FFlash dryers are the most economical for drying solids that have been de-watered or inherently have a low moisture content. Also known as "pneumatic dryers," the systems makes the simplest gas suspension dryers with the smallest footprint. A single operation provides mixing, heat transfer, and mass transfer to dry a solid. Residence time within the dryer is very short, usually less than three seconds.
Feeds are:
1- Moist, powdery, granular, or crystallized
2- Wet solids discharged from centrifuges, rotary filters, and filter presses
3- Small in particle size
4- Reasonably dry, friable, and not sticky.
Advantages
1- Relatively simple in operation
2- Take little space
3- Generally require lower capital investment than other types of dryers
4- Excellent choice for processing heat-sensitive or easily oxidized feed materials
5- Product inventory in the flash-drying system is very low
6- Easy to change product or product grade with minimum downtime
7- Control of the flash-drying process is very simple
8- Control system responds very quickly to operational changes.