Infrared technology has many practical applications in the plant, including electrical systems, power transmission, and HVAC. It’s especially useful for monitoring or troubleshooting these systems, but the type and number of applications continue to grow.
“The application of IR technology is only limited by a person's imagination,” says Brad Gilbertson, certified level III infrared thermographer and principal consultant at Sandhills Thermal Imaging in Fayetteville, North Carolina. “Any problem with any system within a plant will present some form of thermal anomaly which can be detected by an imager. When compared to similar items, a problem item will have either a noticeable increase or decrease in temperature. The true limiting factor is if the time spent finding the problem is worth the money and effort. Finding problems in electrical switchgear and power transmission equipment is worth every penny of an infrared survey. IR is useful for finding problems before they cause costly shutdowns during production runs.
Maintenance can be scheduled and repairs planned in advance, instead of as faults occur. When potential problems are found during production runs, their condition can be monitored. Management can be advised about the problem and planning can begin to prevent unexpected slowdowns.”
Facility managers may also be interested to know about the use of thermography to locate water damage, says Gilbertson. “Thermography can help document the extent of water damage in an area,” he explains. “The areas of water damage show up in an infrared image before they are visible on a wall or other surface. The imager can help trace moisture back to the source. And the damage can be located and documented without the need of opening a wall or some other destructive means. Along similar lines is the use of infrared to check the condition of the plant’s roof. A roof membrane can leak for years without the water ever manifesting itself inside the plant. The moisture soaks into and is trapped in the insulation. A thermographer is able to find the damaged areas of insulation.” The facility manager can then spend money on fixing smaller portions instead of replacing the entire roof.
“Thermal imaging is ideal for monitor and troubleshooting complex systems,” says Kevin Lesnewski, product manager, thermal imaging division, Testo. “The power of IR technology is the safety it provides, by being a non-contact inspection, and the ability to visually see a system’s thermal properties in real time. Thermal imaging is a very versatile tool and most times personnel are looking for hot spots generated by electrical shorts or mechanical friction. One powerful aspect, which is often overlooked, is the detection of cold spots. Areas where fluid or air handling systems are not working correctly such as water chillers, hydraulic pipes and valves, and fuel systems. Looking for cold spots is indicative of a system with a potential blockage. With all this time looking at manufacturing equipment, the building envelope protecting it from the elements is sometimes forgotten. Thermal imaging is very good at locating insulation gaps, water intrusion, and drainage problems.”
The best solution is a combined approach, offers Gary D. Lux, managing partner, Cold Mountain Infrared, in Asheville, North Carolina. “An infrared camera in the hands of a trained thermographer is a powerful PdM and post-PM tool for locating problems in all sorts of applications,” he explains. “But no one technology is better than two. I really like combining thermal imaging with ultrasound. Of course we can't overlook oil analysis and other extremely valuable tools. But the combination of thermal imaging and ultrasound is a true PdM dynamic duo for trending and early problem detection. If your infrared guy isn't talking to your ultrasound guy, then you have a ‘Cool Hand Luke’ situation. Use both technologies, and you’ll be on top of your PdM game.”
IR inspection is useful during all stages of an asset’s life starting with acceptance inspections of new installations, explains Gary Orlove, PE, curriculum manager, application engineer, InfraMation Thermography Conference co-chairman. “After that, periodic inspections correlated with other condition monitoring test methods are performed to assess the condition of the assets and help to determine when maintenance should be performed,” he says.
“Rising temperatures and rapid or excessive heat buildup often signal malfunctions and abnormal or fault conditions for many types of systems, machinery and components,” says Karen Kwong, product development engineer, General Tools & Instruments. “The ability to gather and analyze temperature data in real time and over time helps to pinpoint existing issues and identify the onset of emergent problems. These include problems brought on by wear; imbalance; misalignments; insufficient cleaning or lubrication; friction and electrical issues in rotating machinery, such as motors, turbines and compressors, and their bearings, couplings, and gearboxes, and other types of process equipment, such as pumps, valves, heat exchangers, steam traps, heaters, conveyor belts, rollers, heaters, and furnaces. Temperature spikes and differentials can also signal problems with energy efficiency issues. Both scanning infrared thermometers (IRTs) and thermal imaging cameras are useful in recognizing and evaluating such problems.”
|Mike Bacidore is chief editor of Plant Services and has been an integral part of the Putman Media editorial team since 2007, when he was managing editor of Control Design magazine. Previously, he was editorial director at Hughes Communications and a portfolio manager of the human resources and labor law areas at Wolters Kluwer. Bacidore holds a BA from the University of Illinois and an MBA from Lake Forest Graduate School of Management. He is an award-winning columnist, earning a Gold Regional Award and a Silver National Award from the American Society of Business Publication Editors. He may be reached at 630-467-1300 ext. 444 or firstname.lastname@example.org or check out his Google+ profile.|
IRTs only conduct single-point analysis, while thermal imaging cameras collect thermal data in an array or matrix, explains Kwong. “This advanced capability helps users to visualize problems much more easily,” she says. “Accordingly, thermal imaging cameras are best for applications, such as diagnosing heat exchanger, motor or compressor maintenance issues; locating invisible or inaccessible thermal leaks and pinpointing leak sources in piping, tanks or ductwork; inspecting integrity of thermal insulation; revealing overheated electrical circuits; checking/monitoring combustion or temperature-controlled processes; assessing the thermal envelope of buildings and detecting specific areas of energy loss; and supporting maintenance and repair efforts by documenting problem areas.”
The technology can help most areas within your facility, from incoming power and power distribution to control systems and final components, explains Tony Shockey, thermography product manager at Fluke.
Electromechanical applications include identifying unbalanced loads, overloaded systems with excessive current, loose or corroded connections, insulation failure, component failure, wiring mistakes, underspecified components, worn or loose bearings, and bearing lubrication condition. “In process industries, the technology can show damaged structures caused by worn or leaking pipes and thermal insulation, abnormal heat flow and heat gradients, defective valves and steam traps, gas or steam leakage, and tank levels and sludge build-up,” says Shockey. “For building inspection, use it to find improperly installed or missing insulation, heat loss through damaged seals in multi-pane windows, damaged heat ducts and buried steam line leakage, defective seals on doors and windows, and problems with HVAC installations. Infrared identifies abnormalities, giving you a better idea of what issues you might have and where to spend your time.”