Agglomeration means getting smaller particles to adhere to each other to form a powder consisting of bigger conglomerates/agglomerates, which are essential for an easy reconstitution in water. To produce a powder that is easily reconstituted, i.e. wetted, dispersed and dissolved in water (hot or cold), a powder consisting of single particles often falls short.

The so-called 'instant' powders are today generally required by the end users. Modern spray dryers like the Fluidized Spray Dryer FSD can produce powders in an agglomerated form ready to be dissolved in water. Powders from traditional spray dryers producing single particles can be "made instant" in a special agglomeration plant by a combination of rewetting the surface of the particles and a mechanical treatment to make the single particles 'glue' together before redrying and cooling.

Depending upon product, different agglomeration techniques are applied: 

  • For milk products with high protein content, the particle surface is wetted by warm moist air condensing on the surface of the particles. After a mechanical impact, the formed agglomerates are dried again. 
  • For milk products with high fat content, the particle surface is wetted by droplets of water. The agglomeration takes place by collision of the wetted particles followed by redrying. 
  • For coffee the agglomeration takes place on a rotating drum. Here the coffee particles that have been wetted by a mixture of steam and water form agglomerates before they are discharged into a VIBRO-FLUIDIZER™ for final drying and cooling.

All flowsheet animations are available in the GEA Niro download area.