The countercurrent extractor decanter

This type of decanter is patented [3] and built by Westfalia. and is used for countercurrent extraction. It is similar to a three-phase decanter, except that the second liquid phase is purposely added separately to pass, in the bowl, through the first liquid phase. The two liquid phases are caused to run countercurrently in the bowl and the wanted product is leached from one phase into the other. Separate designs are available each for heavy and light raffinate. This type of decanter is often used in the pharmaceutical industry. 

Many processes, particularly in the petrochemical industry, require the decanter to operate at elevated temperatures and pressures, say up to 400°C and 10 atm. In these cases special designs and materials are used for bearing seals and lubricants. For the higher pressures, mechanical seals will be used. 

These decanters are made in both horizontal and vertical construction, although those that supply the vertical design claim that this design is the most reliable for the application, while others would hotly dispute it. 

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