Abstract
In order to determine the critical separating condition of an inclined disc separator with a spiral scraper, a series of experiments was carried out by using mixtures of spherical (alumina spheres) and non-spherical (silica sands) particles under various disc inclinations (3-13°) and rotating speeds (1-50rpm). Critical conditions in terms of the disc inclinations, rotating speeds and friction factors between non-spherical particles and the disc surface were discussed on a basis of a single non-spherical particle motion in the separating zone of the separator.
The separation efficiency increased exponentially with the values of a dimensionless group (nrθc dpi2ρpi/Fi) as a function of the radial non-spherical particle number passing through the separating zone below the critical values of the disc inclination and rotating speed, where dpi, ρpi and Fi are average particle diameter, particle density, and feed rate of non-spherical particles, respectively, and n is speed of rotaton, rθc radius vector at θ=π. The fraction of non-spherical particles sliding into the products of spherical particles was approximately calculated by introducing the distribution of the sliding friction coefficient of non-spherical particles on the separator surface.
