MechChem Africa November-December 2021

⎪ Minerals processing and materials handling ⎪

Kwatani develops specialised spiral elevator in-house

Kwatani’s depth of local engineering expertise and technical capability was leveraged to design and fabricate a specialised spiral elevator for a mobile containerised sorting plant for a diamond mine in Australia. Although not the first spiral elevator to be produced by the company, this particular one was a first-of-a-kind design and was engineered from scratch and manufactured by Kwatani in South Africa.

ture. “The client had specific functional anddi - mensional requirements for this design, with the available space for installation being very constrained,” says Kwatani senior mechani- cal engineer, Gideon de Villiers, who led the team in developing the two metre high spiral elevator. “We were also pleased to be able to meet the client’s throughput needs first time around with this specific design and build.” The unit will convey up to 3.5 t/h of dia- mondiferous ore between sorters in amobile containerised sorting plant, which is destined for a diamondmine in Australia. Thematerial to be moved up the spiral elevator ranges in size from 5.0 mm to 30 mm. De Villiers highlights that Kwatani al- ready has an established reputation with the sorter OEM, creating the necessary trust in Kwatani’s custom-engineering capability. “Our extensive knowledge of feeders and vibration dynamics placed us well to suc- cessfully tackle this innovation,” he says. “We started with the basic engineering calcula- tions to clarify what dynamic movement we required, working through factors such as planned tonnages, isolationof dynamic forces,

friction value of ore, and motor orientation and direction.” Designs were simulated using specialised software before Kwatani’s skilled teamof ar- tisanwelders tackled the task of construction and platework. This included finite element analysis to identify areas of potential ‘hot spot’ stresses. Working with relatively light plates of 3.0 mm to 4.5 mm thickness, the elevator comprises S355 structural steel to cater for dynamic vibrations. The footprint was kept to around 700 mm, with two unbalanced motors at the base. “Due to the high value of the diamonds in the material, the structure also had to include static covers welded to the body, as well as maintenance doors with anti-tamper seals,” De Villiers says. Once fabricationwas completed, the team embarked on a thorough testing programme lasting two weeks, conducted in Kwatani’s dedicated test laboratory. This allowed for the adjustment of various parameters, with close collaboration between the design and fabrication teams. www.kwatani.co.za

D emonstrating its depthof local en- gineering expertise and technical capability, local vibrating screen specialist Kwatani has designed and fabricated a specialised spiral elevator for a mobile containerised sorting plant for a diamond mine in Australia. Although not the first spiral elevator pro - ducedby the company, this particular onewas thefirst-of-a-kinddesignandengineered from scratch and manufactured by Kwatani. Better known for its large, robust vibrating screens and feeders, the Kwatani 450 kg cus- tomspiral elevatorwasan interestingcontrast for theengineering team, whoagainproduced results that reflect the company’s usual standards of excellence. Within a timeline of just 10 weeks, the project combined first principles of physics with Kwatani’s decades of experience in customdesign andmanufac- Gideon de Villiers, senior mechanical engineer at Kwatani.

Left: Kwatani designed and fabricated a specialised spiral elevator for a mobile diamond sorting plant. Right: The Kwatani spiral elevator feeder in operation on site at a diamond mine.

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