BUCHI Multivapo P-12 - Manual (Page 29)

4 Description of function
29 Multivapor™ Operation Manual, Version E
a Evaporation area
The solvent is heated by means of a heating plate. Horizontal orbital movement of the heating plate
results in a thorough vortex of the mixture within the test tubes. Thus, the solvent surface is increased
which in turn leads to a higher evaporation rate and reduction of boiling retardation.
b Cooling area
Each sample is individually connected to the vacuum cover with glassware specific adapters. The
vapor is collected and then transferred to the condenser via a ribbed PFA vacuum tube. In the
condenser the heat required for transmitting the solvent from the liquid into the gas phase is trans-
ferred to the coolant. Water, dry-ice in acetone or any coolant suitable for a recirculating chiller is
typically used for this purpose.
c Receiving flask
The condensed vapor is collected in the receiving flask. It is recommended to empty the flask after
each run. For evaporation of solvent mixtures or at low temperatures an optional refrigerated receiver
is recommended to prevent re-evaporation of the condensate. This reduces the evaporation time and
prevents interruption between runs.
d Vacuum
The evaporation performance is dependant on the pressure, the temperature of the solvent and the
coolant, and the vortex. In order to evaporate solvent at a given temperature and revolution, pressure
needs to be reduced accordingly via a vacuum pump. A vacuum controller regulates the pump by
continuously reducing the vacuum until the set point is reached. This task is performed either manually
or automatically.
4 .1 .2 Functional principle of the Multivapor-Rotavapor edition
1
3
4
2
5
Fig. 4.3: Combination of the Multivapor P-6/P-12 with the Rotavapor R-215
The vacuum tube of the Multivapor is connected to the T-piece a which is installed between the
condenser and receiver of the Rotavapor. The key feature of this setup is that the condenser assembly
b, the vacuum pump c and the vacuum controller d are shared between both the Multivapor and
the Rotavapor. Therefore both single evaporation of large flasks and parallel evaporation of small test
tubes is achievable with the same setup using little space. However, simultaneous performance of
both tasks is neither feasible nor advisable due to physical reasons, as the cooling capacity of the