1995 Volume 57 Issue 3 Pages 29-36
The same unit as part 1 was used to carry out drying test on shiitake mushroom with 12kg total weight. Air flow rate of 161kg/h was adopted referring recent drying method, and the drying characteristics when the air flow rate was increased were compared with those when an electric resistance system was adopted. Drying rate in the heat pump system was lower compared to the electric resistance systemm at the same air flow rate, because air temperature was fixed at 40°C in the heat pump system while in the resistance system it increased from 40 to 55°C. However, when the air flow rate in the heat pump system was increased, the drying rate would become higher. It was found that the selection of proper air flow rate is important in the heat pump system, and the timing to stop the drying in this system depends on dehumidifying coefficient.
