The possibilities for thermography in industrial facilities seem endless. In the hands of a skilled thermographer, thermal or infrared (IR) imaging cameras can detect temperature anomalies in just about any electrical, mechanical, or refractory application before they become a costly problem.
Growing awareness of the value of this nondestructive testing technique is sparking interest from the executive suite to the plant floor and prompting action from industry regulators and standards bodies. At the same time, a tidal wave of new technology innovations, feature-rich offerings, vendor options, and sharply declining price points are helping to spur funding for new and expanding thermography programs.
Robin Thon, a sales/service engineer at Albany International, a global advanced textiles and materials processing company in Eau Claire, Wisconsin, and Adam Harsha, a reliability engineer at the ArcelorMittal plant in Riverdale, Illinois, are advocates and active practitioners of thermography.
|Sheila Kennedy is a professional freelance writer specializing in industrial and technical topics. She established Additive Communications in 2003 to serve software, technology, and service providers in industries such as manufacturing and utilities, and became a contributing editor and Technology Toolbox columnist for Plant Services in 2004. Prior to Additive Communications, she had 11 years of experience implementing industrial information systems. Kennedy earned her B.S. at Purdue University and her MBA at the University of Phoenix. She can be reached at email@example.com.|
How is thermography used in the real world? “We have three thermographers who are level II certified and about 10 who are Level I certified across the United States,” says Thon. “Thermography is not our full-time job, however; we are sales/service engineers. We have a few short wave cameras but use the long wave more. We use the camera mostly for paper web cross direction profile images. We also use the camera to check liquid ring vacuum pumps to make sure the water is making a seal, and we combine that with an ultrasound probe for pipe line blockage and bearings.”
In its Riverdale facility, ArcelorMittal uses thermography as a means to troubleshoot some new and existing issues and better determine what may or may not be causing them, says Harsha. “In particular, we have been using thermography to help identify when we do not have a normalized apparent temperature across cooling hood structures.”
The benefits of thermography are numerous. “Tracing down a profile issue can help us to find and fix the issue to make a more consistent moisture on the paper web, because wet streaks on the paper will cause coating and printing problems on the end product,” says Thon. “Checking the vacuum pumps to identify issues can help to make the pumps more efficient, because a bad seal ring will cause less vacuum to be applied and more energy will need to be used in the dryer section. Using ultrasound and infrared for bearings will help to identify a problem in the bearing before it fails, which will save unscheduled downtime and premature bearing failure.”
The ArcelorMittal team has been able to identify manufacturing defects in some of the installed components, says Harsha. “We have been able to present this data to the manufacturers so that they can correct their processes and deliver the best product possible,” he explains.
“I’d recommend looking at each of the cameras available and choosing the best for your application,” suggests Thon. “Bearings and steam traps can use a less expensive camera. For profile issues like ours, you would need a more expensive camera for better resolution. I would definitely recommend investing in training through the Infrared Training Center. One or two people should be involved in developing and maintaining the program as more experience will give better results in troubleshooting.”
Harsha recommends starting with a consistently top-performing piece of machinery. “That way it will make it extremely easy to see variances in apparent temperatures,” he explains. “If the pilot machine is inconsistent, it will not allow new thermographers to learn when and what to diagnose. Also, be sure to make thermographers available for both a predictive program and some troubleshooting, as this will give them more exposure and help to promote the technology across departments. Just be cautious of only using it for troubleshooting; it can do so much more in a predictive role than in a reactive one.”
Companies like Albany International and ArcelorMittal would not be investing in thermography if there were not clear benefits to be had. “Infrared thermography is a highly reliable technology that is rightfully considered as one of best predictive maintenance tools available,” says Gary Lux, an Infraspection Institute staff instructor and certified Level III infrared thermographer, as well as a partner at Cold Mountain Infrared.
Figure 1. Thermal imaging cameras allow you to inspect, troubleshoot, and diagnose problems without interrupting processes and operations.
Thermography allows maintenance teams to spot potential problems before a component failure causes an unscheduled production shutdown. “The teams can see which components are having problems, assess the problems, order parts, and plan to repair or replace those components during regularly scheduled shutdowns, instead of performing emergency repairs at odd hours or in the middle of production runs,” explains Brad Gilbertson, owner and principal thermographer/consultant at Sandhills Thermal Imaging. Gilbertson also is an Infraspection Institute certified Level III infrared thermographer.