Available in the UK from Labtex, Pope Scientific short-path/wiped-film stills (WFS) and wiped-film evaporators (WFE) successfully separate volatile and less active components for use in oils, fats, chemicals, polymers, nutraceuticals and fragrances, etc. A gentle process uses the thin-film wiping action of feed liquid through a heated cylindrical vacuum chamber at high vacuum (vacuum distillation/evaporation). Key benefits include
- Short residence times of the feed liquid.
- Significantly lower temperatures owing to high vacuum capability.
- Optimal mass and heat transfer efficiency.
- The brief (seconds) exposure of the feed liquid to heated walls is a result of the slotted wiper design, which forces the liquid downward under strict residence time, film thickness and flow characteristic controls.
Using the WFS process for distillation delivers efficient thermal separation with minimum product decomposition and maximum product quality. It offers far superior performance compared with flash evaporators, falling film stills, rotary evaporators and similar equipment in any processing application where heat-sensitivity is a factor.
The Pope dimension of excellence
Pope adds superior design and construction to the basic wiped-film still process. This has enabled Pope stills to sustain pressures down to 1 µm for either solvent stripping or molecular distillation. The variable speed control of the wipers, coupled with the ability to reverse rotation, allows for an extremely wide variation of hold-up times for the process fluids in the evaporator body. Pope supplies either Teflon or carbon wiper blades; the latter is recommended for applications running at temperatures higher than 200 °C. labtex.co.uk
