The GEA Niro NOZZLE TOWER™ is a spray dryer designed especially for the spray drying of coffee. It produces a free-flowing powder consisting of single individual particles.

Drying air is introduced at the top of the drying chamber through an air disperser of special design to obtain a low velocity co-current air curtain downwards in the drying chamber. The coffee concentrate is atomized by a low pressure nozzle assembly situated just below the air disperser. This ensures a gentle drying of the coffee particles as they fall down in the tall formed drying chamber.

The drying air is exhausted from the drying chamber through the "bustle", formed by an enlarged conical section. The smallest particles entrained in the air are separated in a cyclone and/or bag filter, from where they can be returned to the nozzles for agglomeration or discharged directly into a pneumatic cooling and conveying system. The main fraction can be pre-cooled by introducing cooling air into the lower part of the chamber cone, before it is discharged into the same conveying system to a single bagging-off place.

 

All flowsheets are available for download in the Animation Download area.


Agglomeration
If the pneumatic conveying system is replaced by a GEA Niro VIBRO-FLUIDIZER™  for final drying and cooling and the fines are returned to the nozzles, it is possible to produce an agglomerated product that will dissolve instantly in hot water. If the air disperser is replaced to a high velocity design, this spray dryer can be used for many other food products.

The NOZZLE TOWER™ spray dryer forms the key element in a complete process line for food and dairy powders.

Safety aspects
All plants designed and supplied by GEA Process Engineering will enable the end user to obtain approvals put forward by the EU directive.