Sewage works achieves energy self-sufficiency
Sludge monitors have helped Severn Trent Water to make one of its large sewage works energy self-sufficient. A significant increase in electricity generation at Stoke Bardolph sewage works has been aided by eight sludge interface monitors supplied by Pulsar Process as part of a process improvement project.
In common with many large sewage treatment works, Stoke Bardolph uses the gas produced in the digesters to drive turbines, generating electricity. The more gas produced, the more electricity can be generated.
An important determinant of gas volume is the quality and density of the sludge being delivered to the digesters. Managers at Stoke Bardolph wanted to increase sludge density from an average of around 2% up to a target of 6%.
The project included a move to positive displacement pumps and installation of sludge density monitors. Before the Pulsar units were installed, sludge blanket measurement was made using a dip tube.
The measurement needed to be taken every day, which involved climbing onto the rotating bridge of the clarifier and operating a long dip tube. This was a potentially hazardous operation and did not provide the dynamic measurement required to make the process work efficiently.
Pulsar says its Sludge Finder 2 monitor, which features a self-cleaning ultrasonic transducer, allows continuous measurement of the sludge blanket level. The instrument signal is taken off the rotating bridge through the slip rings and fed back to the site’s SCADA system. It is used by the system to determine the optimum time that the pumps are in operation.
The scheme has been a resounding success. Stoke Bardolph now generates 5.5MW at full power, enough energy to power equipment on site and return a net surplus to the National Grid, making the site energy self-sufficient.
- Effects of microplastics in sewage sludge on soils 'overlooked' Researchers are concerned about the lack of knowledge regarding the potential consequences that microplastics may have on... Read More >
- Tamesis and AMK in Deephams battle Joint venture (jv) companies Tamesis and AMK are battling it out to win a multimillion-pound contract with Thames Water to... Read More >
- Record-breaking pumps ordered for Hull A contract for the design, manufacture and installation of one of the world's largest Archimedes screw pumping stations... Read More >
- Innovation Zone: Boosting biogas production Regulatory changes mean that now is a good time for technologies that can help boost biogas production from sludge. Here... Read More >
- Turning the circular economy into reality The Europe-wide INCOVER project, which was among the winners at the Water Industry Awards 2018, shows how technology and... Read More >
- The hidden gems inside an AC drive Dismissing variable speed drives (VSD) as nothing more than motor controllers is to miss the huge cost-saving potential... Read More >
- Air Quality and the MCPD: Something in the Air Air quality regulations that come into force next year are making water and wastewater companies reconsider the role of... Read More >
- Comment: Optimising energy usage in the water industry Servelec Technologies' technical director, Marcus Fowler, discusses how the potential of demand-side response... Read More >