Pulse Combustion: An Advanced Technology for Efficient Drying

This paper provides a comprehensive overview of pulse combustion, as applied to industrial drying. A concise description is given, of the pulse combustion process and its basic features. Pulse combustion experimental data on drying kinetics for solid materials are compared to those of continuous combustion, and interpreted in terms of water bonding and internal/external drying conditions. Two drying mechanisms are postulated, based on data from the literature and from the authors' experiments in the drying of solids and dispersed liquids. Experimental (LDA analysis) and theoretical (CFD modeling) approaches are presented, to describe the flow field generated by the pulse combustor in the drying chamber. Environmental aspects (acoustic noise and pollutant emissions) are discussed. Finally, the issues of user-acceptance and reliability of pulse combustion drying are raised, in regards to noise level and combustor-dryer interaction.