The electric arc furnace uses primarily electrical energy to supply heat to melt scrap steel, sponge iron, or. Electric furnace, heating chamber with electricity as the heat source for achieving very high temperatures to melt and alloy metals and refractories. Eaf optimization framework intended to define optimal control profiles for the eaf. The electrode column assemblies contain all facilities to hold, slip, backslip and regulate the. The furnace operating on this principle is known as direct arc furnace. Optimization of the electric arc furnace process ieee xplore. Electric arc furnace design operation and working principle. An electric arc furnace used for steelmaking consists of a refractorylined vessel, usually. 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. In the recycling industry, the recuperation of zinc from electric arc furnace dust by the waelz process generates important quantities of slag. Electric arc furnace electric arc process learn and grow. Process control in order to comply with the special requirements of the electric arc furnace, the process. Though arc furnaces are useful and can process large amounts of.
An electric arc furnace was designed and constructed to melt approximately 5kg of steelcast iron scraps, using locally produced soderberg electrodes. An electric arc furnace is a type of furnace that heats up materials using a very high current. Bessemer converter and electric arc furnace methods for manufacturing of steel pdf. In electric arc furnaces which are more common among the two processes, high voltage electric arc struck between carbon electrodes and the charge becomes the source of a very high temperature. The goal of this paper is to define the conditions required to obtain and control optimum foamy slags in the electric furnace. The use of eafs has expanded and now accounts for nearly 23 of steel production in the united states. Some twin shell furnace operations are achieving taptotap times of 35 to 40 minutes. Jun 16, 20 electric arc furnaceelectric arc furnace. Compared to the bos process, the eaf requires less chemical reaction for refining. Carbon monoxide explosion hazards in electric arc furnace steelmaking operations.
The eaf is the central process of the socalled minimills. The flexibility and easy adoptability of eaf steelmaking to. Foamy slag fundamentals and their practical application to. The story of a marine grunt in the first battle of khe sanh april 1967 duration. Two kinds of electric current may be used in electric arc furnaces. Scraps, direct reduced iron, pig iron, and additives are melted through highpower electric arcs formed between a cathode. The first electric arc furnaces eafs appeared in the late 19th century. Primetals technologies offers the right electric arc furnace to meet its customers requirements.
Productivity is a function of the net rate of energy input and percent of that input utilized for scrap melting. The interrelation of these operations is shown in a general flow diagram of the iron and steel industry in figure 1. Carbon monoxide explosion hazards in electric arc furnace. A variety of furnace types, including submerged electric arc furnaces, exothermic metallothermic reaction furnaces, and electrolytic cells can be used to produce ferroalloys.
By striking the arc between the charge and electrode. The electric arc furnace eaf has been used since the early 1900s for the efficient conversion of scrap steel to molten metal. In the electric arc furnace, the heat is generated by an electric arc. 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. Comprehensive electric arc furnace electric energy consumption. Design and prototype development of a minielectric arc furnace.
The features of eafs are described in a prior cmp techcommentarytitled introduction to electric arc furnace steelmaking tc1077. Modelling and control of an electrode system for a threephase electric arc furnace by mariuspeens submittedinpartialful. Lrf furnace pdf an electric arc furnace eaf is a furnace that heats charged material by means of an electric arc. Dec 30, 20 electric arc furnace steel making free download as powerpoint presentation. An electric arc furnace eaf is a furnace that heats charged material by means of an electric arc. Electric arc furnace an overview sciencedirect topics. May 30, 2018 an electric arc furnace is essentially a giant heatresistant kettle powered by three graphite spikes. External arc heating permits better thermal control than does the basic oxygen process, in which heating is accomplished by the.
Power control of ac arc furnaces electric principles of dc. Plants are available that combine high capacity with maximum availability, process a variety of charging materials, and produce a wide range of steel grades without long. The process of slag foaming can be simply stated as. Electric arc furnaces use highvoltage electric arcs that are bounced between three graphite electrodes to produce massive amounts of heat. Products ironmaking and steelmaking electric arc furnaces. Main melting period these furnaces use a tremendous quantity of power. In this furnace, the arc may be created by the following different ways. Ironmaking and steelmaking electric arc furnaces fastarc is the trademark for a stateoftheart electric steelmaking process technology that optimizes melt shop practices according to the available types of ferrous charge materials. Pdf modeling and simulation of an electric arc furnace. The electric arc furnace uses primarily electrical energy to supply heat to melt scrap steel, sponge iron, or mixtures of scrap and other iron units. In the electric arc furnace, steel is produced only through scrap fusion.
In this method, the heat is directly conducted and taken by the charge. Process modeling of the steel refining operation was performed. Modeling and simulation of an electric arc furnace process. Reactions that generate gas bubbles are required along with the proper slag to sustain these bubbles. Eafs are often used in steelmaking operations to produce carbon steels, as well. Direct reduction scrap ladle refining electric arc furnace steelmaking iron ore pellets electric arc furnace steelmaking continuous casting design by cover photo. Oxygen is injected through a watercooled top lance which can also be slewed. The rods which are made of graphite for its semiconductive properties heat up and create a plasma that can be directed to melt metals. Used worldwide, these furnaces are featured in minimills that recycle iron scrap for reuse. In the metallurgy of nonferrous metals, the electric smelting furnace has had a greater application for the treatment of zinc ores than in the metallurgy of any of the other nonferrous metals except aluminum the process has not been applied to any great extent because of the difficulty of condensing the zinc vapor produced in smelting in the. A resultant simplified system is identified, and directions for further study are indicated toward control of electric arc furnaces. The bos process uses pure oxygen, injected by a lance, for refining the relatively impure hot metal and scrap is used for temperature control.
Chemical energy is supplied via several sources which mainly include oxyfuel burners and oxygen injection. 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. Scrap is by far the most important resource, accounting for about 80% of all electric arc furnace metal feedstock. Process description a vim furnace is simply a melting crucible. Nov 04, 2016 electric arc furnace electric arc process learn and grow. The molten metal is then decarburized and refined in a special aod vessel to less than 0. High power rectifiers for the dc arc furnace industry the. Modelling and control of an electrode system for a three.
As a result, the term time utilization has been coined as a measurement of efficiency of a furnace. Dc arc furnaces past, present, and future rodney t. Studies were carried out on the charge material and energy required by an eaf for production of liquid steel using heuristic method. The electricity has no electrochemical effect on the metal but simply heats it. Pdf chemical and process engineering research process. Electric arc furnace heating your electrical guide. 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. Modelling and simulation of the electric arc furnace processes vito logar faculty of electrical engineering, university of ljubljana, slovenia, vito. Electric arc furnaces eaf have the capabilities required for furnaces used for metallurgical research. Oxygen in steel, electric arc furnace, electricity in eaf, eaf steel making, steel. The steel production process in an electric arc furnace can be defined in the following order. Electric arc furnaces work on the principle of the electrode forming an arc between itself and the top layer of metal to be melted. Depending on the upstream process, the slag is either. In addition, the carbon monoxide that evolves helps to flush nitrogen and hydrogen out of the metal.
An electric arc furnace eaf is a furnacethat heats charged material by means of anelectric arc. Pyrometallurgy, dc arc furnace, electric arc, smelting abstract dc arc furnaces were first used industrially for the reductive smelting of chromite fines to produce ferrochromium thirty years ago. In smelting choice of slag composition to give the optimum balance of basicity and. Investigation of electric arc furnace chemical reactions and. The detailed explanation of bessemer converter and electric arc furnace was presented below. The electric arc furnace operating cycle is called the taptotap cycle and is made up of the following operations. Electric arc furnace dust an overview sciencedirect topics. Modern electric furnaces generally are either arc furnaces or. Matte smelting can be conducted at lower melting point than metal oxide smelting. Efforts are ongoing to maximize the energy delivery rate and its effective use to achieve reduced heat times. 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.
Aod provides an economical way to produce stainless steel with a minimal loss of precious elements. Electric room operating platform cover removed crucible pouring mold car fig. 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. In this process electric arc or electric high frequency furnaces are used. These improvements to the processing of scrap steel comprised of larger more efficient and higher capacity furnaces. About onequarter of the worlds steel is produced by the electric arc method, which uses highcurrent electric arcs to melt steel scrap and convert it into liquid steel of a specified chemical composition and temperature. In most cases, the submerged electric arc furnace produces the desired product directly. At the same time, minimum network disturbance must always be guaranteed. Understanding electric arc furnace steel making operations. Dec 12, 2019 bessemer converter and electric arc furnacemethods for manufacturing of steel pdf.
Electric arc furnace eaf steel making technology is more than hundred years old. Furnace charging melting refining deslagging tapping furnace turnaround modern operations aim for a taptotap time of less than 60 minutes. Design of an experimental electric arc furnace cdc stacks. 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. It is part of a duplex process in which scrap or virgin raw materials are first melted in an electric arc furnace eaf or induction furnace.
Lecture 15 electric furnace steelmaking contents nptel. Industrial arc furnaces range in size from small units. The charge is collected directly from an open hearth furnace. The furnace has a removable watercooled lid that holds the graphite spikes and is connected to large power lines that act as electrodes.
Eaf history, process and thermodynamics of eaf steel making. 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. Eafs are often used in steelmaking operations to produce carbon steels, as. Furnaces energetic modelling of the electrical arc furnace. It may produce an intermediate product that is subsequently used in additional processing methods. Electric arc furnace steel making free download as powerpoint presentation. Directions in electric arc furnace steelmaking are towards increased clean iron unit usage, chemical upgrading of scrap to remove copper and zinc, cryogenic technologies to allow controlled scrap sizing, reduction of electrical energy usage by chemical energy input, improved practices for energy reduction. Advantages and disadvantages by koblenzer harald vucinic bojan synopsis available raw material and energy, socio economic development, industrialization level, steel export versus import policy, required product mix from steel quality point. 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. 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. These furnaces are used for production and refining of. 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.
Electric arc furnaces eafs are widely used in steelmaking and in smelting of nonferrous metals. The electric arc furnace operates as a batch melting process producing batches of molten steel known heats. 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. Matte smelting is normally carried out in a reverbatory furnace. Design and prototype development of a minielectric arc. Furnace operations the electric arc furnace operates as a batch melting process producing batches of molten steel known heats. Electric arc furnace steel making steelmaking steel. Steelmaking in electric arc furnace has emerged as an important steelmaking process in recent years. Modelling and simulation of the electric arc furnace processes. Mass analysis of an electric arc furnace eaf at a steel. Sms siemag submerged arc furnaces and electric smelters 2 for more than 100 years it has been our business and tradition to work out solutions in the field of submerged arc furnaces and electric smelters. Jones, nupro corporation courtesy of mannesmann demag corp.
During the melting process, other metals ferroalloys are added to the steel to give it the required chemical composition. Furnace descriptions and their ferroalloy products are given in table 12. A deadly but preventable problem by scott ferguson and nick zsamboky, systems spraycooled 2 o ver the past 3040 years, electric arc furnaces eafs used in steelmaking and other processes have been running longer, harder and faster as facilities. The submerged arc process is a reduction smelting operation.
An electric arc furnace eaf is a furnace that heats charged material by means of an electric. There are two methods for the manufacturing of steel which are as follows. Vacuum arc remelting var is a secondary remelting process for vacuum refining and manufacturing of ingots with improved chemical and mechanical homogeneity. Abstractthis paper presents an electric arc furnace. The electricity needed for this process is enough to power a town with a population of 100,000. In this study, a mass analysis is accomplished for an electric arc furnace at a steel company in turkey. Using oxygen reaction as electricity saving in electric arc furnace. The submerged electric arc furnace saf has proven a versatile unit in numerous metallurgical. Electric arc furnaces account for ap proximately 40 pct of the total u.
Our technology assures the success of our customers in. Overview eaf automation packages energy supply and power control for a safe and stable plant operation furnace switchgear switchyard and compensation systems for meltshop and mill, nucor. Modeling and control of an electric arc furnace cim, mcgill. Salzgitter the process shown above is illustrative only and is not designed to show the steelmaking process in detail.
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