May 30, 2018 an electric arc furnace is essentially a giant heatresistant kettle powered by three graphite spikes. The electric arc furnace temperature of the molten metal is around 2970f, but alarmingly the temperature of the arc is something in the region of 1f. The main parts of electric furnace are the roof, hearth lower part of a furnace, where molten metal is collected, electrodes, and side walls. The heat energy is primarily generated by the burning arc between the electrodes and the scrap, or its melt. Eafs use highpowered electric arcs for melting scrap along with oxygen reactions in the heat for meltingrefining scrap into steel. The liquid hot metal that is produced by the furnace can be used as hot metal feed for an electric arc furnace eaf or the hot metal can be directly cast as pig iron using a pig casting machine. Most eaf articles and videos i have seen describe threephase megawattscale equipment used at recycling plants. These devices are highly nonlinear loads the current waveform of which is characterised by an increasing arc current limited only by the network impedance. Steel cost modelling notes the steel costing model the economic model shown above is prepared only to shown how liquid steel cost can be calculated through a simple cost benchmarking type approach. Electric arc furnace method for manufacturing of steel. Electric arc furnace design operation and working principle.
Eafs typically melt and refine scrap at around 2,900f, with capacities over 100 tons. They are roughly 25 feet in diameter, with a volume of 6,630 cubic feet. Comprehensive electric arc furnace electric energy consumption. Electric arc furnace refractories steel production resco products. They use a lot less energy than blast furnaces and can be quickly. An electric arc furnace eaf is a furnace that heats charged material by means of an electric arc industrial arc furnaces range in size from small units of approximately one ton capacity used in foundries for producing cast iron products up to about 400 ton units used for secondary steelmaking. Pdf a simulator and an algorithm for the automatic creation of operation. The furnace exploded and emitted hot steam and flying debris, blowing out. Department for industrial furnaces and heat engineering, rwth. Electric arc furnace means an extremely hot enclosed space, where heat is produced by means of electrical arcing for melting certain metals such as scrap steel without changing electrochemical properties of the metal. The power of these furnaces is used to melt scrap quickly for the production of a wide variety of steels. As a result, the term time utilization has been coined as a measurement of efficiency of a furnace. Hot briquetted iron beyond the electric arc furnace. As a global partner to the steel industry, calderys offers a complete range of high grade refractories and.
Scraps, direct reduced iron, pig iron, and additives are melted through highpower electric arcs formed between a cathode. The hot dusty gas generated from the furnace causes a strong heat con. The direct reduction process uses pelletized iron ore or natural lump ore. In the electric arc furnace, steel is produced only through scrap fusion. Electric arc furnaces, arc welders and electric discharge lamps are all forms of electric arcing device. Having little or no heat can be tricky to diagnose.
Providing secure ground protection for electric arc furnaces. Arc furnace range in size from small units of approximately one ton capacity up to 400 tons. The hot dusty gas generated from the furnace causes a strong heat convection. Electric arc furnace is a furnace that heats the charged material by mean of an electric arc. Furnace switchgear the furnace switchgear solution is perfectly adapted even for the extreme requirements of ultra highpower arc furnaces. This is where the application of prebaked graphite electrodes in a dc arc furnace came about. Diagram of an arc furnace the advantage of arc furnaces is that they use scrap metal rather than iron ore as the main fuel.
The furnace operating on this principle is known as direct arc furnace. Electric arc furnace eaf systems spraycooled the systems. Highimpedance furnace today, highimpedance furnaces are state of the art. About onequarter of the worlds steel is produced by the electricarc method, which uses highcurrent electric arcs to melt steel scrap and convert it into liquid steel of a specified chemical composition and temperature.
The arc furnace shown in figure 2 is one of two 140 mw dc arc furnaces. The roof consists of three holes through which the electrodes are inserted. These improvements to the processing of scrap steel comprised of larger more efficient and higher capacity furnaces. Optimization of the electric arc furnace process ieee xplore. An electric furnace can be a convenient way to heat a home. The first benefit is that the use of electric arc furnace allows steel to be made from a 100% scrap metal feedstock. The electric arc furnace eaf has been used since the early 1900s for the efficient conversion of scrap steel to molten metal. Understanding electric arc furnace steel making operations. Electric arc furnace an overview sciencedirect topics.
The eaf performance was evaluated in terms of heating and melting rate, transformer efficiency. Electric based steelmaking enjoys a much comfortable position than integrated classical blast. Whats the difference between a blast furnace and an arc. There is a broad variety of steel scrap, both in terms of composition from plain carbon steel through to highly alloyed tool steel and geometry from finely shredded sheet through to. Nonetheless, further improvements of the eaf operation are possible using different additives and heat recovery systems 9, 10 as well as. Tetronics testwork, and the scaleup potential of aseas dc arc furnace. Jones, nupro corporation continued furnace charging melting refining deslagging tapping furnace turnaround top refining refining operations in the electric arc furnace have traditionally involved the removal of phosphorus, sulfur, aluminum, silicon, manganese and carbon from the steel. The electric arc furnace eaf process is the main process for recycling of ferrous scrap 1 and the second most important steelmaking process route in terms of global steel production 2. Sep 18, 2015 ho scale model animated with sound and lighting effects.
In the electric arc furnace, the heat is generated by an electric arc. In this furnace, the arc may be created by the following different ways. Most of the reduction reactions taking place in the submerged arc furnace are highly endothermic and are listed in table 1. External arc heating permits better thermal control than does the basic oxygen process, in which heating is accomplished by the. The furnace has a removable watercooled lid that holds the graphite spikes and is connected to large power lines that act as electrodes. J stones, in electrical engineers reference book sixteenth edition, 2003. Hot direct reduced iron hdri is dri that is transported hot, directly from the reduction furnace, into an electric arc furnace, thereby saving energy. An electric arc furnace eaf, firebricklined ushaped, magnesia carbon brick, slagline. The arc furnaces are sized for 165 tapping tons, while carrying a 33ton heel. Electric arc furnace eaf steel making technology is more than hundred years old. As a global partner to the steel industry, calderys offers. Aug 09, 2018 electric arc furnace means an extremely hot enclosed space, where heat is produced by means of electrical arcing for melting certain metals such as scrap steel without changing electrochemical properties of the metal.
It has a wide range of properties that are largely determined by its chemical composition carbon and other alloying elements. Arc furnaces range in size from small unitsof approximately one ton capacity used infoundries for producing cast iron productsup to about 400 ton units used for secondarysteelmaking 3. When something goes wrong, it can become a nightmare. Electric arc furnace melting is the primary method of manufacture in steel foundries. An electric arc furnace eaf is a furnacethat heats charged material by means of anelectric arc. Hbi has for long been perceived, primarily and correctly, as a metallic feedstock material for the eaf. Ho scale model animated with sound and lighting effects.
The furnace is similar to traditional electric furnaces in that it utilizes electrodes for the melting process. Progress of emission control system in electric arc. An electric arc furnace eaf, aka carbon arc furnace caf, melts metal with an arc between movable carbon electrodes and the charge metal in a conductive crucible. Arc furnaces used in research laboratories and by dentists may have a capacity of only a few. Providing secure ground protection for electric arc. Design and prototype development of a minielectric arc. The predicted total costing shown is not meant to represent an actual cost for any real steel company.
The furnace is equipped with one set of electrodes which are connected to a transformer and can be slewed alternatively to each of the two shells. Most modern furnaces are equipped with watercooled panels in the upper half of the sidewall, rather than refractories, which allow for longer arcs and higher energy input to the furnace. However, hbi offers potential for use as a blast furnace burden material under certain conditions, a potential that has been evaluated and exploited by. Typical design requires different materials for the bottom, lower sidewall and upper sidewall cold and hot spots. Over the years, the ac furnace has been improved in design and further developed. How eaf steam explosions occur in the fatal accidents described above, and in many others documented as well, there is a common denominator. The electric arc furnace is mostly accepted by steel making companies, thus a large quantity of graphite electrode are consumed. Design and prototype development of a minielectric arc furnace.
Development of an electric arc furnace simulator based on. The sms demag conarc furnace combines the conventional converter process with electric arc steelmaking in a furnace with two identical shells. The hot metal product from bfs and smelting reduction processes, and dri contain unwanted elements. In this method, the heat is directly conducted and taken by the charge. If you know how to troubleshoot properly, you can save yourself time and money. China electric arc furnace manufacturers select 2020 high quality electric arc furnace products in best price from certified chinese boiler manufacturers, electric shock suppliers, wholesalers and factory on. Troubleshooting common problems with your electric furnace. The sounds are an edited recording of an actual eaf in operation. Furnace turnaround this technical document will focus primary on furnace charging, melting, and refining, and will discuss these operations in detail in the sections that follows. The model was first displayed at the 2015 steel mill modelers meet in. Mar 05, 2015 zinc has a relatively low melting point 787. Tests were carried out on the eaf to assess its operation and evaluate its performance. Subsequently, the arc is lengthened by increasing the voltage to maxi mum power.
Eaf, electric, arc, furnace, electric steelmaking, electric arc furnace. Electric arc furnace of minimizing the time between tap and the subsequent power on as well as maximizing the energy input per minute from power on to tap. Electric arc furnace heating your electrical guide. Tenova melt shops business line supplies also tailormade melting solution for special purposes such as the recovery of precious metals from waste and the production of ceramic materials. Co 2 abatement in the iron and steel industry 5 steel is basically an alloy consisting of iron, 0. Here, electric arc is produced between the electrodes. These are removed in the basic oxygen furnace bof or electric arc furnace eaf. When the lid is raised, the furnace can be loaded with any combination of iron scrap, iron ore, flux and. Products ironmaking and steelmaking electric arc furnaces. Progress of emission control system in electric arc furnace. Pdf electric arc furnace as thermoenergetical unit. Hotbriquetted iron hbi is a compacted form of dri designed for ease of shipping, handling and storage.
The fundamental laws and calculating formulae of heat transfer processes. Type of fume collection system, types of steel produced, total nominal capacity of each eaf 000 metric tonsyear, hot heel % of the heat size keywords. The melt charge consists of a combination of recycled manganese castings, gates, and feeder heads plus lowphosphorus ferromanganese, silicomanganese, and. The dri melter can be designed to operate in either a smelting or melting mode. For electric arc furnaces calderys is committed to providing complete refractory solutions for the electric arc furnace eaf, tailored to speci. Advantages of electric arc furnace for steelmaking hgraphite. Use of hot riquetted iron hi in the electric arc furnace eaf for steelmaking steel production in the eaf continues to grow both in north america and worldwide. The electric arc furnace eaf process is the main process for recycling. A normal melt of 100t would take just over an hour to complete, using about 400kwh of power. By striking the arc between the charge and electrode. The roof and electrodes are raised and are swung to the side of the furnace to allow the scrapcharging crane to move a full bucket of scrap into place over the furnace.
These furnaces are used for production and refining of. Submerged arc furnace an overview sciencedirect topics. A reference is be made to the use of alternative raw materials, as drihbi, pig iron and hot metal. Use of hot riquetted iron hi in the electric arc furnace. In relation with the eaf design, factors to be analyzed are the. Dec 12, 2019 electric arc furnace method for manufacturing of steel. Electric arc furnace innovation addressing the technology challenges electric arc furnace innovation addressing the technology challenges steel industry series table 1 key innovation challenges for low carbon eaf steelmaking currently in the design phase, a technology demonstrator is planned, utilising the institutes 7t pilot scale eaf and. Some things will require a professional, while others can be easily fixed with a few simple tools. Since then, that concept has been applied in a number of areas.
Eaf electric arc furnace eu european union fb fluidised bed. The second world war saw a steep increase in the use of these furnaces leading to the modern electric arc furnace design operation and working principles. Electric arc furnace steelmaking costs 2020 conversion costs for electric arc steelmaking. An electric arc furnace is essentially a giant heatresistant kettle powered by three graphite spikes. The past 5 years have seen increases in the supply and use of pig iron, direct reduced iron dri, and hot riquetted iron hi in the eaf. A basic lined furnace is necessary since the manganese slag will readily attack acid refractories. Carbon monoxide explosion hazards in electric arc furnace. Energy recovery hot water cooling system scrap preheating influence of various process parameters to the electric energy demand of eaf 4 in this paper, we investigate empirical models to. An electric arc furnace is a typical batch melter with repeated cycling of operations that include a roof opening, scrap charge, roof closing, melting, refining, tapping, and repair in about an hour. Water leaks into a hot furnace in large enough quantities to become superheated and trigger a violent steam explosion. The iron content of the metallic charge is the determining factor when. Todays ac furnaces are ultra highpowered furnaces with specific transformer ratings up to and more than 1 mvat.