Thames Water Beckton is one of Europe’s largest sewage treatment works, serving 3.5 million people in the area of east London. A £190 million improvement project is underway at the site that will enable it to treat up to 60% more sewage and fully treat increased flows during heavy rainfall. The result will improve the quality of the River Thames and also allow for a 10% population increase until 2021.
A key area of the improvement is the motorisation of manually operated valves, upgrading of obsolete actuation equipment and the expansion of Profibus DP digital two-wire control and monitoring throughout the site. Rotork’s specialist Retrofit department is closely involved with these activities, continuing Rotork’s long associated with Thames Water and a series of previous valve upgrade programmes at Beckton.
One of these recently included the installation of Rotork IQPro intelligent electric actuators on the site’s inlet penstocks, replacing manually operated electric hoists and chains. The actuators here are programmed internally to pause when opening the substantial 150 x 300 centimetre penstocks at 10% of the travel position, in order to prevent any build-up of sludge from potentially overwhelming the inlet screening plant.
The latest Rotork retrofit project has focussed on the upgrade of valve actuation on the site’s primary settlement tanks and activated sludge plant. Seventy-five IQPro actuators have been installed on existing valves and penstocks in a scheme that includes the introduction of fully actuated operated of the blowers with Profibus monitoring and control. In addition to the sizing, supply and installation of the new actuators, Rotork’s contract has included the design and manufacture of associated valve adaptation parts.
The residual sludge produced at Beckton is burnt in the site’s SPG (Sludge Powered Generator), which produces 7.5MW of electricity for use on-site.
The Beckton improvement project is due for completion in 2014, by which time a 1.5MW wind turbine will also have been installed to provide a further 8% of the energy needed to run the site. In a separate project, all sixteen of Beckton’s primary settlement tanks – an area the size of ten football pitches – are being fully covered in order to reduce odour emissions by 50%.
