Kwatani was brought in to consult on possible solutions to assist one of the largest coal processing plants in the country, to not only return its screening throughput performance to its original design parameters but to increase it further as well.

Kenny Mayhew-Ridgers, chief operating officer of Kwatani, said: "Having evaluated the challenges on site and consulted extensively with the plant personnel, we determined that the suggestion to incorporate a bigger gearbox onto the screen would fail."

The screen lifespan was in excess of six years and Kwatani determined that it would not be able to accommodate substantially larger gearboxes offering 50% more output than the already installed exciter gearboxes. Mayhew-Ridgers stated: ""This would have resulted in irreplaceable damage to the screens."

Because the customer was also looking for a quick and cost-effective solution, purchasing new screens with larger vibration capabilities was not an option.

Having evaluated the challenge, Kwatani realised the simplicity of the solution. "The plant was achieving 450t/h on 480t/h screens and was looking to increase this to about 525t/h," noted Mayhew-Ridgers. "This equated to roughly a 17% increase in performance. Replacing the screen's existing gearboxes with those that could deliver greater vibration but would not exceed the output torque that the 37kW drive motor could provide was the answer."

With a range of locally designed and manufactured exciter gearboxes in its portfolio, Kwatani was quickly able to provide the customer with two new exciter gearboxes which were delivered to site, installed and operational in the two week time frame the customer was looking for. Mayhew-Ridgers said: "The increase in screen throughput was immediate."

The success of the retrofit saw Kwatani secure the order to replace the customer's three additional screens with new exciter gearboxes which are now currently operating at 550t/h - 22% more than the original requirement.

Mayhew-Ridgers added: "Our success has proven our capabilities and screening knowledge and we have further secured all the screen repair work as well. We have positioned this business to offer expertise that extends beyond the supply of screening equipment. Our product knowledge enables us to correctly specify the right equipment and components for the application - in a case-by-case scenario."