Working conditions of refractory for tubular furnace cover
It is well known that the lining of the furnace cover is the weak link of the whole furnace.
The refractory of furnace cover is affected by operation and structure factors. Operating factors include operation rate, maximum power consumption, oxygen volume ratio, deoxidizing furnace number ratio and slag furnace number ratio. The main structural factors are the size of furnace, the thickness of furnace cover and the distance between molten pool and furnace cover.
To sum up, factors affecting the life of furnace cover include:
(1) thermal shock. Abrupt temperature changes caused by arc heating, steel outlet and furnace cover movement;
(2) Chemical erosion. Molten steel splashes to the brick surface, causing chemical erosion and the effect of CO, CO2 and SO2 in the furnace;
(3) Arc radiation. Melting loss caused by thermal radiation from arc heating;
(4) Wear of high-speed airflow formed by high-speed dust extraction in the furnace;
(5) Under the action of self-weight, the structure of the arch roof becomes loose due to the first damage of brick joints.
The comprehensive action of these factors has great influence on the life of furnace cover. The chemical erosion is aggravated by the ultra-high temperature caused by arc radiation. The erosion of molten steel leads to the thickness reduction and structural change of refractory lining, which accelerates the spalling and damage of refractory under the action of thermal shock.
Therefore, the refractory for furnace cover is required to have good thermal shock resistance, corrosion resistance to slag splashing at high temperature, as well as good integrity, firm structure, cracking and so on.
The development trend of refractory for furnace cover is: brick → precast block → whole pouring, the specific conditions of different countries are different, the use of materials are not the same.
On 2018-08-08 11:45:46
