An agricultural waste-fuelled furnace for mechanical dryers

A heat exchanger-type furnace suitable for agricultural wastes like sugarcane bagasse, cotton stalk, coconut shell, etc., as fuel has been developed. A maximum of 90°C hot air temperature was obtained at 25·4 m³/min air flow rate at 18 kg/h of feed rate with sugarcane bagasse as fuel. With an increase in air flow, the hot air temperature decreased. It took 10·2 h to reduce the moisture content of paddy from 22·4% (wb) to 13·87% (wb) at 63°C and 33 m³/min air flow rate and 24 h for coconut (copra) from 50% (wb) to 7% (wb) at 65°C and 53·5 m³/min air flow rate in the mechanical dryer to which the furnace was supplying the hot air. There is provision to regulate the temperature of hot air by mixing in atmospheric air.