Field performance of BAU-STR paddy dryer in Bangladesh

Paddy is the staple crop in Bangladesh. Harvested paddy contain 22 to 28% (wet basis) moisture content which need to be dried properly for reducing post-harvest losses. BAU-STR dryer would be an effective method as alternative to open sun drying of paddy for small holder farmers and traders. The performance study of BAU-STR dryer was conducted during Aman season, 2016 at selected areas of Netrokona, Mymensingh and Jessore districts. The dryer was evaluated with three verities: Gutisorna, Punja, and BRRI dhan49 at three different locations. The results showed that the temperature and moisture distributions at different layer of the grain bin in BAU-STR dryer were uniform. The mean drying air temperatures were 39.7±2.4, 39.0±2.6 and 39.6±1.5°C to reduce moisture from 23.2 to 13.1%, 25.2 to 13.4%, and 19.9 to 11.9% for the three treatments, respectively. The required drying time was 4.0 to 4.7 hrs for 500 kg dryer capacity. Drying rates were 2.3, 2.5 and 2.0% moisture content per hour which varies with initial moisture content of paddy for three treatments, respectively. The drying efficiencies were about 61%, 65.9% and 57% for Jessore, Netrokona and Mymensingh districts, respectively. The operating costs of paddy drying were found Tk. 0.87 per kg (diesel engine operator) and Tk. 0.74 per kg (electricity operated) in BAU-STR dryer whereas in traditional sun drying method the operating cost was Tk. 1.0 per kg. The payback period was found less than one year. BAU-STR dryer can be replicated and used in other developing paddy growing countries in the world.