Vaporization of water into air in a wetted$-$wall column. In a test on the vaporization of H$2$O into

air in a wetted$-$wall column, the following data were obtained: tube diameter $=1\mathrm{.}46$ cm; wetted$-$

tube length $=82\mathrm{.}7$ cm; air rate to tube at $24$ C and $1$ atm $=720$ cm$3/$s; inlet and outlet water

temperatures are $25\mathrm{.}15$ C and $25\mathrm{.}35$ C$,$ respectively; partial pressure of water in inlet air is $6\mathrm{.}27$

torr and in outlet air is $20\mathrm{.}1$ torr. The diffusivity of water vapor in air is $0\mathrm{.}22$ cm$2/$s at $0$ C and $1$

atm. The mass velocity of air is taken relative to the pipe wall. Calculate: $(10$ pts$)$

$($a$)$ rate of mass transfer of water into the air; and

$($b$)$ KG for the wetted$-$wall column