EVNA, a waste-to-energy plant, asked Cetim to assess the toothed wheel of a steam turbine. The analysis of its remaining useful life confirmed that it could continue to be used while the replacement wheel was being manufactured.
The waste-to-energy plant EVNA is operated by Suez in Haguenau Saverne (Bas-Rhin, France). It produces and supplies hot water and steam to local manufacturers. The excess steam is used to produce electricity with a 3 MW turbine.
During a periodic maintenance operation, the company tasked with carrying out the maintenance identified wear marks on a toothed wheel that is fundamental for the proper operation of the equipment. It therefore recommended that EVNA replace this toothed wheel. However, it takes around nine months to manufacture the toothed wheel that is approximately one meter in diameter and weighs 600 kg. As EVNA could not afford for its turbine to be out of action for such a long time, it asked Cetim for a second opinion. “We wanted Cetim’s specialists to perform the relevant analyses to assess the condition of the toothed wheel and accordibngly determine whether it could remain in operation while the new part was being manufactured”, explained Mélanie Ruedy, head of the EVNA plant.
Extended and safe operation
Further to a thorough visual inspection of the toothed wheel by a gear expert, Cetim’s teams tasked with assessing the remaining useful life of equipment and structures carried out various analyses. In addition to dimensional measurements, hardness tests confirmed that the metal core was as resistant as the surface layer, while non-destructive magnetic particle inspections detected no buried cracks. “Following these expert assessments, and backed up by test reports, Cetim assured us that the toothed wheel could continue to safely operate while its replacement was being manufactured”, disclosed Mélanie Ruedy.
The toothed wheel was therefore reinstalled and the turbine at the EVNA plant continued to seamlessly operate during the time needed to procure the new part thereby generating substantial savings.
