Particle velocity and concentration characteristics in a horizontal dilute swirling flow pneumatic conveying

An experimental study concerning particle behaviors in a horizontal dilute swirling now pneumatic conveying was performed. Measurements of particle velocities and concentration profiles have been carried out using the photographic image technique. From the experimental results, it is found that mean particle velocity of swirling flow pneumatic conveying is lower than that of conventional pneumatic conveying in the range of high gas velocity, but the higher mean particle velocity in swirling flow pneumatic conveying can be obtained at low gas velocity. The particle concentration profiles in the swirling flow pneumatic conveying exhibit symmetric distributions with respect to the pipe axis and the higher particle concentration appears near the wall in the acceleration region. In developed region, the particle concentration profiles of the swirling flow pneumatic conveying show anti-symmetric distributions, and the higher particle concentration appear at the bottom of pipe. However, the particle concentrations of the swirling flow pneumatic conveying at the bottom of pipe are lower than that of axial flow pneumatic conveying. (C) 2000 Elsevier Science S.A. All rights reserved.