ABSTRACT
The general aim of drying experiments is as follows: choice of adequate drying equipment, establishing the data required for planning, investigation of the efficiency and capacity of existing drying equipment, and investigation of the effect of operational conditions on the shape and quality of the product. The calculation of drying processes requires knowledge of a number of characteristics of drying techniques, such as the characteristics of the material, the coefficients of conductivity and transfer, and the characteristics of shrinkage. The direct methods consist essentially of determination of the moisture content of a sample by drying carried out in a drying oven with or without blow through of air, or by drying in a vacuum chamber or in a vacuum desiccator. Most frequently applied is the indirect method—determining the dry and wet bulb temperatures or measuring the dew point temperature, which requires a slightly more expensive instrument.
