The drying of hygroscopic, thermoplastic and slowly crystallising products involves handling of very sticky intermediate materials at a lower temperature level than that possible in conventional spray dryer layouts.

Completion of drying requires the powder to be processed at close to critical conditions for a long time.

The FILTERMAT® uses nozzle atomization in a co-current tower that directs the semi-dried particles downward onto a moving belt. The material is then gently conveyed as a porous layer through zones of post-drying and cooling, resulting in a crisp cake-like structure, that breaks up at the end of the belt and is discharged through a final particle size control system. The exhaust air streams pass through the material layer on the belt.

Product: Coarse or very coarse, agglomerated / granulated free-flowing dustless powders can be produced.