COMPUTER-AIDED GRAPHICS OF LIQUID-LIQUID EXTRACTION

An algorithm has been developed and tested for steady-state liquid-liquid extraction, using rectangular coordinates. It is capable of handling common types of stagewise contact, i.e., single stage extraction, multistage cross-current, and continuous countercurrent multistage extraction. The results depend on the nature of the extraction scheme and the extent of separation desired. While equilibrium data for some systems are stored in its data bank, the present portable computer simulator ( LIQEXT) has the flexibility of reading equilibrium data for other systems, as well as overriding stored data Both design and rating cases can be performed. In the design mode, i.e., given the feed and solvent rates and the outlet concentration, it calculates the number of stages, the exit stream flow rates, and the concentration profile. In the rating ( or simulation) mode, i.e., given the feed and solvent rates, and the number of stages, it computes the exit streams flow rates and compositions, and the concentration profile. In both cases a graphical output of the concentration profile is produced, either on the screen or on a hard-copy plotter.