Temperature monitoring on the walls of a tank intended for the manufacture of aluminium
Thursday 29th april 2021
Objective of the project:
Deploy a distributed optical fiber temperature monitoring solution to characterize the thermal propagation of a tank for aluminum manufacturing.
The solution implemented is an alternative to the measurement via thermocouples. Thus, a more precise and resistant measurement to the strong electromagnetic field is deployed.
This instrumentation poses certain problems in particular as we said previously the very high temperature present at the level of the aluminium in fusion but also at the level of the bottom of tank and on the sides. These temperatures are of the order of 1000°C for the molten aluminum and 200°C on the bottom of the tank and 600°C on the sides of the tank. The electromagnetic environment also present in this area made things more complex. The magnetic field in the work area is very large (several hundred times that of the Earth).
Implementation by Cementys:
In order to meet these various constraints as well as the fact of having the most accurate mapping of this tank, Cementys proposed a distributed temperature measurement with the SensoLogger T interrogator in order to have an accurate measurement all along the optical fiber. The optical fiber installed by our engineers was specially chosen to withstand the harsh conditions of use.
The system, which has been operational since 2018, is provided to the RioTinto LRF and also includes a human-machine interface developed specially for this project.
Two tanks were instrumented by Cementys in 2018 and 2019, the start of temperature monitoring for this second tank took place at the end of 2020. Our engineers were therefore involved in the installation of the fiber but also in the spatial calibration of the overall instrumentation with the calibration of the measurement device.
Thanks to this distribution we can easily make a temperature map of the whole tank.