m_ w is the mass transfer (kg/s), hD is the mass transfer coeffi-
cient (m/s), A is the surface of the product (m2
), R is the universal
gas constant 8.314 kJ/kmol K, and Mw is the molecular weight of
water vapor (kg/kmol). Pv,i and Pv,a are the partial pressures at the
interface temperature and the air medium temperature (kPa). To
determine the mass transfer coefficient, the experimental data are
fitted to Eq. (1) by the method of least squares