Chute Modelling Capabilities & Future Directions Paul Munzenberger Adam Mayers

Agenda Continuum Chute Modelling (PM) Discrete Element Method (DEM) Chute Modelling (AM) The future of chute modelling Aspec Engineering Team Meeting, Sydney, 3/7/2018

Continuum Modelling Continuum modelling predicts material flow through transfer chutes using classical dynamic equations and Coulomb friction. When studying transfer chutes, continuum modelling involves tracing the flow of a bulk solid from when it leaves the discharge conveyor to when it lands on the receiving conveyor. Most commonly the top and bottom of the flow at the symmetry plane of the flow are traced. Continuum modelling is also used to estimate silo and hopper wall loads. Aspec Engineering Team Meeting, Sydney, 3/7/2018

Continuum Modelling Continuum flow has the following advantages:– It is fast. It requires less calibration parameters. It requires no special software. Presents a means by which chute components can be placed mathematically rather than by looks. It is regarded as being more accurate than DEM in many situations. Aspec Engineering Team Meeting, Sydney, 3/7/2018

Continuum Modelling Continuum flow has the following disadvantages:– Typically two dimensional. Requires knowledge of advanced calculus, differential equations and numerical methods. Relatively poor under low speed flow conditions. Difficult to calculate the extent of off-centre loading of the receiving conveyor. Aspec Engineering Team Meeting, Sydney, 3/7/2018

Continuum Modelling Aspec Engineering Team Meeting, Sydney, 3/7/2018

Continuum Modelling Aspec has developed a MatLab based continuum model that promises to enable the efficient design of chutes. The Matlab continuum model is available as an application that simplifies the analysis process. An automatic report is produced as part of the analysis. The flow paths are based on relatively simple equations that don’t take flow widths, convergence/divergence or depth into account. Aspec Engineering Team Meeting, Sydney, 3/7/2018

DEM Modelling Discrete Element Modelling (DEM) models the interaction of many discrete particles. ASPEC utilise Bulk Flow Analyst (BFA) and have completed several chute designs / studies. DEM has become the “in-vogue” tool for chute analysis and design as it provides a very detailed simulation output, however has a number of shortcomings: Easy to get fooled by flawed simulations Slow to run – each run may be 4-8 hours Difficult to analyse results and perform design development. Have set up material validation models – most suitable for free flowing materials (e.g. coal, grain, sugar). Aspec Engineering Team Meeting, Sydney, 3/7/2018

DEM Modelling Aspec Engineering Team Meeting, Sydney, 3/7/2018

REPORTING IS ALWAYS A CHALLENGE! DEM Modelling REPORTING IS ALWAYS A CHALLENGE! Aspec Engineering Team Meeting, Sydney, 3/7/2018

The Future of Chute Modelling Continuum modelling is an important part of chute modelling as it is – or should be – the first stage in a DEM analysis and it acts as an alternative method to check DEM results. Future work:– Merge the detailed continuum analysis into the Matlab code. Refine the Matlab application. Develop a parametric model of a “standard” chute in inventor – driven by excel / Matlab continuum model. Implement a semi-automated system that covers continuum modelling, DEM, 3D modelling, detailed drawings. FEA integration could also be integrated for silos etc.. Improve DEM reporting method. Aspec Engineering Team Meeting, Sydney, 3/7/2018

Thank you Questions? Aspec Engineering Team Meeting, Sydney, 3/7/2018