Rotating disc extractor

T. Misek, Rotating Disc Extractors and Their Calculation, State Publishing House, technical Hterature, Prague, C2echoSlovakia, 1964. 

A similar principle is used in the rotating disc extractor. Fig. 4.14. In this case the vessel diameter is much greater and a comparatively narrow vertical rotor is fitted with horizontal discs at intervals of a few inches. Annular discs are also attached to the internal vertical wall of the stator, opposite the spaces between the rotor discs. The rotor revolves at fairly high speeds and so increases the path lengths of the two phases that theoretical stage... 

Fio. 4.14. Rotating-disc extractor. (By permission from Nuclear Chemical Engineering by Benedict, M. and Pigford, T. H. copyright 1957. McGraw-Hill.)... 

The extractors are York rotating disc contactors, 3-inch ID by 48-inch long. Three contactors are to be used, one each for extraction, scrubbing, and stripping. The system will be used to investigate the recovery of plutonium and americium from MSE waste salt solutions using 30% DHDECMP in diisopropylbenzene. 

Fig. 6.3-4 Typical performance data of ten different extractor designs for the system tolulene/acetone/water. MS mixer-settler, SE static sieve tray column, PC static packed packed column, RDC rotating disc contactor, PSE pulsed sieve tray column, PPC pulsed packed column, RZE agitated cell extractors...

Extraction apparatus with continuous phase contact Spray column Packed column Pulsed packed column Rotating disc contactor, Oldshue-Rushton column, Graesser-Contactor, Kuhni column Podbiehiiak- Extractor, Luigi-Westfalia- Extractor, De Laval-Extractor... 

The raw material which is pre-heated to around 115 °C, is fed at atmospheric pressure to the extraction column (e.g. rotating disc contactor, sieve tray extractor), where the aromatics are preferentially dissolved by sulfolane. The solvent is separated from the aromatics mixture at a temperature of around 190 ""C and a pressure of just 1 bar. The sulfolane which boils at 287 °C, remains at the base of the column and is recycled to the top of the extraction column. The aliphatics are recovered by counter-current washing with sulfolane and subsequent distillation. 

The RE process proceeds in three major types of equipment mixer-settler systems, column extractors, and centrifugal extractors. Countercurrent column extractors can be further subdivided into nonagitated nonproprietary columns and agitated proprietary extractors. Agitating the liquid-liquid system breaks up droplets and increases the interfacial area to improve the mass transfer and column efficiency. Various forms of energy input are used, e.g., rotation of propellers, impellers, and discs pulsation, vibration, and ultrasonic devices and centrifugal devices. 

With mechanically agitated countercurrent extractors, energy is induced by rotating internals. Agitators are usually mounted on a central column shaft at certain distances from each other (double blade mixer, disc mixer, blade mixer, turbine mixer, helical screw mixers, etc.). Installation of stators (ring discs, punched metal sheets. 

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