What kind of refractory bricks are suitable for cupola furnace lining?
Cupola furnaces are equipment used in foundries to melt cast iron. The furnace lining requires the use of refractory bricks with high refractory properties to withstand high temperatures and chemical corrosion. What kind of refractory fire bricks are suitable for cupola furnace lining?
Cupola furnace consists of: front furnace and back furnace. The forehearth is divided into a taphole, a slag outlet, a hearth in front of the furnace cover and a bridge. The back furnace is divided into three parts, the top furnace, the waist furnace and the hearth.
Common refractory bricks materials used for cupola furnace linings include: clay bricks, high alumina bricks, corundum bricks, etc. The working temperature of the cupola furnace: the furnace bottom and hearth parts are 1400-1500°C; the combustion zone temperature is as high as 1400-1600°C; the preheating zone is 800-1200°C; and the temperature near the charging port is 300-500°C.
Refractory bricks for cupolas also suffer from the erosion of molten slag and the effects of sharp temperature changes between open and closed air. Furnace gas contains a large amount of reducing gases. The CO2 content is about 10%. According to the working environment of the cupola, the refractory material must be selected to meet the working temperature conditions, have good wear resistance, thermal shock resistance, and resistance to molten iron and slag erosion.
The tuyere zone and slag zone are easily damaged due to the effects of high temperature, slag and air flow, so high alumina refractory bricks or magnesia bricks with good corrosion resistance must be used, or high-strength corundum bricks can be used.
The working layer of the rest of the furnace body generally uses high-strength clay bricks or semi-silica bricks, and high-alumina bricks can also be used.
The insulation layer of the furnace body is generally made of clay insulation bricks or new lightweight bricks.
When selecting refractory bricks, the specific working conditions, temperature, atmosphere and chemical composition of the material of the cupola need to be considered to ensure that the selected refractory bricks can meet the requirements and have a long service life.
