Abstract

A solar cabinet dryer of 2m² collector area was developed to dry perishables. The unit consisted of a rectangular insulated box with absorption plates covered with two layers of 3 mm thick transparent glass kept at a space of 25 mm. The solar cabinet dryer was intensively evaluated for drying copra, cassava and chillies. The temperature of air inside the cabinet dryer was observed as 84-86°C at 13-14 h when the ambient temperature was 34°C. The dryer took 8 h to dry Copra pieces of 40-60 mm size from 46 to 5 per cent moisture content. Cassava chips of 5-7 mm thick took 8 h to dry from 62 to 5 per cent moisture. Red chillies with moisture content of 68 per cent dried to 15 per cent in 5 h. Similarly a cabinet dryer with solar energy collector having 36 m² area was developed to dry paddy and bajra. The payload of the dryer was 500 kg per batch. The maximum hot air temperature recorded in the cabinet dryer with energy collector was 55- 56 C. Paddy at 23.5 per cent moisture content was dried to 11 per cent in 9 h in the cabinet dryer with energy collector, whereas bajra was dried from 23.2 to 11.8 per cent in the same time.

Keywords: Cabinet dryer, Solar drying