Monitoring the safety status of a blast furnace hearth using cooling stave heat flux

Abstract

Hearths are an accident-prone component in blast furnaces. Accidents, especially hearth burnthrough, cause substantial economic losses and even casualties. Ensuring safe operations is a challenging task as it is impossible to directly observe the internal state of a hearth. Measured data from thermocouples arranged in the hearth lining are often used to evaluate the furnace safety status. However, thermocouples are easily damaged due to their long-term operation at high temperatures. This paper proposes an approach to assist in the safety monitoring of a hearth using heat flux from cooling staves. The method is proposed through a series of finite element simulations to construct the heat flux monitoring calculation model. The No. 3 blast furnace of an iron making plant is taken as an example. The three-dimensional finite element simulation method to calculate the monitoring value of the cooling stave heat flux is described in detail. The simulation results demonstrate that the heat flux monitoring of different cooling staves can vary. Even for the same cooling stave, the monitoring value varies with the increased lining erosion. To ensure safe operations, the monitoring value should be updated when the erosion profile of the lining changes significantly.