2. Major dryer technology families

Many of the criteria mentioned above (operating mode, energy input, residence time, etc.), plus the dryer's operating principle, could be used to classify dryers. Classification based on the principle of drying would enable technologies to be discriminated on the basis of water migration mechanisms, drying flows and hydro-thermal trajectories. These would be referred to as entrainment dryers or boiling dryers.

Nevertheless, pre- and post-treatment operations contribute significantly to the overall cost of the plant, and can add organizational constraints. It is therefore advisable to avoid unnecessary transformations of the product and to choose a process that allows the product to be dried in its final conformation. In addition, handling and transport of the solid in the dryer can be problematic. A presentation of technologies based on the structure of the wet...