Welsh Water turns to smart stator technology
10 Nov 2010
Welsh Water has specified that all existing and new Seepex progressive cavity pumps on site be upgraded to the supplier’s smart stator technology.
The move follows work by seepex to solve the failure of impeller pumps used in biogas production at a Welsh Water Cog Moors sewage treatment plant. This resulted in a higher yield of better quality gas and increased gas production for the generators on site.
When the WWT plant in South Wales was experiencing reduced gas yield from its on-site digestion of sewage sludge, Welsh Water called in engineers from established supplier seepex engineers to resolve the issue.
The engineers found that the digester recirculation tanks were producing small amounts of gas causing the impeller pumps to lock and stop flow. The was leading to downtime, reduced heat retention in the digester and poor gas yields were the result. Ragging was causing additional downtime issues with the existing pumps.
Within 2 days seepex shipped a loan pump to Cog Moors to provide an immediate solution to the problem. Its engineers assisted in the commissioning of the seepex self priming positive displacement pump.
The loan pump enabled the plant to continue effective gas production. Meanwhile a larger seepex pump was designed to provide the exact flow rate and eliminate the ragging issues. The new pump was designed with smart stator to allow easy in situ maintenance without dismantling the pipework.
The pump’s ability to handle entrained gas together with the features of smart stator and the fitting of an anti-ragging device has improved gas yield by providing a constant flow of sludge. This, in turn, has resulted in the correct temperature of sludge feeding the digester.
