The Fluid Bed Dryer operates under the direct drying principle of direct contact between a heated gas/air and the product to effect heat transfer and mass transfer. The process gas stream enters through the fluid bed air plenum passing through the gas distributor plate, which retains the solids above. This fluidization process of the fluid bed dryer is effective for such operations as drying, heating, cooling, calcining, reacting, dedusting, or agglomerating.
The stationary fluid bed dryer has no moving parts. Fluidization enables the product to flow continuously through the fluid bed, overflowing at the opposite end. Multiple zones in the Fluid Bed Dryer allow heating and cooling in the same unit. Each zone has independent control for temperature, dew point and fluidizing velocity. Residence time can vary up to four fold in the unit by adjusting the weir height for each zone.
The Fluid Bed dryer's gentle but efficient drying action is well suited for friable or soft agglomerated particles. It works best drying products within a narrow particle size range.
- Enhanced heat and mass transfer through intimate contact and mixing with the fluidizing gas
- Heat sensitive materials can be dried at temperatures lower than the boiling point due to reduced vapor pressure
- Indirect heat transfer surfaces can be added to increase capacity or reduce bed area
- Closed cycle Fluid Bed systems, in which inert gases can be recycled, are available to handle toxic products, oxygen sensitive products, or flammable solvent wetted material
Photos (click to enlarge):