Authors: S.K. Shukla, A.K. Sharma
Addresses: Department of Mechanical Engg., Institute of Technology, Banaras Hindu University, Varanasi-221005, India. ' Department of Mechanical Engg., Institute of Technology, Banaras Hindu University, Varanasi-221005, India
Abstract: A solar air heating system that does not require a conventional auxiliary heater, but can still provide a daily load fraction exceeding 90% and supply hot air at a steady temperature and flow rate continuously for ten hours a day, has been developed. The system, which combines flat plate solar collector heat exchanger and blower, was evaluated by drying Aonla and Cabbage using air at 60°C and 90 m³/h. The Aonla was dried from 80.0% moisture (w.b) to 7.29% over 20 hours of continuous drying. The dryer reduced the drying time by 70% compared to open sun drying, and provided 92.5% load fraction during the ten-hour operation. The temperature of hot air supplied was stable at 60±3°C for about ten hours for two days during the entire drying duration.
Keywords: drying systems; dryer efficiency; solar dryers; optimum collector temperature; Aonla drying; collector efficiency; solar air heating; heat exchangers; hot air temperature.
International Journal of Materials Engineering Innovation, 2010 Vol.1 No.3/4, pp.338 - 349
Published online: 10 Sep 2010 *Full-text access for editors Access for subscribers Purchase this article Comment on this article