Northumbrian Water upgrades Darlington STW
19 Oct 2010
Darlington, UK – Northumbrian Water has completed a major refurbishment of its Stressholme sewage treatment works on the outskirts of Darlington, Co Durham. Key project partners included Entec UK Ltd, as consulting engineers and main contractor Carrillion PLC.
The project included the retrofit installation of an automated storm tank flushing system into the six existing concrete storm tanks.
The scope of works included the design, manufacture, supply, offload, contract lift, install, test and commission 12 No tipping buckets and associated wash water supply pipework, actuated valves, traced heating and thermal insulation.
The 47m long x 13.5m wide x 3.0 m deep tanks, with a 1% fall, were each divided into two separate lanes of 6.5m width by a 400mm high x 600mm wide dwarf concrete dividing wall.
The plant has twelve 1,300 l/m tipping buckets in 304 stainless steel, which were installed into the six tanks. The buckets were mounted on brackets attached to the side and intermediate dividing walls of the tanks.
The filling system is via stainless steel pipework, trace heated and lagged, which provides final effluent. The actuated valve opens on a signal from an ultrasonic sensor mounted within the tanks.
When the bucket is full it automatically swings on its bearings as the tipping point is reached. As the bucket tips a proximity switch closes the actuated valve. The bucket automatically returns to its balance point and is set for the next storm event.
Deliveries for the project commenced in January 2009, with installation of the buckets carried out in three phases so that only one set of storm tanks were out of action in at any one time. The final phase of the project was completed in September 2010.
