The refurbishment of three stacker reclaimers at a local coal mine is well under way, with transmission solutions company SEW-Eurodrive supplying 39 new drives for the project.

Work on the project began late last year and the client aims to have completed the refurbishment of all three machines – which were originally built in 1984 – towards the end of next year.

The 39 drives – divided equally among the ageing stacker reclaimers – include three IG X-series boom stacker drives to power the conveyors on the machines, 12 IG P-series slew drives to facilitate the horizontal pivoting of the arms, and 24 SEW 7-series travel drives to allow for the physical relocation and repositioning of the machines on the ground.

The company mitigated the high volume of units procured by the client through the staggered delivery of transmission solutions for the project, SEW-Eurodrive branch manager Jonathan McKey tells Mining Weekly.

The delivery of the drives for the first reclaimer was completed in July. The installation of the drives and the recommissioning of the first machine is now under way.

The drives for the second reclaimer will be delivered towards the end of this year, while delivery of the final drives for the third machine will be completed by mid-2020.

SEW-Eurodrive not only supplied the drives but also engineered some custom modifications for the multimillion-rand project.

“We had to modify the torque arms for the machine’s boom stacker solutions, owing to limited space and other restrictions defined by the original 35-year-old design. We also redesigned the mounting pedestals for the planetary slew solutions to make the drives more compact and easier to handle for maintenance,” McKey says.

He explains that the client issued SEW-Eurodrive with a list of the drives required to allow for minimal and convenient amendments to the original machines’ structures. Further, these amendments needed to conform to strict quality and reliability standards.

“We turned to our colleagues in Germany and the engineering departments at SEW-Eurodrive Johannesburg to accommodate these requirements. We then formulated highly efficient, compact solutions in line with the most recent technological components used globally,” McKey notes.

SEW-Eurodrive standardised its use of IE3 energy efficient motors and drives in 2017, owing to stricter international regulations, which, in turn, meant that all two-, four- and six-pole asynchronous motors with a power rating of 0.75 kW to 375 kW must meet the requirements of the IE3 energy efficiency class in the European Union (EU).

Although South African energy efficiency regulations are not as strict as those in the EU, SEW-Eurodrive has opted to standardise on IE3 use across all international markets.

Maintenance

The drives supplied for the project are equipped with condition-monitoring systems for operational functioning and wear monitoring. Specialised braking technology is also included in the units.

McKey explains that the wearing of components – between the boom stacker, slew and travel drives – may vary, owing to their daily operational requirements.

However, all the components were designed with longevity and long-term reliability in mind.

“As long as consumables – such as oil and breathers – are monitored and managed appropriately, the drives supplied should be operational for a long time,” he says.

Although the client can maintain the units, McKey notes that SEW-Eurodrive prefers to do repairs on its own products.

“We do not endorse anybody in South Africa to repair our products, as we employ qualified technicians and maintain huge volumes of local stock to support our own products,” he says.

He explains that the client has the option to sign a maintenance or field service assessment contract, which entails that an experienced SEW-Eurodrive team assess the condition and reliability of the drives on an agreed intermittent cycle, and issue advice based on product-specific reports.

Thermal imaging analysis of the units is possible, as well as oil sampling and laser alignment checks, which are included in the contract.

“SEW-Eurodrive offers 24- hour maintenance and service support staff. In this and all new project cases, we offer free initial commissioning assistance on all drives supplied,” McKey says.

Further, integrated software solution DriveRadar can be used in monitoring and the continued upkeep of the refurbished stacker reclaimers.

SEW-Eurodrive launched DriveRadar this year, in Germany. The solution provides condition monitoring and predictive maintenance, allowing for the integration of components, machines, plants and entire factories into a digital network that transcends the boundaries of indivivdual companies.

The technology also provides an end-to-end digital map of drive components and system solutions so that clients can obtain detailed insight into them and the associated processes.

“We intend to propose this technology to all our clients going forward, allowing for more versatile monitoring possibilities,” McKey concludes.