Southern Water operates CHP plants at a number of its wastewater treatment sites, many of which use Cat engines running on the biogas generated as a byproduct on site. At its Canterbury facility, a Cat G3412 engine had run for 132,000 hours prior to the overhaul.
The decision was made to remove and overhaul it instead of replacing it with a new one. Southern Water worked with its partner Finning to consider the options available to them, as Andy Leather, Finning customer account manager, explained:
“We have worked with Southern Water for over 20 years, providing the engineering expertise through preventative maintenance and service agreements to keep their range of Cat generators running as productively as possible. With a detailed understanding of their business we were able to confidently recommend that the best course of action to maintain site availability within budget requirements was to overhaul the existing CHP set at the Canterbury waste treatment plant.”
The overhaul involved removing the engine from its container on site and transporting it to the Finning Component Rebuild Centre in Leeds. Here work began by disconnecting the alternator to then be reconditioned by specialist technicians, beginning a detailed process over several weeks to examine components and identify what further work would be needed.
This was achieved by stripping the engine down. Cat certified engineers then cleaned and inspected every item to assess what could be reconditioned or replaced to ensure the engine ran like new. With this complete, it was then reassembled and given a fresh coat of paint. Post site installation, the engine was put through its paces to test performance and confirm it was ready to go back into operation.
Kenan Griffith, Southern Water's regional maintenance manager for Hampshire, said: “Finning has been a valued partner for many years, helping to keep engines like the Cat G3412 at Canterbury running smoothly far beyond what we would usually expect of a generator. Taking the rebuild route made sense to us on a few levels, not least due to the financial and environmental benefits.”