文摘
The present study aimed at investigating the drying rates and inversion temperatures of modelporous particles undergoing low-pressure superheated steam and vacuum drying. Molecularsieve beads, which were used as the model material in this work, were dried as a single layerin a low-pressure superheated steam dryer. The effects of steam temperature and pressure onthe drying rates of these particles were determined. The same dryer was also operated in avacuum mode to determine the effects of the above-mentioned operating parameters as well asthe variation of the inversion temperature of the processes with the operating pressure. Thedifferences between the values of the inversion temperature calculated only from the rates ofdrying in the constant rate period and those calculated from the whole drying period are pointedout and discussed. Page's equations and a single-term exponential equation were found tosatisfactorily describe the kinetics of low-pressure superheated steam- and vacuum-dryingsystems, respectively.