Agitated Dryers

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Agitated Dryers

The Agitated Dryers are presently used widely over the chemical Industry. These are naturally of 2 different types. These are:

  1. Agitated Thin Film Dryers
  2. Agitated Vacuum Dryers

Agitated Thin Film Dryers

Mechanically Agitated Thin Film Dryer is an indirectly heated continuous dryer. The feed can be in the form of a solution, slurry, wet cake or paste. If required it operates under vacuum. We offer both vertical and horizontal versions. Mechanically Agitated Thin Film Dryer is an indirectly heated continuous dryer. The feed can be in the form of a solution, slurry, wet cake or paste. If required it operates under vacuum. We offer both vertical and horizontal versions.

Working Principle

The drying in a agitated thin film dryer is a continuous operation under vacuum. Operating pressures can be as low as 1 mbar and operating temperatures can be as high as 350oC. Drying time depends on material being dried, amount of solvent to be removed, desired final moisture content, permissible jacket temperature etc.The vertical Agitated Thin Film Dryer has a jacketed cylinder with a closely fitting rotor at the centre. During operation the rotor revolves at high speed. The feed distributor spreads the incoming feed uniformly over the cylinder top periphery. The rotor blades pick up the material, spread it over heated surface in a thin film and agitate the film intensely, as it rapidly travels down. The material transforms from solution to slurry, wet cake, wet powder and finally dry powder as it travels from top to bottom. The vapour generated rises counter-currently to the inbuilt entrainment separator. Here the entrained droplets are separated from the vapour stream. The clean vapour leaves the dryer through the vapour nozzle at top.The horizontal version of the dryer is used for drying of wet cake, pastes, wet powders. The wet feed enters at one end and dry powder leaves from the opposite end. The vapours move counter currently to the powder flow and leave through vapour nozzle.


  • Once step drying eliminates number of steps like pre- concentration, filtration or centrifugation
  • Feeds can be processed without pre-concentration or dilution
  • Indirect heating and drying in absence of air. Particularly effective for heat, light and oxygen sensitive products. Best suited for solvent bearing products for complete solvent recovery
  • Quick processing time, best suitable for heat sensitive products
  • Probably the most energy efficient dryer in the market. Thermal efficiency exceeds 90%
  • Fine powder of uniform consistency can eliminate pulverizer from downstream step
  • Intense agitation suppresses fouling, keeps heat transfer surface clean
  • Operating pressure under vacuum, up to 1 torr
  • Excellent turn down capability
  • Low product holdup, ideal for hazardous applications
  • Different rotor configurations to suit variety of applications



  • APIs, bulk drugs and intermediates
  • Dyes, pigments and intermediates
  • Organic and inorganic salts


  • Solvent and products from thick dry residues
  • DMSO from salt bearing organic residues
  • Glycerine from salt bearing organic residues
  • Water from organic and salt bearing waste water streams

Agitated Vacuum Dryers

It is specially designed for drying the most delicate fine chemical products. Drying is an important part of the synthesis process and it is usually located down line of the filtration operations. The aim of this process is to remove the majority of the solvents contained in the solids. A heated agitator adds to the systems efficiency.


  • Batch Sizes from 30 to 5,000 liters.
  • Automation for preset speed control of the main agitator
  • Temperature control
  • Vacuum control
  • Other processes


  • Variable speed impeller
  • Breaker
  • Glass process vessel of 1900 ml. for 350 - 1.400 ml./batch (5 different vessel-sets available to cover 50 - 3.800 ml.)
  • Vacuum system; dust filter, glass condenser, bypass, vacuum pump, process pressure control
  • Nitrogen purge
  • The system can be build on a frame to be incorporated in a hood
  • Critical process data: impeller torque, product temperature, impeller speed, process pressure, mass recovered liquid, process vessel/condenser/filter jacket temperature, mass recovered liquid, RH (optional), vapour temp (optional)
  • PC/PLC automation package: "real-time"-trending and batch reporting in Excel of all critical process data and batch identification


  • Chopper for de-lumping
  • 21CFRPart11 compliant software
  • RH control in process vessel, vapour Temp
  • Trolley GAS assisted drying
  • Hastelloy C22 product contact parts
  • Cooling & heating unit
  • NIR or MIR probe integration
  • Different vessel-sets to cover 50 - 3800 ml
  • Combined unit with Nutsche Filter Dryer
  • Validation IQ/OQ/SQ
  • Integration in Containment isolator (Stainless Steel, Polycarbonate, PE,..)