Equipment Maintenance: Thermal Imaging Changes the Picture

Pharmaceutical plant benefits by taking a different look at equipment.

By Jeff Fleming, CMC icos Biologics, Inc.

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As a contract manufacturer of pharmaceuticals, CMC icos Biologics, Inc., Bothwell, Wash., must comply with current Good Manufacturing Practice established by the U.S. Food and Drug Administration. As the company’s manager of engineering operations, I use a variety of monitoring strategies to keep us in compliance. Most recently, I have added thermal imaging to the mix, for semi-annual preventive maintenance inspections and troubleshooting equipment issues and process problems.

Until 2008 an outside contractor performed all our thermal scans, which provided baselines for subsequent monitoring of critical equipment. That year we brought thermography in house. We acquired a Fluke Ti10 Thermal Imager. This instrument produces infrared (IR) images that reveal the surface temperature of objects and links each image to a regular (full visible light) image.
Alarm mode image
Figure 1. Alarm mode image:
Combining regular and thermal
images pinpoints motor areas
of concern.

This allows me to place a visible light picture as a frame of reference around a thermal image. Or I can blend the visible and IR image in any ratio to create a single image with enhanced details. Or, my favorite, I can create an “alarm mode” image, in which only temperatures that fall above, below or within a specified range appear in IR while the rest of the scene is full visible light. It’s powerful to be able to see the two images together.

The motor image in Figure 1 illustrates the alarm or limit function. I use this a lot to isolate the exact location of hot areas. Software that comes with the instrument enables me to adjust alarms, add more temperature data and zero in on the heat location. Having a diagnostic tool that can get rid of all non-critical values makes my job easier.

Wide Applicability
I’ve already used the thermal imager on a broad range of equipment:

Motors. Efficiently operating motors have a normal thermal pattern. My background in electrical and mechanical systems means I’m familiar with that pattern and helps me both identify and diagnose abnormal heat signatures. In general, the more familiarity the thermographer has with the equipment being inspected, the more effective the diagnosis. For example, in Figure 1, it was clear to me that the problem was a bad winding and not something else, e.g., inadequate airflow, unbalanced voltage, an overload, a failing bearing, insulation breakdown or shaft misalignment.
Steam trap operation Steam trap operation
Figure 2. Steam trap operation:
is operating correctly but trap  

Scanning shows trap on left
on right has failed.

Electrical Panels. When I’m scanning these panels I’m usually looking for signs of loose or corroded connections that increase resistance at the connection and show up as hot spots before failure occurs. My team and I scan all electrical service components at the plant, including main distribution elements such as switchgear, transformers and transfer switches. This has enabled us to detect installation issues as well as operating problems. For instance, we found an abnormal temperature increase in a breaker just after it was installed. Physical investigation discovered a loose leg. We even scan oil-cooled transformers that are maintained by a contractor. I keep baseline images and monitor semi-annually just in case. I look for significant hotspots toward the ends of the cooling fins.

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