BUCHI Extraction System B-811 LSV - Manual (Page 24)

4 Description of function
24 B-811 Operation Manual, Version G
1
a Lower heating element activated
Fig. 4.9: Procedure of Continuous Flow
4 .4 .2 Rinsing - Step 2
Once the extraction (step 1) is completed (time and/or number of cycles are reached), the glass valve
opens on all positions and the solvent is released into the beaker. The solvent evaporates, rises up to
the condenser, condenses and flows down along the condensation tube through the sample into the
beaker. The condensed solvent washes final traces of soluble matter from the sample and from the
interior of the extraction chamber (cleaning glass parts).
Fig. 4.10: Procedure of Rinsing - Step 2
Step 2 without following steps (step 3 to 9); step 2a is inactive
Do not enter any parameters in step 3 to 9, if the program should stop after step 2 (without drying).
Only in this case the solvent containing the extract remains in the beaker at the end of the rinsing step.
The glass valve is open for the entire rinsing time. This is operation is recommended for volatile and/or
heat-sensitive analytes.
Step 2 with following steps (step 3 to 9); step 2a is active
The step 2a cannot be programmed (hidden in step 2), but prepares the drying process and supports
the solvent recovery.
When the rinsing time (step 2) is expired the program switches to step 2a. The samples are lifted
up automatically. Then the valve closes and the solvent evaporates, rises up to the condenser and
condenses. The freshly condensed solvent is collected in the extraction chamber. When the solvent is