THE APPLICATION OF FEM TECHNIQUES IN THE DEVELOPMENT OF COPPER STAVES FOR THE HIGH HEAT LOAD AND HEARTH AREAS OF THE BLAST FURNACE

摘要

Using FEM analysis techniques parameters influencing the thermal and mechanical behaviour of copper staves have been investigated and their effect on the stave performance has been shown. In the FEM models it is possible to simulate the accretion layer loss of a copper stave in the furnace by calibrating the model parameters. Some design variables increase the stave temperatures and the heat flux; rib to hotface ratio and insert conductivity. Other variables promote simultaneous increase in heat flux and decrease in stave temperature; cooling channel diam., cooling channel interdistance, water speed, water inlet temperature, copper conductivity. The importance of certain variables, for example water speed and pressure has been reconfirmed. The choice of the fixing system has been explained, and the security of the hearth staves against the expansion pressures for the hearth has been analysed. With the results from the FEM models the effect of each variable on the performance of the Cu-stave has been quantified, i.e. stave design can proceed on a sound design basis. In general the results support the view that a stave exhibits a better performance in the furnace if the equilibrium temperatures of the stave, and the refractory in the grooves (without accretion layer), are lower, or the heat flux accommodated by the stave is higher. Both indicate a large cooling capacity and the ability to freeze an accretion on the bare stave in a short time.