Fluidised bed technology processes benefit from:
- the intensive mixing of the original solids
- the large available particle surface
- the fine distribution of liquid droplets
A fluidised bed consists of a bed of solid particles that are lifted by an upward flow of air and thereby converted into a liquid-like state, i.e. fluidised. By spraying a solid-bearing liquid with an average droplet size of 50 µm (1 liter of water = 15 billion droplets) onto the fluidised bed, granules or agglomerates can be produced.
Further possible steps are coating or matrix encapsulation phases. After any subsequent drying or further thermal treatment, the finished product can easily be discharged from the system.
Addition of liquid is carried out with a positive-displacement pump by spraying, using a two-substance nozzle. Compressed air is generally used for nebulization. The use of other gases (for example: steam, nitrogen) is possible.
The filtered and heated supply air is fed to the granulator and distributed evenly over the entire cross-section of the fluidised bed by means of a specially developed AMMAG air distributor plate.
The smaller particles, carried along in the exhaust air, are then separated from the air by a JET filter and returned to the fluidised bed.
Due to their design fluidised bed technology systems can be used very flexibly.
The specific configuration of the system allows a variety of different processes, such as:
- Spray drying
- Spray drying granulation
- Granulation / agglomeration
- Spray solidification (spray cooling)
- Matrix encapsulation
- Roasting / Maillardisation
- Digestion of starch-based raw materials
The following product features are achieved through these processes:
- Low-dust, free-flowing end or intermediate product
- Optimised dosing
- Optimised solubility / re-dispersibility
- Stable mixing behaviour and homogeneous component distribution
- Reduced hygroscopicity
- Targeted release of an active ingredient
- Protection of the granulate from environmental influences
- Production of surfaces that are visually and tastefully attractive