Scale protection layer: Guardian of blast furnace cooling walls

　　The cooling wall, as a core structural component of the blast furnace—a crucial metallurgical facility—plays a pivotal role. It directly affects not only the blast furnace's operational efficiency and lifespan but also profoundly impacts the overall effectiveness of steel production. Blast furnace cooling walls come in numerous types. Classified by material, they mainly include cast iron cooling walls, cast steel cooling walls, pure copper cooling walls, and a special type of composite cooling wall. This composite cooling wall uses copper on the hot side and steel on the cold side, combining copper's excellent thermal conductivity with steel's superior mechanical properties. It is a widely used advanced cooling wall in modern blast furnaces.

　　The design of the surface of the cooling wall facing the inside of the blast furnace is equally critical. To optimize heat transfer and refractory lining adhesion, cooling wall surfaces vary in morphology. There are designs with smooth, mirror-like planes, complex concave-convex groove structures, and various other innovative structural forms. However, in practical applications, the concave-convex groove structure has become the mainstream choice due to its unique advantages. This structural design not only increases the contact area between the cooling wall and the refractory material, improving the stability and durability of the refractory lining, but also facilitates the embedding of a refractory material protective layer on the cooling wall surface. More importantly, when the refractory material gradually wears down due to long-term high-temperature operation, the concave-convex groove structure allows slag to more easily form a new layer of hanging slag protection on the cooling wall surface. This naturally formed protective layer acts as a barrier, effectively reducing the direct erosion of the high-temperature furnace gas on the cooling wall, thus significantly extending the service life of the cooling wall and ensuring the safe and stable operation of the blast furnace.