South African state-owned power utility, Eskom’s Research, Testing and Development (RT&D), in collaboration with the Council for Scientific and Industrial Research (CSIR) National Laser Centre (NLC), have developed a mobile laser beam welding (LBW) system for repairing leaks and cracks in stainless steel water reservoirs.

Maintenance improved

According to a company statement, the utility said that a laser beam welding research facility has been established at the CSIR NLC to support Eskom’s maintenance programme for dealing with various maintenance challenges on high value equipment such as precision weld repairs on turbine blades.

Of particular interest is rebuilding blades with erosion as well as mechanical damage, the utility added.

The utility has bolstered efforts and remained in control of its maintenance programme over the past few months, following a period of power outages due to aged infrastructure that was not properly cared for.

Last month, the CSIR and Eskom entered into a five-year agreement, which aims to synergise the research capabilities of the two state-owned organisations in support of Eskom’s strategic and operational needs.

At the time of the signing, Eskom’s Group Chief Executive, Brian Molefe, said: “The partnership will further strengthen our collaborative relationship and, accordingly, provides a long term platform to perform scientific and operational research and evaluation tasks and provide scientific decision support towards the realisation of Eskom’s strategic and operational needs.”

The CE added: “We look forward to collaboration with the CSIR as we forge ahead with delivery on our mandate of ensuring reliable power to stimulate economic growth for our country and address socio-economic challenges faced by our people.

“We will prioritise projects that will ensure our operational and financial sustainability as we refurbish our current plant and deliver on new infrastructural projects to provide much-needed electricity.”

Mobile laser beam welding

By implementing this welding technology, the utility can save money and extend the production lifespan of its turbines.

A large number of turbine blades are scrapped during turbine maintenance and repair projects since the tenons of blades need to be ground down to remove the blades from the turbine rotor.

Removed blades cannot be used again as the remaining tenon stub is too short to be riveted a second time.

Eskom explained that by rebuilding the tenons by welding, it is a viable and cost-economic option to repair the blades for further use and should result in substantial cost savings.