Effect of different desiccant bed designs in a desiccant column on dehumidification performance

Abstract

The main objective of this study was to develop a desiccant column with enhanced air dehumidification. Multilayer desiccant beds with and without air ducts were designed in the column. The desiccant material was silica gel. Air dehumidification characteristics and psychrometric properties of air of various desiccant bed designs were investigated. Dehumidification rate, percentage adsorbed water, desiccant column effectiveness of each design were evaluated at an air flow rate of 1.2 m3 min-1, where the control was a single layer packed bed design. Both kinds of multilayer bed designs (with and without air ducts) exhibited a significantly better dehumidification rate, percentage adsorbed water, and desiccant column effectiveness than the control. The experimental dehumidification psychrometric process was consistent with the theoretical adiabatic dehumidification process. The percentage dehumidification rate as time passed for every multilayer bed design was better than that of the control. The 15-layer bed design with air ducts exhibited the highest values of about 15.73 g water min-1 dehumidification rate, 51.59% dehumidification efficiency, and 0.998 desiccant column effectiveness. This design shows good dehumidification performance and can be simply applied to many processes requiring air dehumidification.