Distillation And Evaporation

Evaporation and Distillation

Short Path or Wiped-Film Distillation

Pope systems provide efficient thermal separation with minimum product decomposition and maximum product quality. These are results you can expect using Pope Wiped Film-Short Path systems for distillation, evaporaton, concentration, separation, purification or deodorization. Performance is far superior to flash evaporators, falling film stills, rotary evaporators and similar equipment, in any processing application where heat-sensitivity is a factor. Pope Short Path/Wiped-Film Stills (WFS) and Wiped-Film Evaporators (WFE) successfully separate volatile from less volatile components in oils, fats, chemicals, polymers, nutraceuticals, fragrances etc. with a gentle process utilizing the thin-film wiping action of feed liquid through a heated cylindrical vacuum chamber. Keys to the superiority of this process include short residence time of the feed liquid, a significantly lowered temperature due to high vacuum capability, and optimal efficiency in mass and heat transfer. The brief (seconds) exposure of feed liquid to heated walls is due in part to the slotted wiper design which forces the liquid downward with strict control of residence time, film thickness, and flow characteristics. High quality components, state-of-the-art fittings and materials, and total quality control during all phases of design, fabrication and testing result in processing equipment offering the highest performance possible. Pope engineers and fabricates systems using Wiped Film Short Path Process including stills, evaporators, hybrid configurations that include fractional columns with distillation units, condensors, evaporation and processing vessels that meet our customer's application requirements, with superior results.

Process Description

Wiped Film (Short Path) Distillation or Evaporation  Feed liquid is admitted into still under vacuum, immediately spread into a very thin film and forced quickly down the evaporation surface. Heated walls (orange) and high vacuum (yellow) drive the more volatile components (distillate) to the closely positioned internal condenser as the less volatile components (residue) continue down the cylinder. The resulting fractions exit through individual discharge outlets. Depending on application, the desired product is either the distillate or the residue fraction. Condensable low MW compounds collect in a cold trap upstream of vacuum system. For high solvent loads, an optional external condenser may be installed immediately downstream of the still. (With external condenser incorporated, the internal condenser may be removed to provide a typical "WFE" or Wiped-Film Evaporator configuration.) * refer to Pope still graphic below Pope adds superior design and construction to the basic wiped-film/short path still process. This has enabled Pope stills to sustain pressures down to one micron for either molecular distillation or solvent stripping. Pope variable speed control of the wipers coupled with the ability to reverse rotation, allows an extremely wide variation of hold-up time for the process fluids in the evaporator body. A Wiped-Film Molecular (Short-Path) Still should be used where the distillate is of high boiling point. High vacuum (to 0.001 torr) and a close proximity internal condenser are utilized. AWiped-Film Evaporator (WFEshould be used where there is a significant percentage of moderate or low boiling distillate. Medium vacuum (to 0.1 torr) and a high surface area external condenser are utilized.


  • Pharmaceutical
  • Biomaterial Concentration
  • Polymer Devolatilization
  • Molecular Distillations Of Esters, Fatty Acids, Mono, Di, & Triglycerides
  • Residue Removal / Decolorization
  • Vitamin, Nutraceutical, Essential Oil Isolation
  • Wax Fractionation
  • Oil Deodorization
  • PCB, Insecticide Removal
  • Water Removal - ppm Level
  • Food, Flavor Purification
  • Solvent Recovery


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For more information call 01484 600 200

Evaporation and Distillation

Distillation And Evaporation