(p91) Study on burden distribution with bell less top in blast furnace of Hyundai steel company

摘要

The Hyundai steel's Dangjin works has operated three blast furnaces since September, 2013. The inner volume is 5,250 m3 and 2.23 t/d/m3 of productivity with 150-170 kg/thm of PCR has operated stably. The Hyundai steel performed the burden distribution test before blown-in to establish the optimized burden distribution technology. It is necessary for operator to acknowledge the characteristics of own burden system including the burden amount and the burden trajectory from chute. And it is important to control the burden distribution, which affects the gas flow pattern in the blast furnace. Gas efficiency of the blast furnace is influenced by the gas flow pattern, which is dictated by the burden profile. Additionally, selection of the charging pattern is important as it affects the burden trajectory and stock profile. Test results are composed of the falling burden trajectory and stock profile depending on chute positions. The burden trajectory is determined by tilting angle, friction coefficient, and falling velocity. Stock lines are formed by the angle of repose, which is affected by the burden trajectory and falling velocity. Based on test results, the existed mathematical model was modified to be used in normal operation. Whenever it is required to change the burden distribution, the operator simulated the numerical model to check the effect in advance.