Wiped Film Still Components - Part X - Cold Trap and Control Systems

A key component of a wiped film still is a cold trap.  Wiped film stills are often operated at deep vacuum.  Operating at this pressure level can lower the boiling point of smaller molecules to extremely low temperatures.  These materials can easily travel to the vacuum system and condense in the vacuum oil.  Over time, they can cause vacuum pump breakage.  The role of the cold trap is to catch these vapors and remove them from the gas phase.  Cold traps are often run between -50°C and -90°C.  They are placed in line between the still and the vacuum pump.

The final component of wiped film stills is an optional one.  Still systems can be equipped with digital control systems, where every setpoint can be programmed and trended.  However, the systems can also be run manually.  The amount of control is up to the preference of the operator.  There are advantages to both approaches.

This concludes the wiped film still components series.  I hope it was useful.

Picture courtesy of Pope Scientific Inc.