Today, it’s impossible to imagine the building industry without cement. As an important component of masonry mortar and concrete, the manufacturing of and use of cement products make cement one of the most valuable and useful mineral products in the world. Cement production is a complex process, in which one of the steps consists of blending limestone – cement’s main ingredient – with other components in big rotary furnaces. These furnaces or kilns are a critical asset of a cement production plant, heating their contents to temperatures up to 1,500°C. There is however a risk of overheating, which can cause serious damage to the kiln shell. In order to monitor this delicate heating process and prevent possible damage to the kiln, thermal imaging cameras from FLIR are used to measure temperatures on a 24/7 basis.
The IRT KilnMonitor® system includes FLIR A-Series cameras, which monitor the kiln temperature in real time. In addition, it gives a kiln visualisation module (2D and 3D) and a thermographic analysis module.
High resolution: The FLIR A315 and A615 are a compact and affordable thermal imaging camera,fully controlled by a PC. With a thermal sensitivity of < 50 mK, it captures the finestimage details and temperature difference information. “We definitely need the high resolution. For an ideal installation, we often opt for a 90° lens, because then you only need to use two or three cameras to cover the entire kiln length.
The IRT KilnMonitor makes use of three A315 cameras each scanning one third of the 60m long rotary kiln. These thermal video streams are distributed to a visualisation system inside the central control room, and provides operators with a 24/7, real-time view of the kiln operation and performance. The kiln has a rotation time of around 30 seconds and the IRT KilnMonitor® is synchronised to the rotation time to build up a thermal image. Whenever the kiln shell reaches an undesired temperature, operators receive dedicated software alerts which allow them to take the appropriate remedial actions. For example, hot spots in the thermal image of the furnace can indicate that refractory bricks got detached from the refractory lining and that the protective kiln layer is getting less thick. This may require the furnace operators to reduce the temperature of the burner or even shut the system down in order to prevent severe damage and a huge cost!