Isothermal dehumidification of air in a parallel passage configuration

The performance of a single parallel passage of a dehumidifier was examined under isothermal conditions both experimentally and theoretically. The passage was coated with silica gel using a polyester tape. The transient response of the silica gel test cells to a step change in air inlet humidity was obtained experimentally and compared with the predictions of a pseudo-gas-side-controlled mass transfer model. The transient response of the test cell depended on the air flow rate, aspect ratio, and temperature. Although the general trend of the experimental and predicted results were similar, the comparisons were not satisfactory. The observed discrepancies were attributed to the uncertainties in the pseudo-gas-side mass transfer coefficient and equilibrium isotherm.