Crown Iron Works

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

Figure 6. Photograph inside a modem direct soivent-extraction piant processing soybeans (courtesy of Crown Iron Works, Minneapoiis, MN). (This figure is avaiiabie in fuii color at http //www.mrw.interscience.wiiey.com/biofp.)...

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. 

Dehulling systems are most commonly supplied by Buhler of Switzerland, Crown Iron Works of the United States, De Smet of Belgium, Kice of the United States, and Rotex of the United States. Decortication systems are most commonly supplied by Buhler of Switzerland and Carver of the United States. 

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 10. (a) Desolventizer toaster. Courtesy of Crown Iron Works, (b) Phase equilibrium. 

This countercurrent desolventizer/toaster was originally developed in Germany by Heinz Schumacher and put into service in about 1982. Crown Iron Works Co. (Minneapolis, Minnesota), Extraction de Smet (Zaventem, Belgium), and Krupp Maschinentechnik (Hamburg, Germany) obtained licenses to build and sell this desolventizer in various countries of the world. 

Figure 6. Scraped-surface heat exchanger. Courtesy of Crown Chemtech U.S.A., a division of Crown Iron Works Co., Minneapolis, Minnesota.

The details of glycerine refining via the Crown Iron Works Co. process, which is representative of the continuous distillation process used by a large portion of suppliers for soap lye crude glycerine, are detailed here (Figure 6). 

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. 

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

Fig. 11.6. Aerial (A) and interior (B) photographs of direct-solvent-extraction soybean plants (aerial photograph provided by Bunge Corporation, St. Louis, MO interior photograph provided by Crown Iron Works, Minneapolis, MN).

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... 

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