Spray Bed Dryers

Function and Principle of Operation

The drying process involves atomizing the product into a fine spray, which mixes with recycled fines and the fines elutriated from the integral fluid bed. The primary airflow enters at the top of the chamber, while the secondary airflow enters through the fluid bed, where second-stage drying occurs.

The agglomerated products falling into the bed are dried to the correct moisture content before being discharged from the chamber.

To optimize particle size control, the product caught in the spent drying air is separated in the cyclone or textile filter and returned to the atomization zone within the drying chamber. The degree of agglomeration and particle size are influenced by operating conditions, which alter the residual moisture level of particles within the atomization zone. A wide range of particle sizes can be formed. Both soluble and insoluble products can be agglomerated in this process.

Capacity and System Options

Capacity Profile

• From 5 kg/h to 10 t/h

Available Designs

• Open-cycle systems using atmospheric drying air
• Closed-cycle systems, either as low-Ox or inert gas (nitrogen)

Advantages

• High thermal efficiency
• Improved control over particle size distribution
• Minimal fines generation
• Straightforward CIP (cleaning-in-place)
• Customized to individual requirements
• Proven reliability and high availability
• Long service life
• Full traceability

Key Applications

The Spray Bed dryers are used for a wide range of applications where energy-efficient drying and non-dusty end-products are required under hygienic conditions. They are designed to dry and agglomerate heat-sensitive materials, but can also be used for powder conditioning e.g. lecithination.

The Spray Bed Dryers are used in the dairy, food & beverage, pharmaceutical and chemical industries to produce dust-free, agglomerated, dispersible, and free-flowing powders. The typical product applications for the Spray Bed Dryers are food ingredients, yeast products, plant extracts, flavours and fragrances, agro chemicals, tanning agents, dyestuffs, fertilizers and detergent ingredients.