Wiped Film Evaporators



Evaporation applications that involve high boiling points, high viscosity, heat sensitivity or fouling products can be troublesome. GMM Pfaudler’s extensive experience and expertise in this area and our EQUILLOY brand Wiped Film Evaporators (WFE) are the solution.

The Wiped Film Evaporators (WFE) are designed to continuously separate volatile compounds by introducing a mechanically agitated thin film of feed material to a heated surface for efficient and reliable processing of a wide variety of products. WFE’s operate under high vacuum in order to reduce operating temperatures for high boiling and heat sensitive products. The short residence time minimizes the heat history to prevent thermal degradation. Special WFE designs provide for efficient processing of viscous materials like polymers and resins. The wipers continually clean the heat transfer surface making the WFE ideal for fouling applications

Operation video

WFE Design Features

The operating features of our WFEs, such as high vacuum (short path) distillation, short residence time and a highly agitated thin film of feed product on a heated surface, makes WFEs ideally suited to handle a wide range of heat sensitive, high boiling, fouling, and viscous materials.

With WFE sizes ranging from 1.2 sq. ft. (0.1sqm) to 500 sq. ft. (46.5sqm), no application is too small or too big for our capabilities. Each of our Wiped Film Evaporator is thoroughly tested and inspected prior to shipment via Factory Acceptance Testing including a vacuum rise test, internal and jacket hydrostatic pressure test, and a operational test with water to ensure the WFE is operating precisely to our standards prior to shipment.


Technical features

Wiped Film Evaporator Systems

Pressure Vessel Design

Drive Units

Entrainment Separators

Internal Condensers

Wiper Blades

Unique WFE Design Advantages

Slotted Wiper Blades
Unique wiper blade designs effectively spread the material in a thin film on the wall for better heat transfer. Blades move the product down the heated wall in matter of seconds to minimize residence time.

Low Rotor Speed
High rotor speeds are not necessary with EQUILLOY WFEs. The high heat transfer coefficient, provided by the WFE design, requires lower rotor speeds, which greatly extends the service life of the wiper blades, mechanical seal and drive bearing.

No Bottom Steady Bearing
Unlike a typical fixed clearance evaporator design, the WFE rotor is supported entirely from the top drive and bearing assembly, all mounted to the WFE top cover and main shell flange. This is accomplished by means of our robust overhung design. With no bottom steady bearing, no flux oil is required, which is critical when non-volatiles are the product.

Low Horsepower Requirements
The low rotor speed significantly reduces horsepower requirements. This provides a significant savings in use, especially when compared to the same size fixed clearance evaporator.

Expandable WFE Sizes
For some models, additional thermal sections can be installed above the original thermal section at your plant site to provide increased capacity for existing WFEs. Easy Rotor Removal Any size WFE rotor can be removed and reinstalled in 30 minutes or less. Simply disconnect the motor leads, feed line, and bolts, then lift the rotor out of the shell as one complete assembly. This allows for quick, easy, inspection, maintenance, and cleaning.


Internal Condenser
Our design with no bottom steady bearing allows for the installation of an internal condenser. WFEs with internal condensers minimize pressure drop compared to external condensers, allowing for high-vacuum operation. The high vacuum, and the proximity of the condenser surface area to the heated wall, provides better separations and ensures complete condensation and sub-cooling.

Efficient Entrainment Separators
Specially designed, full-length entrainment separators for standard and high-vacuum operation effectively remove entrained droplets from the vapor stream and improve the purity of the distillate product.

High-Vacuum Operation
The high-vacuum design of our WFE can operate with vacuums as low as one micron (.001 torr). Operating at deep vacuum lowers operating temperatures and prevents thermal degradation.

Bottoms Outlet
For viscous materials with high melting points, the WFE bottom head can be heated, and extruder blades can be utilized to mechanically aid in discharging heavy material.

Low Maintenance
Depending on the application, we recommend only one shutdown per year for 1-2 days for inspection and maintenance. Mechanical seals typically last for many years. There is no bottom bearing and thus no costly maintenance.

Our Drives
Our unique WFE drive assembly enables our customers to easily access the mechanical seal for replacement without having to remove the complete rotor assembly, minimizing down time and extra costs associated with overhead cranes.

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Wiped Film Evaporators, the problem solver for your difficult separation

Pfaudler has been manufacturing Wiped Film Evaporators (WFEs) since the 1950’s with installations throughout the world in challenging applications ranging from food to radi...


Wiped film evaporators

FAQ Wiped Film Evaporators (WFE)

A WFE is a speciality thin film evaporator for difficult separations. Internal rotating components wipe the process material into thin film for improved heat transfer.

The WFE is used in difficult separate applications, including HIGH VISCOSITY (for example polymers) and HEAT SENSITIVE PRODUCTS (for example nutraceuticals) and HIGH FOULING (for example used motor oil re-refining) and HIGH BOILING POINT PRODUCTS (for example any high molecular weight material where operation at very high vacuum is necessary to reduce temperature).

Typically, the WFE is fabricated with stainless steel, duplex stainless steels or high nickel alloys, but is also available in glass and glass-lined steel construction.

Watch our WFE Operation Video to see the components of the WFE and how it operates.

The WFE was invented in Rochester, NY, and GMM Pfaudler acquired the rights in the early 1950's and has been providing WFEs and complete WFE Systems globally since then.