When hot blast furnace is working, the insulation ceramic board of the furnace lining is affected by the sharp change of temperature during the heat exchange process, the chemical erosion of dust brought by the blast furnace gas, the mechanical load, and the erosion of combustion gas. The main reasons for the damage of hot blast furnace lining are:
(1) Thermal stress. When heating the hot blast furnace, the temperature of the combustion chamber is very high, and the temperature of the furnace top can reach 1500-1560 ℃. The temperature gradually decreases from the furnace top along the furnace wall and checker bricks; During air supply, high-speed cold air is blown in from the bottom of the regenerator and gradually heated. As the hot blast stove is constantly heating and supplying air, the lining of the hot blast stove and the checker bricks are often in the process of rapid cooling and heating, which make the masonry crack and peel.
(2) Chemical corrosion. The coal gas and combustion supporting air contain a certain amount of alkaline oxides. The ash after combustion contains 20% iron oxide, 20% zinc oxide and 10% alkaline oxides. Most of these substances are discharged out of the furnace, but a few of them adhere to the surface of the furnace body and penetrate into the furnace brick. Over time, the furnace lining insulation ceramic plate and other structures will be damaged, fall off, and the strength will be reduced.
Next issue we will continue to introduce reasons for damage of insulation ceramic board of hot blast furnace lining. Please stay tuned!
Post time: Nov-21-2022
