Spray Dryer & Coating Granula

 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.