EVALUATION OF A HORIZONTAL AIR FLOW IN-BIN GRAIN DRYING SYSTEM

摘要

Drying is the major post-harvest operation carried out to reduce the moisture content of harvested grains to increase storage period and reduce storage losses. A prototype horizontal airflow in-bin drying system was developed and evaluated for drying wheat. The results proved that the moisture front moved radially from the center to the sidewall of the bin throughout the grain bulk and there were no significant differences (p0.05) in drying at the bottom, middle, and top layers of the grain bulk when the airflow control valve was set at 2 m (equal to radius of the bin) from the top surface of the grain bulk. When the airflow control valve was set at 4 m (diameter of the bin), there were significant dfferences among the drying patterns at the three different heights. The results of the air pressure measurements showed that the air pressure distribution was equal around the radius of the bin. These results indicated that the current prototype dried the grain evenly from bottom to top of the grain bulk and can be used effectively at commercial level to dry grain in hopper bottom bins (tested) as well as in flat-bottom bins.