Vertical Thin Film Dryer

Operating principle

The vertical thin film dryer consists of a cylindrical, vertically arranged body with heating jacket and a rotor inside. The rotor is equipped with rows of pendulum blades all over the length of the dryer. The hinged blades spread the wet feed product in a thin product layer over the heated wall and mix the product layer material intensively. Therefore the volatile components evaporate continuously from the product layer with high evaporation rates. The hinged blades are designed with a minimum gap to prevent fouling of the heating surface by product, but are never in contact with the heated wall.

The product enters the dryer at its top. The evaporation starts after heating to the boiling point. In the slurry zone first solids are formed and with advancing evaporation of the volatiles and continued shearing by the hinged blades the paste breaks up to powder. The final solid product is discharged by gravity at the bottom of the dryer via a suitable air lock.


The unique benefits of the vertical thin film dryers are:

  • In one step from liquid to solid
  • Small product hold-up
  • Short residence time cares for minimal product degradation
  • Fast start-up and shut-down
  • High performance even when scaling

Typical applications

The vertical thin film dryer is used in many applications:

  • Chlorides, bromides, sulfates
  • Glycerin recovery
  • Carbonates, phosphates
  • Silane recovery
  • Silicon, silicon carbide
  • Sodium formate  
  • Agrochemicals (Atrazine etc.)
  • Waste water and spend liquors
  • Benzosulfic acid
  • Solvent recovery from waste
  • Xanthates
  • Dyes and pigments
  • Metallurgy boron carbide, boron nitride      
  • Food, caffeine, condiments
Vertical thin film dryer