A wetted-wall column of 2.0-cm inner diameter and 50-cm wetted length is used to oxygenate blood as a continuous, steady-state process, as shown in the figure below. Blood containing 1.0 gmole/m3 of dissolved oxygen enters the top of the wetted-wall column at a volumetric flow rate of 7,8x10^-5 cm3/min. Pure, 100% O2 gas at 1.0 atm and 25C enters the bottom of the column at a volumetric gas flow rate of 5,0x10^-4 cm3/min. A very simplified description for estimating the equilibrium solubility of 02 dissolved in blood is

where pa is the partial pressure of 02 in the gas phase, H =0.01 atm m3/gmole for 02 in the blood plasma.

At 25C, the kinematic viscosity of blood is 0.040 cm?/s and the density of blood is

1.025 g/cm3. You

may assume that the diffusion coefficient of 02 in blood approximates the diffusion coefficient of O2 in liquid water, which is 2.0 x10-5 cm2/s at 25C.

a. What is the mass-transfer coefficient for 02 into the flowing liquid film?

b. What is the concentration of dissolved oxygen in the liquid exiting the bottom of the column, CAL, out?

PA,i=HCA,i Liquid in (blood + dissolved O2 )