This method has been applied in the study of particle flow in various industrial processes and shown to be very useful in understanding the fundamentals (Yu, 2004, Zhu et al., 2007, Zhu et al., 2008). While this is often difficult to realize with the existing experimental techniques, numerical simulation based on the so-called Discrete Element Method (DEM) (Cundall and Strack, 1979) is an effective way to perform such studies. Therefore, it is very helpful to understand the screening phenomena on a particle scale. In principle, the bulk behaviour of particles in a system depends on the collected outcome of the interactions between individual particles and between particles and boundary walls. However, this treatment mainly considered the motion of a single particle but failed to account for the effect of surrounded particles, hence is not generally applicable to screening processes (Li et al., 2003). Some simple models have been proposed following the reaction kinetic theories and probability theories, such as the “first-order kinetics” for predicting the sieving rate (Kaye, 1962), which has been discussed for batch (Standish, 1985) and continuous (Standish and Meta, 1985, Standish et al., 1986) sieving. The particle flow in a screening process is controlled by many factors and is difficult to model. This is due to the lack of insight understanding of screening processes (Standish, 1985). Most of the mathematical models of screening processes currently in use are phenomenological models.
MULTIDECK COMPOSITE DECKING HOW TO
How to control and optimise this new kind of screen to suit different conditions is an important issue for its applications, which requires fundamental understanding of this screening process. However, when sieving 0.5 mm particles in coal plants sometimes its performance is seriously low (Meyers et al., 2000).
This kind of screen has been reported to be able to double the capacity in the ore processing.
As an innovation in particle separation, the banana screen was first applied to coarse particles in iron ore processing (Lockwood, 1993), and later extended to fine particle sieving in coal preparation (Leonard, 1991, Lockwood, 1993, Meyers et al., 2000). This is normally realized by a combination of multi-decks having different incline angles. Banana screen is a specially designed vibrating screen in which the slopes of the screen change from steep at the feed end to flat at the discharge end in order to maintain a constant bed thickness (Lockwood, 1993). It is widely used in industries ranging from the traditional mineral and metallurgical sectors to the contemporary fast-growing food and pharmaceutical engineering (Wills, 1997, Perry and Green, 1997). Screening or sieving is an important unit operation for the separation of particles according to their sizes.
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