Severn Trent installs reliable oil-free screw blowers from Atlas Copco in six water treatment plants
Severn Trent Water has chosen to install reliable and energy efficient ZS oil-free rotary screw blowers from Atlas Copco at six of its water treatment plants in the UK. This forms part of a major infrastructure refurbishment programme, including upgrades to its Rapid Gravity Filters (RGF) processes installations that require low pressure air for sand de-scouring duties.
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The latest phase of the project has seen ZS blowers installed at the Little Eaton Water Treatment Works in Derbyshire, which supplies safe, clean drinking water to the growing community in the city’s North-West area. Over time, it became clear that the site’s RGF process required a significant overhaul in order to improve operational efficiency, which would require the replacement of its existing blower installation.
Using rotary screw blowers for Rapid Gravity Filtration (RFG) of drinking water
Severn Trent Little Eaton waste water facility
Oil-free rotary screw blowers installed at Severn Trent Water waste water facility in Little Eaton, Derbyshire
How do ZS rotary screw blowers reduce contamination risk in drinking water treatment?
The ZS blower units comprise a complete, fully integrated package based on a simple internal principle: precision timing gears maintain minute clearances between two intermeshing dry screw elements that never touch. No lubrication is required in the compression space and special seals stop any rotor bearing oil from entering the compression chamber. Intake air is compressed between the rotors and their housing and 100 per cent oil-free, pulsation-free air is delivered at an output rate of up to 3325 m3h dependent upon process demand.
ZS rotary screw blowers are compatible with existing control systems
ZS rotary screw blowers are commonly available with integrated VSD control. However, the new blowers at Little Eaton were supplied as variable speed units linked to the plant’s own existing inverter control system. Commenting on the successful installation progress, MWH project manager Kelvin Smith said:
Atlas Copco’s distributor, Cooper Freer were very pro-active at the design phase in accommodating quite a few changes at an early point in the progress of this project. The blowers arrived on time and were successfully installed on the high ground level site. We found that they were always on hand to discuss any issue arising from design and installation and were very safety conscious during the construction stage resulting in a very successful project completion.
Stephen James, Severn Trent Water’s project manager for the upgrade at Little Eaton, stressed the importance of the ZS blowers in guaranteeing the supply of clean drinking water:
Not only do the blowers enable a smoother flow in the filter de-scouring process, they also provide the peace of mind in providing 100 per cent oil-free air to reduce the risk of contamination to the drinking water supply.
Severn Trent Water chose MWH as one of the design and construct contractors for its AMP6 framework. MWH will work alongside Severn Trent Water’s own staff to manage the operation, supporting the delivery of its programme of work throughout AMP6; which runs until March 2020. Apart from Little Eaton, Cooper Freer has installed four Atlas Copco 90 kW ZS variable speed blowers to replace all the existing lobe blower technology at Severn Trent Water’s Worcester treatment plant.