Circulating type grain drying machine

A circulating type grain drying machine comprising:

• a heating section for heating grains equipped with a plurality of heating pipes through which heated air from a first heated air generating means passes;
• a drying section arranged under said heating section, for drying grains by supplying heated air having passed through each heating pipe together with heated air from a second heated air generating means;
• an air exhaust means for sucking the heated air of said drying section and exhausting the heated air to outside the drying machine;
• a drying heated air temperature detecting means for detecting a temperature of the heated air supplied to said drying section;
• a heating pipe heated air temperature detecting means for detecting a temperature of the heated air supplied to said heating pipes;
• a water content detecting means for detecting water content values of grains;
• an input section for inputting the amount of filled grains;
• and
• a control means electrically connected to each of said first heated air generating means, said second heated air generating means, said drying heated air temperature detecting means, said heating pipe heated air temperature detecting means, said water content detecting means and said input section,
• said control means controlling, during the drying operation, said first heated air generating means to change the temperature of the heated air supplied into each heating pipe according to the detected value of water content of the grains, and said second heated air generating means to change the temperature of the heated air supplied into said drying section according to the detected value of water content of the grains and the value of filled grains.