2.20'. Mass transfer in a packed bed Wilke and Hougan (1945) reported the mass transfer in beds of granular solids. Air was blown through a bed of porous celite pellets wetted with water, and by evaporating this water under adiabatic conditions, they reported gas-film coefficients for packed beds. In one run, the following data were reported: cosity at the average liquid film conditions is 1.02106m2/s, and the diffusivity is 1.25109m2/s. The solubility of NaCl in water at 291K is 0.35g/cm3, and the density of the saturated solution is 1.22g/cm3 (Perry and Chilton, 1973). Answer: 0.86kg/h