Expanding apparatus for agricultural product such as tobacco material

An expanding apparatus for continuously expanding an agricultural material comprising:

• an impregnating vessel;
• an expanding agent supply means for supplying carbon dioxide as an expanding agent to said impregnating vessel, the expanding agent supply means maintaining a predetermined impregnating pressure;
• material supply means for continuously supplying the material to said impregnating vessel, the material supply means increasing a pressure of the material;
• material discharge means for continuously discharging the material from said impregnating vessel, the material discharge means decreasing the pressure of the material;
• said expanding agent supply means comprises:
• a heat exchanger for cooling carbon dioxide by performing heat exchange between carbon dioxide and a coolant before the carbon dioxide is supplied to said impregnating vessel;
• cooling means for cooling said coolant to said heat exchanger;
• and
• control means for controlling a heat exchange amount to the carbon dioxide before the carbon dioxide is supplied to said impregnating vessel, said control means detects a temperature of gaseous carbon dioxide or material in said material discharge means, and controls the heat exchange amount to the carbon dioxide before the carbon dioxide is supplied to said impregnating vessel in accordance with the detected temperature, thereby controlling the heat exchange amount.