1990 Volume 76 Issue 11 Pages 1978-1985
The LD-converter process has a great influence on the cost and productivity of the overall steelmaking process. Therefore it is very important to establish a "Just in Time" LD-converter process which can punctually supply molten steel to the continuous casting machine. At Kakogawa Works, Kobe Steel, through the installation of hot metal Pre-treatment and a ladle-arc refining furnace, we have reduced the burden of the LD-converter. In addition we have been developing and improving blowing control models ; techniques which detect reactions in the vessel such as the measurement of hot metal level and slopping prediction, along with the quick tapping technique. However there was still room for improvement in establishing a "Just in Time" process, particularly, because all the decisions for blowing control depended on the individual operator and there was variation because of this. So based on the above mentioned techniques, we have decided to apply a fully-automatic blowing system to our converters by which we can produce a wide range of carbon steel. In the system, a DDC (Digital Direct Controller) automatically controls blowing following the commands of the process computer. As a result of its implementation. Steelmaking time and variation have improved remarkably, and has made it possible for a single man to operate both blowing and the OG exhaust gas recovery system.