Four-electrode large DC submerged arc furnace is a kind of equipment used to reduce smelting ore and other raw materials in metallurgical industry.
Structural features:
Furnace body: It is usually composed of furnace shell and furnace lining. The furnace shell plays a supporting and protective role. The furnace lining is made of high-alumina bricks and other refractory materials to withstand high temperature and erosion of materials in the furnace. There is a furnace inside the furnace body to accommodate the furnace charge.
Electrode system: it has four electrodes arranged in rectangular shape. Generally, graphite electrodes or self-baking electrodes are used. The electrode is connected with the power supply through the electrode accessory system, which can realize lifting, pressure release and other operations to adapt to different production requirements.
Smoke hood: located on the top of the furnace body, it is used to collect the flue gas generated during ore smelting, prevent the flue gas from being lost to the environment and facilitate the subsequent flue gas treatment.
operational principle
The four electrodes are inserted into the furnace charge, and the alternating current transmitted by the substation is converted into direct current by the rectifying device, and the direct current is transmitted to the transformer, and then transmitted to the electrode auxiliary system by the transformer, and then transmitted to the electrode. The current enters the furnace charge through the electrode to form a main circuit between the electrode and the carbonaceous material at the bottom of the furnace, the metal aggregate in the furnace charge and the electrode, generate an electric arc to heat the furnace charge, make the furnace charge reach high temperature and generate a reduction reaction. At the same time, the carbon materials from the electrode to the furnace bottom, the carbon materials from the furnace wall and the secondary circuit back to the electrode are used to ensure the electrical balance and stable operation in the furnace.
Advantage
High-efficiency and energy conservation: DC electric heating has higher thermal efficiency, less energy loss and higher heat utilization rate, which can reduce power consumption compared with AC electric submerged arc furnace.
Environmental protection and emission reduction: due to high efficiency, the generated waste gas, waste residue and other pollutants are relatively less, and the waste gas emission can be further reduced by optimizing the furnace structure and smoke exhaust system, meeting the environmental protection requirements.
Stable operation: the electrode has good stability and is not easy to flash, making the temperature distribution in the furnace more uniform, which is conducive to stable production and improving product quality.
High utilization efficiency of electric energy: avoid induction, noise, skin effect and other problems of AC submerged arc furnace, high power factor and effective utilization of electric energy.
application area
It is mainly used in the production of iron alloy, such as smelting of silicon iron, manganese iron, chromium iron, tungsten iron, silicon manganese alloy, etc. It can also be used in the production of chemical raw materials such as calcium carbide, etc. It can process various ores and mineral powders, such as manganese ore, chrome ore, silica, manganese ore powder, nickel ore powder, etc.