Development and performance investigation of a novel solar-biomass hybrid dryer

In this article, a novel drying system incorporated with energy storage has been developed to operate on 24-hours basis and utilize renewable energy-solar and biomass as heat source. Study of literature revealed that such a system has not been considered by past researchers. There was also lack of experimental studies on heat and mass transfer in potato during intermittent drying; while the drying behaviour of chayote under intermittent conditions was entirely missing. Therefore, impact of four heating/drying methods-constant hot air drying (CHAD), constant vacuum drying (CVAD), intermittent hot air drying (IHAD) and intermittent vacuum drying (IVAD) on heat and mass transfer, drying kinetics and physical attributes like shrinkage, porosity, bulk density and particle density were evaluated for two bio-products-chayote (Sechium edule) and potato (Solanum tuberosum). Results showed that the developed system was capable of operating without interruption of the drying process between day and night. Intermittent drying had 16.7% lesser effective heating time but produced similar final moisture levels in the products. The average drying rate for CHAD and IHAD were respectively 0.4935 and 0.4889 kg/kg-hr for potato and 1.25 and 1.11 kg/kg-hr for chayote showing a greater positive impact on potato as compared to chayote.