Top charging Electric arc furnace with National patent technology

    Steel making method by heating furnace charge with heat effect of electric arc. The alternating current is fed into the furnace through three graphite electrodes, and an electric arc is generated between the lower end of the electrode and the metal material. The furnace charge is directly heated by the high temperature of the electric arc, so that the steel making process can be carried out. Electric arc furnace steel making takes scrap steel as the main raw material. According to different furnace lining materials and slagging materials, there are alkaline method and acidic method. The most commonly used method is the alkaline method. Electric energy is used as the heat source for arc furnace steel making, which avoids the pollution of sulfur contained in gas heat source to steel; Flexible operation process, slag and furnace gas can be adjusted into oxidizability or reducibility; Strong reducing property can minimize the burning loss of valuable elements such as chromium, nickel, tungsten, molybdenum, vanadium and titanium contained in the furnace charge; High furnace temperature and easy control; High product quality. 
        Electric arc furnace steel making is a method that electric energy is input into the electric arc furnace through graphite electrode, and the electric arc between the electrode end and the furnace burden is taken as the heat source for steel making. With electric energy as the heat source, the arc furnace can adjust the atmosphere in the furnace, which is very beneficial to smelting the steel with more readily oxidizable elements. It was used for smelting alloy steel soon after its invention. And has been greatly developed. With the improvement of electric arc furnace equipment and smelting technology, the development of electric power industry, the cost of electric furnace steel is continuously reduced. Now, electric furnaces are not only used to produce alloy steel, but also a large number of ordinary carbon steel. The proportion of their output in the total output of steel in major industrial countries is increasing.
The origin of arc furnace steel making dates back to 1853, when the French Pisson used two horizontal electrodes to indirectly heat the molten metal by arc over the molten pool. In 1879, Siemens (K.W.Siemens) used an upright electrode to directly generate an arc with the metal molten pool to heat the molten pool. In 1899, someone in the United States tried the method of directly heating the molten pool with two vertical electrodes, but the DC power supply was still used, and the power was not enough to melt the scrap steel, so it was not used for production. The prototype of modern electric arc furnace for steel making is P.L.T. Herault electric arc furnace - three-phase alternating current electric arc furnace appeared in America in 1907. Due to its high power, flexible process, scrap steel as raw material and high product quality, it has won the market and then been promoted to various countries.
     Electric arc furnace steel making is the main method to produce medium and high alloy steel and high quality steel. Ordinary carbon steel produced by electric arc furnace has an increasing share in the market in developed industrial areas with abundant and cheap electric energy and scrap steel resources. With the development of industry and technology, the demand for alloy steel and high-quality steel continues to increase. By the end of 1980s, the annual output of arc furnace steel accounted for about 30% of the world's total crude steel output (see Table 1). Due to different resources, technologies and social conditions in different countries, the output of electric furnace steel fluctuates occasionally, but the growth momentum remains unchanged. By the end of the 20th century, the world's share of arc furnace steel will reach 35%. In 1980s and 1990s, the capacity of electric arc furnaces was 40~120t, and 200t electric arc furnaces were also common. The maximum capacity of electric arc furnaces was 400t. However, 75% of the output of electric arc furnaces in the world came from the so-called "small steel mills", that is, steel mills with continuous casting machine and small rolling mill with an annual output of 50000t~25000t.
           The basic process of electric arc furnace steel making includes slag raking, charging, power transmission, melting, oxidation, reduction refining and tapping. sectd  psz9  linex0  headery709  footery709  colsx425  colsx425  endnhere  sectlinegrid312  sectdefaultcl  sftnbj. There are different operation methods according to the characteristics of the steel types to be smelted. The traditional process mainly has three stages of operation: melting, oxidation and reduction. The reduction period adopts diffusion deoxidation and precipitation deoxidation, and white slag or carbide slag shall be produced. Each furnace requires 3-4h smelting, and the power consumption is up to 600-700kWh/t. With the continuous development of technology, the steel making process of electric arc furnace has also undergone great changes. Auxiliary energy is used to accelerate the melting during the melting period, such as blowing oil – oxygen, natural gas – oxygen or pulverized coal – oxygen. The melting time of each furnace is shortened by 15~20min, and the power consumption can be reduced by 50~60kWh/t; Measures such as dephosphorization in advance, strengthening oxygen consumption, powder spraying for foaming slag and rapid temperature rise can be taken during the oxidation period to reduce the amount of oxidation and decarbonization from 0.3% of the traditional process to 0.1% - 0.15%, thus the oxidation period can be shortened by more than 50%. In the reduction period, the traditional process is changed from diffusion deoxidation to precipitation deoxidation, supplemented by diffusion deoxidation, which can not only achieve the expected refining effect, but also ensure the steel quality and shorten the reduction time by over 60%. While the quality of molten steel is guaranteed, the production rate is increased by about 20%, the power consumption is reduced by 10% - 15%, and the electrode consumption is reduced by about 8%, so as to obtain considerable economic benefits.

HX 系列三相炼钢电弧炉基本参数

HX series three-phase steel making electric arc furnace
Main application: smelting ordinary steel, high-quality carbon steel and various alloy steel, stainless steel.
Equipment features: HX series electric arc furnaces are charged by screwing off the furnace cover. Divided into ordinary power, high power and ultra-high power according to power matching; It can be divided into two types: do operation and right operation; The tapping form is divided into tapping slot tapping and eccentric bottom tapping.
Equipment composition: furnace body, short network, tilting mechanism, electrode lifting mechanism, furnace cover lifting and rotating mechanism, water cooling system, hydraulic system, high-voltage system, electric furnace transformer, low-voltage system automation control system, etc.