How to Prolong the Lifespan of Graphite Anode Plates

Graphite materials are highly versatile and increasingly recognized for their excellent properties, making them suitable for various applications. Among these, graphite anode plates are widely used. However, like all materials, graphite has a finite lifespan. To maximize the lifespan of graphite anode plates, consider the following precautions:

Control Current Load:

1. The higher the current applied to the graphite plate, the higher its surface temperature. Use the smallest possible surface load density (power) to avoid overheating.
2. Note that the recorded values at the cold end of the graphite plate (current and voltage at 1000°C in air) may not align with actual usage conditions. Typically, the surface power is determined by the relationship between the furnace temperature and the plate’s surface temperature. It’s recommended to use surface power at 1/2 to 1/3 of the graphite plate’s limit density (W/cm²).

Parallel Connection:

1. Whenever possible, connect graphite plates in parallel. If the resistance values of the graphite plates differ, connecting them in series can lead to a concentrated load on the plate with higher resistance, causing a rapid increase in resistance and a shorter lifespan.

Oxidation Protection:

1. When heated in air, a dense silicon oxide film forms on the surface of the graphite plates, acting as an anti-oxidation protective layer and extending their lifespan.
2. In recent years, various coatings have been developed to prevent cracking and are used in furnaces with different gases. These coatings help lubricate and protect the graphite plates.

Temperature Distribution:

1. The temperature distribution characteristic of graphite plates should be carefully monitored. For new shipments, the temperature difference within the effective heating length should be within 60°C to be considered acceptable. Over time, this distribution may widen to 200°C as the plates age.
2. The specific temperature distribution may vary based on furnace atmosphere and operational conditions.

Gradual Resistance Increase:

1. When using graphite plates continuously, aim to increase the resistance slowly to maintain a longer lifespan.

Temperature Management:

1. The higher the operating temperature, the shorter the lifespan of the graphite plates. When the furnace temperature exceeds 1400°C, the oxidation rate accelerates, reducing the plates’ lifespan. During use, avoid allowing the surface temperature of the graphite plates to become too high.

Given the wide use of graphite due to its excellent properties, it is essential to follow proper usage guidelines to ensure the longest possible lifespan for graphite anode plates. Adhering to these precautions can help maximize their efficiency and durability in industrial applications.