Listening to production noise to reduce costs

16 May 2024

Every factory or production plant is noisy, to various levels. It’s a consequence of machinery, pneumatics, hydraulics, motors, pumps, compressors, bearings, chains and other equipment used to manufacture and assemble products. Each sound tells a story.

Some sounds are equipment working well and some sounds are from worn equipment, slight vibrations, loose fittings, air leaks, worn bearings, etc.

The sounds which tell a story about the health of equipment are the important ones, there are additional sounds outside of the range of human hearing which provide information about equipment health too. 

Isolating and interpreting these sounds may sound like a specialist skill, but it has become something that most people can do with little-to-no training, thanks to acoustic imaging cameras like the FLIR SI2 which includes AI severity assessments to help identify where the most urgent intervention may need to take place. 

Acoustic imaging can play several roles in the maintenance and cost saving of manufacturing or production sites, across all industries. 

Often bearings can be one of the lowest-cost components in a production site however a failed bearing can bring production to a stand-still. Furthermore, a seized bearing can cause damage to other componentry which could impact the cost and time taken to repair. 

It is a safe bet to say that in most factories, at least some of the background noise will come from bearings that are showing signs of wear and degradation. Some of these bearings will have many years of perfectly good performance left, but some may be coming closer to the end of their serviceable life, or even failure. Listening to the audible and inaudible sounds emitted from these bearings will help form part of a predictive and preventative maintenance regime.

The FLIR Si2 acoustic imaging camera is capable of filtering out all background noises, to only ‘hear’ the sound frequencies associated with unhealthy bearings. The camera its-self has a clear, colour touchscreen which visually highlights the location of an unhealthy bearing, and displays numeric values called the ‘Crest Factor’ and ‘Kurtosis’ which can be used to monitor bearing condition, allowing early intervention before failure occurs. 

The same principles above can be applied to other mechanical equipment with direct ‘line of sight’ such as open gears, shafts and other equipment which experiences friction. 

What makes this process stand-out from other condition monitoring processes such as vibration monitoring or traditional contact or non-contact ultrasonic monitoring is that the FLIR Si2 acoustic camera has a wide field of view, it is a non-contact camera which works exceptionally well at distances of up to 30 meters, and even detects issues at distances of up to 200m in specific applications – in the presence of significant background noise. There are no fixed installation hurdles, wiring considerations, or other complex requirements – the FLIR Si2 is a portable, hand-held camera which can be used to inspect a full manufacturing or production site several times a year, to build-up a picture of the health of the facility. Most importantly, this acoustic camera can inform users where the equipment threats are, what may be deuterating at a slightly faster rate, and where maintenance intervention may be needed more urgently. 

One of the most common sources of power in production facilities is through compressed air or vacuum systems which are typically lower-cost to install and easier to maintain. Yet these pressurised systems are prone to developing leaks which go unnoticed, costing businesses significant amounts of money. 

Many factories will be aware of leaking pipework, joints, connections, filters, etc but if the key equipment still performs then there is no need to repair known leaks. While it is true that the main priority is to ensure core processes are operational, the additional costs incurred to generate pressure will often go unnoticed. 

It is similar to trying to heat a house in winter, with the heating on full power, and the windows and doors open. You can generate warmth by running the heating to the maximum, but most of that warmth will leave the house and the heating will need to stay on its maximum setting permanently. This would work fine until you see the energy bill, which would cause you to quickly close those doors and windows, and turn the heating down significantly.

The FLIR acoustic imaging camera is turned to hear the sound of turbulent air, often inaudible to the human ear. The camera visualises the leak on its touchscreen, allowing users to photograph or video the leaks location for reporting and later repair. Furthermore, when a leak has been identified by the camera, the leak rate, and even a cost estimation can be displayed to help prioritise whether the leak is worth repairing, and in the case of multiple leaks -what order the leaks should be repaired in. 

With the same principals as detecting compressed air and vacuum leaks, the FLIR Si2 is capable of detecting gas leaks too, with specific quantification information built into the camera for Hydrogen, Helium, Ammonia, Argon, Methane, Natural Gas and Carbon Dioxide; with more gasses to be added over time too.

Detecting these types of gas leaks can be more challenging in low-pressure applications, but the consequences of these leaks can be significantly higher compared to air leaks and their impact on the compressor or pump electricity bill. 

Industrial gasses are significantly more expensive to purchase than generating compressed air, so like-for-like leaks can be 10x, 20x or even more expensive. It would be an exceptionally rare situation to find one of these gas leaks and decide to monitor or ignore it, yet most product demos or initial inspections typically do find industrial gas leaks!

Some of these gasses are heavier than air, which adds a risk of suffocation, especially in enclosed locations, pits or wells where in rare instances such leaks have proven to be fatal. Other gasses such as methane and natural gas are highly explosive, so these leaks must be found and repaired. 

Typically, volatile gasses are regulated and require specialist Optical Gas Imaging cameras to be compliant in finding leaks. While the FLIR Si2 acoustic imaging camera can not provide regulatory compliance, if your facility brings in a consultant with an OGI camera to be compliant at regular intervals, a FLIR Si2 on-site can be a welcome asset in between contractor visits.

In summary
Acoustic imaging has many more applications, such as high-voltage condition monitoring for corona effect and partial discharge, sealed vessel testing, interior noise testing, and more. Applications around leak detection tend to offer more in immediate cost saving, and safety improvement; compared to bearing and high-voltage inspections which are predictive maintenance activities. With most production facilities treating condition monitoring and cost saving as often contrasting priorities, the FLIR Si2 quickly becomes a valuable tool to support both imperatives.

Available in three variants, the FLIR SI124-PD has been designed with dedicated high-voltage applications in-mind, as such it does not include the bearing or leak detection features. The FLIR SI124-LD has been designed for production facilities and is able to detect both air and gas leaks, and mechanical failures however, this model does not include the high-voltage partial discharge detection. The FLIR SI2 Pro has all functionality included. 

Inspection reports can be generated using online software, or FLIRs Thermal Studio software, for more information visit and discover how acoustic imaging could support your business. FLIR offer telephone consultations or on-site demos to present the Si2 acoustic camera in your facility, testing its capability in person to prove how beneficial it can be to your organisation.  

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