Central to all spray dyers is the design of the chamber. The design of the chamber depends mostly on the heat sensitivity of the product, type of atomisation and residence time (the time taken to remove moisture from the particle as it falls down the chamber).
Other factors that can be considered is the KST value of the product, the higher the figure the more chance there is of an explosion.
The type of atomisation employed has a big impact on the chamber design.
There are two basic types of atomisation:
1/ Nozzle atomiser
2/ Disc atomiser.
Nozzles spraying down the chamber require a smaller diameter and a longer length of chamber, disc spray outward thus requiring a wide cylinder chamber but shorter in length. It’s worth noting that the volume of the chamber remains the same regardless of the type of atomisation.
Nozzle atomiser spray dryers are often referred to as the Tall Form Dryer due to its narrow long chamber. This type of dryer has many advantages over the disc atomising wide body spray dryer.