Spray Drying: Powders from the Gentle Drying of Liquids

Precursors for Spray Drying

In spray drying too, liquids, such as aqueous solutions, emulsions, or suspensions are the precursors. Waxes and other fusible raw materials can be processed as melts, melt emulsions or melt suspensions.

Here too, before atomisation, many raw materials must first be converted to a suitable, sprayable liquid form. In our plants we can mix, disperse, emulsify, heat, cool and, where appropriate, neutralise or carry out chemical conversion reactions immediately before spraying.

Process Technology for Spray Drying

Spray drying is the classical thermal drying process based on convection, in which efficient, controlled drying is combined with production of fine particles (20 – 200 µm).

Starting from aqueous solutions, emulsions or suspensions, spray drying takes place under precisely defined temperature conditions. Short contact times, with intensive heat exchange between atomised liquid droplets and the volume of air used for drying, generate powdery particles with particle sizes in the 20 µm to 200 µm range.

Results and Advantages of Spray Drying

  • Fast and controlled drying in seconds
  • Short duration of thermal loads on the droplets being dried and the particles produced
  • Production of hollow spheres with valuable dissolution characteristics