Helical ribbon impellers are commonly used for mixing high‐viscosity fluids, but they are expensive to manufacture. To address this, the authors developed the Advanced Mixing (AM) impeller, which demonstrated higher mixing efficiency compared to other high‐viscosity impellers. In a subsequent study, the authors explored reducing the number of basic components in the AM impeller to further lower costs. The development process of the AM impeller and its high mixing efficiency have been described in detail in our previous studies (Furukawa et al., 2023, 2025), and the present results further demonstrate the consistent high performance of this impeller. Meanwhile, many multistage impellers for high‐viscosity applications, produced by both domestic and international manufacturers, feature blades arranged with a 90‐degree phase shift. Therefore, the authors evaluated the performance of the AM impeller using the same configuration. They found that using the concept of pitch ratio allows for the simultaneous evaluation of the number of stages and phase, enabling the determination of the optimal configuration for the AM impeller.
Furukawa et al. (Thu,) studied this question.