Chemical Engineering and Processing, Vol.73, 67-80, 2013
Influence of the meandering channel geometry on the thermo-hydraulic performances of an intensified heat exchanger/reactor
In the global context of process intensification, heat exchanger/reactors are promising apparatuses to implement exothermic chemical syntheses. However, unlike heat exchange processes, the implementation of chemical syntheses requires to control the residence time to complete the chemistry. A way to combine the laminar regime (i.e. enough residence time) with a plug flow and the intensification of both heat and mass transfers is the corrugation of the reaction path. In this work, the experimental set-up is based on plate heat exchanger/reactor technology. 7 milli-channel corrugated geometries varying the corrugation angle, the curvature radius, the developed length, the hydraulic diameter and the aspect ratio have been designed and experimentally characterized (heat transfer, mixing times, pressure drops, RID). The objectives were to assess their respective performances to derive some correlations depending on the channel design. The results confirmed the benefits of the reaction channel corrugation. Heat and mass transfers have been intensified while maintaining a plug flow behaviour in the usually laminar flow regime. Moreover, whatever the meandering channel's curvature radius, the results highlighted the relevance of considering the Dean number as the scale-up parameter. This dimensionless number, more than the Reynolds number, seems to govern the flow in the wavy channels. (C) 2013 Elsevier B.V. All rights reserved.
Keywords:Heat exchanger/reactor;Wavy channel;Corrugation;Dean number;Scale-up;Process intensification