Chemical Engineering and Processing 41 (2002) 251 – 258 Application of a novel-opposed-jets contacting device in liquid – liquid extraction Asghar Molaei Dehkordi * Department of Chemical Engineering, Amirkabir Uniersity of Technology, Tehran, Iran Accepted 18 April 2001 Abstract Liquid – liquid extraction of the recommended test system, cumene – iso butyric acid–water (CBW) as a typical example of liquid – liquid extraction processes has been carried out in a new two-opposed-jets contacting device (TOJCD). The experimental results clearly indicate that TOJCD provides much higher overall volumetric (capacity) mass transfer coefficients, K L a, than those of conventional extractors. This high overall volumetric (capacity) mass transfer coefficient, K L a, indicates greater performance capability of TOJCD relative to those of conventional contactors. In addition, the effects of the upper disk speed, solution flow rate, disk diameter, and the distance between disks on the extraction efficiency have been investigated. Furthermore, the effectiveness of two-opposed jets was evaluated by employing another new non-opposed-jets contacting device. © 2002 Elsevier Science B.V. All rights reserved. Keywords: Opposing jets; Impinging streams; Impingement zone; Impinging jets; Liquid – liquid extraction; Solvent extraction; Mass-transfer performance www.elsevier.com/locate/cep 1. Introduction There are many chemical engineering operations in- volving contact of two liquid phases. Examples are liquid – liquid extraction, suspension polymerization, ni- tration, etc. The former is widely used in chemical industries. The most common method of mixing of two phases is carried out by mechanical agitation. Impinging streams (or opposing jets) configuration has attracted research efforts in several scientific and industrial fields recently. In this scheme oppositely di- rected fluid streams are made to impinge normally. As a result of their collision a relatively narrow zone of high turbulence intensity is formed which offers excel- lent conditions for enhancing interphase heat- and mass-transfer rates. This special characteristic of im- pinging streams makes them a good contacting tech- nique applicable in various fields. Tamir [1], for example, has developed the application of such a tech- nique in heat- and mass-transfer processes. Kudra and Mujumdar [2] have also presented a good literature review concerning the different aspects of opposed-jets technique and its applications. The method has been successfully applied to the absorption and desorption of gases [3–7]; dissolution of solids [8]; drying of solids [9]; dust collection [10]; absorption with chemical reactions [11,12]; two liquid-phase chemical reaction [13]; mixing [14], bioreaction [15] and evaporative cooling of air [16]. In the present investigation, an attempt was made to examine the use of opposing jets to achieve fast mixing of two liquid phases in a new two-opposed-jets contact- ing device (TOJCD). In order to achieve this goal, an experimental investigation was conducted on the liq- uid – liquid extraction of iso -butyric acid by means of cumene from its aqueous solution (CBW) in a TOJCD. In the experiments, the effectiveness of the two-op- posed-jets contacting device was tested by employing a non-opposed-jets contacting device (another new ex- tractor). The major objective of the present investiga- tion was to verify the capability of TOJCD in liquid – liquid extraction processes. * Fax: +98-21-2071251. E-mail address: amdehkordi@yahoo.com (A.M. Dehkordi). 0255-2701/02/$ - see front matter © 2002 Elsevier Science B.V. All rights reserved. PII: S0255-2701(01)00141-6