Analysis of the Drying Rate during the Falling Rate Period in the Drying of a Bed of Granular and Powdered Materials

Abstract

Drying mechanism of a bed of granular and powdered materials during the first falling rate period was analysed. The drying rate curves obtained from the present analysis represent sufficiently the experimental drying rate curves. Drying mechanism during the second falling rate period was analysed from the same considerations. The drying mechanism must be analysed as the phenomena of a simultaneous heat and mass transfer. Drying periods of a bed of non-adsorptive granular and powdered materials are distinguished to constant rate period, first and second falling rate periods from experimental results. The drying mechanism during the second falling rate period was analysed from such consideration in our previous reports. In this report, we will discuss the mechanism for the first falling rate period. The same argument is applied to the second falling rate period also.