Mathematical Model for Drying of Highly Shrinkable Media

Abstract

Drying of heat-sensitive materials of high moisture content requires exact knowledge of kinetics and reliable control of a drying process. A physical-mathematical model was compiled for the description of heat and mass transfer, and was coupled with the elastic behavior of the material. To check the validity of the mathematical model, drying experiments were carried out. Potato was chosen as a testing material. Experimental conditions were as follows: drying temperatures of 38, 42, and 47°C, relative humidity of 14, 20, and 23%, and air velocities of 1.5, 3, and 4.5 m/s. Representative drying and temperature curves as well as moisture and temperature profiles are presented and discussed. Comparison between predicted and experimental results provides satisfactory agreement. Stress field developed during drying and obtained using the rheological behavior of the material was also presented and commented.

Keywords:

• Convective drying
• Heat and mass transfer
• Shrinkage
• Elasticity
• stress