BUCHI Rotavapo R-220 SE - Manual (Page 68)

6 Operation
68 R-220 SE Operation Manual, Version F
6 Operation
This chapter gives examples of typical instrument applications and instructions on how to operate the
instrument properly and safely. See also section 2.5 “Product safety” for general warnings.
6 .1 Evaporation in three steps
a Preparational steps
•
System must be in good working order. See final installation check, section 5.21.
• Check level of heating transfer medium as described in section 5.13.
• Fill the evaporating flask with the product to maximally slightly below the half. Install the flask at the Rotavapor.
OR
Mount the flask and establish a weak vacuum e.g. 800 mbar. Feed the evaporating flask via the feeding-valve to
maximally slightly below the neck of the flask.
• Close the splash protector if installed. Select the target heating bath temperature and start heating.
b Evaporation process
•
Establish working pressure. Press the 'Start' button at the controller or manually set the vacuum level.
• Lift up the heating bath completely. The evaporation will start shortly.
• With the heating bath at temperature start rotation and set rotational speed to the target value. At this time the
cooling medium flow must be established!
• NOTE the condensation zone of the cooler during evaporation!
Optimal cooling to evaporation ratio for safe use is reached at approx. 75-80% condensation zone height at the
first condenser. It is recommended to adjust the evaporation parameters to reach optimal condensation height
e.g. to alter the cooling medium flow during operation.
• Foam formation under vacuum can be interrupted manually at any time during evaporation.
Press the 'Aearate' button at the lower panel in short steps to let the foam collapse
OR
press the ' ↑P ' button at the controller to increase the pressure permanently during the ongoing evaporation
process. Stop increasing the pressure shortly above the foam formation limit for best process performance.
c After evaporation
•
In case the Rotavapor is equipped with a controller, pressing the 'Stop' button at the controller will automatically
stop heating, rotation and vacuum. Aeration will be done via both aeration valves.
OR
Stop heating, stop rotation and drive down the heating bath manually. Depending on the device setup it might
be necessary to switch off the vacuum source manually. Aerate the Rotavapor and wait approx. 5 minutes
before interrupting the cooling medium flow.
• Open the splash protector if installed.
• Unmount the evaporating flask.
NOTE
To remove solvent residues after evaporation remount the empty evaporating flask, close the system
and evacuate the system to a very low pressure. Then aerate via the outlet of the receiving vessel
and the filler-cock. Let the flask rotate to dry the seals at the gearbox thoroughly.