18
BÜCHI
Rotavapor
R-187EL
5 Operating the Rotavapor
•
the configuration level. This level is available after keying in
another special code. This level is programmed in the factory.
User level
Setpoint temperature:
•
Press key «P/3» for 1 sec. The display shows: «USr».
•
Press key «P/3» again; the display shows: «SP.1».
•
Increase the set point-temperature with the key «(/2», or
decrease the setpoint-temperature with the key «(/4». Confirm
the changed temperature by pressing the key «P/3».
The key «*/1» is for sevice-works by authorized service
technicians only.
Explanation of the symbols
«P.nr»
number of the actual program
«USr»
user level
«SP.1»
setpoint channel 1
«SP.2» setpoint channel 2
«PAr»
entrance into the level in which all the parameters are
stored. This level is for servicing the instrument only.
5.3 Points to note when using the Rotavapor
Selecting the distillation temperature
For optimum conditions of distillation, the energy transferred
to the distillation from the bath must also be removed by the
condenser. To guarantee this relationship, it is advisable to
apply the following rule of thumb.
Cooling water
∆
T2 Boiling temperature
∆
T1 Bath
max. 20 ºC
40 ºC
60 ºC
How do you obtain these conditions?
•
Set the bath temperature to 60°C.
•
Set the cooling water to a temperature of no higher than
20°C.
•
Have the cooling water flow through the condenser at an
approximate rate of 600-700 litres/h.
•
Select the working vacuum so that the boiling point of the
solvent becomes 40°C.
•
Consult the solvent table on page 21 for the corresponding
vacuum value.
Advantages of a bath temperature of 60°C:
•
You can handle the evaporating flask without risk of
scalding.
•
Water does not evaporate from the water bath at a high
rate.
•
The heating bath energy is utilized with optimum efficiency.
The goal is to have condensation of solvent take place with
in approximately 2/3 to 3/4 of the cooling coils.
