Acoustic imaging for gas leak detection
Acoustic imaging for gas leak detection: enhancing efficiency and reducing costs
Leakage of pressurised gases in industrial installations can be dangerous, leading to explosion or fire risks, damaging to the environment, or even detrimental to the health of those in the vicinity of the leak. In addition, leaks are expensive, even when the gas itself is not inherently valuable. For example, a compressed air leak may seem minor, but the additional energy required to maintain system pressure while the leak persists can quickly accumulate substantial costs.
Traditional leak detection methods, such as soapy water or ultrasonic probes, have limitations in terms of efficiency and effectiveness. These methods often require manual, point-by-point inspection, making the process time-consuming and labour-intensive.
For these reasons, a fast, efficient and reliable method of leak detection is needed and, ideally, this should be suitable both for surveying large sections of plant for situations where it is evident that a leak is present but even its approximate location is not known, and for pin-pointing the leak at a later stage in the investigation. For most users, it will also be important that the method can be used irrespective of the type of gas leaking; it might be necessary, for example, to deal with a compressed air leak on one occasion, a steam leak on another, and the leak of some gaseous reagent on yet another.
How acoustic imaging advances gas leak surveys
The leak detection technology that best meets these needs is acoustic imaging. This relies on the simple observation that escaping gases and vapours invariably generate acoustic noise, sometimes in the audible range, sometimes in the ultrasonic range and often in both. An acoustic imager uses an array of highly sensitive microphones to pick up these noises. Using a specific microphone array design and advanced internal digital processing, the imager can determine the direction and approximated size of the leak using a technique known as “beam-forming”. This information is used to produce an image with the leak represented by a colour “cloud map” that represents the sound pressure being measured. For ease of interpretation, the “could map” is overlayed onto an ordinary digital image of the plant or equipment under investigation.
Acoustic imaging works equally well with any gas or vapour and has many other practical benefits. One of the most important is that it can detect leaks at a considerable distance – up to 120 metres with Megger’s MPAC range. Not only does this make it easy to survey large sections of plant quickly, but it also means that you can avoid approaching potentially dangerous areas of the plant and survey elevated or otherwise inaccessible locations. Of course, when necessary, acoustic imagers can also be used at much shorter distances, which is particularly useful when pinpointing the exact source or location of a leak.
For all its benefits, acoustic imaging is very easy to use; no steep learning curve is involved. With the latest acoustic imagers, all that’s needed in most applications is to adjust two parameters: frequency range and dynamic range. The instrument does everything else and displays the result on its integrated screen. The MPAC range will also provide the user with an estimation of the leak rate and – if a volume cost is known – how much revenue is lost annually. This allows planned remedial actions to be easily prioritised.
To ensure reliable operation even in high noise environments, Megger acoustic imagers have an advanced focus feature that helps minimise the effect of unwanted sounds adversely affecting the measured value. All models also have internal storage for acoustic images, videos, digital camera images and test data, all of which can be reviewed on the instrument’s screen or downloaded to the supplied software for additional analysis or archiving.
Operational efficiency gains with acoustic imaging
Adopting acoustic imaging technology for gas leak detection offers substantial operational efficiency improvements. By significantly reducing inspection times and labour requirements, facilities can optimise their maintenance resources and minimise the impact of leak detection and rectification activities on production schedules.
The ability to detect leaks from a safe distance is another notable benefit. Maintenance personnel can survey potentially hazardous or difficult-to-access areas without the need for close physical proximity, enhancing safety and efficiency. This remote detection capability eliminates the need for scaffolding, ladders or other access equipment, further streamlining and accelerating the inspection process.
In addition, acoustic imaging can enable early leak detection, preventing minor issues from escalating into major problems. By identifying and addressing leaks promptly, facilities can extend the lifespan of their assets, minimise the risk of catastrophic failures and optimise maintenance planning. Early detection also helps prevent the waste of valuable resources associated with prolonged leaks.
Achieving cost reductions by detecting leaks early
The early detection of gas leaks using acoustic imaging technology can lead to significant cost savings for industrial facilities. By promptly identifying and repairing leaks, organisations can prevent substantial product or energy losses. Even seemingly small leaks can result in considerable financial waste over time, making early detection and remediation crucial for cost control.
The ability to locate leaks precisely and repair them quickly minimises production interruptions and downtime. Unplanned shutdowns due to leaks can be incredibly costly, resulting in lost productivity and potential damage to equipment. By using acoustic imaging to identify leaks accurately and efficiently, facilities can avoid these expenses and maintain optimal operational continuity.
Early leak detection is also vital in regulatory compliance. Many industries are subject to strict environmental regulations and emissions standards, and non-compliance can lead to substantial fines and reputational damage.
Conclusion
As industries continue prioritising efficiency, cost control and environmental impact, adopting acoustic imaging for gas leak detection has become a standard practice. Acoustic imagers enable organisations to optimise their maintenance processes, reduce waste and enhance safety.
The value of acoustic imaging extends beyond immediate cost savings. By detecting leaks early, facilities can prevent minor issues from escalating into major failures, extending asset lifespans and minimising unplanned downtime. The ability to survey large areas quickly and pinpoint leak locations precisely significantly reduces inspection times and labour costs, allowing maintenance teams to focus on other critical tasks.
Acoustic imaging provides a convenient, dependable and affordable way of detecting and locating gas leaks. It saves time, money and helps to minimise the waste of resources that’s always associated with leaks. In short, an acoustic imager is a small investment that delivers big dividends!
