The spray drying consists of transforming a concentrated fog in a chamber where the droplets thus formed solution with a diameter ranging from 50 to 200 microns, are entrained by a stream of hot air which dried. To atomize the liquid, it can be passed through a spray nozzle or a rotating disc. The dried product finally falls to the bottom of the device where it is discharged. The drying time does not exceed a few seconds , to avoid overheating while smaller the larger are not yet dry particles , it is necessary that the diameter of the droplets is as uniform as possible. The drying air typically enters at a temperature of 200oC and exits at a temperature from 90 to 100oC. The fine particles are then separated from the final product through the cyclone separator and are expelled with moist air to the filter.
Drying of liquid.
|Manufacturer and model||GEA Niro|
|Maximum temperature of the inlet air|
|Maximum temperature of the air leaving|
|Maximum speed of disk rotation||40 000 RPM (air pressure of 6 bar)|
|Suggested pressure with spray nozzle||0.5 to 2 bar|
Between 10 and 30o
|Air drying||Air temperature at the inlet||Air temperature at the outlet||Evaporation capacity|
|85 kg/h||150oC||80oC||1,3 kg/h|
|85 kg/h||170oC||85oC||1,7 kg/h|
|80 kg/h||200oC||90oC||2,5 kg/h|
|80 kg/h||240oC||90oC||3,4 kg/h|
|75 kg/h||350oC||90oC||7,0 kg/h|