DESIGN DEVELOPMENT AND PERFORMANCE STUDY OF A SMALL SCALE GRAIN SEED DRYER

Abstract

Bangladesh is a tropical country characterized by hot and humid weather. The climatic condition dictates the need for more effective drying of crops, specially, seeds. Seed is the vital input among the main inputs in crop production. Quality seed is important for healthy plant and high yield. Drying is the process that reduces grain moisture content to a safe level for storage. It is the most critical operation after harvesting of a grain. A small scale grain seed dryer was designed and developed in the Agricultural and Industrial Laboratory-1, Hajee Mohammad Danesh Science and Technology University, Dinajpur using locally available materials. The size of the dryer was 1.52 m height and 1.04 m wide. A rotary drum was used inside the drying chamber to keep the seeds drying operation. The drum size was 0.81 m long and 0.41 m diameter. A 0.5 hp motor was used to rotate the drum for auto stirring the grain seed and uniformly drying. In this experiment sample was taken 2 kg, 4 kg and 6 kg paddy seeds and dried in 350C, 400C and 450C temperature respectively. Paddy seeds were also dried in a laboratory dryer at 350C, 400C and 450C temperature to find out the bone dry weight of grain seeds and to find the moisture content. The minimum moisture content of paddy was found to be 9.8% (wb) at 450C. The paddy was dried for a period of 6 hrs. Moisture content removal was possible from 14.4% to 9.8% (wb) in 6 hours’ time. This dryer was designed for 20 kg of paddy and the total cost of dryer to materials and fabrication was 52,000 Tk. The total drying cost of the dryer 32.47 Tk/kg.