Expanded local production capacity from drive systems company SEW-Eurodrive’s new Aeroton facility includes the assembly of SEW M-Series air-cooled condenser (MACC) drives for delivery at a rate of three units a week, reducing current lead times from overseas original-equipment manufacturers (OEMs) by about 36 weeks.

Built as part SEW-Eurodrive’s M-Series modular industrial gear units, the MACC is a purpose designed gearbox solution for driving the modern fan-based air-cooled condenser (ACC) systems used in steam-driven power generation plants.

SEW-Eurodrive business development, sales and marketing national and Africa manager Jonathan McKey says the first SEW MACC drives were installed at a South African concentrated solar thermal plant in the Northern Cape. “This was followed by a further 24 units, which have now been installed at a utility station in Limpopo. These size 09 MACC drives are the largest ever built by SEW-Eurodrive.”

The units were assembled in SEW-Eurodrive’s factory in Nelspruit, but a new assembly line is now being built in Aeroton, Gauteng, to expand production capacity.

An ACC fan works in the same way as any cooling fan, but in power stations and industrial condensing systems they need to generate huge air flows to efficiently condense exhaust steam from turbines.

“Our MACC drives adopt a modular design concept and gearing technology with specific [enhancements] to make them better suited to these applications,” he explains.

Highlighting key innovations, McKey says a stiffer case with built-in cooling veins has been developed for improved cooling.

“Our internal extended bearing distance [EBD] system has also been incorporated, which better enables the gearbox bearings to accommodate the very high axial and radial forces transferred through the fan and the drive shaft.”

An optional dry-well is also included to better prevent oil leakage at the output shaft, while still allowing standard mounting dynamics to be used.

With the EBD and the stiffer casing, SEW MACCs offer larger service factors, can handle higher loads and the whole drive train is stronger and more robust.

“We have also built in a maintenance brake so that when servicing is required, wind from the outside can be prevented from turning the fan and the main shaft, [reducing] safety risks and making the boxes easier to maintain in situ,” he says.

To help plant operators retrofit SEW-Eurodrive MACCs, SEW offers customised adapter plates to enable its design to be easily installed as a direct replacement for any older-generation boxes currently in use. “We also customise the output shaft length to perfectly match the ACC infrastructure onsite and to establish the ideal fan position for maximum efficiency,” says McKey.

Local Production

SEW-Eurodrive offers a single casing with key ratios that will be able to accommodate all of the different ACC requirements of South Africa’s power stations. “Our stocking policy is very simple: we will stock a single casing size with multiple components and specific ratios, depending on which power station requires the drive,” he points out.

This modular approach will enable the new Aeroton facility to custom-assemble SEW MACCs to suit any local power station at a rate of two to three units a week.

“We have already ordered the components for the 30 units we intend to hold in stock, and we expect to be assembling units here by September.

“Current typical lead times from overseas OEMs is around 36 weeks, no matter how many boxes are being ordered. Our new local assembly capability gives South and Southern African clients massively reduced lead times for replacement ACC drives,” says McKey.

In terms of service and repairs, SEW-Eurodrive is already operating at its Aeroton and Nelspruit branches, with its new assembly line equipment and test bench out on delivery. These components precisely replicate SEW-Eurodrive’s assembly and testing capability in Finland.

“This is a bold step that demonstrates our commitment to being part of solving South Africa’s power problems,” he states.

As such, SEW-Eurodrive also expects to attract business from global ACC users who may also be experiencing long delays when they find they have to replace an ACC gearbox.

“SEW-Eurodrive [is] on a mission to localise our modular drive concept for a variety of industrial drive applications so as to best meet local needs and conditions and massively reduce lead times.

“Local assembly is key to achieving this and, going forward, we hope to be closing the local supply and service loop for all users of our drives,” McKey concludes.