Buchi Rotavapor R-220, Руководство пользователя

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BÜCHI Rotavapor R-220
5 Operation
Adjusting the Optional Automatic Lowering of the
Bath in Case of a Power Interruption
• Press the button “LIFT down”
햳
, simultaneously switching
on the main breaker switch
햲
.
This results in the display “ON” or “OFF”.
On = The lift lowering has been switched ON
Off = The lift lowering has not been switched ON.
• To switch back and forth between ON and OFF, press
repeatedly on the button “LIFT down”
햳
.
• The input is stored and the unit switched into the operating
mode only after the “AERATE” button
햽
is then pressed
repeatedly.
5.3 Tips and Tricks
Selection of the Distillation Temperature
In order to attain optimum distillation conditions, the energy
supplied to the distillation from the bath must be dissipated
again across the cooler. In order to ensure this, it is best to
work according to the following rule of thumb:
Cooling water
∆
T2 Boiling temperature
∆
T1 Bath
max. 20 ºC 40 ºC 60 ºC
How do you attain these conditions?
• Set the bath temperature at 60 ºC.
• Adjust the cooling water. Its temperature should not be
higher than 20 ºC.
• Allow the cooling water to flow through the cooler at a rate
of about 120–150 liters/hr.
• Select the working vacuum so that the boiling point of the
solvent is at 40 ºC.
• Obtain the corresponding value for the vacuum from the
Table of solvents.
Advantages of a Bath Temperature of 60 °C
• Evaporating flasks can be changed without any danger of
scalding.
• The rate of water evaporation out of the heating bath is
not yet very high.
• The energy in the heating bath is being utilized very efficiently.
The solvent should condense out in approx. 2/3 to 3/4 of the
lengths of the cooling coils present.