9th ECCC European Continuous Casting Conference – ECCC 2017

A new advanced radiometric sensor for mould level measurement in closed stream casting has been designed by SMS Concast. The unique feature is to determine both the real position of the steel meniscus and the thickness of the lubricating powder on top. Compared to the conventional instrumentation this refined setup overcomes the limitation of measuring only a single intermediate level with no possibility to discriminate between contributions of the two materials. The new technology gives access to precious metallurgical information. It also adds the opportunity to tune automatically the powder thickness with no human intervention and leaving the meniscus position undisturbed. This is made possible by an innovative patented design exploiting a vertical stack of multiple scintillator crystals instead of a single one: the crystals are read in parallel to monitor the count profile of the radiation coming from a 60Co rod source. Through a sophisticated algorithm the two distinct levels can be evaluated, being the profile a function of the different material (density) inside the mould tube. Steel level and powder thickness are so determined by means of one instrument only. Laboratory and also plant hot tests have fully confirmed the performance of this new concept. The final engineering design of this new radiometric multi-crystal detector, CONGAUGE LB 6755, has been developed in collaboration with Berthold Technologies, based on their consolidated technological skills. Quick retrofitting into the existing plant configuration is granted on most cases. A calibration tool allows assisted calibration for different casting sections and different flux densities. CONGAUGE LB 6755 will significantly improve surface quality in the continuous casting of steel. This paper explains how initial strand shell formation will become a technologically controlled area.