Installation of EMF Sensors at BF Shell
 

Progress of estimated liquid iron level H* in two opposite taphole segments
 

To ensure trouble-free blast furnace operation and extend hearth life, liquid iron levels must be continuously monitored. This has been carried out successfully for years with the special temperature independent EMF sensor system developed by BFI.

In applications at advanced high-capacity blast furnaces, eight EMF sensors were mounted in each case to provide a monitoring capability with taphole segment resolution. Evaluation of the EMF readings obtained enables qualitative monitoring of liquid iron levels in the blast furnace. A stable blast furnace process is indicated by liquid iron levels close to taphole level in the respective taphole segments. Major deviations are a reliable sign of non-uniform tapping from the hearth.

Spatially resolved monitoring of the liquid iron filling levels is an important and reliable tool for online monitoring and control of the inner states of the blast furnace hearth. It provides a significant contribution to improve hearth drainage and to reduce wear of the blast furnace hearth.