Extraction in thin liquid films generated by impinging streams

A new device for liquid-liquid extraction was developed tested, and modeled, based on two immiscible thin films flowing one on the top of the other while exchanging mass. The films are formed by impinging streams: collision of two immiscible jets flowing one toward the other on the same axis. Thus the flow of the films is in a direction perpendicular to the initial flow of the jets. Two liquid systems (diluent - solute - solvent) were tested: water-iodine-kerosene and aqueous solution of HCl-pure water. In the latter case, HCl is transferred from its initial solution comprising one film to the other film of pure water flowing on the top of it. The experiment determined geometrical parameters of the thin film, mass-transfer coefficients of the solute between the films, as well as power input. For a relatively identical power input, the measured mass-transfer coefficients were higher by a factor of 10-200 compared to conventional devices. in addition, the mean residence time in the new device is shorter than in conventional devices due to minimal dispersion of the phases during the extraction stage, making the settling stage relatively simple and short.