Outstanding merits of shaft electric arc furnace:
1) Scrap entered from top into shaft in batches. High temperature flue gas and scrap flowed reversely. Effect of scrap preheating is obvious. Due to the reduction of the weight of each batch of scrap steel and the reduction of scrap¡¯s standing time on shaft finger. The possibility of bonded scrap steel is eliminated. Meanwhile, shock of scrap steel on finger is reduced.
2) Lower fingers in the furnace can lift to avoid the damage caused by the falling of scrap steel.
3) The charging basket enters closed chamber firstly before it enters into shaft. Scrap steel is added into shaft in fully sealed condition. So, when adding scrap, escape of fume and dust is avoided. It is very helpful to environmental protection.
4) Vibrating continuous feed and 50% of remaining steel capacity is adopted to ensure the condition of molten pool. Electric arc doesn¡¯t contact with materials of steel. Electric arc is stable. Fluctuation and flicker of voltage is sharply reduced. Noise is very low.
5) Because there is no direct contact between electric arc and scrap steel, volatile substance is reduced. The amount of dust is reduced because of filtration of scrap to flue gas. It lays the foundation of dedusting system.
6) Due to reduction of volatile substance and the control of foaming slag, the iron recovery is increased 1.5-2.0%.
7) The rotary operation of furnace lid is not to reduce subsidiary operation time. Radiation heat of rotating furnace lid is avoided.
8) High impedance technology is adopted to improve the secondary voltage and to reduce the secondary current. Consumption of effective power is reduced 6-8%. Weight of short net system is effectively relieved.
9) Device configuration is concise and reasonable. It overcomes the shortages such as taking up large area, too much height of shaft plant. Thus, the cost of investment is lowered. |