Abstract
The drying characteristics of porous materials immersed in the superheated steam fluidized bed drying (SSFBD) under reduced pressure were examined, experimentally. The B2 brick ball (Φ20 mm) and the glass beads (Φ0.12 mm) were used as the drying sample and the fluidizing particle, respectively. The effect of pressure in drying chamber on the drying characteristics for SSFBD was compared with that of hot air fluidized bed drying (HAFBD).The sample temperature in drying is almost equal to the boiling point of water even in the case of SSFBD. The sample temperature becomes lower as the pressure in drying chamber decreases since the boiling point of water decreases. The drying time becomes shorter as the pressure in drying chamber decreases. The drying characteristics of SSFBD become almost equal to those of HAFBD at the relatively low pressure (less than 20 kPa in this study), though the sample temperature in drying is higher and drying time is longer in the case of SSFBD than in the case of HAFBD at atmospheric pressure.
