Sublance is a measurement lance that carries sensors into the steel bath of the BOF converter vessel. Various sensors could be mounted on the tip of the sublance. The sensors could carry out direct measurement of the melt without interrupting the Oxygen blow and without requiring turn-down of the vessel. Sublance system therefore could provide highly reliable and accurate measurements with performance exceeding Off-gas analysis or drop sensors.
A sublance system is comprised of the following major sub-systems, sublance main equipment, sublance control systems and measurement instrument. The sublance main equipment can be further divided into the following components, sublance body, sublance hoisting system, sublance slewing / translational system, automatic probe charger (APC), seal cap & slag remover, probe collection chute, valve stations and piping.
Sublance system enables measurement of the steel melt during the Oxygen blow, combined with state of the art BOF process models, could significantly increase the endpoint hit rate. Sublance systems also enable swift tapping decision based on the measurement results after the blow end. Significant benefit could be realized due to shorter tap-to-tap time, less refractory wear, reduced heat loss, higher yield of metallic charges, etc. The total benefits ranges typically at least several Euros per ton of liquid steel produced, thus payback time of less than one year is regularly realized.