KD Scientific Centrifan PE - Manual (Page 22)

Chapter 2
2-6 Centrifan TM PE Personal Evaporator
2.7 Connections for Evaporation with Inert Gas
If you desire to purge the drying enclosure of air by bleeding dry nitrogen or another gas
into the process as it runs, then procure a length of 1/8” ID tubing. It should be long
enough to connect from an inert gas of choice to the back of the Centrifan
TM PE unit and
also for providing a vent connection to any convenient exhaust system such as a fume
hood or elephant trunk.
a) Locate the Centrifan TM PE a convenient distance from both the supply of inert gas
and the hood or exhaust trunk which will be used to vent the system.
b) The 1/8 barb fitting screwed into the larger ½” fitting closest to the cold trap should be
connected to a nitrogen, argon, or other inert gas supply at a very low pressure.
c) The 1/8 barb fitting located on the fitting above the power connector should be
connected to a length of 1/8” ID tubing which will serve as the means of venting an
equal gas volume to that being introduced through the other fitting. This
arrangement maintains approximate atmospheric pressure within the enclosure at all
times.
d) To visualize and help set the low volume of gas introduced to the system, it may be
helpful to dip the end of the vent tube in a beaker of water and regulate the minimal
inert gas bleed by monitoring the trickle of bubbles within the beaker.
Figure 2-4: Inlet (left) and Vent (right) Connections for Inert Gas Evaporation
Outlet for
Inert Gas Inlet for
Inert Gas