14 Feb Why thermal imaging is a hot topic in mining
There are a number of benefits that thermal imaging cameras can bring to a mining operation but perhaps the most salient of these is how they can improve safety.
“A very plausible example would be at a coal mine where you would have tailings, or discarded coal that can’t be used and is stockpiled. When stockpiled, coal has a tendency to spontaneously combust – an obvious safety hazard. This is a scenario where a thermal imaging camera could be used to see how hot the stockpiles are,” explains CBC Engineering Solutions Manager, Mark Slaughter. “The camera will indicate a problem whenever the temperature is above or below a standard. And this notification will be channelled to the right personnel, who can then take action to prevent an incident.”
While thermal imaging – or thermography – is not new, the scope of its applications is only just being realised by the mining industry. Thermography is predominately used as a form of condition monitoring for predictive maintenance on electrical and mechanical systems on a mine site, but can also be used in other applications to identify safety hazards.
Slaughter works closely with Flir Systems thermal imaging cameras – firstly, because CBC distributes these industrial-purpose cameras in Australia, and secondly, because he personally uses the cameras when providing engineering services to customers.
“We distribute a lot of Flir Systems thermal imaging cameras to customers because they are globally-recognised as an industry leader with this technology. The cameras are most commonly used for condition monitoring,” he explains. “While we have customers who want to do the work themselves, we still need to provide training for them to understand how to use the cameras. Additionally, we have a lot of customers who prefer us to come to the site, and perform inspections or provide an ongoing condition monitoring service to them. Either way, because we are using the product ourselves in our services, we have the expertise and experience to guide and advise customers. ”
The thermal imaging camera works by interpreting radiated energy from an image and showing the temperatures as colours. The hotter the section of an image is, the colour will be a vivid red that transforms to white. The colder a section is, the darker the image will be – dark blue, verging into black. Slaughter and the CBC engineering team often use the cameras to identify potential fire risks at a site.
“In terms of electrical thermography, we would inspect a customer’s electrical cabinet by looking through the camera to see if there are any ‘hotspots’ that could cause a fire. In mine sites, all the machinery is hooked up to the switch rooms, so we will use the cameras to check those rooms for hazards,” he says.
Moreover, the reason the technology is used in condition monitoring is because it measures temperature. Just as in human health, anomalies in temperature are often an indicator that something is wrong with the equipment.
Importantly, Slaughter points out that adopting thermal imaging technology is not as simple as purchasing a thermal imaging camera. Having an understanding of the science behind how the camera works and how to interpret the images is essential. He also emphasizes the need to establish reference temperatures for particular components so they can be compared for analysis.
“It’s all about interpreting the image, knowing what the image is telling you and knowing your piece of machinery. A lot of analysis you do with a thermal imaging camera is comparative,” he explains. “For example, if you have two bearings on the same shaft, going at the same speed, and subjected to the same loads, you would expect their temperatures to be similar, provided there are no external influences. So, if one bearing is 20 degrees hotter than the other, that is a clear sign that the equipment is under stress and may fail. That’s why establishing reference temperatures is essential.”
Slaughter also reiterates how important the relationship is between CBC and Flir Systems in providing customers with an efficient service.
“When a customer needs the product, we can get them ordered in and delivered quickly from Flir Systems, and can also ensure that they have been properly calibrated to meet the customer’s specific needs.”