화학공학소재연구정보센터
Chemical Engineering Research & Design, Vol.126, 19-31, 2017
Hydrodynamic performance evaluation of a novel eductor liquid-liquid extractor using CFD modeling
The hydrodynamic aspect of a novel eductor type contacting device for liquid-liquid extraction (LLE) system has been evaluated by computational fluid dynamics (CFD) modeling. CFD results were validated by droplet rise velocity and dispersed phase holdup in water/toluene system; errors were 20.7% and 15.4%, respectively. The results of CFD simulation have shown that the existence of venturi above the nozzle-jet improves the mixing due to extension of mixing region. Educator mixing performance was investigated by the effects of the parameters: jet velocity, the throat to nozzle area ratio (A(t)/A(n)), the column to nozzle diameter ratio (D-c/D-n), the projection ratio (L-tn/D-t), and two phases flow ratio Q(c)/Q(j) on the dispersed phase holdup, the suction ratio (R-s), the mixing efficiency (eta(m)) and the mixing energy efficiency eta(e)). A new efficiency named "overall efficiency" was defined as eta(o)=eta(m).eta(e) to determine the optimum operation and design condition of the eductor. The values of important parameters were determined as a) the jet velocity less than 2 m/s; b) A(t)/A(n) around 100; c) the ratio of D-e/D-n < 50; d) 1 < L-tn/D-t < 2 and the value of Q(c)/Q(j) although being flexible, but smaller values are preferred for achievement of higher mixing efficiency. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.