HYGROTHERMAL AND QUALITY PROPERTIES APPLICABLE TO DRYING - DATA SOURCES AND MEASUREMENT TECHNIQUES

The efficient dryer design and the optimization of existing drying pro cesses require both effective drying models and hygrothermal propertie s. Following extensive research during the previous decades, today's e xisting models for the drying process are mostly adequate. Thus, most of the requirements for appropriate process design and operation depen d on the existence of data for the various properties. The correct est imation of properties is of fundamental importance for the design, opt imization and control of the process. The existing knowledge is adequa te regarding the hygrothermal properties of the drying medium (air). M ost of the efforts should address the problem of finding and standardi zing appropriate measuring techniques and selecting and compiling the existing data, concerning hygrothermal and quality properties of the p roduct being dried. The article identifies those areas, where adequate data not exist and future research is needed or data banks should be created.