Carbon reactor furnace is the core equipment for producing graphite electrodes, aluminum anodes and other products. Its function is to coke the binder (such as coal tar) through high-temperature heat treatment (usually 800~1300℃) to improve the mechanical strength and conductivity of the product. Since the roasting process involves harsh working conditions such as high temperature, reducing atmosphere, volatile atmosphere erosion, etc., the selection of refractory bricks directly affects the life of the furnace, energy consumption and product quality.
Carbon reactor furnace working conditions: high temperature, high pressure, strong oxidation. According to the heating method and structure, Carbon reactor furnace are mainly divided into: ring roasting furnace (mostly used for large-scale production) and tunnel kiln (suitable for small and medium-sized or special carbon products). Ring roasting furnaces are composed of multiple furnace chambers arranged in a ring, heated by fire channels, and flue gas is recycled. The advantages are high thermal efficiency, suitable for continuous production, and large production capacity (such as aluminum anode roasting). The disadvantages are high investment and complex temperature rise curve control. The tunnel kiln products move in the kiln car and pass through the preheating, roasting and cooling zones in turn. Its advantages are precise temperature control and suitable for multi-variety production. The disadvantages are high energy consumption and high maintenance costs. Therefore, when selecting refractory bricks, the specific operating conditions of the reactor furnace must be fully considered. Under the continuous influence of high temperature, the temperature peak can rise to above 1300℃, requiring the refractory fire bricks not to soften or melt.
The selection of refractory bricks for Carbon reactor furnace requires comprehensive consideration of factors such as temperature, atmosphere, mechanical load and chemical erosion: High temperature zone (>1300℃): Silicon carbide combined with silicon nitride bricks is an ideal choice, but the cost is high. Medium temperature zone (800~1300℃): High alumina bricks have the best cost performance and need to control porosity. Anti-carburization core: low porosity (≤15%) + chemically inert material (such as SiC) is the key.
Analysis of the characteristics of each brick type of carbon roasting furnace:
Advantages of high alumina bricks: low cost and good high temperature resistance (refractory ≥1770℃).
Disadvantages: general thermal shock resistance, prone to cracking under long-term thermal stress.
Applicable: furnace wall, furnace roof and other areas not directly impacted.
Advantages of silicon carbide bricks (SiC): good thermal conductivity (15~20 W/m·K), strong thermal shock resistance, and resistance to CO/asphalt erosion.
Disadvantages: high price (3~5 times that of high-alumina bricks), slightly poor oxidation resistance at high temperatures (silicon nitride combined with SiC refractory bricks is required for optimization).
Applicable: high-temperature scouring areas such as fire channels and combustion chambers.
Advantages of lightweight insulation bricks: low thermal conductivity (0.3~0.5 W/m·K), reducing heat dissipation of the furnace body.
Disadvantages: low strength, cannot be directly exposed to high-temperature flames. Applicable: furnace insulation layer, used in combination with high-alumina bricks or castables.
The performance of Carbon reactor furnace depends on the selection of refractory materials, temperature control and maintenance management. Reasonable selection of refractory materials such as high-alumina bricks and silicon carbide bricks and optimization of roasting processes can significantly improve product quality and extend the life of the furnace body.
