10-1562 Issue 3-7 March 2014 31
Condenser
The condenser is controlled by the evaporator so requires little intervention from the user.
Using the programmable features of the evaporator’s software, condenser defrost and drain
cycles can be set up to occur automatically at end-of-run or at key points during the
evaporation process, alternatively condenser defrost and drain can be initiated manually
from the evaporator’s Select Run screen.
Automatic defrost and drain
Select the automatic End of Run Defrost and Drain option from the evaporator Run Data
screen.
The condenser behaves differently depending on whether the run is part of a linked series:
If a linked run follows, the condenser performs a short defrost and drain (sufficient to
remove any frozen solvent from the outlet pipe) then the linked run commences.
If no other runs are linked, or if the run is the end of a chain of linked runs, the system
performs a full defrost and drains the condenser.
Automatic defrost and drain can also be used to facilitate the drying of mixed boiling point
solvents in a single automated process. Multiple boiling point mixtures (such as DCM and
DMSO) are almost impossible to evaporate in one operation, but using automatic defrost and
drain, methods can be set up to perform multiple operations without the need for manual
intervention between stages.
Automatic defrost and drain also helps achieve excellent final dryness when evaporating
HPLC fractions.
It is generally advisable to enable automatic defrost and drain so the system will always be
ready to go, having defrosted and drained at the end of the previous use. However, in order
to protect the system and / or samples from solvent damage, there are certain circumstances
when auto-defrost and drain should not be used.
Do not use automatic end of run defrost and drain:
When evaporating TFA or other strong acids. Vapour may travel back from the
condenser with long term exposure causing degradation to the evaporation chamber.
Intermediate (short) defrost and drain is permitted but full defrost and drain should not be
used. Instead, stop the system, open the door and then perform a manual defrost and
drain. For this application, Genevac strongly recommend the use a fume cupboard or
fume extraction system.
At the end of a lyophilisation method. Water vapour may travel back from the condenser
to the chamber and cause the lyophilised powders to collapse. Remove the samples
first, then perform a manual defrost and drain.
Caution: Do not use automatic end of run defrost and drain when evaporating
TFA or at the end of lyophilisation methods.
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