Solar dryer using evacuated tube solar thermal collector with thermal storage

Abstract

A solar dryer was developed using an evacuated tube solar thermal collector and solar photovoltaic (SPV) panel to supply the electrical energy. Paraffin wax was packed in a well-sealed aluminum package and stored in the bottom of the drying chamber near the entrance of hot air enabling recharge and store thermal energy. A DC fan was used to supply hot air to the drying chamber. The chamber was made of locally available material with glass wool as insulation. The overall dimensions were 0.6 m × 0.55 m × 1.05 m with 7.0 trays having 0.25 m2 per tray. The capacity of the dryer is 5.0 kg. The maximum temperature that could attain inside the drying chamber during clear sunny days was 45 to 60ºC. The efficiency of the dryer is 27%.