Extractor Bollman-type

The Bollman-type extractor shown in Fig. 18-76 is a bucket-elevator unit designed to handle about 2000 to 20,000 kg/h (50 to 500 U.S. tons/day) of flaky solids (e.g., soybeans). Buckets with perforated... 

FIG. 18-76 Bollman-type extractor. (McCahe, Smith, and Haniott, Unit Operations of Chemical Engineering, 5th ed., p. 616. Copyiight 1993 hy McGraw-Hill, Inc., New York. Used with permission of McGraw-Hill Book Company.)... 

The Bollman-type extractor shown in Fig. 18-85 is a bucket-elevator unit designed to handle about 2000 to 20,000 kg/h (50 to 500 U.S. tons/day) of flaky solids (e.g., soybeans). Buckets with perforated bottoms are held on an endless moving belt. Dry flakes, fed into the descending buckets, are sprayed with partially enriched solvent ( half miscella ) pumped from the bottom of the column of ascending buckets. As the buckets rise on the other side of the unit, the solids are sprayed with a countercurrent stream of pure solvent. Exhausted flakes are dumped from the buckets at the top of the unit into a pad-... 

Figure 12.8-2. Equipment for moving-bed leaching [a) Bollman bucket-type extractor, (b) Hildebrandt screw-conveyor extractor.

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