dedert's fluid bed dryer provides for gentle yet efficient drying action, which is ideal for friable or soft agglomerated particles with a fairly narrow particle size distribution and medium size particles (200 – 400 microns).
product is fluidized by the process gas stream entering the dryer through the distributor plate. dedert has a variety of distributor plates available depending on the application.
process drying air could be designed as multi-zone to enhance drying characteristics in different parts of the bed. exhaust air leaves the dryer through a hood and is further cleaned in cyclones or bag filters to maximize product recovery while meeting emission guarantees.
fluidized heating and cooling zones can be integrated into a single unit in a fluid bed dryer. submerged extended surface heat exchangers can also be incorporated: this approach maximizes the heat transfer rate. submerged heat transfer area can be retrofitted to existing fluid bed dryers to increase evaporative capacity.
dedert ring dryers are used when products cannot be efficiently dried in single pass flash dryers. in cases where particular powders, pastes, cakes or slurries require extended drying times, the dedert ring dryer is the solution.
the differentiating technology between the flash dryer and the ring dryer is the incorporation of a classifier (manifold), which enables the recirculation of semi-dried product back to the initial heat zone for additional drying and dispersion. the classifier achieves this by the adjustment of blades which cut into the layer of material that has been centrifugally classified. the splitter blades are adjusted and set by qualified dedert engineers during the commissioning of the ring dryer and need not be adjusted once set.
the recycled material on the ring dryer allows a comparatively lower exhaust temperature to be used while achieving the desired final moisture content. drying efficiency is improved and variations in product quality are limited.
dedert has designed and built the world’s largest partially-closed ring dryer at 179,000 acfm and is able to evaporate 34 tons of water per hour in a single unit.