Thermal imager spots gas leaks

Process operators at theBorealis high-pressure, low-density polyethylene (LDPE) plant in Stenungsund, Sweden are using a FLIR Systems optical gas imaging camera to detect potentially dangerous gas leaks, seeking infrared (IR) radiation signatures.

In the LDPE production process, ethylene -- a highly flammable hydrocarbon -- is converted into polyethylene in a high-pressure polymerization reaction. In the past, to detect any ethylene leaks, process operators at Borealis used gas "sniffers," devices that measure the concentration of the gas in one single location and generate a concentration reading in parts per million (ppm).

But with the purchase of the FLIR GF306optical gas imaging camera, they can detect leaks visually. Process operators can scan approximately 80% of the entire plant in 30 min.

FLIR optical gas imaging cameras can spot the gas leaks because the gas absorbs IR radiation, blocking radiation from objects behind it, which causes the leaks to appear as either a black or a white plume in the thermal image, depending on whether the user opted for the "white hot" or the "black hot" settings.

The use of the IR camera, however, does not mean that the process operators have abandoned the sniffers completely. The thermal imaging cameras detect any leaks, whereas the sniffers are still used to quantify them.