Scottish sewage-to-fuel plant notes maintenance gains

Glasgow - SMW, part of Scottish Power Group, produces waste-derived fuel from sewage sludge, which is used to generate electricity at Longannet power station on the banks of the Firth of Forth. The Glasgow-based company's processes create fuel pellets which are burned to contribute 90,000 MWh electricity to the national grid every year and reduce coal consumption.

With machinery at SMW's six-year-old plant being subject to conditions of heat, wear and moisture, an effective maintenance programme is vital to ensure the risk of premature equipment failure and production downtime is minimised. As part of a preventative maintenance approach, the company works with lubrication company Rocol to ensure that all machinery is lubricated in accordance with a specified schedule.

According to Iain Russell, SMW's senior maintenance engineer, Rocol service engineers have helped the company to overcome an issue with difficulties in lubricating bearings for its regenerative thermal oxidisers (RTOs) that clean the odorous gases generated during the drying process. This, he said, meant SMW no longer has to shut down this process in order to conduct routine lubrication.

Another process improvement involved simplifying the pipework from the auto lubrication system to drying drum rollers. These bearings require regular lubrication but the pipework was prone to blockages resulting in plant stoppages. Working with Rocol, the Scottish company simplified the pipework, resulting in fewer blockages and a significant reduction in downtime.