separator for Immiscible Liquids. A vertical cylindrical set$-$

tler$-$separator is to be designed for separating a mixture flowing at $20\mathrm{.}0\frac{m^3}{h}$ and con$-$

taining equal volumes of a light petroleum liquid $({}_B=875k\frac{g}{m^3})$ and a dilute solu$-$

tion of wash water $({}_A=1050\frac{kg}{m^3}).$ Laboratory experiments indicate a settling

time of $15$min is needed to adequately separate the two phases. For design purposes

use a $25-$min settling time and calculate the size of the vessel needed, the liquid levels

of the light and heavy liquids in the vessel, and the height $h_{A2}$ of the heavy$-$liquid

overflow. Assume that the ends of the vessel are approximately flat, that the vessel di$-$

ameter equals its height, and that one$-$third of the volume is vapor space vented to the

atmosphere. Use the nomenclature given in Fig. $2\mathrm{.}2-6.$

Ans. $h_{A2}=1\mathrm{.}537m$