A review on modern variants of the partitioned pipe mixer: designs, performances, and applications

This paper presents a comprehensive review of the partitioned pipe mixer (PPM) and its design variants: the barrier-embedded partitioned pipe mixer (BPPM) and the groove-embedded partitioned pipe mixer (GPPM). These mixers utilize chaotic advection as their mixing mechanism in the laminar flow regime. The review first focuses on the flow and mixing characteristics of these mixers, considering the influence of the operating conditions and design variables. The advantages and flexibility of the BPPM and GPPM over the original PPM are highlighted. The investigation covers mixing performance in both the creeping and non-creeping flow regimes. In addition, this review examines the impact of thixotropy and fluid inertia on mixing performance of the mixers, revealing irregular trends. It emphasizes the importance of carefully considering thixotropy and inertia when selecting appropriate mixing protocols and operating conditions. Furthermore, the potential use of chaotic mixing by the BPPM in filtration processes is briefly reviewed. In conclusion, the review summarizes the limitations of the previous studies and suggesting future research directions. Further studies are expected to explore the potential of these types of mixers in improving mixing performance in various industries, particularly those dealing with rheologically complex fluids. Graphical abstract