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.
