FLOW MEASUREMENT AND EFFICIENCY MODELING OF CYCLONES FOR PARTICLE COLLECTION

Gas flow within a Stairmand high efficiency cyclone was visualized using small, helium-filled soap bubbles that had the same density as air. The bubbles were illuminated using a modulated arc lamp. The resultant bubble streaks were photographed and digitized to determine radial and tangential components of velocity. Axial velocity was determined indirectly based on the conservation of mass. All measurements were made assuming azimuthally symmetric flow. A smooth-spline fitting algorithm was applied to the radial and tangential velocity profiles to compensate for the instability of the measurements. After obtaining velocity profiles for the cyclone, a Lagrangian description of particle trajectories within the cyclone was written and run for different particle sizes to determine the cyclone's grade efficiency. Results compared well with efficiency data obtained from experiments by Iozia and Leith (1990). Agreement appeared better with this model than models of Barth (1956), Dietz (1981), and Iozia and Leith (1990).