MechChem Africa July-August 2020

Industry learns the complexity of chute design – the hard way

Chute design is one of the most complex and under-rated aspects of materials handling – as a number of large equipment suppliers have discovered to their cost, argues Weba Chute Systems’ MD, Mark Baller.

“A s a company with 30 years of experience designing bespoke transfer chutes, it has been interesting over the years to watch who enters – and exits – our market,” saysMark Baller, managing director ofWeba Chute Systems. “For instance, of a number of global players who started producing chutes about 20 years ago; most have had to with- draw from this activity to refocus on other areas of strength.” This highlights thewidespread perception in the mining sector that anyone can build a transfer chute, says Baller, and that the construction is little more than platework. It is this misunderstanding that has lured companies into thinking chute manufacture poses an easy opportunity to fill a gap in their broader product offering. “Nothing could be further from the truth,” he says. “For a start, the transfer point in any materials handling system needs to accom- modate very specific conditions related to its application – so it cannot be an off-the-shelf item. Itmust by its naturebe custom-designed if it is to be fit-for-purpose.” Thematerial’ssizedistributionanddensity – as well as its speed and trajectory – are just some of the key variables that will determine the most efficient design. Baller highlights

thatWeba Chute Systems has spent decades perfecting both its scientific understanding of material flow and its capacity to design and construct chutes based on these sound principles. “Awell-designed chutemust also enhance the performance of other equipment in the system, especially expensive items such as conveyor belts,” he says. “It must ensure, for instance, that material does not free-fall onto a belt and cause costly damage and downtime.” Then consider the harsh operating condi- tions anddemandingduty that the chutemust withstand, he says. Asub-optimal productwill not onlywear quickly but will create environ- mental hazards such as dust and spillage. To reduce these dangers and extend wear-life, Weba Chute Systems employs design tech- niques such as discrete element modelling (DEM), whichmodels the interactionbetween individual particles andboundaries topredict bulk solids behaviour. “This tool canmodelmovingboundaries to giveus abetter understandingof particleflow dynamics,” he says. “We apply these findings to enable ultimate flowvelocity and direction control through our chutes, which improves productivity, safety, environmental impact and cost-effectiveness.”

Baller emphasises that the company’s ongoing product development combines field experience with constantly improving technologies – leveraging its learning from almost 5 000 chutes already installed across the globe. Professional chute design can therefore not be done on the strength of just a training course with the relevant software. “We welcome competition in the mar- ketplace, as it helps keep everyone on top of their game,” says Baller. “However, entering thismarketwithout thenecessary knowledge andexperience–especiallywhen it is not core business – does not really make sense.” He urges stakeholders rather to collabo- ratewith expert businesses that have proved their worth, so real value can be added to the end-customer’s operations. The alternative poses considerable risk and cost – not only to a newentrant but to themining customers themselves. He concludes by emphasising that, despite its relatively lowvalueas aproportionof over- all plant costs, the transfer chute represents a critical item. “Any failureof a chute toperform optimally can easily undermine – if not bring to a halt – the smooth operation of a plant,” he says. “This makes it worthwhile to work with proven service providers who offer quality bespoke designs.” q

Left: Weba Chute Systems employs design techniques such as discrete element modelling (DEM), which models the interaction between individual particles and boundaries to predict bulk solids behaviour. Right: Chute design is one of the most complex and under-rated aspects of materials handling. Weba Chute Systems has spent decades perfecting its scientific understanding of material flow and its capacity to design and construct chutes based on these sound principles.

8 ¦ MechChem Africa • July-August 2020

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