purple Chinese yams

A.  Temperature-raising phase: Tile sliced yams on drying racks and push into the drying cabinet. Start the dryer to send warm wind into the cabinet to raise the temperature to 50°C for 0.5– 1.5 hours. Start moisture removal function when humanity rises. DRYTECH heat pump drying and dehumidifying machine can keep the constant temperature over the moisture removal.

B.  Drying and moisture-removing phase: There are two sub-phases, high humanity and low temperature, and medium humanity and medium temperature. In the first sub-phase, remove the moisture when the temperature ranges from 40°C to 50°C to avoid color of yams changing due to high temperature and high humanity. Watch water vapor on the surface of yams so as to remove it at any time. This phase shall last 3-3.5 hours. In the second sub-phase, the temperature ranges from 50°C to 60°C . If necessary, use fresh air to remove moisture based on density of moisture,

C.  Speed-reducing and shaping phase (also known as a low-humanity and high-temperature phase): the temperature ranges from 60°C to 70°C . In the first half phase, the temperature shall not be higher than 70°C . In the second half phase, the temperature shall be not lower than 75°C . The whole phase lasts 5-7 hours.