The blast furnace (BF) is a crucial stage in the iron-steel making process. Pulverized coal injection (PCI) and natural gas (NG) have been utilized in blast furnaces as a substitute fuel source for reducing coke rate. Due to introduction of injected fuels into a blast furnace, the combustion and heat transfer in the tuyere/blowpipe region affects the tuyere/blowpipe structure. A comprehensive computational fluid dynamics (CFD) model including PCI/NG combustion, multi-mode heat transfer for the blowpipe/tuyere region of a blast furnace at AK Steel Dearborn Works has been developed, considering detailed material properties in the blowpipe region. The model has been validated by comparing the blowpipe skin temperature profile with thermographic images under typical operating conditions. Based on the developed CFD model, the detailed PCI/NG co-injection combustion has been investigated and the thermal effect on the tuyere tip has been revealed.
