Operating characteristics and lifetime of blast furnaces depend on the cooling capacity of copper staves installed on the furnace wall. An oxygen blasting furnace is a furnace that produces iron by using anthracite and oxygen as a fuel. The structure and operating characteristics of the furnace are different from those of a coke furnace, so the structure and working conditions of the copper stave installed on the furnace wall of oxygen blasting furnaces are also different from those of coke furnaces.
Oxygen blasting furnaces have a constant height of liquid slag of 1500–1700℃ inside, so the temperature of their upper parts is also high, unlike coke furnaces. Therefore, oxygen blast furnaces should be designed to use copper with high thermal conductivity as stave material, and the structure of the copper stave should also be designed to enhance cooling capacity. In the copper pipe-mounted casting method, the cooling water is injected through the inside of copper pipe to prevent the melting of the copper pipe by hot copper solution. If the cooling capacity of cooling water is too high, fine gaps can be produced between the copper pipe surface and stave body. These micro-gaps are responsible for lowering the thermal conductivity and reducing the cooling capacity of copper stave.
To ensure normal operation of oxygen blasting furnaces and increase their lifetime, Choe Kyong Chol, a section head at the Faculty of Materials Science and Technology, has newly designed the structure of a wall copper stave, evaluated its cooling capacity and developed a casting process of the newly designed wall stave.
He determined the external dimension and wall thickness of the wall copper stave for a 20m2 oxygen blasting furnace as 910mm×645mm×90mm and 25mm, respectively. The inlet diameter and length of the cooling water passing region are determined as ϕ70mm and 220mm, respectively.
For more details, please refer to his paper “COOLING CAPACITY EVALUATION AND OPTIMAL CASTING PROCESS DESIGN OF CORE-MOUNTED COPPER STAVE FOR 20m2 OXYGEN BLASTING FURNACE BASED ON SIMULATION RESULTS” in “International Journal of Metalcasting” (SCI).