Crown Iron Works extractors

FIGURE 10.3-9 Crown Iron Works extractor, (Reproduced by permission. Chemical Engineering Progress, American Institute of Chemical Engineers.)... 

Fig. 34.13. Rectangular loop-type continuous countercurrent solvent extractor. (Courtesy of Crown Iron Works Company, Minneapolis, MN.)...

A small-scale chain conveyor type of extractor was developed in the 1940s at Iowa State University with the intent of using trichloroethylene solvent to extract soybeans. Crown Iron Works of Minneapolis, Minnesota, licensed the technology and extractor design, and supplied several continuous solvent extraction plants in 1951 using the new extractor and trichloroethylene solvent (6). The meal from these plants proved detrimental to animals, so the plants were either closed or converted to petroleum-based solvents (7). The chain-type extractor apparatus continued on and is the basis of the modern Crown Iron Works Model III extractor used today. 

Figure 9. (a) Soybean cellular structure. Courtesy of USDA-ARS. Special thanks to Dr. Robert Yaklich and Dr. Charles Murphy at the Soybean Genomics and Improvement Laboratory in Beltsville, MD, for creating this electron transmission micrograph especially for this chapter, (b) Crown extractor. Courtesy of Crown Iron Works, (c) Reflex extractor. Courtesy of De Smet Group, (d) LM extractor. Courtesy of De Smet Group. 

Figure 27. Internal view of rectangular loop extractor (Courtesy of Crown Iron Works., Minneapolis, Minnesota).

Crown Iron Works of Minneapolis, Minnesota has developed two specialty extractors that are finding use in the nutraceutical industry. Both types of extractors feature continuous, countercurrent percolation operation, requiring minimal operator time. These extractors are modifications of Crown s oilseed extractors that have been used for several decades. 

The extraction principles employed by most percolation extractors are the same, but the method by which each achieves countercurrent flow of solvent to flakes is different. The shallow-bed, chain extractor (Fig. 11.12), which resenibles a full-loop conveyor, is one of today s widely used extractors. Crown Iron Works (Minneapolis, MN) manufactures this type of extractor. In early versions that still exist in the industry, flakes are fed into an inlet hopper and are conveyed down the first leg of the loop where they are washed with moderately dilute miscella to extract surface oil and penetrate the cells. As the flake bed moves into the bottom horizontal section, full miscella is recycled through the bed for filtering, and then to a liquid cyclone for final... 

Fig. 11.12. Depiction of a shallow-bed, chain-type extractor early design (A) and more recent design (B) (provided by Crown Iron Works, Minneapolis, MN).

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