Numerical Estimation of Hearth Internal Geometry of an Industrial Blast Furnace

Since the campaign of a modern blast furnace (BF) is usually restricted by its hearth integrity, monitoring the hearth internal geometry is of crucial importance for strategic operation planning. To provide an overall picture of the hearth inner geometry of a large-scale BF in Chinese steelworks, a wear model based on the solution of an inverse heat conduction problem is developed. Using the wear model, the evolutions of erosion and skull lines in the hearth are tracked for the period from the blow-in of the BF to its present state. The main findings are outlined herein, where a detailed analysis and discussion of some observations are made to gain a deep understanding of the internal state of the hearth. A correlation between the thickness of the estimated skull layer and taphole length is demonstrated. The results indicate that the skull layer in the bottom of the BF hearth is much thicker than that in the sidewall and that lining erosion of the hearth mainly occurs in the sidewall. In addition, a thicker skull layer preventing the sidewall from excessive lining erosion correlates well with a longer taphole.