EXAMPLE $26\mathrm{.}6-1.$ Tray Diameter of a Valve$-$Tray Absorption Tower

A valve$-$tray absorption tower is being used to absorb and recover ethyl alcohol vapor in air by pure water. The tower operates at $30C$ and a pressure of $110$kPa abs$.$ The entering gas contains $2\mathrm{.}0$mol$\%$ ethyl alcohol in water, and $95\%$ of the alcohol is recovered in the outlet water. The inlet pure aqueous flow is $186$kgmo$\frac{l}{h}$ and the inlet gas flow is $211\mathrm{.}7$kgmo$\frac{l}{h}.$ Calculate the required tower diameter. A tray spacing of $0\mathrm{.}610m(2\mathrm{.}0ft)$ will be assumed. Use a factor of $0\mathrm{.}95$ for possible foaming.