Application of Modified Correction-Factor Analysis to Solvent Extraction In Rectangular Membrane Modules with External Recycle

    The expressions of mass transfer rate for membrane extraction through a rectangular module with external recycle have been derived under cocurrent-flow, countercurrent-flow and cross-flow operations based on the modified correction-factor analysis coupled with the mass balances. These expressions are explicit and the results can be readily calculated without using try-and-error method, which should be employed in the classical correction-factor analysis for designing heat and mass exchangers. For cross-flow operation, the correction factors are function of flow rate, mass-transfer area, distribution coefficient and overall mass-transfer coefficient, and some values of them are given graphically. Considerable improvement in mass transfer rate is achievable if the devices are operated with recycle, leading to increase the mass transfer coefficient.