Bulk solid interactions in belt conveying systems

In the field of bulk solid materials handling, belt conveyor systems play an important role in the productivity of mines, ports and processing plants. A vast range of bulk solid materials are handled and understanding the influence of their characteristics on the interactions throughout the system is critical to ensuring performance and reliability. Integral areas of belt conveying systems include transportation, discharge, re-direction, transfer, loading and acceleration of bulk solid materials. In all of these areas, bulk solid interactions occur within the material itself, with the conveyor belt and the encompassing environment. To date, techniques used to investigate bulk solid material interactions in belt conveying systems have been based on classical engineering mechanics and conventional continuum “lump” based analyses. These analyses traditionally rely on bulk solid material properties which are extracted from standardised tests and measurement procedures. Based on a determined set of parameters describing the characteristic nature of the bulk solid material handled, existing theoretical approaches are presented and applied in the analysis of the belt conveyor system. Testing procedures for the determination of these parameters are also presented. In contrast, Discrete Element Modelling (DEM) analysis focuses on the intrinsic constituents (individual particles) that effectively make up the “lump” and allows a more detailed investigation into such interactions. Due to the dissociation between existing standardised tests and measurement of parameters required for DEM analysis, calibration techniques are developed from which a set of characterising parameters of the modelled bulk solid material may be obtained. A number of calibration tests implemented for the selection of characterising modelling parameters are applied and presented with results compared to laboratory and full scale tests. Following selection of DEM parameters, an in-depth study of each area of bulk solid interactions in belt conveying systems is presented. The work embodied in this thesis will investigate and evaluate the existing theoretical approaches through the application of continuum mechanics and DEM, both individually and in combination. Laboratory experiments, full scale tests and site observations are used to validate the analyses presented.