진공건조기 내부 압력 변화에 따른 수분 이동에 관한 연구

A Study on Transfer of the Moisture According to Inner Pressure of the Vacuum Dryer

The method of drying agricultural, marine, and forest products is different according to the kinds of dried products, but can be classified into hot air drying, vacuum drying, freezing drying and electro-magnetic wave drying. The present vacuum drying keeps pressure within the body in state of high vacuum pressure, eventually it lowers the saturation temperature and dries products in 20-30℃, which is the same as natural drying temperature, in the state that oxygen is shut-off. Vacuum drying technique, whose drying time and quantity of exhausting energy is about 1/ 3-1/4 of hot air drying, is very excellent in the drying efficiency. As the results. it took about 20 hours for material to reach about 18% of the final moisture content in order to store products for a long time, from about 45％ of the early moisture content at the beginning of drying, and maximum drying rate comes to about O.30kg/m²hr at about 350% of the moisture content.