DETERMINATION OF THE CONSTANT-RATE MASS-TRANSFER COEFFICIENT FOR DRYING DURING TAPE CASTING

Abstract

Ceramic suspensions for tape casting are known to dry in two stages; the first stage is called the constant-rate period, and the second stage is the falling-rate period. During the constant-rate period, the drying rate of a material is constant. During the falling-rate period, the drying rate gradually decreases as the moisture content of the material falls. A mass-transfer coefficient is estimated for the constant–rate period of drying of water-based alumina suspensions for tape casting. A model based on the mass-transfer coefficient is also presented for the drying rate in the constant-rate period. The model is compared with experimental data and good agreement is obtained if the mass-transfer coefficient is taken to be 7.55 x 10^-9 kg/m²s Pa.


JMDMES Vol.2(1) 2003: 83-88