1970 Volume 56 Issue 6 Pages 807-812
Water-cooled type sub-lance 12.8 in in length and 216 mm in outer diameter is installed in No 1 LD furnace of No 2 steel making plant in Tobata Area Works, in order to catch the condition of LD process. It is inserted into LD vessel through the upper-hood at an incline of 74° with a speed of 2-60 m/min by means of manual or automatical remote control. Measurements can be performed within 75-450 sec with expendable sensors set in the head of sub-lance.
Three types of sensors with a single function are prepared and applied to process analysis as follows:
1) Level sensor: to measure the change of bath level depending on lining life and that of foaming slag level during blowing.
2) Temperature sensor: to measure the change of bath temperature during blowing.
3) Sampler: to take a sample from metal bath during blowing. Sub-lance is effective in an LD process control and process analysis.