1. Furnace lining Leakage
Meaning
Furnace lining leakage is one of the most dangerous and common faults of steel shell furnaces. It is mainly characterized by local redness/hotness of the furnace shell, frequent beeping of the furnace leakage alarm system, coil discharge, and leakage of molten iron.
Root Causes:
l Furnace lining leakage is mainly caused by the following reasons:
l The furnace lining is not densely knotted, has impurities, and is too thin in parts.
l Furnace age is too long, slag line erosion is severe, thermal expansion and contraction cracks.
l Rapid cold and rapid heat.
l Residue accumulation at the bottom of the furnace, overheating and burning through.
Solutions:
l Immediately cut off power and stop heating.
l When it is safe, tip the furnace and pour the molten iron into the accident pit.
l It is strictly forbidden to pour water on the red furnace area.
l Demarcate a warning zone and inspect after cooling.
l Repair local small cracks, thin large areas and rebuild the furnace.
2. Furnace lining cracks, falling blocks, and slag hanging
Root Causes:
Furnace lining cracks, falling blocks, and slag hanging are mainly caused by the following reasons:
l Poor furnace construction quality and poor sintering.
l The charge block is too large and hits the furnace lining.
l The slag system does not match the furnace lining (acidic/alkaline).
l Frequent rapid cooling and rapid heating.
Solutions:
l Small cracks: cleaning and repairing.
l Blocks falling/severe erosion: Relining the furnace.
l Adjust slag/furnace lining material matching.
3. Furnace structure and mechanical failure
Furnace structure and mechanical failure mainly manifest as steel shell deformation, bulging, and weld cracking.
Root causes:
l Heat leakage and local overheating of the furnace lining lead to annealing deformation of the steel shell.
l Thermal stress, mechanical stress, welding defects.
l Uneven stress on tilting furnace.
Solutions:
l Mild deformation: reinforcement, correction.
l Crack: Excavation and repair welding (using structural steel such as Q345R).
l Severe deformation: replace furnace shell.