Welsh Water has improved maintenance and operational procedures at a wastewater treatment works by introducing a maintenance-in-place rotary lobe pump.
As well as reducing downtime at the plant in Llanfoist near Abergavenny, one of the key roles for Börger as main contractor was to achieve, without cavitation, the long suction distance of drawing 4-6% sludge from four separate lagoons through more than 130 metres of pipework, compared to suction lifts of just 2-3 metres in typical applications.
Börger also made the 3kW pump reversible, so that mixed homogenised sludge can be pumped back out of the tank to the lagoon to help improve mixing consistency at the inlet source. The reverse option allows engineers at Llanfoist to purge any entrained air in the long suction lines and clear any blockages.
Geraint Michael, Welsh Water’s operational supervisor at Llanfoist, explained: “Using Börger’s pump has given us a far cleaner, more flexible system. Our previous submerged pump [hydraulic] worked okay, but when it became blocked or needed servicing it was a major health and safety event requiring winches to get it out of the lagoon before we even started the lengthy process of stripping them down.
“However, with Börger, who provided us with very good preparatory calculations, we now have a reliable, surface-mounted pump that can handle the levels of rags and debris we need it to, with the added benefit of easy access that significantly reduces downtime.”
