Air-tight energy saving at materials company Marshalls

London – Compressed air is used in almost all industrial businesses, and uses more than 10% of electricity supplied to industry. However, the process of compressing air can be wasteful and of the total energy supplied to a compressor, as little as 8-10% is converted into usable energy at the point of use.

Despite the high cost of production, many systems waste around 30% of the compressed air through leaks, poor maintenance, misapplication and poor control.

UK landscaping product supplier Marshalls is a major user of compressed air at its numerous manufacturing operations. The company is constantly seeking to reduce air leakage and improve efficiency in compressed air usage in a drive to save energy and reduce associated costs.

Marshalls approached Brammer to conduct an air leak audit at its manufacturing facilities. Brammer has completed nine surveys at Marshalls sites to date.

The audit involved using specialist equipment to detect all air leaks, identifying each leak with a number, photographing the leaking units, and specifying the appropriate parts for repair in order to make it easier for the completion of remedial work.

On completion of this stage of the process, Brammer’s engineering team worked on site to address any issues likely to hamper the remedial work and initiated alternative plans to eradicate such problems before the ‘fix’.

Nigel Cork of Brammer believes a compressed air audit has the capability to provide immediate energy savings which could be as high as 30%. When the potential to reduce operating costs by 50% is also taken into consideration, the overall impact on the bottom line is sizable.

“It normally includes an examination of both air supply and use, and the interaction between supply and demand,” said Cook. “The output of a compressed air system, energy consumption in kilowatt-hours, and the annual costs of operating the system are calculated.

“The auditor also measures total air losses from leaks and locates those that are significant. All components of the compressed air system are inspected individually and problem areas identified, a report is then prepared with a recommended course of action.”

Following the audit and completion of the remedial work, Brammer is now working with Marshalls to lower the pressure at the compressors and to install line-side monitoring equipment so that any future leakages can be identified as soon as they occur.

This enables remedial work to be factored in to either a planned maintenance programme, or undertaken as part of an unscheduled outage.

“[The project] has enabled us to reduce our carbon footprint by 426 tonnes. Future work includes video tutorials for staff on better air management to achieve further savings,” reported Peter Stevens, group carbon & energy manager at Marshalls.