Generally, the busbar between the output end of the DC graphitization furnace rectifier cabinet and the conductive electrode of the furnace head is called a short net, and the busbar used in the graphitization furnace is generally rectangular. The busbar of the graphitization furnace is made of copper and aluminum. Copper has high mechanical strength, good electrical conductivity and strong corrosion resistance. Aluminum is slightly less conductive, but aluminum is relatively cheaper and has a lighter weight.
Table 3-2 Relevant performance data of copper and aluminum
| 材 料 | 比重 | 极限强度（MPa） | 电阻率（µΩm） | 电阻的温度系数（1/℃） |
| 紫 铜 | 8.9 | 220 | 0.016 | 4.3×10-3 |
| 铝 | 2.7 | 110 | 0.025 | 4.7×10-3
|
Since the furnace resistance of the graphitization furnace is small, especially in the later stage of power transmission, the furnace resistance becomes smaller, and the pressure drop of the short net is increased, resulting in an increase in power loss. Therefore, whether the graphitization furnace can operate safely and economically has a close relationship with the characteristics of the short net.
The most basic principle is to minimize the impedance of the short net and keep the entire short net with a small pressure drop. There are various contacts in the short mesh of the graphitization furnace. If there is contact between the conductive electrode and the copper bus, the contact between the copper soft bus and the aluminum bus, the contact between the aluminum bus, etc., these contacts will produce contact resistance, affecting the characteristics of the entire short net. The contact resistance of a conductor having a connection point depends not only on the nature of the material, but also on the contact area and contact pressure at the time of contact connection. For this reason, the most basic one when connecting the busbars is: the polishing is tight.
Table 3-3 Contact resistance of 1cm2 graphite and 1cm2 metal
The most basic principle is to minimize the impedance of the short net and keep the entire short net with a small pressure drop. There are various contacts in the short mesh of the graphitization furnace. If there is contact between the conductive electrode and the copper bus, the contact between the copper soft bus and the aluminum bus, the contact between the aluminum bus, etc., these contacts will produce contact resistance, affecting the characteristics of the entire short net. The contact resistance of a conductor having a connection point depends not only on the nature of the material, but also on the contact area and contact pressure at the time of contact connection. For this reason, the most basic one when connecting the busbars is: the polishing is tight.
Table 3-3 Contact resistance of 1cm2 graphite and 1cm2 metal
| 压力 | 石墨–石墨µΩ | 石墨—铜µΩ | 石墨—铝µΩ |
| 0.2 | 70 | 100 | 6000 |
| 0.5 | 40 | 70 | 2600 |
| 1 | 25 | 50 | 1300 |
| 2 | 14 | 32 | 500 |
| 4 | 7.5 | 16 |
Table 3-4 Contact resistance of 1cm2 carbon and 1cm2 metal
| 压力 | 炭–炭µΩ | 炭—铜µΩ | 炭—铝µΩ |
| 0.05 | 750 | 2100 | 20000 |
| 0.1 | 520 | 1800 | 16000 |
| 0.2 | 380 | 1400 | 10000 |
| 0.4 | 290 | 850 | 4000 |
| 0.6 | 250 | 600 | 1700
|
Post time: Sep-16-2019