| Abstract: | An application of a cascaded Clarke-Gawthrop self tuning regulator (STR) to a Karr liquid-liquid solvent extraction column is presented. The Karr column, a reciprocating plate column, exhibits nonlinear asymmetric responses which are complex functions of the operating conditions and requires adaptive control in order to prevent instability. The outer loop of this cascade scheme controls the extract concentration of the continuous phase while the inner loop controls the hydrodynamic holdup in the column and prevents flooding. The manipulated variable was the frequency of reciprocation. The STR-STR cascade arrangement is compared with a fixed parameter Proportional plus Integral (PI) controller in the outer loop and an STR in the inner loop. |
