VSD vacuum pump saves energy at Polestar printing plant

When Polestar was confronted with the need to make major repairs to one of its three existing fixed speed vacuum pumps at its £100 million purpose-built Sheffield Gravure plant - a production site that has received environmental awards for its green credentials - it made sense to re-assess the combined operation to establish the potential savings that could be made by installing a more energy-efficient replacement.

Recognising the clear synergies between compressed air and vacuum in the field of air movement, it was a logical move by Polestar Sheffield to seek the recommendations of Halifax-based Pennine Pneumatic Services (PPS) for the optimum solution to its vacuum needs. Atlas Copco Compressors’ premier distributor in Yorkshire,
PPS has been a long term supplier of compressed air systems, both fixed speed and VSD-driven, pipework and maintenance services to the company. As a result, a GHS900 VSD+, one of Atlas Copco's new generation of intelligent, oil-sealed, plug-and-play rotary screw vacuum pumps, was installed on a trial basis to show how it could deliver peak performance at the required operating pressure, and help achieve substantial energy savings.

Of the three existing units, the two smaller fixed speed vacuum pumps previously used by Polestar Sheffield were running at approximately 20kW an hour (one rated at 11kW and the other at 9.7kW combined). The single GHS VSD+ vacuum pump that replaced them is a 15kW unit, which
operates at approximately 20 percent load, equating to just 4kW. Based on an operation of 8,000 hours per annum, the estimated savings are expected to exceed £10,000 (16KW x £0.08 x 8,000 hours).

Ensuring reliability and harnessing advanced technology are key to Polestar Sheffield's success, which has led to the site winning the prestigious ERA (European Rotogravure Association) printing award. While the gravure process is traditionally employed for long print runs, the latest engraving technology allows for short-run work with significant paper usage savings. Polestar’s printing site produces around 2.5 million high-quality catalogues, magazines, brochures and supplements every 24 hours. 

A vacuum system plays an essential role within the transfer of work from the presses
to the print finishing and bindery operations. In addition to its modern rotary gravure printing facilities, Polestar’s £34 million investment has included a purpose-built web offset 96- and 64-page size press installation together with multiple stitching stations.

As Simon Robinson, Engineering Manager at Polestar Sheffield explained, the company pride itself on using the latest technology and continually look at ways to save energy which is why it made sense to accept PPS’ recommendation to trial a variable speed drive rotary screw vacuum pump. The Atlas Copco GSH900VSD+ has proved a success and the projections are for major savings on the energy bills over the course of a year.

The GHS 350-900VSD+ rotary screw vacuum pump range
represents a quantum leap forward in rough vacuum technology that is based on Atlas Copco’s proven, advanced screw compressor principles. The GHS VSD+ breakthrough range offers compelling benefits to manufacturers. Benefits include average energy savings of 50 percent compared to conventional oil-sealed and dry vane pumps, as well as best-in-class noise levels and oil retention properties. Primarily, its VSD technology enables users to precisely adapt their vacuum generation requirements to match the demands of their production processes.

With approximately three quarters of all UK companies that employ rough vacuum requiring oil injected pumps - which are traditionally fixed speed - there is massive potential for energy savings derived from the new VSD technology to be gained across many sectors of UK manufacturing industry.