A comprehensive two-day course in chute design and modelling was recently held at the Centre for Mechanised Mining Systems (CMMS) at the University of the Witwatersrand, Johannesburg, endorsed by the Conveyor Manufacturers Association (CMA) and the South African Institute of Materials Handling (SAIMH). The course was presented by leading Australian and South African experts in chute design, and approved for three CPD credits by ECSA.
Course attendance entitled candidates to register with the CMA and write an assignment and examination. Those who pass both the assignment and examination will be issued a CMA certificate of competency. Results of successful candidates will be announced in due course.
Schematic shows a typical guided flow transfer chute.
Design of chutes, which are a vital link in any conveyor system, are often an afterthought when designing the main conveyor system. However, they are in fact, a most important feature, enabling the smooth transfer of bulk materials from a higher conveyor belt to a second, lower belt, guided through a carefully angled, sloping channel or slide. The correct design of chutes is essential in order to avoid costly process interruptions due to blockages or mechanical failure. Appropriate and regular maintenance is also necessary to prevent breakdowns.
The course objectives included understanding internal angles of friction and how chute angles are determined and applied to the chute design; interpretation of a comprehensive bulk solids report and applying the various results to the equipment design; explanation and use of the chute angle adhesion tester and its application in design.
A packed schedule discussed, inter alia, operation and maintenance of chutes; chute liners and their applications; calculation of bulk materials trajectories, velocities and pressures; DEM and calibration techniques; practical application of continuum and DEM modelling; interpreting the comprehensive bulk solids report and applying results to equipment design; single particle analysis; wear minimisation and flow optimisation; shear properties; aspects of material properties; dust control; flow tests.
The presenters included:
• Henk Brink is an experienced and well recognised authority in the South African materials handling industry with a focus on design and project engineering, particularly complex multi-conveyor and transfer chute systems above and below ground. He has been involved in major projects for several mining, engineering and construction organisations, locally, trans-border and abroad in such places as Qatar, Zimbabwe, the DRC and Bulgaria. Operating from Cedotech, a specialist materials handling consulting company, he provides services ranging from pre-feasibility and concept design to construction and commissioning.
• Ed Birtch from South Africa, holds an HND in Mechanical Engineering from the UK and has over forty years of experience in bulk materials handling, working extensively on both small and multi-billion rand mining projects as a designer, project engineer and project manager.
Birtch is a consultant with TBSA, responsible, together with Dr August Lamos, for the development of the TBSA Laboratory at Wits, and for the engineering design on bulk solids flow design projects.
• Dr Kenneth Williams, GM for Research at TUNRA Bulk Solids at the University of Newcastle, Australia, coordinates a wide spectrum of research projects. He is primarily involved in the application of stress-based analysis for the design of bulk material handling systems, the prediction and design of pneumatic conveying, fluidisation and air slide systems for dense and dilute phase flow, and the prediction of wear in bulk material handling systems.
• Dr Dusan Ilic, senior consulting engineer with TUNRA Bulk Solids, also at the University of Newcastle, has operated as a materials handling consultant for over ten years. His main areas of expertise involve auditing, concept design, optimisation, numerical modelling and analysis of transfer systems.