Electric arc furnace eaf shanghai jeven technology. The chemistry of steelmaking in an electric arc furnace. This said and detailed, the chapter continues with a discussion of the co2emissions of the electric arc furnaces. The electric arc furnace is the most important scrap recycling process. Pdf aspect of design and developments in eaf researchgate. When the lid is raised, the furnace can be loaded with any. 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. Design and prototype development of a minielectric arc. Unfortunately, maintaining a predictable and consistent foamy slag for every heat has eluded many steelmakers for a long time. The decarburization process is an important source of energy. Comprehensive electric arc furnace electric energy.
Whereas the contribution from arc ignition is similar for different types of eafs, other contributions depend on furnace equipment and operation, e. The steel production of electric arc furnace eaf occupies more and more proportion in the total steel output of major industrial countries. Ac and dc eaf a modern eaf is a concentrate of technology combining knowledge from different fields, tenova offers the market some of the most advanced solutions for eafs leveraging on a holistic approach to the steelmaking process. Heavy metals dust from electric arc furnace ipcbee. Electric arc furnace the sequence of operations is similar to that in the bos furnace, except that, after charging, the charge must be melted down. Arc furnace power transformers power transformers up to 300 mva for over 40 years, ges electrical arc furnace eaf power transformers have been meeting the very high current supply needs of the steel industrys arc furnaces around the world. Ertas project and contracting department cvs makina by far, the most important engineering and construction material in the world, steel application figures prominently in many aspects of human life, from civil structures to automotive manufacture, from paper clips to refrigerators and washing machines and from aircrafts. 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. Providing secure ground protection for electric arc furnaces.
Case study of an organic rankine cycle orc for waste heat recovery from an electric arc furnace eaf. Power transformers special transformers furnace and. The fraction 0 to 8 mm of demetallized slag was used. It produces liquid pig iron for consumption in an eaf. Whether melting metal or nonmetal, dc arc furnace can save more than 20% energy than ac furnace, because melting material will be turned up from bottom following electric current just like. The situation is not the same in the emerging countries, where scrap is not always available in the required amount. Applications electric arc furnace eaf transformers are required for many different furnace processes and applications. In addition, energy is lost every time the furnace.
Providing secure ground protection for electric arc furnaces during inrush conditions dennis boyd nucor steel berkeley trevor saunders nucor steel birmingham mark lanier atlantic power sales, llc larry wright schweitzer engineering laboratories, inc. The electric arc furnace eaf has evolved into a melting reactor. May 30, 2018 an electric arc furnace is essentially a giant heatresistant kettle powered by three graphite spikes. 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. Sep 12, 2017 the socalled operating costs constitute the remaining 25 %, while the costs of energy, electrodes and refractories account for about 60 % of the latter 3.
Power transformers special transformers furnace and rectifier. The steel it produces is cast in a sixstrand continuous caster into. The sequence of making steel in an electric arc furnace. This is a very high energy process and the function of the refractory eaf roof or delta is to enclose the furnace and minimise energy losses. Abb industrial transformers has direct access to all the combined transformer. During the 20052014 period, participation of steel production via electric arc furnace was increased, for example, in italy for 12,3%, in usa for 7,5%, in russia for 14,3%, but a due to strong increase of steelmaking production in china mainly with oxygen blowing.
Comprehensive electric arc furnace electric energy consumption. Design, manufacturing, installation, sales and aftersales servicing of steelmaking machinery, nonferrous metal producing machinery, and cokemaking machinery as well as related equipment for use in japan and overseas. From manual scarfing operation scrap collection is carried out by means of. The chemistry of steelmaking in an electric arc furnace the. This study was conducted to explore the possibility of utilization of electric arc furnace eaf slag produced in bangladesh as fine aggregate in concrete blocks. Arc furnace slag was collected from a steel plant in chittagong.
Heavy metals dust from electric arc furnace cristiana zizi rizescu1, elena valentina stoian1, constata ittu1, dan nicolae ungureanu1, zorica bacinschi1 1 department of materials, equipments, installations and robotics, university valahia targoviste address. Abb industrial transformers abb industrial transformers. At the beginnig, the separate parameters that form the furnace circuit. It makes steel from what would otherwise be unsightly and environmentally damaging scrap metals. Feasibility study of bangladeshi electric arc furnace. It is well known, therefore, that a considerable amount of the energy input into the furnace is not utilized for making steel but leaves the furnace with the offgas, in the form of sensible heat and chemical heat of noncombusted carbon monoxide and hydrogen. Refining steels produced in electric arc furnace 1 both during transport and secondary treatment period, the molten metal is stirred by injecting ar gas through the porous plug thus obtaining chemical composition and temperature uniformity and the flotation of nonmetallic inclusions. Electric arc furnace eaf transformers are required for many different furnace processes and applications. Table 1 includes a sample listing of serious eaf accidents caused by steam explosions during the past two decades. Sarwat 1department of electrical and computer engineering, florida international university, miami, usa abstractmagnetic shielding in electric arc furnace eaf transformers is of a great importance for stray loss reduction.
Use the electric arc furnace steelmaking to melt recycled steel and refine the composition to produce the required new steel. The electric arc furnace eaf is a central element and the highest energy consumer in the recycled steel processing industry. Previously, this practice was prohibited because of the damage of the refractory walls and a. It features two preheating shafts for scrap drying and preheating. Electric arc furnace, eaf introduction in 2003, aim market research conducted a survey of electric arc furnace eaf steel producers in north america to characterize. Continuous offgas measurement and energy balance in. Pdf recent electric arc furnaces are equipped with ultra high power transformers to provide maximum. Carbon monoxide explosion hazards in electric arc furnace. The steel production process in an electric arc furnace can be defined in the following order. Effect of foamy slag height on hot spots formation inside. The eaf contains electric energy, with a moderate addition of chemical energy, that is used for generating the required heat for the melting of recyclable scrap. The energy input and output into the electric arc furnace can be subdivided into continuous and discontinuous parts.
Eaf heat balance comparing old and new eaf energy inputs and outputs inputs. Mass analysis of an electric arc furnace eaf at a steel. The mini mill is equipped with a quantum electric arc furnace with a tapping weight of 100 tons, a twin ladle furnace, and a twin vacuum degassing plant. The sms demag ac furnace has proven its capability worldwide at many installations since the beginning of the electric steelmaking process. Effective magnetic shielding in electric arc furnace transformers using interphase wall shunts masood moghaddami 1, arif i. The electricarc furnace eaf is a squat, cylindrical vessel made of heavy steel plates. Effective magnetic shielding in electric arc furnace. In integrated mill, iron ore is the primary raw material which is charged to blast furnace bf, whereas minimill is charged by almost 100% scrap. Minimizing these deadtimes helps to maximize the productivity of the furnace. In addition, the carbon monoxide that evolves helps to flush nitrogen and hydrogen out of the metal.
Charge is loaded from the scrapyard to the charge conveyor, where it is continuously transferred to the eaf while being preheated by offgases. Report on best available techniques bat in the electric steelmaking industry final draft. The arc is about 3000celcius and scrap steel is melted in three charges to get around 40 tonnes of steel to be further processed in the ladle furnace. The current eaf steel production has accounted for more than 30% of world steel production1. The voltasaf eaf regulator is a rack based, high speed, digital signal processor that allows any choices. Furnace rhf and submerged arc furnace saf technology. Optical emission from electric arc furnaces jultika oulun yliopisto. In this study, a mass analysis is accomplished for an electric arc furnace at a steel company in turkey. An electric arc furnace can reach temperatures in excess of 1700 degrees, with that the electric arc furnace roof is subject to exposure from various slag and metal oxides. Eaf steelmaking in north america an overview marc liebman aim market research 3380 babcock boulevard pittsburgh, pa 15237 u. Electric arc furnace eaf, scrap continuous preheating equipment, submerged arc furnace saf, ladle refining furnace lf, lrf, basic oxygen furnace bof, aod, vod vd furnace and etc for steel industry and ferro alloy. Carbon monoxide explosion hazards in electric arc furnace steelmaking operations. The main cause of temperature and composition fluctuations in the electric arc furnace eaf process is the scrap used as a raw material.
Electric steelmaking a full array of advanced and energysaving solutions finetuning eaf technology to achieve an optimum balance of charge materials, process control, cycle times, logistics, and productivity requires both indepth experience and. 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. In the first part 200 kg and 300 kg of demetallized slag were added to eaf charge. Electric arc furnace eaf we can produce one electrode and three electrodes dc electric arc furnace, this will base on the equipments producing capacity. 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. The electric arc furnace eaf is today the most common way to recycle steel from scrap. Interior of electric arc furnace enclosure showing copperblock and electrode configurations. Dust formation is strongly linked to the process which can be divided into five steps.
An electric arc furnace is essentially a giant heatresistant kettle powered by three graphite spikes. Smelting of other materials duty steel arc furnace transformers operate under very severe. Pdf case study of an organic rankine cycle orc for waste. Eaf furnace accidents have unfortunately been widespread and do not seem to be abating.
Main charging solid scrap scrap ratio 0 to 30 % up to 100 % alloy content 0 to 5 % 0 to 100 % finalccontent ca. 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. Sms group website plants all plants electric steelmaking eaf electric arc furnace the arccess family boosting your electric arc furnaces sis oxygen injection and burner system you want to boost your eaf productivity and reduce your electricity consumption. The application is less demanding for the transformer than smelting, because the arc is rather stable. Raw material may be up to 100% scrap or various mixes of hot metal, pig iron, dri hot andor cold and hbi, utilizing electrical and. Two kinds of electric current may be used in electric arc furnaces. Jul 28, 2017 the aim of this simulation is to melt raw materials to obtain between 80 and 110 tonnes of liquid steel and refine the heat to a target composition and temperature. In the recycling industry, the recuperation of zinc from electric arc furnace dust by the waelz process generates important quantities of slag. Pdf effect of foamy slag height on hot spots formation inside. Modeling of electric arc furnaces eaf with electromagnetic. In the developed world, 100% steel scrap is the most common charge. Innovative energy conservation through scrap preheating. Conventional scrap preheating systems use asymmetrical scrap charging equipment. Continuous offgas measurement and energy balance in electric arc steelmaking robert kuhn.
Electric arc furnace our refractory solutions and innovations lining wall lower part ancarbon inert gas purgingstirring plug radex dpp hearth ankerharth perramit dola wall upper part ancarbon pre wear area anker rocs hot spot ancarbon backfilling ankerfill roof center piece ankoform compac sol taphole systems bottomlateral ankertap. Electricbased steelmaking enjoys a much comfortable position than integrated classical blast. The furnace has a removable watercooled lid that holds the graphite spikes and is connected to large power lines that act as electrodes. Industrial bottom stirring systems in electric arc furnace ii. Eaf ems electromagnetic stirrer for electric arc furnace electromagnetic stirring in eaf was developed 70 years ago for the secondary reefing phase of the eaf. Comparative study for eafs reactive energy compensation methods and power factor improvement deaconu sorin ioan1, popa gabriel nicolae1, tihomir latinovic2 1 department of electrotechnical engineering and industrial informatics. Nikko has optimized the combination of furnace diameter and electrode pcd transformer capacity and strengthened the ascentdescent and rotation of furnace roof, ascentdescent of electrode, and the tilting speed of furnace body that promotes efficient melting in nikkos unique electric arc furnace. The extent of the losses depends on the furnace design, the fuel used, and the method of imparting heat to the metals.
For color version of this figure, the reader is referred to the online version of this chapter. Providing secure ground protection for electric arc. Electric arc furnace dust an overview sciencedirect topics. A reference is be made to the use of alternative raw materials. The electric arc furnace eaf offers an alternative method of bulk steel manufacture.
Other rhfsaf processes and advanced iron smelting processes are being considered by both eaf and integrated steelmakers to provide needed virgin iron units for their operations. Electric arc furnace the allrounder for steelmaking. The voltasaf arc furnace regulator is designed to provide increased smarts and improved communication capabilities. Nowadays electromagnetic stirring is the perfect tool for increasing the kinetics in the eaf and it is a proven and reliable technology with inexpensive operation. In fact, these furnaces can be found anywhere in the uk where there is a good supply of scrap. Report on best available techniques bat in the electric. Dmitri kopeliovich electric arc furnace eaf is a steel making furnace, in which steel scrap is heated and melted by heat of electric arcs striking between the furnace electrodes and the metal bath.
The paper presents procedure of stress and temperature calculations in the delta closure plates of an electric arc furnace. For instance, the mostly eafbased nafta countries are nowadays the region where the production of steel generates lower specific emissions. In order to increase the melting rate it is mandatory to increase the arc length. Ac arc furnace transformers applications electric arc furnace eaf transformers are required for many different furnace processes and applications. Eafs are often used in steelmaking operations to produce carbon steels, as well. A noticeable feature of this kind of furnace is the extra thick hearth safety lining. Todays ac furnaces are ultra highpowered furnaces with specific transformer ratings up to and more than 1 mvat.
Design of an experimental electric arc furnace cdc stacks. Ferroalloy furnaces and similar with short or submerged arc. The arcing occurs between the electrodes and the molten steel. Process conditions in eaf can vary significantly from heat to heat because there is no accurate information of scrap composition.
This slag presents good mechanical properties, and for the most siliceous slag, a high stability which would enable its use by total or partial substitution of certain granulates in civil engineering. Here, electric arc is produced between the electrodes. Comparative study for eafs reactive energy compensation. Electric arc furnace dc furnaces are gradually growing in popularity where plants are either being upgraded or new plants are being built.
Electric arc furnace roofs eafdc roof deltas precast. The electric arc furnace operates as a batch melting process producing. Tenovas consteel process involves continuous feeding and preheating of scrap charge to an electric arc furnace eaf. Pdf electric arc furnace eaf is more popular due to good quality product of alloy steels. The sharc shaft arc furnace at hlv is a 100ton, 54mw directcurrent electricarc furnace. With the improvement of eaf equipment and smelting technology, the cost of eaf steelmaking continues to decline. The furnace charge melts when an electric arc passes between the electrodes and the scrap metal. An electric arc furnace eaf is a furnace that heats charged material by means of an electric arc. To cite a few examples of the most highly publicized. Steel furnaces, mainly long arc ladle furnaces ferroalloy furnaces and similar with short or submerged arc duty steel arc furnace transformers operate under very severe conditions. It also consumes much less energy than the bos furnace. Pdf electric arc furnace eaf is more popular due to good quality product of alloy. 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.
Slag foaming in the electric arc furnace eaf has not only lowered refractory and electrode consumption, but has also had a significant impact on improving thermal efficiency and decreasing melting time. The faster it melts results in higher productivity. Electric arc furnace, eaf, electromagnetic stirring, cfd, flow modeling abstract electromagnetic stirring can play an important role in modern electric arc furnaces eaf, as they often operate far from equilibrium conditions, with taptotap times of 45 minutes or less, high electric power input and significant. Pdf electric arc furnace transformer secondary circuit. The electric arc furnace eaf, designed for steelmaking from recycled scrap iron figure 1, also coproduces between 15 to 25 kg of dust per ton of steel. Exhibit 1 compares the efficiency and metal loss for different types of furnaces. Electric arc furnace furnaces producing in excess of 200 tons per hour. Operating costs are directly related to the performance of the electrode positioning controls. Over the years, the ac furnace has been improved in design and further developed. It has a dishshaped refractory hearth and three vertical electrodes that reach down through a domeshaped, removable roof see figure. Old eaf new eaf electricity 82% 65% burners 0% 5% bath reactions 18% 30%. The past 5 years have seen increases in the supply and use of pig iron, direct reduced iron. Use of asic pig iron in the electric arc furnace eaf for. The energy consumption in eaf steelmaking has been investigated many times.
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