Estimation of thermophysical properties of a drying body at high mass transfer Biot number

Abstract

This chapter analyzes the problem of simultaneously estimating the moisture content and temperature dependent moisture diffusivity together with the heat and mass transfer coefficients, by using temperature measurements. In convective drying practice, usually the mass transfer Biot number is very high and the heat transfer Biot number is very small. This leads to a very small temperature sensitivity coefficient with respect to the mass transfer coefficient, relative to the temperature sensitivity coefficient with respect to the heat transfer coefficient. Under these conditions the relative error of the estimated mass transfer coefficient is high. To overcome this problem, the mass transfer coefficient is related to the heat transfer coefficient through the analogy between the heat and mass transfer processes in the boundary layer.