Abstract

A solar dryer (PAU domestic model) was evaluated with sapota, chilli and bitter-gourd. It is a natural convection type with a capacity of 15 kg (Aperture area - 0.36 m2, No. of trays -3, 620(w) x 620(l) x 350(h) mm and weight 17 kg). Sapota, chilli and bitter- gourd were dried and comparison was made on moisture content, drying time and drying efficiency. Results show an initial moisture contents of the three products with 74.0, 56.0 and 89.0 per cent reduced to 6.10-6.50 percent in 19, 27 and 16 hours on an average global radiation plane of solar collector 550 W/m2, 580 W/m2 and 580 W/m2 respectively. Over all efficiency of the system while drying the sapota, chilli and bitter-gourd was found to be 25, 28 and 26 per cent respectively. Solar dried food produce will fetch higher value due to its quality compared to traditionally (open sun) dried produce

Keywords: Domestic solar dryer, sapota, chilli, bitter-gourd, moisture content, drying time