Effect of Cyclone Dimensions on Gas Flow Pattern and Collection Efficiency

According to the static-particle theory for particle collection in a cyclone, a partical of critical size remains suspended at the edge of an “inner core,” where tangential velocity is at a maximum, and inertial and drag forces on the particle balance. This article reports an investigation of the tangential velocity profile of the gas within a pilot-scale cyclone with adjustable inlet, outlet, length, and airflow. Equations to predict the maximum tangential velocity and the length of the inner core from cyclone dimensions can be used with the static-particle theory to predict cyclone collection efficiency. This approach has a better least-squares performance index than the theories of Lapple (1950), Barth (1956), Leith-Licht (1972), and Dietz (1981) for cyclone efficiency data taken from the literature.