Spray drying is the most widely used industrial process for particle formation and drying. It is well suited for a continuous production of dry solids in powder or agglomerated particles form from a liquid feedstock. The feedstock can include solutions, emulsions, and pumpable suspensions. The technology is ideal when the end-product must comply with precise quality standards such as particle size distribution, residual moisture content, bulk density and particle morphology.
During spray drying, an enormous heat and mass transfer takes place within a fraction of time. It starts with the atomization of a liquid feedstock into a spray of droplets (1 liter of concentrate is atomized to 1,5 x 1010 droplets with a diameter of 50 microns with a total surface of 120 m2 and the evaporation takes place from the surface of all these particles). The small droplets are created by an atomizer - either a rotary wheel or a high pressure nozzle. The droplets are introduced into a hot airstream, which is cooled down due to the evaporation of the water or a chemical solvent from the concentrate. This now colder and humid air is discharged from the dryer through a cyclone, bag filter or a combination of the two. After separation of the now dry particles, the air is discharged into the atmosphere. The dry particles can be cooled and bagged off after separation from the process air.
The spray drying process entirely depends on the composition of the product. Some products are very easy and others very difficult to dry. In this context it should be stated that a GEA Niro dryer is designed and the process parameters selected to ensure:
Best product quality Low energy consumption Protection of the environment Long operation time between cleaning Fulfill EU Directives
To support our design engineers when they select the spray drying parameters and thereby the size of the spray dryer, use our DRYNETICS? method is used.