Integration of a rotary desiccant wheel into a hot-air drying system: Drying performance and product quality studies

A desiccant rotary wheel was coupled with a hot-air drying system and used to dry coarsely chopped coconut pieces. Silica gel was selected as the desiccant material. The drying performance and end color of the dried coconut were examined and compared with coconut dried in a pure hot-air drying system. The results showed that the desiccant dehumidification system can work properly in removing water vapor from humid drying air, resulting in significantly shortened drying time and a higher drying rate than a pure hot-air system. However, energy consumption was higher, mainly due to the energy required for silica gel regeneration. The color of the dried coconut was affected by all drying conditions, but the most important parameter causing the product to become considerably darker was the relative humidity of the inlet drying air.