Pulse Combustion and Supercritical Fluid Techniques as Examples of Innovative Drying Technologies

In this paper the need for innovative drying techniques is suggested. Pulse combustion and supercritical fluid techniques which were developed in the drying laboratory of the Lodz Technical University are presented as examples. In the section concerned with pulse combustion, valved and valveless pulse combustors are described and several features of both types are identified. The advantages and drawbacks of the pulse combustor are presented. The selection of a pulse combustor, its geometry and atomizer as well as enhancement of drying rate are discussed. The importance of the high driving force in this process intensification is stressed. In the section dedicated to supercritical fluid techniques, high- and low-temperature procedures of drying are described. The most important aspects of the drying cycle are discussed with special reference made to the kinetics of diffusive solvent exchange inside a wet gel body.