Theoretical and experimental investigation on the radial flow desiccant dehumidification bed

In the present work, a theoretical and experimental investigation of the radial flow solid desiccant dehumidifier has been reported. In the experimental study, spherical particles of silica gel (indicating type) of 3 mm average diameter were used as the working desiccant in the dehumidifier. The bed under investigation was of radial flow and cylindrical shape. Five experimental test units of hollow cylindrical bed with different values of diameter ratio were used. For all units, the total mass of dry silica gel in the bed was nearly the same. In the theoretical part of this study, a mathematical model has been developed and its output results were compared with the experimental data. The effect of bed design parameters on the desiccant bed dynamic performance was discussed. Results show that for efficient operation of the hollow cylindrical bed, dehumidification period is limited to 15 min for the diameter ratio of 7.2. This period increases with decrease in air flow rate and bed diameter ratio. The increase in diameter ratio increases the pressure drop within the bed and rises the bed adsorption capacity for short operation periods. This analysis allows us to identify and quantify the energy losses in the air blowing system for the specified dehumidification capacity of the desiccant bed.