A FLIR Systems GF306 optical gas imaging camera is being used by a Swedish LDPE plant for gas leak detection safely, quickly and accurately.
Leak detection is of vital importance in petrochemical plants that handle invisible gaseous hydrocarbons, many of which pose some sort of safety hazard in terms of toxicity, flammability, or long term exposure. Others can be explosive, and most of them will have a negative impact on the environment if they enter the atmosphere in large quantities.
The Borealis high-pressure, low-density polyethylene (LDPE) plant in Stenungsund, Sweden produces LDPE products for the cable and wire sector and has an annual production capacity of 350,000 tonnes. The Borealis cracker facility delivers the main ingredient, ethylene, which is converted into polyethylene in a high-pressure polymerisation process. Ethylene is a highly flammable hydrocarbon.
To further increase the safety within the plant and reduce the environmental impact, Borealis has purchased an optical gas imaging camera from FLIR Systems. Using this gas leak detection tool, Borealis ensures that no gas leak escapes the attention of the process operators.
An optical gas imaging camera is a quick, non-contact measuring instrument that can visualise gas leaks in real time. Where many other measuring instruments only present the inspector with a number, optical gas imaging cameras present visual information, making the leak detection process more intuitive. Optical gas imaging cameras can also be used in hard-to-access locations, since they can detect small leaks from a distance.
Shift supervisor LDPE Jan Åke Schiller was sceptical of the new technology in the beginning but after seeing these optical gas imaging cameras in action, he quickly realised that they had immense potential for leak detection at the polyethylene plant and in petrochemical plants in general.
Before the purchase of the FLIR GF306 optical gas imaging camera, Schiller and his colleagues used sniffers - devices that measure the concentration of a certain gas in one single location and generate a concentration reading in parts per million (ppm).
According to Schiller, the main advantage of the optical gas imaging camera is that it has the ability to detect gases visually. Where sniffers just give a number, an optical gas imaging camera helps detect gas leakage anywhere within the field of view of the camera, speeding up inspections considerably.
The new FLIR GF306 optical gas imaging camera allows them to cover approximately 80% of the entire plant in about thirty minutes; one would need a team of ten people with sniffers to work for two full days to reach the same result.
Schiller says they still use the sniffers alongside the optical gas imaging camera with the FLIR camera being used to detect the leak and the sniffer to quantify the leak. Schiller was surprised to see how sensitive the FLIR GF306 optical gas imaging camera was, as it could detect leaks of below 100 ppm; when operating in the High Sensitivity Mode, it can be used to detect even smaller gas leaks from about seventy metres, enabling the operator to perform these inspections from a safe distance.
All leaks to be repaired are reported to the maintenance crews. The optical gas imaging cameras are also used in this process with the team simply attaching a video file to the work order for the maintenance crew to see for themselves the location of the leak.
Schiller’s team has been able to carry out inspections more frequently than the annual inspections conducted earlier with the sniffers. Using the FLIR GF306 optical gas imaging camera, they are able to cover all of the pipework extending to over 100km in length in one day using just one person. Apart from inspecting the entire plant twice a year, they now perform a quick inspection at every startup.
All FLIR GF-Series optical gas imaging cameras are ergonomically designed in a lightweight and compact form factor to prevent back and arm strain. With its rotating handle, direct access buttons and tilt-able viewfinder and LCD screen, the FLIR GF306 optical gas imaging camera is designed from the end-user's perspective, offering advanced ergonomics to improve worker safety. At 2.4kg, the FLIR GF306 optical gas imaging camera is also relatively light and compact.
The FLIR GF306 optical gas imaging camera contains a cooled Quantum Well Infrared Photodetector (QWIP) that produces thermal images with a resolution of 320 x 240 pixels at a thermal sensitivity of 25 mK (0.025°C). The gas visualisation functionality of the FLIR GF-Series optical gas imaging cameras is based on infrared absorption.
Recording video footage
Apart from real time visualisation the FLIR GF306 optical gas imaging camera is also capable of recording both visual light video and thermal video footage. For leak reports the video recording is started in the visual video mode to show the location to the maintenance crew, switched to the gas detection mode to show the leak, and again switched back to visual video mode to verify the leak location.
Worth the investment
Schiller observes that some companies might be reluctant to buy an optical gas imaging camera due to the price tag; however, the hardware cost can be offset by costs saved on the labour and time intensive sniffer process. Very importantly, leaks in unexpected locations are difficult to find and easy to miss with sniffers, so using optical gas imaging cameras will help ensure the safety of personnel and of the inhabitants of the surrounding area.
Additionally, timely and quick use of optical gas imaging will help reduce the amount of gas lost to the atmosphere due to leakage. By reducing the leakage the optical gas imaging camera will earn back its purchase cost.