Thordon Bearings reports it has completed bearing and filtration system upgrades to the 7.8-MW Swift Rapids hydropower station, the oldest and largest of Orillia Power Generation Corporations’ generating stations.
Swift Rapids is located on the Trent-Severn Waterway, about 32 km north of Orillia, Ontario, Canada. Two of the plant’s three 2.6-MW horizontal Kaplan-type turbines are fitted with Thordon’s SXL water-lubricated guide bearings. Greg Auger, Thordon’s hydro business unit manager, explained that the poor quality of the water supply was impacting the expected longevity of the elastomeric bearings.
“Abrasive waters, particularly from significant zebra mussel growth, were resulting in excessive bearing wear, with Orillia Power having to replace the bearings more frequently than is typical of these bearings,” he said. “The existing filtration system was quite old, with the operator experiencing frequent breakdowns and expensive maintenance. It was also a single central system, supplying all three turbines, so there was no redundancy in case of breakdown.”
When Thordon supplied the most recent replacement bearing and carried out a site inspection in early 2019, the company recommended installation of its Water Quality Package for each shaft line, allowing each turbine to have its own dedicated filtration unit.
Thordon replaced all of the water intake, cooling and lubrication pipework with copper piping, which zebra mussels have difficulty settling on. The water filtration system incorporates a cyclonic separator to remove large and abrasive debris larger than 100 micron and includes an automated purging valve on the drain line that flushes any accumulated debris through to a central drain.
Thordon also installed additional flow and pressure instrumentation to allow Orillia Power Generation to more accurately monitor and adjust system flow rates to individual devices. An HMI (Human-Machine Interface) system was also fitted on each filtration unit, with feedback to the central plant supervisory control and data acquisition (SCADA) system.
“Orillia Power is looking to lessen the manual interventions across its hydro power plants over the next few years and we consider upgrading to the Thordon filtration system as a way of reducing the maintenance intervention requirement,” said Troy Mannell, manager of generation projects, Orillia Power Generation. “The reliability of Thordon turbine guide bearings with their advanced water filtration, and separate systems per turbine, can help us achieve greater levels of remote operation, while strengthening plant availability and operability.”