In addition to thermal treatment of solids, fluid bed processes are used for drying tasks, for building up granules from powders or from liquids, and for coating particles.
Fluid Bed Technology
Optimal technology for individual design of granules and pellets from solid and liquid raw materials
Trust in the extensive expertise from the pioneer of fluid bed technology!
Glatt and fluid bed technology are inseparably linked. Our heart beats for the fluid bed. That’s why Glatt has had a decisive influence on its worldwide spread and development over the past decades.
Fluid bed technology – Simply perfect for adjusting specific properties in product formulation.
For the formulation of ingredients for the food and feed industry, there is a wide range of sophisticated mixing and drying systems that provide excellent service. However, as soon as specific properties are required – for example in terms of free-flowing properties, dust-free properties, abrasion resistance or a defined size and particle shape – one inevitably ends up with fluid bed technologies.
Fluid bed technology is used in many industries to agglomerate powders into readily soluble and instant products, to dry liquid ingredients into granules or pellets, to enclose sensitive active ingredients such as microorganisms or volatile essential oils in microcapsules and, if required, to coat them with a functional film or melt. The process is suitable for economically drying, granulating and functionalizing raw materials in a single – batchwise or continuous – process step.
The positive properties of fluid bed processes make the technology popular not only with contract manufacturers who dry and refine a wide variety of products. In addition to the product properties, economic efficiency and safety play a decisive role.
Excellent heat and mass transfer and gentle treatment of temperature-sensitive materials
A fluidized bed is created when upward flowing process air lifts a layer of solid particles – it fluidizes. The process air serves to generate the fluidized bed condition. At the same time, it supplies the thermal energy required for the drying-based particle technology processes.
Fluidized bed technology is characterized by excellent heat and mass transfer. All particles are separated and always mixed so intensively that a uniform treatment temperature is ensured everywhere in the entire fluid bed. The fluidized particles are accessible all around and in intensive contact with the process gas. This condition is ideally suited for wetting with spray liquids and for simultaneous drying of the resulting liquid film. This not only enables a very well controllable drying process, but also gentle treatment of temperature-sensitive materials.
Efficient drying in the fluidized bed enables a variety of other processes. In addition to the thermal treatment of solids, fluid bed processes are used for more specialized drying tasks, for the build-up of granules from powders (agglomeration) or from liquids, such as solutions, suspensions and melts (spray granulation), as well as for the coating of particles with functional films by means of coating (film coating or lipid/hot melt coating) as embedding of sensitive substances in a homogeneous, solid matrix (micro-encapsulation).
Extended operating ranges for process pressures, process temperature and special gas atmospheres
- Processing of solvent-containing extracts and temperature-sensitive substances
However, extraction, precipitation or crystallization processes often require organic solvents and the outstanding quality of some functional coatings is based on water-insoluble polymers. The processing of solvent-containing substance systems always requires special safety precautions, especially in terms of explosion protection. The design of the process gas system as a closed loop enables the economical and efficient use of protective or inert gases – such as nitrogen – and at the same time allows almost complete recovery of the solvents used. The processing of solvent-containing extracts and temperature-sensitive substances such as microorganisms or enzymes places high demands on process conditions, occupational safety and plant safety. Glatt’s vacuum fluid bed technology is another way of achieving even more temperature-friendly processes by lowering the boiling point at reduced system pressures. Explosion protection is thereby ensured by falling below the minimum ignition pressure. This benefits live cells, products with organic solvents, and also agglomerates with high strength.
- High-temperature processing for simultaneous particle formulation and functionalization at temperatures up to 900°C
Process temperature plays a key role in the development of increasingly complex materials. High-temperature processing offers new possibilities for processing high-performance materials and combining several conventional process steps within one apparatus. Different processes or combinations of them are available to achieve different properties and morphologies. With high-temperature fluid bed systems for particle formulation, Glatt overcomes previously applicable temperature limits and enables the production of, for example, catalyst materials in a single-stage process. For processes to increase particle sizes or for special thermal treatment of particles, Glatt has developed a very flexible high-temperature fluid bed system. Granulation processes and chemical reactions can be carried out simultaneously or consecutively – depending on requirements.
As an extension of the application range of the conventional fluid bed – in particular for the safe handling of substances that are difficult to fluidize – Glatt has advanced the spouted bed technology.
The following images show examples how Glatt is implementing fluid bed technology:
fluid bed process, bottom-spray, Wurster coating, batch mode
fluid bed process, tangential-spray / HP-spray, batch mode
fluid bed process, tangential-spray / rotor, batch mode
fluid bed process, drying, batch mode
fluid bed process, CPS, batch mode
in the fluid bed,
Glatt spray agglomeration
in the fluid bed,
Glatt film coating /
in the fluid bed,
Further information about fluidized bed technology can also be found in the following publications: