Podbielniak Centrifugal Extractor

Figure 14.15. A horizontal rotating extractor and two kinds of centrifugal extractors, (a) The RTL (formerly Graesser raining bucket) horizontal rotating extractor both phases are dispersed at some portion of the rotation RTL S. A., London). (b) Operating principle of the Podbielniak centrifugal extractor it is made up of several concentric perforated cylinders (Baker-Perkins Co.), (c) The Luwesta centrifugal extractor (schematic diagram) Luwa Corp.).

Barson N, Beyer GH. Characteristics of a Podbielniak centrifugal extractor. Chem Eng Prog 1953 49(5) 243-252. 

Fig. 26. Mechanically agitated industrial contactors, (a) mixer-settler (b) rotating-disk column (c) mixco column (d) asymmetric rotating-disk column (e) pulsed packed column (f) Podbielniak centrifugal extractor. (Reprinted from Doraiswamy, L. K and Sharma, M. M., Heterogeneous Reactions Analysis, Examples and Reactor Design, Vols. I and 2, 1984, John Wiley and Sons.)...

FIG. 15-55 Podbielniak centrifugal extractor. (Courtesy of Baker Perkins Inc.)... 

Extraction is a process that utilizes the difference in solubility of the product of interest between two immiscible phases. Liquid-liquid extraction is commonly used in classical biotechnological downstream processing for production of antibiotics and other small molecules. The second liquid phase is usually a water immiscible organic solvent. Reciprocating plate, Podbielniak centrifugal extractors, Delaval contactors, and Westfalia extraction-decanters are examples of some of the equipment available for carrying out extraction. 

Proprietary Extractors. Manufacturers or proprietary design extraction equipment (such as the Podbielniak Centrifugal Extractor or the RTL (raining bucket) Contactor) provide catalogs listing the relative capacities of the various sizes of equipment which are offered. Pilot equipment is usually available for determining extraction performance, and the manufacturer utilizes both the pilot data and experience with similar systems to provide assured commercial designs. 

Most large-scale equipment for liquid-liquid extraction is available for two-phase extraction and usually multistage systems have to be used for obtaining high yields. Ktihni type columns, Podbielniak centrifugal extractors and disk and bowl centrifuges have been used (Kula et al. 1981 Veide et al. 1983 Cunha and Aires-Barros 2002). 

Figure 5.6 Podbielniak centrifugal extractor. Source With permission from B P Process Equipment and Systems LLC.

Alternative The washing can be done in a Podbielniak centrifugal extractor, which is continuous countercurrent extraction. Alternately, the same can be done in a cascade of annular centrifugal extractors configured in the countercurrent mode. It is known that the amount of cold water required and the loss of the API would be far less compared with values for the crosscurrent process [18]. 

The reactor-exdactor chosen was a Podbielniak centrifugal extractor. These units are normally run with countercurrent feed for exdaction and are capable of having two- or three-stage efficiency. The operation, including the... 

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