Why choose a higher secondary voltage in the arcing mode?

Why choose a higher secondary voltage in the arcing mode?

First, the resistance characteristics of nickel-iron melt are that the resistance is large, and the electrode is easy to insert.

The arc smelting feature is that the melting point of the slag is higher than the melting point of the alloy.

The reduction reaction of smelting is carried out on the interface of the nickel ore melt. The heat is mainly generated at the junction of the arc and the slag layer of the material layer. The temperature of the crucible area at the bottom of the electrode paste electrode is the highest, and the temperature field in the rest of the furnace is distributed in layers.

In short, in order to control the reduction of ferrous oxide, the heat is transferred through the slag, and the selective reduction process is used to produce, and the charge mainly composed of nickel ore is in a non-melting state in the furnace. When the charge is in a non-molten or liquid state, matter moves slowly. Therefore, the resistance of the charge is large, and the conductive medium in the furnace is greatly reduced after the electric furnace slag iron is removed.

If the power supply system of low voltage and high current is adopted, the arc of the electrode end is short, and the transmission of current in the charge with little melting is severely hindered, which is prone to interruption or insufficient load.

Second, what are the benefits of high secondary voltage?

Increasing the secondary voltage can increase the arc power, the arc is elongated, the arc is easy to start, the electrode is raised, the high temperature area is moved up, and the power factor is high. It is in line with the characteristics of arc-shielding smelting process.

Third, what are the factors for choosing a high secondary voltage?

1. When the resistance is large, the voltage should be selected to be high (consistent with the resistance characteristics of nickel-iron melt).

2. When the diameter of the polar center circle is larger, the secondary voltage should be selected larger.

3. When the inner diameter of the furnace is larger, the secondary voltage should be larger.

Most of the current nickel-iron furnaces are transformed from smelting other products. From the existing information, most of the furnace parameters are calculated by the Mikulinski coefficient method.

Using the Mikulinski coefficient method, we see that choosing a high secondary voltage also seems to match the rationale for the furnace design.

It is not difficult to see from the above that it is necessary to select a high secondary voltage for arc-shielding smelting.