Particle flow regime in a swirling pneumatic conveying system

Particle fluidization is crucial for pneumatic conveying, combustion, and material drying. In this study, a swirling generator was designed to investigate the effect of the swirling flow on the flow regimes of pebble particles in a vertical pipe, and four different sizes of pebble particles were experimentally evaluated. Experiments were performed to investigate the effect of the axial flow and swirling flow on the flow regime, pressure drop, and suspension height of particles in a vertical pipe. The results indicated that the swirling flow has a significant effect on the particle flow regimes in a vertical pipe when the solid mass flow rate and inlet airflow velocity are constant. The swirling flow reduces the pressure drop and increases the particle fluidization in a vertical pipe, and it lifts the particles only when the inlet airflow velocity is higher than the particle velocity for the choking condition.