Generally speaking, the conductive arm for furnace has the function of supporting large current conduction. In the previous conductive arm for the furnace, the electrode support function and the conductor function were completely separated. Generally, the conductor was partially insulated and supported on the conductive arm.
In order to meet the high-performance requirements of the conductive arm for furnace, the structure of the conductor part is particularly complex, and the use environment such as vibration and induction heating caused by high temperature, dusty gas, electromagnetic force, etc. is extremely harsh. There are many problems with maintenance.
In addition to solving these problems, reduction of reactance is often required as a research topic for large furnaces.
Conductive arms were used for the first time in France in 1960, but they were not widespread. In the early 1980s, copper-clad steel plate products were developed as regular conductive arms.
The conductive arm is different from the previous copper tube busbar structure, and a large current flows directly in the conductive arm for furnace, so that the electrode support and the conductor function are integrated. Now the conductive arm has two ways of cladding copper arm and aluminum alloy arm, and recently copper tube busbar has been almost completely replaced by the conductive cross arm.
The conductive arm is very simple in construction, the secondary conductor part is particularly strong and reliable, and the reactance is sufficiently reduced. In the retrofit of existing furnaces, the arc power is increased due to the reduction of conductor resistance and reactance, and the effect of shortening T-T time and improving productivity has been achieved.
Due to the lightness of the device, the aluminum alloy arm further improves the speed and control performance of the electrode lifting. Due to the vibration attenuation, the stability of the arc can be improved, and the arc power can be increased. This is the reason why aluminum alloy arms should be used instead of copper-clad steel arms to be discussed in this article.
When our existing furnaces use conductive arms, the existing related equipment, such as the capacity of furnace transformers or load impact control devices, cannot achieve the expected increase in input power and productivity.
Therefore, it is necessary to evaluate the effect of the whole system in advance before using the conductive arm for furnace.