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

Abstract

A design with multilayers of solid desiccant and air ducts in a desiccant container was developed to allow good air flow in a zigzag pattern. The desiccant material was silica gel stacked as multiple layers in a column with different numbers of layers and with or without air holes on the upper cover of the container that penetrated through all layers. 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, 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 holes exhibited the highest values of about 16 g water/min dehumidification rate, 52% adsorbed water, and 0.998 desiccant column effectiveness.