French stationary-basket extractors

The French stationary-basket extractor is a variant of this. The flakes are contained in stationary, compartmented beds filled by a rotating spout to feed the solids and are leached with solvent and miscella countercurrently [15, 33]. 

Fig. 8.8. Cutaway drawing of French Stationary Basket Extractor. The deepbed baskets are stationary while the collet/flake loading, extraction, drainage, and unloading stations revolve. By permission of French OH Machinery Co., Piqua, OH.)...

A modification of this type of extractor is the stationary basket extractor (Fig. 11.14), such as was manufactured by the French Oil Mill Machinery Co. (Piqua, OH). Unlike other extractors, the solids do not move. Countercurrent solvent-to-flake flow is accomplished by rotating the flake inlet, the solvent and miscella sprays, the miscella collection cells, and the marc discharge. The bed is divided into cells or baskets to prevent back mixing of oil-lean miscella with oil-rich miscella. Typically the bed depths used in this extractor are much deeper than those of the chain extractor. The drained marc discharges when an opening in the bottom screen and the discharge hopper rotate into appropriate positions. To the author s knowledge none of this type of extractor has been installed for over 12 years, but they do exist in the industry. 

Fig. 11.14. Depiction of a deep-bed, stationary-basket extractor (provided by French Oil Mill Machinery Co., Piqua, OH, rights now owned by Desmet Process and Technology, Marietta, GA).

In the French Oil Machinery Co. stationary basket extractor (Fig. 10.3-5), extract percolates through beds of solids contained in a circular array of sector-shaped compartments with perforated bottoms and drains into sumps positioned below the beds. Unlike crossflow extractors, the solids do not move." Instead, the solid feed spout and solids discharge zone rotate about the circle and the extract feed and discharge connections are switched periodically. These extractors are like automated diffusion batteries in which downflow is used but, because extract backmixes in each sump, the extract concentration leaving a stage is somewhat different from that entering the next stage. 

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