Application: Test of the unit for clients interested in the smallest continuous fluid bed dryer for small-scale production or R&D applications.
Capacity: The evaporative capacity is 2-50 kg/h and the minimum feed requirement is about 50 kg.
Specification: Up to 1500 kg/h of drying air is heated electrically to a maximum inlet temperature of 200°C.
Elutriated fines are recovered in a cyclone and/or a bag filter.
The GEA Niro VIBRO-FLUIDIZER® is a plug flow, vibrating fluid bed – a vibrated powder layer on an air distributor plate (patented design). The effect of this vibration combined with the upward and forward directed flow of air through the plate creates the ideal conditions for processing and powder transport. The unit operates with a shallow powder layer of less than 200 mm. This gives a much more lenient powder treatment, since powder residence times are shorter than in non-vibrating fluid beds which operate with much deeper powder layers.
GEA Niro's VIBRO-FLUIDIZER® is successfully used on all types of powders, agglomerates, and granulates, especially those which normally fluidise poorly due to a broad particle size distribution or highly irregular shape, or require relatively low fluidization velocities to prevent attrition.
The VIBRO-FLUIDIZER® can also be operated as a either separate drying or cooling unit, although it is often associated with a spray drying system to produce agglomerated instant powder or act as a powder conditioning plant for special coating operations.
Fluid bed after cooling Where the drying is divided in two or more steps, the first step being done in a spray drying chamber (transforming the liquid into powder particles and evaporating the main portion of the water), the evaporation of moisture from a particle will become more difficult and require more time, as the residual moisture content approaches 0%. Subsequent drying can be done in a fluid bed.
The fluid bed drying technology is especially suited for this purpose as the residence time in the fluid bed is so long that the moisture from the centre of the particle can reach the surface from where the evaporation takes place.