Drying of kenaf in a flat bed box dryer for animal feed

Abstract

Kenaf drying tests were carried out using the 2.44x2.44x0.91 m flat bed box dryer with the triangular section canopy cover on top. The drying curves obtained were z-shape with very little drop in moisture content during the initial 4 hours of drying followed by a straight line constant drying curve and ended with very little drop in moisture content towards the last few hours of drying. With the kerosene burner set to give a hot air temperature of 85°C, the drying duration was about 20 hours and the overall thermal efficiency was about 33%. On the other hand, with the kerosene burner set to give a hot air temperature of 70°C, the drying duration was 24 hours and the overall thermal efficiency was about 46%. The average drying cost per kg of water removed for the two drying air temperatures was RM0.46 and RM0.44 respectively.