BUCHI Extraction Unit E-816 HE - Manual (Page 19)

4 Description of function
19 E-812/816 Hot Extraction Operation Manual, Version B
4 .2 Functional principle of a hot extraction
The Extraction Unit E-812/816 HE is designed to extract fat quickly and product-friendly from food
and feed. Thereby the sample is extracted in hot solvent. The extraction process consists of 3 steps
decribed in the following.
1
2
3
4
1
a Cooling water
b Receiving funnel c Solvent tank connection
d Beaker with glass sample tube
Fig. 4.2: Schematic overview over an extraction position
4 .2 .1 Step 1 - extraction
The solvent evaporates and the vapor rises up to the condenser. From there the condensed solvent
flows into the 10 ml receiving funnel. When this receiver is full, the solvent flows back into the sample
through the 5 holes of the receiving funnel.
The solvent valve is closed. The sample always stays in the hot solvent. The solvent level remains
constant. When the programmed extraction time is over the system goes to the next step.
4 .2 .2 Step 2 - rinsing
The tank valve in the back of the unit now opens periodically (the default value of 15 minutes can be
modified in the parameter “Drain interval” within the software, see “Defining a method”) and removes
approximately 10 ml of solvent from the process. The solvent level goes down.
When the programmed rinsing time is over the system goes to the next step.