An experimental study of swirling flow pneumatic conveying system in a horizontal pipeline

In order to reduce power consumption, pipe wear and particle degradation in pneumatic conveying system, a swirling flow pneumatic conveying (SFPC) system is proposed in this paper, and an experimental study focuses on the SFPC system in a horizontal pipeline in terms of the overall pressure drop, solid flow patterns, power consumption and the additional pressure drop. Polystyrene, polyethylene, and polyvinyl pellets with mean diameters of 1.7, 3.1, and 4.3 mm, respectively, were transported as test particles in a horizontal pipeline of 13 m length and 80 mm inside diameter. The initial swirl number was varied from 0.58 to 1.12, the mean air velocity from 9 m/s to 24 m/s, and the solid mass flow rate from 0.43 kg/s to 1.17 kg/s. It is found that in the lower gas velocity range, the pressure drop, the power consumption and additional pressure drop for SFPC were lower than those for axial flow pneumatic conveying. The critical and minimum air velocities were decreased by SFPC, the maximum reduction rates being 13 and 17 percent, respectively. The fluctuation of wall static pressure for SFPC was also decreased.