Effects of Swirling Flows on Pneumatic Transport of Solids in Pipes (Keynote)

By applying swirling air flow, particles can be transported with smaller air velocity as compared to the conventional flow without swirl in both horizontal and vertical flows. The total pressure drop along the pipeline is generally larger than that of the flow without swirl, but becomes small and even smaller than that of conventional one when the air velocity decreases. Thus, the swirling flow is effective in low velocity pneumatic transport of suspension mode. By using weak swirl as compared to the previous one, also decreases the particle breakage when the air velocity is low. A numerical simulation shows that the kinetic energy of particles at the wall collision becomes smaller than that in flow without swirl when the breakage is decreased.