The objective of this study was to monitor the drying process of soybean seeds using cooled, dehumidified air. Soybeans seeds of the Campo Mourão cultivar were dried in a stationary dryer, Dry-Excel model, with a radial distribution of the air flow, a 10 ton capacity and a Dry 60® equipment. The drying process consisted of lowering air humidity by cooling below the dew point temperature and subsequently warming up to 33 °C until a 40% relative humidity had been reached. Drying was made by an air flow of 17 m³.min-1.t-1. During drying, seed samples were collected at radial distances of 0.15 m, between 0.15 and 0.45 m and 0.45 and 0.60 m from the central cylinder and at heights of 0.5, 2.4 and 4.3 m from the dryer base. The following evaluations were made: loss of water and temperature of the seed mass at one hour intervals for six hours, germination, first germination count, accelerated aging and speed index of field emergence. It was concluded that it is possible to dry soybean seeds on a commercial scale using air dehumidified by cooling and reduced temperatures. Since the bin dryer has a central perforated tube, drying is not uniform and the drying rates and final moisture contents obtained varied according to seed position in the dryer; seed physiological quality is maintained by drying with air dehumidified by cooling, independently of the seed position in the drier.
Glycine max; stationary dryer; dehumidified air; physiological quality; water removal
