Development of a model for predicting the screening performance of a vibrating screen
CIM Bulletin, Vol. 72, No. 804, 1979
V. K. KARRA, Senior Research Engineer, Process Machinery Division, Rexnord, Milwaukee, U.S.A.
A mathematical model for the performance of a vibrating screen is developed in terms of an oversize partition curve. This is a normalized curve for any assemblage of particles presented for screening when their size is normalized with respect to the 50 per cent passing size (d50 ) under the prevailing screening conditions. Based on the throughfall aperture (hT) of the wire mesh on the deck, the effects of oversize (% > hT), half-size under (%<0.5 hT), deck location and feed rate were evaluated using the existing screen sizing information. All these variables and also the near-mesh (1.25 hT x 0.75 hT) content (%) of the feed affect the d50.Performance data from different decks of a double-deck screen with various feed rates, size distributions and screen apertures were used to evaluate the near-mesh factor. Effects of wet screening and material bulk density are also incorporated in the model. This generalized model is useful for the simulation of a multiple-deck screen. It furnishes the sieve analysis information of all the deck output streams and therefore has a potential use in the over-all circuit evaluation when used in conjunction with relevant crushing and grinding performance models. An example illustrating the prediction capabilities of the model is given.
Mineral engineering, Models, Screening, Vibrating screens, Partition curves, Sieve analysis, Metallurgy.