Significant savings in the air

 

Compressed air is a tertiary form of energy, created through the use of electricity which in turn is generated by the burning of a primary fuel source – coal, gas or oil. Of the original natural resource, only around 4% of the energy can be successfully converted into compressed air as the rest is lost as both waste heat and through transmission lines. This means it is a very expensive form of energy, but one which is vital to the UK manufacturing industry – it is used in some 80% of UK industrial applications and its creation accounts for around 10% of the total electricity supplied to industry. 

 

As such an expensive commodity to produce, any leak or wastage of compressed air can be incredibly costly for manufacturers. The Carbon Trust estimates that a single 3mm leak can cost more than £700 per year in wasted energy, and when this is multiplied across the various pipes, hoses and valves in a large facility, the cost could run into many thousands of pounds. Conversely, effective maintenance of a compressed air system accounts for as little as 7% of the total cost of running a compressor over a 10-year period, showing just how much a small investment could potentially save. 

 

Detecting leaks is not usually a task which can be done manually, meaning the most common method of detection is through ultrasound equipment. Following detection, the second stage is to calculate the total cost of the leak. Here, technical experts will take into account the running conditions of the compressors, the cost of electricity, system pressure, and efficiency of the compressor. The resulting calculations can fully quantify the cost of the leak by machine, department, area or even factory.

 

Case study

Brammer was called upon to conduct such an audit at the Banbury site of Mondelez, one of the UK’s best-known names in food and beverage production. The facility is the company’s largest coffee plant in the world, producing 100 million jars of instant coffee per year. Brammer provides an Insite service to this and four other Mondelez facilities. Effectively a Brammer branch on the premises, an Insite supplies and manages a wide range of maintenance, repair and overhaul (MRO) products, and can also be called upon to support value-adding projects. 

 

In one such instance at Mondelez in Banbury, the Brammer team was asked to investigate when an unplanned interruption to freeze-drying operations threatened to impact heavily on output. At the time, air compressors were running at full capacity meaning a considerable amount of air was being lost from the system, potentially at great expense. 

 

Brammer’s compressed air audit and analysis, using state-of-the-art ultrasound, identified significant leaks which totalled more than £191,000 per year – not including the costs of associated downtime. A programme of bespoke remedial action was prepared by Brammer, which at a cost of just £4000 for components and materials, delivered a huge saving for Mondelez. 

 

Following the successful repairs, a pneumatic equipment awareness day was organised with support from Brammer and one of its key partners Festo, a leading manufacturer of compressed air and pneumatic equipment. Awareness of issues surrounding compressed air among the production team was vastly enhanced, and as a result the facility now conducts an annual survey to identify and rectify leaks before they pose a major issue. 

 

Even if an annual investigation reveals that no leaks are present, cost savings can still be made. As compressed air is usually generated at the compressor’s maximum pressure, even a 10% reduction in pressure can deliver energy savings of up to 5% (based on the compressor working at 7bar, 100psi). The Carbon Trust recommends making ‘small, incremental reductions’, while monitoring the system to ensure operations are not compromised. 

 

The cost of an individual air leak might seem modest, but when leaks occur at multiple points throughout a facility the costs can spiral. Investing a comparatively small amount into planned maintenance and ongoing monitoring – in partnership with an expert provider – can deliver significant cost and energy savings.