Swirling fluidized beds are being operated with several variants of an air distributor. In this study, a new mesh-type variant of the air distributor was used to investigate the swirling fluidized bed dynamics. MATLAB-based particle image velocimetry of the swirling fluidized bed was carried out by considering different sizes and densities of the particles. The velocity fields of the swirling bed were generated at different superficial air velocities. These velocity fields were further processed to obtain an average particle velocity at different locations in the bed. It was revealed that the longer beds form two partially differentiable layers in their swirling regime of operation. A thin layer of particles swirled at the bottom of the bed while a thick layer at the top of the bed followed a bubbling regime. Overall, the average velocity of the particles' inventory increased with superficial air velocity. The particles of 3 mm size swirled uniformly at a superficial air velocity of 1.4 m/s while 4 mm and 6 mm particles underwent stable swirling at superficial air velocities of 1.5 m/s and 2.2 m/s, respectively. © 2018 by Begell House, Inc. www.begellhouse.com.