Motors go through the motions efficiently

Edited by the Engineeringtalk editorial team Feb 11, 2004

Five 200kW Premium Efficiency Eff1 WEG motors have been used in conjunction with Hidrostal energy-saving screw centrifugal impeller pumps to create a high-efficiency wastewater-pumping package.

Five 200kW Premium Efficiency Eff1 WEG motors have been used in conjunction with Hidrostal energy-saving screw centrifugal impeller pumps to create a high-efficiency wastewater-pumping package supplied by Engenica to Thames Water.

The WEG motors were selected to meet the standards set by the Water Industry Mechanical and Electrical Specifications (WIMES) for six-pole electric motors, including quality standards and efficiency ratings.

WEG also met set delivery requirements for the large motors.

Thames Water has replaced the original pumping facilities at Blake's Lock with a new highly efficient pumping installation.

Blake's Lock is situated on the banks of the River Kennet in the centre of Reading.

The buildings of this Victorian pumping station will now be a museum thanks to a grant of GBP 50,000 from the Heritage Lottery Fund, including the original turbine house that spans the River Kennet and contained the turbines that once pumped Reading's sewage.

The pump and motor package are supplied under framework agreement that takes into account whole life costs for the machinery.

Specifying a high quality pumping solution that has very low maintenance costs and a long service life is therefore preferable to a short-term capital cost saving and high running costs.

Five screw centrifugal impeller pumps have been supplied mounted on base plates and coupled to the WEG Premium Efficiency motors, three having already been installed in October 2003.

The complete pumpset units are large, weighing in at over 4t each, though the pumps have a handling capability of 500 litre/s with a 26m total discharge head.

The Hidrostal screw centrifugal impeller offers high peak efficiency and a broad efficiency curve to minimise energy consumption and also features an adjustable impeller clearance to maintain high efficiency over prolonged periods.

The design is a patented solution to the problems of efficiently handling bulky solids, sludge and slurries.

The impeller has a single blade, axially extended at the inlet and developed around its axis much like a corkscrew.

This results in an impeller, which will pass solids of 220mm diameter and inlet geometry optimised to handle rags and fibre without blockage - an important requirement on sewage pump stations like Blake's Lock.

Government published ECA savings of GBP 16,400 are available on each energy efficient six-pole 200kW motor being installed and reflects the high energy saving potential of the unit.

In many instances WEG motors, exceed the required efficiency rating to qualify for Eff1 status.

WEG Premium Efficiency motors meet WIMES specification as standard, though it was not just this that secured the deal; WEG were able to supply the uncommon six-pole configuration as a factory build in a matter of weeks.

More standard AC motors of up to and over 300kW are kept in stock by WEG in the UK.