Solids handling demands call for the right pumps system
17 Sep 2020
When successive storm events increased volumes of rag and debris its waste systems had to cope with, Thames Water sought Vaughan’s aid to find the right solids-handling pumps...
In June 2006, the only auto self-priming chopper pump on the market, a 10” Vaughan SP10R, was installed in the return activated sludge line at Thames Water’s Banbury wastewater treatment station.
It was the first of its kind to be used in the UK and was replacing one of 4 existing old style, extended shaft axial flow pumps. In their heyday these pumps were giving over 720m3/hr in a lift and transfer situation. However, when rag and solids content became more and more evident failures were common due to continual blockages.
The existing axial pumps were situated inside their own pipework with the flow passing through the centre of the pump then out through a reflux and onto the common line. As a consequence, removing them for maintenance was not an easy operation, especially when on some occasions they needed to be lifted twice a day
As floor space in the pump house was restricted, a powerful, yet compact pump set was required and the SP10R with an over/under drive configuration and its suction line simply dropped approx. 3m down the existing axial flow discharge line, with no down well fittings, was installed in 2006.
It has been operating 24/7 for almost 13 years at the Banbury site with a reported flawless performance and no requirements to unblock or inspect the pump. Subsequently, a second SP10R was installed.
Recently, both pumps underwent a much-needed overhaul as a result of general wear and the engineering coordinator at Thames Water commented. The Vaughan pumps were removed one at a time by a sub-contractor and returned to P&M Pumps for an overhaul. Turnaround time for each pump from removal to re-install was approximately two weeks, including the parts being sourced and shipped from Vaughan in the US.
Thames Water’s engineering coordinator reported both overhauled pumps had been running for over a month and are pumping as they were when first installed.
The utility company benefitted not only at Banbury but at numerous other of their waste water treatment sites across the UK. The original investment has returned yearly life-cycle costs for each pump of between £1400 and £1500 over the total 13 year period.