Countercurrent extraction in a rising film column

A 5 cm diameter countercurrent extraction column has been operated in film flow conditions, using the system: water (continuous), kerosene (rising film), acetic acid (transferring solute). The film was supported by vertical Teflon wires (0.80 mm dia.) or perforated Teflon plates. The wire arrangement, with suitable cross-pieces to promote surface renewal, gave the best performance. The film column provides a constant interfacial area and very low holdup of the film phase. The observed volumetric mass transfer coefficients for rising film columns have been compared with literature data for packed and spray columns. The relative performance of the rising film column appears to be best for systems with high interfacial tension.