Drying Characteristics of Porous Materials in Superheated Steam Fluidized Bed under Reduced Pressure

Effect of Fluidizing Particle on Drying Characteristics of Porous Materials in Superheated Steam Fluidized Bed under Reduced Pressure

“…However, the minimum fluidization mass velocity G mf (¼ u mf q G ) was lower in the case of 10 kPa than in the case of 101.3 kPa because the density of the drying gas decreased under reduced pressure. In our previous study, [20] it was confirmed that the change of drying time against the mass velocity of the drying gas was small when the fluidization state was sufficiently vigorous. From this, the mass velocity of the drying gas was adjusted to one and half times as high as the minimum fluidization mass velocity, where the fluidization state was sufficiently vigorous.…”

“…So the effects of characteristics of the drying gas became smaller as the pressure in the drying chamber decreased. [20] The sample temperature in the case of superheated steam was almost equal to the boiling point of water. This is the characteristic of superheated steam drying.…”

“…For the particulate materials, Kozanoglu et al [18] have examined the drying characteristics in the fluidized bed under reduced pressure. In our previous papers, [19][20][21] the drying characteristics of the relatively large material immersed in the fluidized bed (of inert particle) under reduced pressure were examined.…”

“…[22][23][24][25] The combination of superheated steam drying and fluidized bed drying has been also studied. [20,21,[26][27][28] In this study, the hygroscopic porous particle was used as the fluidizing particle for the superheated steam fluidized bed drying under reduced pressure. A relatively large material was immersed in the fluidized bed as a drying sample.…”

Drying characteristics of porous material immersed in a bed of hygroscopic porous particles fluidized under reduced pressure

“…However, the minimum fluidization mass velocity G mf (=u mf G ) decreases with a decrease in the pressure in the drying chamber because the density of the drying gas decreases with a decrease in the pressure. In our previous paper (Tatemoto et al, 2005b), we found that the drying time was unchanged when the fluidization state is sufficiently vigorous. Therefore, the amount of gas needed for the fluidized bed drying becomes smaller as the minimum fluidization mass velocity decreases, i.e., the mass velocity of the drying gas for the fluidized bed drying can be decreased under reduced pressure.…”