Abstract
Problems of countercurrent multiple contact extraction are solved using plate efficiencis, in the case where the equilibrium line is straight. For the extraction of solids we assumed uniform concentration of the underflow, the immiscibility of underflow with overflow, and the constant underflow.
The number of actual plates required for a given separation defined as Eq. (3), may be calculated by Eq. (9). Relations between the over-all plate efficiency Eop, individual plate efficiency EM or EB and extraction factor β are also obtained. The individual efficiencies are defined as Eq. (1)-(2). The over-all plate efficiency Eop, consists of E and ε/N as Eq. (11), where E means the over-all plate efficiency when it is assumed that βN equals β, and ε/G is the correction factor. Fig. 2a and 2b are the charts for calculation of E. Fig. 3, 4 and 5 are the charts for calculation of ε, for several types of operation when distribution constant γ=1 and wf=0. The calculation may be simplified by using these chart.
