Cartography of liquid-liquid flow in corrugated millichannels

Abstract

If the interest of heat exchanger/reactors have been demonstrated for homogeneous liquid phase applications, many chemical syntheses take place in multiphase media (gas-liquid, liquid-liquid, gas-liquid-solid…). Thus, in order to evaluate the versatility of a plate-type heat exchanger/reactor with a 2D-meandering millichannel, this work is focused on the characterization of hydrodynamics of liquid-liquid flow in the reaction channel. Therefore, several prototypes are built with millichannels of increasing dimensions to address the scale-up issue. Flow visualizations are performed with a high-speed camera; four flow regimes with octanol/water fluid system are observed: annular/plug, annular, annular/dispersed, and dispersed. The study shows that interfacial tension and dispersed phase inertia are the main forces driving the interface. A dimensionless map based on the dispersed phase Weber number as a function of the continuous phase internal Dean number is built up. This map turns out to be valid in the range (2–4 mm) of the tested corrugated millichannel size.