Buchi Rotavapor R-200, Руководство по эксплуатации

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BÜCHI Rotavapor R-200/205
5 Operation
5.7 Choosing distillation conditions
To achieve optimum distillation conditions when rotary evapo-
rators are used, the energy, supplied for distillation from the
heating bath, must be removed via the condenser. To guaran-
tee this, operations should be performed according to this
rule of thumb.
Cooling water Vapour Bath
Max. 20°C 40°C 60°C
How can you achieve these conditions?
• Set the bath temperature to 60 °C
• Set cooling water, temperature no higher than 20°C
• Allow cooling water to flow through the condenser at
approximately 40 – 50 l/h
• The working vacuum is to be chosen, so that the boiling
point of the solvent is 40 °C. You can get the corresponding
pressure from the Solvent Table (next page).
Advantages associated with 60 °C bath temperature:
• The evaporating flask can be replaced without risk of
scalding.
• The evaporation rate of the water from the heating bath is
not very high (energy loss).
• The heating bath energy is employed at a good degree of
efficiency.
This rule can also be applied to lower bath temperatures, for
example:
Cooling water Vapour Bath
max. 0°C 20°C 40°C
Optimising distillation:
Depending on distilled solvent, distillation may have to be
optimised again. However, before you optimise distillation again,
the heating bath must have reached 60 °C.
The following applies: condensation of solvent should be 2/3
to 3/4 of the existing condenser coil.
Picture 26: R-205: 20–40–60° C rule
Δ Δ
Δ Δ Δ
T
2
(min. 20°C)
Δ
T
1
(min.
20°C
)