How Does a Spray Dryer Work
A spray dryer works by atomizing a liquid or slurry into a stream of hot gas, which converts it into a dry powder form. The following are the basic steps of the spray drying process:
Atomization: The liquid or slurry is fed into the spray dryer and atomized into tiny droplets using a nozzle or atomizer. This is usually achieved by using high pressure pumps or centrifugal atomizers.
Drying: The liquid droplets are then introduced into a hot gas stream, usually air, heated to a temperature above the boiling point of the liquid to be dried. The hot gas evaporates the liquid in the droplets, leaving a dry powder.
Separation: The dry powder is then separated from the air stream using a cyclone or other type of separator. The air stream is typically cleaned and recycled back to the dryer or vented to atmosphere.
The efficiency of a spray dryer depends on various factors such as feed rate, inlet temperature and humidity, the size and shape of the drying chamber, and the type of atomization used. Spray drying is a widely used and effective method for producing dry powders with various properties and characteristics for various industrial applications.