Blast furnace circumferential process symmetry: effect of flow distribution in hot blast systems

摘要

Blast furnace operators are striving continuously to decrease hot metal cost. A major part of the hot metal cost is the cost of coke. Therefore, blast furnace operation is moving towards lower and lower coke rates by increasing pulverised coal injection (PCI) levels. Annual average coke rates as low as 262 kg coke/tHM are presently reported and in these situations, PCI rates of 200-240 kg tHM~(-1) are required. In addition to this trend, it is well known, that blast furnace productivity can be increased by oxygen enrichment of the blast. While the mentioned levels of coal injection need 5-7% oxygen enrichment in the blast, oxygen enrichment of the blast up to 15-20% has been used, among others at the steel plants in Umuiden and AK Middletown.