Spirax Sarco has helped Northumbrian Water to halve the energy it uses to raise steam at its Bran Sands anaerobic digestion plant. The work has been so successful that the utility company now plans to work with Spirax Sarco and apply the same approach in its new plant at Howdon.
The energy-saving project centred on solving an issue with two boilers at Bran Sands where a low-water alarm would come into operation, even though there was plenty of water in the system. Low-water alarms made the boilers cut out, reducing the time that the boilers were in action. “The issue slowed the process down,” explains Frank Errington, Works Coordinator at Bran Sands. “We’d lose energy as the boilers were on and off constantly and were cooling down during the downtime.”
Northumbrian Water called in Spirax Sarco engineers, who quickly spotted that the existing level probes and controllers were not suitable for the application. Replacing the controls with equipment from Spirax Sarco solved the problem.
Spirax Sarco supplied two LP30 self-monitoring water level probes for each boiler, along with LC3050 level controllers. Rewiring and a new control panel completed the new low-water alarm system.
Bran Sands was also experiencing a growing issue with false alarms in its high-water control systems, although they didn’t cause the same downtime and energy losses as the low-level false alarms. So Spirax Sarco also replaced the high-water probes with its own LP31 probes.
Finally, the utility company opted for a Spirax Sarco service agreement to keep the boilers working properly in future.
“Both boilers are now available most of the time and we’re experiencing stable operations,” says Mr. Errington. “The energy savings equate to about 50% of the energy needed for raising steam.”
Northumbrian Water is so pleased with the success at Bran Sands that it has now asked Spirax Sarco to apply the same boiler controls at its new anaerobic digester facility in Howdon, which is currently under construction.
“Spirax Sarco are very good at what they do. They’re very helpful and very knowledgeable and we get a good response from them.” says Mr. Errington. “They’re similar installations. Howdon is an enhanced version of Bran Sands and the process is the same.”