Karr reciprocating-plate extractors

Table 6.32 Summary of Equations for Sizing the Karr, Reciprocating-Plate Extractor...

When there is no alternative to employing multiple extractions, chemical engineering approaches may afford more efficient operations in a pilot plant or manufacturing facility [10]. Many of these extractors are countercurrent devices, such as the Karr reciprocating plate tower, in which the light phase is continually fed into the bottom of the extractor while the heavy phase is fed into the top of the extractor. 

Laboratory studies of the rearrangement process began with semi-continuous operation in a single, 200-mL, glass reactor, feeding 1 as a liquid and simultaneous distillation of 2,5-DHF, crotonaldehyde and unreacted 1. Catalyst recovery was performed as needed in a separatory funnel with n-octane as the extraction solvent. Further laboratory development was performed with one or more 1000-mL continuous reactors in series and catalyst recovery used a laboratory-scale, reciprocating-plate, counter-current, continuous extractor (Karr extractor). Final scale-up was to a semiworks plant (capacity ca. 4500 kg/day) using three, stainless steel, continuous stirred tank reactors (CSTR). 

Figure 8.1.35. Schematic of various large-scale liquid-liquid extraction devices, (a) Packed tower for solvent extraction (b) sieve-plate extraction column (c) an early Scheibel column extraction design (d) Karr column, in which the plates have reciprocating motions (e) centrifugal extractor (f) porous hollow fiber membrane solvent extraction device (see Figure 8.1.13(a) for a detailed design).

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