Horizontal thin film evaporator

We design vertical and horizontal thin film evaporators to separate a multitude of mixtures, including very high viscous and fouling substances.

Horizontal thin film evaporators consist of a heated, horizontal vessel and a high-speed rotor that maintains a film of product against the heated wall in highly turbulent conditions. A high evaporation rate and short contact time are achieved making processing also thermal sensitive products possible.

We offer a cylindrical or conical vessel (evaporator body) depending on the specific need. A distributor, mounted in front of the top product inlet, distributes the product on the periphery to be collected by the rotor.

Horizontal thin film evaporators reach higher concentration ratios compared to the corresponding size of a vertical thin film evaporator, thanks to longer residence time, and are used when construction constraints exist (e.g., height limitation inside buildings).


Features and options

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  • Standard sizes from 0,05 m2 to 15 m2, smaller and larger depending on process needs
  • Feed flow from 0,1 t/h to 10 t/h
  • Operating pressure from 0,1 mbarg to 2 barg
  • Wide range of operating temperatures depending on product limitations and operating pressure
  • Compatible with various types of heating media (steam, hot oil and hot water)
  • No recirculation
  • Heat recovery configuration


  • Non contacting lobed rigid rotors (L, LV, R, HHV, UHV types): positioned with a fixed and well-defined clearance from the heated wall dependent on the product and process properties
    Available with special toothed lobes (HV, HHV and UHV types) for processing high viscosity products


When designed with a conical stator body the operator can adjust the gap between the stator and the rotor tips to control the residence time or to assure a fully wetted heated surface even at a high evaporation ratio or a low feed rate, without hinged blades.

The most suitable material is selected depending on the nature of the process stream, wastewater and the operating conditions.
The main materials usually selected are the following:

  • Glass lined carbon steel
  • 316L stainless steel
  • Super duplex stainless steels
  • Nickel alloys (e.g., Hastelloy® HC22)
  • Titanium

Configurations to optimise energy consumption are the following:

  • Using hot water from cogeneration
  • Using waste energy (e.g., exhaust gas, steam condensate, process condensate)
  • Combining the abovementioned technologies

To learn more about our design, production and service capabilities, check the DBO section.


  • Heating

  • Bottom Cone:
    • Simple, non-heated
    • Simple, heated (refer to heating options)
    • Simple, heated and scraped
  • Double cone

  • Driving group motor configurations:
    • Coaxial gearbox
    • Parallel gearbox
    • Orthogonal gearbox
  • Driving group shaft seal:
    • Double wet mechanical seal on both ends of the shaft including flushing pot and circulation pump on request
  • Guides with lubrication package on request:
    • Pin and bearing
    • Spider


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  • Condenser:
    • Shell and tube type
    • Mixing type
    • Cold traps
  • Vacuum pump (selected based on process pressure operating range)
  • Chilling units
  • Inverter
  • Cleaning features:
    • Flooding
    • Spray nozzles


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Thanks to the various features and options and our many years of process expertise in thermal separation, our horizontal thin film evaporators are used across multiple industries in a wide range of applications, from industrial processing to wastewater treatment.

Optimally suited to handle very high viscous and fouling products, they are used to treat mixtures with different properties:

  • Viscosity: low to very high
  • Temperature sensitivity: low to high
  • Boiling point: low to high
  • Fouling: low to high
  • Foaming: low

They are used in combination or as alternative to vertical thin film evaporators when extreme drying performances are requested or when there are space constraints (e.g., height limitation within buildings).

Thin film evaporators can be provided as a standalone operation unit or, as the majority of applications require, as part of a plant consisting of several units, including other evaporator types.

More about plants

More about processes

For new or innovative applications or to assess the correct sizing also for consolidated processes, we provide support to customers with software simulations and testing operations, to determine which type of evaporator (or which plant concept) is the most suitable for the performances sought.

More about R&D

Want to know more about the horizontal thin film evaporator?

Contact us