Abstract
There have been many papers on the experimental and theoretical investigations of the rotational flow characteristics of the standard forms of cyclone dust collectors, or of cylindrical vortex chambers. However up to this time, the experimental studies of the rotational air flows in the spherical forms of cyclone dust collectors or in the semisphere and cone combined cyclone dust collectors have seldom been published throughout the world. Therefore in order to recognize the fluid dynamic characteristics of the turbulent rotational air flow in the returned flow types of cyclone dust collectors, the spherical forms and the semi-spherical and cone combined forms of the cyclones were made of transparent acrylic resin. Then, the distributions of the tangential and axial velocities, and also the distributions of the static pressures were measured by the cylindrical Pitot-tube in the five kinds of cyclones. In this paper, the experimental results of the velocity index n of the quasi-free vortex, those of the maximum tangential velocities VθM/Vo and those of the coefficients of the pressure drops which were related to the dimensionless time T=T2/F were described in detail, where T2 means the spin-up time and F means the reside time in the cyclones.
