When drying dairy products, hot air is pumped (temperatures ranging from 160° – 205° depending on the product) into a drying chamber along with concentrated product.
The dried product falls into a ‘fluid’ bath under the drying chamber, which is continually shaken. Air is also pushed up from underneath the drying chamber to cool the powder and keep it in motion. When completely dry, the powder agglomerate exits the system and can be transported.
Incorporating the very latest technologies, Tetra Pak’s spray dryers for dairy products lead the industry. They include for example, a camera monitoring system to continuously check the spray nozzles, and prevent the build up of product.
When spray drying, the finer the nozzles the better (up to a point), since the more droplets you make the greater the surface you can dry. Other keys to success are having the correct size dryer for the application, and the correct degree of agglomeration for the intended application and to prevent fouling inside the drying chamber.