Design Forms of Extraction Apparatus

The extraction process begins immediately after dispersion of one phase into the other and ends when the dispersed phase forms a continuous phase after phase separation. To exchange as much of the key component as possible from the feed to the solvent during the extraction process, the extraction unit must fulfil the following requirements  

Technical extractors are usually constructed with a maximum of 10-15 theoretical separation stages in a single apparatus. Compared with rectification, this reduced number of stages is due to the small stage efficiency (exchange ratio, enrichment ratio, HETS, etc.) caused by the more difficult mass transfer between liquid phases. Mass transfer mainly occurs by diffusion with low key component concentrations and is favored by large, turbulent, constantly renewed interfacial areas. In different extrac- 

In the following, essential features of important designs of extraction apparatus are described in tabular form. Design considerations are included. For further detailed treatment and special design considerations of these extractors, literature is cited. 

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