Drying behavior of thin liquid films in a condenser dryer with a solvent-trapping screen

A novel condenser drier was designed and built to trap condensed solvents on a polymeric screen. The drying kinetics of liquid films was compared for the different surface geometries of (i) a flat surface with a solvent-trapping screen, (ii) a grooved surface, and (iii) a grooved surface with a solvent-trapping screen. The direct drying visualization showed that the screen assists in the spreading and coalescence of droplets on the condensing surface. The mass loss measurements revealed that the drying rates fluctuate with time and deviate from one-dimensional theory above a critical partial pressure gradient of the solvent. The combination of the grooves and the solvent-trapping screen led to a higher critical pressure gradient, resulting in an improved drying limit at higher drying rates.