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Thin film dryers

Thin Film Dryers

Thin film dryers are suitable for drying dissolved or slurried crystallizing or amorphous products to a pourable powder.

Wiped film dryers consist of a vertical or horizontal heated cylinder, on the inner wall a rotating wiper system distributes the crude product to a thin and turbulent film. The film thickness is determined by the distance between the wiper elements and the evaporator wall.

In front of the wiper elements a highly turbulent bow wave is forming; the bow wave ensures constant mixing of the product. The evaporation out of the product film is going on until a covering of the dried material on the evaporator wall is formed at the last evaporator section. This dry material is removed by the wiper elements and discharged out of the evaporator as solid material.

Depending on the application and product properties, thin film dryers can be designed as vertical or horizontal evaporators.

Advantages of thin film dryers

  • Continuous process
  • Low evaporation temperatures within the product film
  • Short residence time
  • High evaporation rates possible
  • Combination with a column to increase the number of stages is possible

Examples for applications for thin film dryers    

  • Glycerin Recovery
  • Catalyst Recovery
  • Organic Pigments
  • “Zero Discharge” Wastewater applications
  • Solvent Recovery from Waste 

Thin film dryers manufactured by VTA

VTA provides thin film dryers from laboratory to production scale in sizes ranging from 0.2 - to 50 m² and for operating temperatures up to 400 °C.

The material for the product wetted evaporator parts will be selected depending on the corrosiveness and the reactivity of the processed products.

Product development in the VTA test centre


In the test centre VTA is able to perform feasibility and pilot tests with thin film dryers. Production runs are also possible on the laboratory and pilot equipment.