Steady-State Continuous Countercurrent Staged Extraction

1 Steady-State Continuous Countercurrent Staged Extraction 

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Clearly extract E and raffinate R will not be the same as those produced by a continuous countercurrent extraction. Subsequent raffinates R and extracts E t E" etc., will approach the desired result, however. One can follow the approach to steady state by observing any conveniently measured property of the raffinates and extracts (density, refractive index, etc.). The properties of R R"y etc., will approach a constant value, as will those of E E"y etc. If this has occurred by the time extract and raffinate Rs in the upper part of Fig. 10.38 is reached, funnels 1 through 5 represent in every detail the stages of the continuous cascade just below. Thus, for example, raffinate R from funnel 3 will have all the properties and relative volume of raffinate R of the continuous plant. 

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