“…The entire flow behaviors described by the solid holdup distributions in the tubular loop reactors are obtained. It is noted that the simulated object is a pilot-plant scale polypropylene loop reactor consisting of loop and axial flow pump with post-guide vane, and some important two-phase flow behavior parameters, such as the turbulent energies, the velocity vectors and the fluid trajectories, are not mentioned, although many flow features, such as the excellent solid mixing, heat and mass transfer properties, can be related to these behavior parameters (Boothroyd, 1971;Akilli et al, 2001;Sheintuch and Nekhamkina, 2004). Furthermore, the influence of adding a guide vane installed on the back of the axial flow pump is also not considered.…”