Principles of Drum Dryer
Drum Dryer involves spreading a liquid or slurry on a rotating heated drum.
As the drum rotates, the material dries and is then scraped off.
Construction
Rotating Drum: Hollow drum heated internally by steam or other means.
Feed System: Feeds material onto the drum surface.
Doctor Blade: Scrapes dried material off the drum surface.
Heating System: Heats the drum internally.
Working
Feeding: Material is fed onto the rotating drum.
Drying: Drum heats the material, causing moisture to evaporate.
Scraping: A doctor blade scrapes off the dried material.
Collection: Dried material is collected for further processing or packaging.
Uses
Drying food products like purees, slurries, and chemicals.
Merits
Rapid Drying: High drying rates.
Compact Design: Space-efficient.
Continuous Operation: Suitable for large-scale production.
Demerits
Limited Material Suitability: Not suitable for heat-sensitive materials.
Product Quality: Can cause degradation in some materials.