Consumption Principle Of Graphite Electrode In Arc Furnace
Consumption Principle of Graphite Electrode in Arc Furnace
Graphite electrodes are the last part of the electric arc furnace power supply network. The end of the graphite electrode generates a robust electric arc to heat the molten steel in the furnace charge. That is, the electrodes are the central hub that converts electrical energy into heat. When working, the electrode is subjected to high temperature and the furnace gas is oxidized. There is also the impact of subsidence and impact, especially where the two electrodes are connected. The resistance is higher than in other places, the conductivity is low, and it is easy to oxidize, fall off, and break off, which will harm the electrode. Increased smelting time and decreased production efficiency.
Regarding the consumption of graphite electrodes, it can be divided into the consumption of graphite electrode ends and surfaces in electric furnaces, the consumption of graphite electrode residues generated during smelting, and the oxidation and peeling of electrode surfaces accompanied by cracking. Direct loss is caused by broken electrodes. No matter which part of the graphite electrode is consumed, it can be divided into two categories: physical and chemical consumption. Physical consumption includes electrode loss caused by mechanical and electromagnetic forces such as electrode breakage and shedding, and chemical consumption mainly has electrode consumption caused by high-temperature oxidation of electrodes and slag corrosion.
During the steelmaking process of graphite electrodes, due to the high ambient temperature, the electrode surface reacts with oxygen to form carbon and oxygen. Graphite electrodes are stable at low temperatures and are easily oxidized at high temperatures. Generally, carbon products oxidize at about 450°C in the air. Graphite products with a high degree of graphitization begin to oxidize at about 600°C, and the oxidation increases sharply after 750°C, which increases with the increase in temperature. It is oxidized when heated to 900°C in water vapor. That is to say, the main factors affecting the oxidation of graphite electrode side are high temperature and oxidizing atmosphere, that is, electrode oxidation consumption, especially with the successive application of new technologies such as furnace door oxygen lance, oil oxygenation, EBT cluster and other new technologies such as oxygen lance and furnace wall oxygen lance. The intensity of the oxygen supply in the furnace increases and the oxidation atmosphere is strengthened, which further increases the electrode consumption. In addition, since the electrode tip is in direct contact with the arc, the tip electrode consumes a lot. The electrode part is in contact with the molten pool, and the carbon element molten pool is eroded and absorbed. The electrode part is in contact with the molten pool, and the carbon element is eroded and absorbed by the molten pool The electrodes are impacted by electromagnetic force, mechanical force, and solid raw materials during operation, causing breakage and huge consumption.