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.
“As a company with 30 years of experience designing bespoke transfer chutes, it has been interesting to watch who enters – and exits – our market over the years,” says Mark Baller, managing director of Weba Chute Systems. “For instance, there were a number of global players who started producing chutes about 20 years ago; most had to withdraw from this activity to refocus on the areas of strength.”
This highlights the widespread 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 that chute manufacture posed 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 accommodate very specific conditions related to its application – so it cannot be an off-the-shelf item. It must by its nature be custom-designed if it is to be fit-for-purpose.”
The material’s size distribution and density – as well as its speed and trajectory ¬– are just some of the key variables that will determine the most efficient design. Baller highlights that Weba 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.
“A well-designed chute must 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 conditions and demanding duty that the chute must withstand, he says. A sub-optimal product will not only wear quickly but will create environmental hazards such as dust and spillage. To reduce these dangers and extend wear-life, Weba Chute Systems employs design techniques like discrete element modelling (DEM, which model the interaction between individual particles and boundaries to predict bulk solids behaviour.
“This tool can model moving boundaries and gives us a better understanding of particle flow dynamics,” he says. “We apply these findings to enable ultimate flow velocity and direction control through our chutes; this 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 5000 chutes already installed globally. Professional chute design can therefore not be done on the strength of just a training course with the relevant software.
“We always welcome competition in the marketplace, as it helps keep everyone on top of their game,” says Baller. “However, entering this market without the necessary knowledge and experience – especially when it is not your core business – does not really make sense.”
He urges stakeholders to rather collaborate with expert businesses that have proved their worth, so that real value can be added to the end-customer’s operations. The alternative poses considerable risk and cost – not only to a new entrant but to the mining customers themselves.
He concludes by emphasising that, despite its relatively low value as a proportion of overall plant costs, the transfer chute represents a critical item.
“Any failure of a chute to perform 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 and quality bespoke designs.”