Estimation of thermophysical propreties of far infrared vacuum drying potato by application of inverse approach

Abstract

In this paper the estimation of the moisture diffusivity, together with other thermophysical properties of a far-infrared vacuum dried potato slices by using an inverse approach were studied. In direct problem a mathematical model of the far-infrared vacuum drying process of shrinking bodies was used. The Leven-berg-Marquardt method was used to solve the inverse problem. An analysis of the influence of the vacuum pressure, temperature of heaters, drying body dimension, and drying time, that enables the design of the proper experiments by using the so-called D-optimum criterion was conducted. The estimated values of moisture diffusivity of potato obtained from this study are within the range from 5.14?10?8 to 5.01?10?9 m2/s. The experimental transient temperature and moisture content changes during the far infrared vacuum drying were compared with numerical calculated values.