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Hot blast stove and the key part for blast furnace

Mar 13, 2021
Hot blast stove bear the following effect: high temperature (1200-1350℃) ; temperature dramatic changes caused by air heat exchange; chemical etching because of blast furnace gas with dust ; erosion of Combustion Gases and mechanical loads. Hot blast stove is a higher structure, the firebricks in regenerator and combustion chamber will appear shrinkage, deformationand crack under Mechanical Load and high temperature, this will affect the life time. So, the basic demand for the brick of Hot blast stove: little creep rate, large heat capacity, high strength under high temperature, good resistance to thermal shock. Firebrick’s choice depend on the hot air temperature. Under 900℃, clay brick is suitable, above 900℃, the lining of high temperature parts are mainly high alumina fire bricks, mullite brick and sillimanite brick. When the air temperature above 1100℃, we select high alumina fire bricks, mullite brick and silicon brick to work as furnace lining. When the air temperature rises to 1200℃, we use quality silicon brick on the top of furnace and the upper part of regenerator and partition. For the little heat capacity for silicon, we have to use high aluminum firebrick with the feature of low creep under the checker brick of silicon brick layer.
By Hot blast stove, the air created by supporting coke burning in the blast furnace will be heated to 1200-1350℃, the vault part is 1350-1400℃. High blast temperature technology is one part for blast furnace modernization technology. Rising the heat air temperature of entering the blast furnace can reduce the coke ratio, and improve the yield of hot metal. In China, the temperature for most blast furnace is 1000-1100℃, even lower than 1000℃, but it is over 1200℃ in Baosteel. Abroad the current average air temperature is 1100-1200℃, minority can reach to 1350℃. Hot air furnace heated by blast furnace gas, sometimes, by using high heating value fuel like coke oven gas or heavy oil.
As the people’s increasingly stringent demand on the quality of steel iron and the trend of blast furnace upsizing, the quality and life demand for Hot blast stove, the key supporting facility, is more stringent.
Blast furnace, hot blast furnace with low creep high alumina brick for blast furnace trough castable system adopts AI2O3-SiC-C series, it has excellent anti erosion, anti erosion, high thermal stability, it can be used in the blast furnace main channel iron line and slag line and swinging spout, residual cans, main channel and main channel cover top cover on both sides, iron slag ditch etc..