Wiped Film Still Components - Part V - Still Heating System

Up to this point we have discussed the feed system, still body, and wiping system.  The feed material flows into the still body and is wiped into a thin film on the inside wall of the still.  Now we need to provide heat to drive evaporation/distillation of the volatile components of the feed material.

The body is most often heated either by electric band heaters or by a heated jacket.  The jacket can be heated by hot oil, hot water or steam.  Electric band heaters are a cheap, effective method for less precise applications.  They tend to be used for smaller, lab scale applications.  However, for production and pilot size equipment, jacketed systems are preferred.  Bands will have temperature variation from band to band and therefore the heat applied will not be completely uniform.  This is good enough for development and feasibility work.

For pilot and plant size systems, it is preferred to use jacketed still bodies.  Most often, these are paired with a hot oil system.  This allows the operator to have a consistent temperature throughout the entire evaporation portion of the still body.  The jacketed still is necessary for repeatable, production size work.

Picture 1 is a still with band heaters and Picture 2 is a jacketed, hot oil still.

Pictures are courtesy of Pope Scientific Inc.