Engineers, inspectors and managers equipped with thermal imaging industrial technology can see things they never would have seen before. They can spot a potential problem before it develops and causes major damage. Thermal imaging allows for non-destructive and non-invasive monitoring of machines and processes, and also allows its users to create new ways to examine operations that were not even available before.
For example, sugar beet farmers in Minnesota typically pile their harvested sugar beets in numerous large pyramids, and then process them one pile at a time. Problem is, if just one beet begins to rot and ferment somewhere in a pile, much like the proverbial apple in the barrel, it can destroy all of its neighbors. Thermal imaging offers an easy solution, clearly revealing which piles are heating up fastest and need to be processed first. The savings and efficiencies are obvious.
Bearings, electrical systems, mechanical inspections, medical examinations, and now even sugar beets are proving the value of thermal imaging.
Thermal imaging can benefit in building construction too. Heat loss due to poor window, wall, and roof performance can be seen and repaired. If insulation is wet due to a leak, it loses its effectiveness, and can cause even worse damage to the interior of the building. Thermal imaging can also determine the air quality of the building. In a building near a highway, for example, it can actually “see” the exhaust gases from vehicles and usually reveal where they are leaking into the building.
Engineering Design and Development
Friction generates heat. The flow of electricity generates heat. No surprises there. But by using thermal imaging cameras, researchers and engineers can examine prototypes and parts and detect where designs might have flaws. Infrared technology enables engineers to design better and longer-lasting parts.
Mechanical inspections often require comparing similar pieces of equipment, as well as their actual operating temperature. For example, two identical motors operating under the same load should look alike through a thermal imager. When they don’t, an impending failure can be detected and replaced before it’s too late. After all, early detection of a failing component allows for scheduled repairs and avoids costly downtime. Using a camera with direct temperature readout, a technician can see if mechanical parts are operating within temperature design tolerances. An engineer can survey drill bits in a machine tool and see by their heat build up whether they’re still sharp, saving working time, quality of work, and possible danger.
All aspects of process applications can be monitored to detect problem areas and ensure proper operating conditions. Robotic operations in assembly lines can be monitored for potential problems.
For example, the paper industry pushes for continual throughput to find inefficiencies in their processes, and thermal imaging is used to check bearings in the sheet and roller feed lines and monitor the temperatures inside coating kilns.
A thermal imaging inspection of paper coming off the mill can even reveal a failing dryer roller. The paper has a wet spot invisible to the eye, but not to the thermal imager. It can also see liquid levels in large storage tanks, so leaks can be detected early, avoiding costly failures and downtime.
Exterior refractory inspections locate “hot spots” in furnaces and process vessels, indicating thinning or missing refractory lining or insulation. Failure to identify these areas can result in catastrophic failure leading to safety-related problems as well as a loss in production. Virtually every major steel plant in the United States has been assessed by thermal imaging for process flow problems.
Predictive Maintenance: Finding a Hot Spot
Noranda Aluminum Inc. (New Madrid, Missouri) purchased a thermal imaging system for industrial maintenance. According to Ben Ashley, PdM Thermographer, the camera has brought excellent results. “We’ve used our thermal imager for a variety of maintenance applications, from checking the safety of power switches to measuring the amount of product in bulk tanks.” Noranda is an aluminum primary reduction plant and produces ten million pounds of aluminum per week. The around-the-clock operation can’t tolerate downtime.
During a routine infrared survey, Ashley, and Director of Predictive Maintenance Dennis Nolan, noticed a hot spot in one of the incoming power line switches. The 161,000-volt high voltage disconnect switch provides electrical power for Noranda potlines and is critical to plant operation. A typical potline in the plant uses over 100 megawatts of continuous power and must remain online. Fortunately the anomaly was found early enough to be corrected before any serious damage or loss of production occurred. “The failure of one of these switches could cost tens of millions of dollars depending on circumstances,” states Ashley.
It is typical for Noranda’s predictive maintenance department to conduct infrared surveys every three months using the thermal imaging camera.