Static mixers are devices equipped with a series of identical internal elements designed to promote or enhance mixing. They are widely used in pipes, channels, columns, and reactors, playing a key role in process intensification by offering advantages such as reduced space requirements, shorter residence times, and lower operatiing costs. Since the first patent was filed in 1874, numerous designs have been developed and commercialized. One of the most critical parameters in selecting a static mixer is its energy consumption, typically characterized by the pressure drop it induces. While engineering handbooks provide a broad range of empirical correlations for predicting the pressure drop across various mixer types under both laminar and turbulent flow conditions, studies specifically focusing on Komax static mixers (manufactured by Komax Systems Inc., Huntington Beach, California, USA) under a turbulent flow remain limited.

This study aims to address this gap through a dedicated experimental investigation conducted in a horizontal pipe (ID = 40 mm, length = 14 m), using water as the working fluid. The static mixers were positioned 5.8 m downstream from the pipe inlet. A key novelty of this work lies in the quantification of the effect of the number of Komax mixing elements (two, three, and four) on the resulting pressure drop. Analysis of the experimental data shows that increasing the number of elements leads to a reduction in the Darcy friction factor. A new correlation is proposed to predict this parameter as a function of the number of elements, showing good predictive capabilities, with an average relative error and an absolute relative error of less than ±10% and ±20%, respectively. The results obtained for the friction factor are also compared with available data from the literature for other types of static mixers. In addition, the power dissipated per unit mass of liquid is analyzed and discussed.