Plant & Works Engineering April 2022

T here is little doubt that energy efficiency remains a top priority for most manufacturing organisations – for both financial and environmental reasons. Cutting electricity use across the shopfloor can significantly reduce monthly energy bills, with the savings going directly to the bottom line. Using less energy is also critical to long-term sustainability efforts. There is a growing number of companies embarking on a journey to net- zero by implementing initiatives that provide incremental value and significant savings over time. The need to optimise compressed air systems Even the most conservative analyses estimate that compressed air systems account for 10% of all energy used in global industry, and of that, between 10 – 30% is wasted on leaks. This wastage is expensive; even a 3mm leak could cost around £2000 a year, with a loss equivalent to 16 tonnes of CO2 emission. So, any optimisation of compressed air systems – no matter how small – impacts performance and efficiency significantly, lowering fuel bills and reducing carbon footprints. But how do plant managers ensure that a compressed air system is operating to its full potential? How do they identify and eliminate air leaks, optimise performance, reduce energy consumption, and drive down costs? The simple and most effective means of achieving these goals is to carry out a health check and energy audit. These assessments can be performed quickly and accurately, and in some cases at no cost, and with zero disruption to the users’ production operations. Just one important aspect of these checks is identifying and eliminating leaks Dealing with compressed air system leaks Leaks can be caused by many issues including corrosion, poor pipe connections and bad seals. And without investigation, these problems can add up to a significant amount of wasted energy over time, resulting in higher bills. There is a variety of techniques that can be employed to locate, log, quantify and rectify air leaks. Initial steps involve little or no technology. In fact, some leaks can be found simply by listening and their location can be identified by the elementary technique of applying a soapy water solution to potential leak points such as joints, flanges, and valves, with bubbling indicating the source. A more precise approach employs advanced technology; the use ultrasonic leak detection equipment, which operates without interrupting plant production, reaches system areas that are hard to access, and locates all air leaks. Furthermore, state-of-the-art acoustic imaging cameras are even morer effective and can help detect leaks in compressed air systems up to ten times faster than traditional methods. Once inspection has been completed, leaks can be marked on-site with weatherproof tags, along with a supporting written report that can provide more details on leak locations, photographic evidence of holes, leak severity in litres/minute, energy costs, positions, and costs to repair. Health checks and energy audits With the technology in place to provide fast, accurate and cost-effective leak detection, leading compressor technology specialists, such as Atlas Copco Compressors, have developed three levels of health checks and energy audits for compressed air installation. Some of these services are offered free-of- charge, while others require an upfront investment which is quickly recouped through energy efficiency improvements, and the subsequent cost savings they bring: Level 1 – Free visual inspection and energy potential calculations (EPC):  A visual assessment covers information such as compressor room environment, determining any air quality issues, and a visual inspection of all compressed air equipment on site, including appropriate capacity, ISO compliance, unproductive running, and pressure levels.  This procedure results in a summary of equipment health, outlining running equipment improvements, as well as wasteful practices or non-conformance with ISO standards.  EPC calculations can also be carried out, focussing on the power usage of the compressors, load v. unload hours, and average leak assessment. This calculation identifies whether there is a requirement for a Level 2 assessment and provides an indication of the tangible savings that it would bring. Level 2- Energy assessment and recommendations through data logging:  While EPC delivers an estimation of potential energy savings, this next level service Process, Controls & Plant Focus on: Compressed Air 30 | Plant & Works Engineering www.pwemag.co.uk April 2022 How to reduce costs Paul Clark - Business Line Manager - CTS Sales and Marketing, Atlas Copco, explains how compressed air systems health checks and energy audits carried out in an industrial environment can reduce costs, improve environmental performance, and help deliver energy efficiency improvements.