The key to optimising plant performance hinges largely on understanding minerology and aligning this with the process flowsheet. Of equal importance is the necessity to understand the parameters and capabilities of the plant’s process equipment which plays an enormous role in achieving/improving production targets.
Vibrating screen manufacturer Kwatani has positioned itself as an expert in both of these areas which recently saw the company assist one of South Africa’s largest coal producers increase its screening throughput quickly and effectively, writes LAURA CORNISH.
“Understanding the true capabilities of our equipment enables Kwatani to provide its clients with the best solution for any screening application. It also enables us to maintain a forefront position on implementing technologies and developing our own intellectual property to ensure optimised product performance,” starts COO Kenny Mayhew-Ridgers.
This approach has seen Kwatani’s position in industry evolve – not only is the company recognised for its screening equipment but also its capabilities as an advisor.
“In an advisory capacity we are able to build trust with our clients and they quickly come to rely on us for our expertise in understanding their process needs and our ability to marry those needs with the right equipment solution,” he continues.
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With ongoing time, investment and effort into research and development, to ensure its products are constantly evolving with the needs of industry, Kwatani’s approach is always evaluation, understanding and questioning, all important elements that must be considered to ensure the correct screen retrofit/installation/upgrade.
Beyond this the company also places a lot of emphasis on products that support its primary screening equipment, and as such it today offers its own range of excitor gearboxes to support the optimal performance of its screens.
Putting theory into practise
Kwatani’s expert and advisory role approach has seen the company deliver numerous successful screening projects for its clients – which more recently included consulting with one of South Africa’s largest coal miners to help it increase throughput capacity on one of its existing screening circuits.
“The client was struggling with underperforming screens which were delivering even less throughput than their design parameters. Above this the client was looking to increase its throughput and exceed those parameters.
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“Having evaluated the problem and consulted extensively with the client, we determined that the suggestion to incorporate a bigger gearbox onto the screens would fail,” Mayhew-Ridgers outlines.
Having already been in operation for over six years, the COO quickly determined that the existing screen could not accommodate the next size gearbox of the specific OEM, that generates 50% more output than the currently installed exciter gearboxes.
“This would have resulted in irreplaceable damage to the screens,” Mayhew-Ridgers states.
The alternative, replacing the existing screen with a new screen incorporating larger gearboxes was considered a costly and timely exercise – something the client was looking to avoid.
The proof is in the pudding
“In essence, the increase in throughput required was relatively marginal. Client was achieving 450 tph on 480 tph screens and was looking to up this to about 525 tph.
“This equated roughly to a 17% increase in performance. This was in fact a simple challenge that required a simple solution – replacing the screen’s existing gearboxes with those that could deliver greater vibration but would not exceed the output torque that the 37 kW motor could provide,” Mayhew-Ridgers outlines.
With a range of locally designed and manufactured exciters gearboxes in its product portfolio, Kwatani was quickly able to provide the client with two new exciter gearboxes which in the space of two weeks were delivered to site and operational.
“With an increase in throughput, the success was immediate.”
The benefits have been further reaching. The screen efficiency improved and owing to a lower material bed depth on the screen due to the new screen operating parameters the drive motors drew less Amps, which relates to less power consumption.
The success consequently saw Kwatani retrofit the client’s three additional coal screens with the new exciter gearboxes which are currently operating at 550 tph – 22% more than the original requirement.
“Our performance has established a solid relationship with the client and we have since secured all the screen repair work as well,” Mayhew-Ridgers adds.
“This project is a clear example that demonstrates the importance of understanding the true workings and capabilities of process equipment. Because only then can you make the right recommendation to deliver on optimising that equipment’s performance,” he concludes.