To provide an exhaust air circulating type grain drier enabling not only high-speed drying but also energy-saving drying suppressing energy consumption by taking advantage of efficient use of a heat source by exhaust air circulation.
The exhaust air circulating type grain drier includes: a grain drying section circulating, flowing and drying grain by making introduced outside air enabled to control its temperature by the heat source circulate by an exhaust fan; and an exhaust air control section dividing and controlling exhaust air from the grain drying section and mixing the exhaust air with the introduced outside air. When grain temperature (T1) in the grain drying section exceeds outside air temperature (T0), the introduced outside air is made to circulate while the heat source is stopped, and then, the divided exhaust air is mixed with the introduced outside air by the exhaust air control section. When the grain temperature (T1) is less than the outside air temperature (T0), the introduced outside air is made to circulate while the heat source is stopped, and then, all exhaust air is discharged to the outside of the drier by the exhaust air control section.
Maki Reiko
Kimio Kikutani