Sludge success
The Cotton Valley Sludge Treatment Centre (STC) is one of Anglian Water’s 10 main sludge treatment centres where sludge is dewatered and treated anaerobically to produce bioenergy.
In 2008, an advanced digestion thermal hydrolysis process (THP) was commissioned to speed up the anaerobic digestion (AD) process. As part of an upgrade, a sludge handling facility was designed to handle about 160 tonnes a day of imported dewatered sludge from satellite works.
Long standing problematic application
Progressive cavity (PC) pumps were installed to back mix the dewatered sludge and pump it into the THP.
The two pumps overall cost approximately £100,000 (€113,000) per annum due to rotors and stators changing every three to six months. Their inability to transfer no more than 3.5m3/h (bottleneck and limiting gas production) meant the site was not able to meet the design...