Prediction of blast furnace hearth condition: part II – a transient state simulation of hearth condition during blast furnace shutdown

Abstract

The extent of hearth cooling is critically important in determining the feasible duration of an extended blast furnace maintenance shutdown. Based on a fixed domain method, a transient numerical model has been developed which considers the effect of solidification enthalpy of liquid iron in a coke-free bath, enabling the progress of hearth cooling to be monitored. The model was initially verified by comparing calculations with actual refractory temperatures during shutdowns of shorter duration (typically 1-2 days) at BlueScope's No. 5 Blast Furnace. It was then applied to estimate the hearth condition during an extended shutdown period (typically, 5-6 days). The calculated refractory temperature differences were reasonably matched with the measured data over the extended shutdown period. This allowed visualization of the temporal variation of refractory temperatures and the extent of liquid bath cooling during extended shutdowns, providing useful guidance for furnace engineers.

Manganese Distribution between Slag and Metal in the Egyptian Blast Furnace

“…The standard free energy change,∆𝐺𝐺 𝑀𝑀𝑀𝑀 𝑜𝑜 , of this reaction is [8] ∆𝐺𝐺 𝑀𝑀𝑀𝑀 𝑜𝑜 = −399154 + 120.54 𝑇𝑇 (10)…”

“…The activity of 𝑀𝑀𝑀𝑀𝐶𝐶 in the slag,𝐶𝐶 (𝑀𝑀𝑀𝑀𝑂𝑂) , can be estimated from [8,9] 𝐶𝐶 (𝑀𝑀𝑀𝑀𝑂𝑂) = 10 −3 (𝑀𝑀𝑀𝑀𝐶𝐶) �1.6 + 5.9…”

Numerical Simulation Model for Evaluating Protection Measures of Blast Furnace Hearth

“…It promotes the formation and adhesion of the solidified iron layer. If there is a scale or air gap in the hearth, it has a great impact on the heat transfer system [11][12][13]. The heat cannot be transferred in time.…”

“…Besides, the influence of parameters on the formation of the solidified iron layer was discussed, including lining performance and structure, cooling water temperature, flow rate, and hot iron production rate. Dong et al [12] established a transient numerical calculation model considering the solidification phase transition of hot iron. The actual measured value of the refractory material was compared and verified with the calculated value.…”

Prediction of blast furnace hearth condition: part I – a steady state simulation of hearth condition during normal operation

“…However, these temperature variations cannot sufficiently illustrate the internal liquid flow distribution and relevant bed structure. In this respect, Part I and II [1] in this two part series will apply numerical modelling to help understand the internal state of the hearth during normal furnace operation and long maintenance shutdown periods.…”