This study empirically evaluates the mixing performance of Micro Coiled Flow Inverters (MCFIs) with 90° periodic bends in helically coiled tubes, enhancing radial mixing via Dean vortices. Six MCFI reactors were tested using the Villermaux–Dushman reaction, comparing mixing efficiency and pressure drop to a conventional helical coil reactor at 6–9 mL/min flow rates. MCFIs significantly improve micromixing efficiency with a moderate pressure drop increase. A novel performance ratio, defined as the segregation index improvement to friction factor increase relative to straight coils, balances mixing efficiency and energy cost. All MCFI configurations achieved a performance ratio exceeding one, with the highest (up to 1.5) for the eight-bend reactor. Computational Fluid Dynamics (CFD) simulations using ANSYS Fluent analyzed flow in MCFIs (0.78 mm tubing, curvature ratio δ=0.052), confirming skewed velocity profiles and Dean vortices. Experimental pressure drops aligned within 5–10% of CFD predictions. The results support MCFIs as efficient micromixing devices for continuous flow processes, combining enhanced performance with simple reactor geometry.
