To Next Page

To Previous Page

Product Service: Domestic 1-800-522-7658, International 816-333-8811

Chapter 4: Using Your Freeze Drye

Purge Valve

The optional purge valves are installed between the

Freeze Dryer collection chamber and the vacuum

pump. When the green LED above the PURGE

switch is illuminated, the purge valves are closed

and the vacuum pump is isolated from the Freeze

Dryer collection chamber.

During Freeze Dryer start-up, the refrigeration

system pulls the collector coil down to

temperature. While the collector coil cools, the

purge valves can be closed and the vacuum pump

allowed to run. This allows the vacuum pump oil

to warm which will evaporate and expel condensed

solvents from the oil. When the collector coil is

down to temperature and the freeze dry process is

started, the warm pump oil is less likely to

condense solvent vapors that are not trapped by the

collector coil. When the Freeze Dryer is operated

in the Automatic Mode, the purge valve and

vacuum pump will operate automatically to

perform this function. In the Manual Mode the

user must manually activate the purge valve and

vacuum pump to perform this function.

During shut down the vacuum pump can be run for

several minutes with the purge valves closed. This

will allow the warm pump oil to evaporate and

expel solvent vapors that condensed in the pump

oil during the freeze dry process. Whether the

Freeze Dryer is run in the Automatic Mode or the

Manual Mode, the user must manually activate the

purge valve and vacuum pump to perform this

function.

If power to the Freeze Dryer is interrupted during

the freeze dry process, the purge valves will close

during the power outage. This will prevent the

pump oil from back streaming out of the vacuum

pump into the Freeze Dryer.

Labconco FreeZone 6 User Manual

Questions and Answers: