Study on psychrometric properties of air in a hot air drying system with a desiccant wheel

บทคัดย่อ

A hot air drying system with a desiccant wheel (HA-DW) was developed in this study to provide dehumidified air in the system. The rotary desiccant wheel (DW) with silica gel could reduce humidity of fresh air as shown by its lower relatively humidity (RH) and humidity ratio of 33.9% and 16 g water/kg dry air, respectively. The RH and humidity ratio of regeneration air at the temperature of 60°C exiting the DW were increased from 15.5% to 42.6% and from 19 g water/kg dry air to 26 g water/kg dry air, respectively. In the HA-DW system with a given drying temperature of 90°C, the RH of 42.6% (17.5 g water/kg dry air) at the inlet decreased to 33.6% (9 g water/kg dry air) at the outlet of the DW during dehumidification. In the section of DW regeneration, the RH increased by 13.8% (7.5 g water/kg dry air) after passing through the DW. The HA-DW system was proved to provide this drying system with lower humidity following the theoretical dehumidification and regeneration process in a psychrometric chart.