Spray Dryer A spray dryer, as the name implies, is a device for drying, utilizing a spray. A spray dryer mixes a heated gas with an atomized (sprayed) liquid stream within a vessel (drying chamber) to accomplish evaporation and produce a free flowing dry powder with a controlled average particle size.
The unit operation of spray drying includes the following key components:
- A method for atomizing a solution or slurry
- An air/gas heater, or a source of hot air such as a waste flue gas
- A gas/spray mixing chamber with adequate residence time and droplet trajectory distance for achieving the heat and mass transfer
- A means for recovering the solids from the gas stream
- A fan to induce the required air/gas through the spray drying system
The unique feature of a spray dryer is the surface area per unit weight generated by atomization of the liquid feed. It is this fact that enables a spray dryer to work.