Early Detection of Slag Crucible Damage Through Thermal Imaging

Thermographic Process Monitoring with Automated Alarm Function

For reliable slag crucible monitoring, Optris offers high-resolution long-wave infrared cameras such as the PI 640i and Xi 640. Both thermal imaging cameras operate in the spectral range of 8 to 14 µm and feature an optical resolution of 640 × 480 pixels. This enables detailed thermal imaging of heavily stressed, oxidized, or eroded metal surfaces. Temperature measurement is performed without contact from a safe distance and can be directly integrated into industrial process monitoring.

In the described application, the infrared camera is mounted on a fixed bracket approximately 25 meters from the slag casting area. A suitable telephoto lens ensures that the relevant slag crucible surface is captured in sufficient detail. The Optris PI 640i offers a choice of optics, a thermal sensitivity of 40 mK, and a frame rate of 32 Hz. Alternatively, the compact Xi 640 features motorized focus, a thermal sensitivity of 80 mK, and a frame rate of 32 Hz. Both infrared imaging devices can measure temperatures up to 900 °C in the corresponding measurement range, while the PI 640i offers an optional measurement range of up to 1,500 °C.

The thermal data is evaluated using Optris PIX Connect software. Multiple predefined measurement areas monitor the surface temperature of the slag crucible. If a measurement point reaches the application-specific threshold of 600 °C, an alarm is triggered automatically. The signal is transmitted via the process interface to the plant control system, which interrupts the slag casting process and notifies the responsible control center. A local computer processes the thermal images and enables remote access from a control room approximately 400 meters away.

To protect against mechanical impacts and potential slag splashes, the camera is installed in a suitable Optris protective housing. An unobstructed view of the slag crucible enables direct infrared temperature measurement without requiring additional transmission correction for protective windows.

The combination of a high-resolution thermal imaging camera, automated measurement area evaluation, and industrial signal integration provides continuous thermographic monitoring during the filling process. The solution can be adapted to different plant layouts and safety requirements.