Solar Dryers

The energy, exergy and economic analysis of indirect type solar dryer (ITSD) was performed while drying green chilli under forced and natural convection. Fans powered by PV panels were used for forced convection setup. The collector and drying efficiencies of the forced convection dryer were found to be 63.3% and 10.4% and the same was 53.84% and 8.90% in natural convection ITSD, respectively. The specific moisture extraction rate (SMER) of green chilli in ITSD was found to be 0.6526 and 0.5603 kg/kW-h under forced and natural convection, respectively.
This study investigated the drying behaviour of purple-speckled Cocoyam and the effect of drying temperature (40 °C, 60 °C and 75 °C), slice thickness (4 mm, 7 mm and 10 mm) and pre-treatments (blanching in boiling water for 3 min, blanching in boiling water for 3 min followed by dipping in 0.1 per cent sodium metabisulfite for 5 min) and non-pre-treated slices. The process and quality criteria under consideration included the total drying time, rehydration ratio, colour difference, browning index and specific energy consumption.