Liquid extraction, sometimes called solvent extraction unit, is the separation of constituents of a liquid solution by contact with another insoluble liquid. The unit described here is for a semi-batch operation.
The liquid to be extracted is poured into an extraction vessel. The solvent is boiled in a reboiler vessel and condensed in an overhead condenser, the condensed liquid collecting in a reflux divider and passing through pipework to the extraction vessel.
The pipework incorporates valves in order that the solvent can enter the extraction vessel at either the base or the top, depending on the relative densities of the solvent and liquid to be extracted.
The solvent and the extracted liquid pass back to the reboiler and the process is repeated until the extraction is complete.
The extraction vessel is then drained and the solvent evaporated from the reboiler vessel and collected in the extraction vessel enabling the two liquids to be drained form their respective vessels.
The extraction unit is available in vessel sizes of 10, 20, & 50L and is suitable for operation under atmospheric pressure.