Although the shared-savings business model of technology service provider and manufacturer of advanced composite fans MechCal is a paradigm shift for the mining industry, MechCal MD Gavin Ratner reports that the company is registering a posi- tive response to the new way of thinking.

Ratner explains that despite the current state of uncertainty in the mining sector, most companies’ ability to spend capital remains contrained. “We have developed and secured a funding stream to supply our fans to the mines at no capital cost,” he adds. Owing to the energy efficiency of the fans, a variable rate is agreed upon, whereby the company will share the savings in energy that the mine realises in the reduced energy bill.

Ratner explains that a reasonably small shaft might require about 200 fans, averaging R50 000 each.

“However, mines incur even bigger costs with the operational costs of fans, as it is much greater than the capital cost,” he notes, adding that, for example, if 200 of the company’s 45 kW fans are installed at an energy saving averaging 12 kWh, the mine will realise a saving of between R11-million to R12-million a year.

Over the last year the company has supplied about 1 300 of the 45 kW fans. Ratner notes that the product range has also expanded, to include 15 kW, 22 kW and 75 kW fans.

Meanwhile, additional augmented products such as an automated control system for the fans that enable users to control mass flows to a predetermined value allowing additional savings, he says, adding that “through all of the installations already done, it was noted through measurements undertaken to verify the savings, that a majority of the fans installed are operating way off their best efficiency points. With the inclusion of a control system, MechCal fans can now be operated at specific variable operating points automatically, regardless of the system resistance, which will increase operational efficiencies of the fan installations”.

He adds that about 17 months ago, the company changed from using composite impellers to steel impellers in its fans, as the composite impellers started to break down.

Ratner explains that originally, the composite impellers had undergone a trial period, whereby ten of the fans were successfully installed at the back-end section of gold producer Sibanye Gold.

Sibanye Gold’s operations are historically some of the most productive mines in the industry and boasting reserves of 13.5-million ounces and resources of 74.2-million ounces at the end of 2012.

However, when the fans were installed at the development ends of the mines, composite blades were damaged owing to the impact of explosive debris that was ingested.

“The fans were redesigned with steel-cast blades, and there have not been any structural failures since,” he adds.

The fans are developed and manufactured in South Africa. Currently the only component that cannot be sourced locally, at a cost that is competitive, is the electric motor says Ratner, noting that it is hoped that through collaboration with specialist motor manufacturers Transelectric Motors, the company will be able to design and manu- facture a competitive motor locally.

Ratner explains that a large ventilation consultancy recently carried out an intensive study, whereby consecutive tests compared MechCal’s product with seven different fan products on the market. The study assessed the total operating cost of the company’s fan, which includes capital cost, maintenance and savings. “MechCal’s product finished top by a large margin,” he says.

The company aims to have a bigger presence internationally and to use the shared-savings business model on larger surface ventilation systems, Ratner concludes.