Distillative sepn. of soln. contg. non-evaporating component - using vapour diffusion promoted by heat of mixing

A method of distillative sepn. of solns. contg. a non-volatile component utilises the heat generated by spontaneous distillative mixing of two solns. of differing chemical potential to produce the distillative sepn. of another soln. Pref., the spontaneous distillative mixing takes place between two solns. of differing concns. In the prefd. arrangement, a number of closely spaced, vertical walls have liq. films trickling down both their surfaces; the succession of films is as follows: first and fifth film is a soln. of lower concn., second the same but at higher concn.; third film is the soln. to be sepd., and fourth film is of the pure volatile component. Differential vapour pressure causes the volatile components from first film to evaporate and, by diffusion across the mixing chamber to ppte. on the second film, thus releasing heat which passes through the wall to the third film, where it causes evaporation of the volatile component, which in turn diffuses across the sepn. chamber to the cooler surface on which the film of pure volatile component is pptd. Extremely high thermal efficiency, resulting from the elimination of conventional heating and cooling processes in evaporation and similar systems.