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. 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. An electric arc furnace eaf is a furnacethat heats charged material by means of anelectric arc. The submerged arc process is a reduction smelting operation. In smelting choice of slag composition to give the optimum balance of basicity and. Carbon monoxide explosion hazards in electric arc furnace. 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. Productivity is a function of the net rate of energy input and percent of that input utilized for scrap melting. Lecture 15 electric furnace steelmaking contents nptel. Abstractthis paper presents an electric arc furnace. An electric arc furnace eaf is a furnace that heats charged material by means of an electric arc. The interrelation of these operations is shown in a general flow diagram of the iron and steel industry in figure 1. The detailed explanation of bessemer converter and electric arc furnace was presented below.
Modelling and simulation of the electric arc furnace processes vito logar faculty of electrical engineering, university of ljubljana, slovenia, vito. Furnace charging melting refining deslagging tapping furnace turnaround modern operations aim for a taptotap time of less than 60 minutes. Aod provides an economical way to produce stainless steel with a minimal loss of precious elements. The furnace has a removable watercooled lid that holds the graphite spikes and is connected to large power lines that act as electrodes. Scrap is by far the most important resource, accounting for about 80% of all electric arc furnace metal feedstock. Foamy slag fundamentals and their practical application to. These furnaces are used for production and refining of. 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 three. In addition, the carbon monoxide that evolves helps to flush nitrogen and hydrogen out of the metal. Chemical energy is supplied via several sources which mainly include oxyfuel burners and oxygen injection. Investigation of electric arc furnace chemical reactions and. Studies were carried out on the charge material and energy required by an eaf for production of liquid steel using heuristic method. Furnace descriptions and their ferroalloy products are given in table 12. 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. Using oxygen reaction as electricity saving in electric arc furnace. As a result, the term time utilization has been coined as a measurement of efficiency of a furnace. The operation begins with a delivery of steel scrap to the scrap bay, located at one end of the eaf building. 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. An electric arc furnace is a type of furnace that heats up materials using a very high current. Efforts are ongoing to maximize the energy delivery rate and its effective use to achieve reduced heat times.
These improvements to the processing of scrap steel comprised of larger more efficient and higher capacity furnaces. 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. Electric arc furnace eaf steel making technology is more than hundred years old. Process description a vim furnace is simply a melting crucible. The decarburization process is an important source of energy. Eaf optimization framework intended to define optimal control profiles for the eaf. The steel production process in an electric arc furnace can be defined in the following order. In most cases, the submerged electric arc furnace produces the desired product directly. In this method, the heat is directly conducted and taken by the charge. Modeling and control of an electric arc furnace cim, mcgill. Comprehensive electric arc furnace electric energy consumption. 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.
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. Dc arc furnaces past, present, and future rodney t. Power control of ac arc furnaces electric principles of dc. 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. 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. Jones, nupro corporation courtesy of mannesmann demag corp. Salzgitter the process shown above is illustrative only and is not designed to show the steelmaking process in detail. High power rectifiers for the dc arc furnace industry the. By striking the arc between the charge and electrode.
The rods which are made of graphite for its semiconductive properties heat up and create a plasma that can be directed to melt metals. The bos process uses pure oxygen, injected by a lance, for refining the relatively impure hot metal and scrap is used for temperature control. Eaf history, process and thermodynamics of eaf steel making. A variety of furnace types, including submerged electric arc furnaces, exothermic metallothermic reaction furnaces, and electrolytic cells can be used to produce ferroalloys.
Dec 12, 2019 bessemer converter and electric arc furnacemethods for manufacturing of steel pdf. 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. The eaf is the central process of the socalled minimills. The story of a marine grunt in the first battle of khe sanh april 1967 duration.
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. Process modeling of the steel refining operation was performed. An electric arc furnace was designed and constructed to melt approximately 5kg of steelcast iron scraps, using locally produced soderberg electrodes. The electrode column assemblies contain all facilities to hold, slip, backslip and regulate the. Modeling and simulation of an electric arc furnace process. Bessemer converter and electric arc furnace methods for manufacturing of steel pdf. A resultant simplified system is identified, and directions for further study are indicated toward control of electric arc furnaces. Electric arc furnace design operation and working principle. The electric arc furnace uses primarily electrical energy to supply heat to melt scrap steel, sponge iron, or. The electricity needed for this process is enough to power a town with a population of 100,000. Two kinds of electric current may be used in electric arc furnaces. Modelling and control of an electrode system for a threephase electric arc.
External arc heating permits better thermal control than does the basic oxygen process, in which heating is accomplished by the. Modelling and control of an electrode system for a threephase electric arc furnace by mariuspeens submittedinpartialful. Electric arc furnaces eafs are widely used in steelmaking and in smelting of nonferrous metals. 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. Design of an experimental electric arc furnace cdc stacks. The electric arc furnace operates as a batch melting process producing batches of molten steel known heats. 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. May 30, 2018 an electric arc furnace is essentially a giant heatresistant kettle powered by three graphite spikes. Electric arc furnace steel making steelmaking steel. Steelmaking in electric arc furnace has emerged as an important steelmaking process in recent years. 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.
Pdf chemical and process engineering research process. Process control in order to comply with the special requirements of the electric arc furnace, the process. Electric arc furnace dust an overview sciencedirect topics. Reactions that generate gas bubbles are required along with the proper slag to sustain these bubbles. The process of slag foaming can be simply stated as.
Modern electric furnaces generally are either arc furnaces or. The flexibility and easy adoptability of eaf steelmaking to. Oxygen is injected through a watercooled top lance which can also be slewed. Dec 30, 20 electric arc furnace steel making free download as powerpoint presentation.
Nov 04, 2016 electric arc furnace electric arc process learn and grow. Electric furnace, heating chamber with electricity as the heat source for achieving very high temperatures to melt and alloy metals and refractories. Some twin shell furnace operations are achieving taptotap times of 35 to 40 minutes. The electricity has no electrochemical effect on the metal but simply heats it. Lrf furnace pdf an electric arc furnace eaf is a furnace that heats charged material by means of an electric arc. Electric room operating platform cover removed crucible pouring mold car fig. Electric arc furnaces use highvoltage electric arcs that are bounced between three graphite electrodes to produce massive amounts of heat. 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. During the melting process, other metals ferroalloys are added to the steel to give it the required chemical composition. Vacuum arc remelting var is a secondary remelting process for vacuum refining and manufacturing of ingots with improved chemical and mechanical homogeneity. The goal of this paper is to define the conditions required to obtain and control optimum foamy slags in the electric furnace. Electric arc furnace steel making free download as powerpoint presentation. Jun 16, 20 electric arc furnaceelectric arc furnace. Though arc furnaces are useful and can process large amounts of.
Oxygen in steel, electric arc furnace, electricity in eaf, eaf steel making, steel. Electric arc furnaces account for ap proximately 40 pct of the total u. The first electric arc furnaces eafs appeared in the late 19th century. In this process electric arc or electric high frequency furnaces are used. Industrial arc furnaces range in size from small units.
Primetals technologies offers the right electric arc furnace to meet its customers requirements. Modelling and simulation of the electric arc furnace processes. In this furnace, the arc may be created by the following different ways. Furnaces energetic modelling of the electrical arc furnace. In the electric arc furnace, the heat is generated by an electric arc. 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, steel is produced only through scrap fusion. The electric arc furnace operating cycle is called the taptotap cycle and is made up of the following operations. 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.
Eafs are often used in steelmaking operations to produce carbon steels, as well. 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. An electric arc furnace eaf is a furnace that heats charged material by means of an electric. Depending on the upstream process, the slag is either. Carbon monoxide explosion hazards in electric arc furnace steelmaking operations. 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. Matte smelting is normally carried out in a reverbatory furnace. Optimization of the electric arc furnace process ieee xplore. In this study, a mass analysis is accomplished for an electric arc furnace at a steel company in turkey. Mass analysis of an electric arc furnace eaf at a steel. Eafs are often used in steelmaking operations to produce carbon steels, as. Electric arc furnaces eaf have the capabilities required for furnaces used for metallurgical research. 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.
An electric arc furnace used for steelmaking consists of a refractorylined vessel, usually. Understanding electric arc furnace steel making operations. The use of eafs has expanded and now accounts for nearly 23 of steel production in the united states. The eaf is different from the blast furnace as it produces steel by using an electrical current to melt scrap steel andor direct reduced iron. Electric arc furnaces work on the principle of the electrode forming an arc between itself and the top layer of metal to be melted. Furnace operations the electric arc furnace operates as a batch melting process producing batches of molten steel known heats. Electric arc furnace electric arc process learn and grow. Compared to the bos process, the eaf requires less chemical reaction for refining. 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.
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. Matte smelting can be conducted at lower melting point than metal oxide smelting. Our technology assures the success of our customers in. The electric arc furnace operating cycle is called the taptotap cycle and is made up of the following. In the recycling industry, the recuperation of zinc from electric arc furnace dust by the waelz process generates important quantities of slag.
Products ironmaking and steelmaking electric arc furnaces. Electric arc furnace heating your electrical guide. Scraps, direct reduced iron, pig iron, and additives are melted through highpower electric arcs formed between a cathode. The submerged electric arc furnace saf has proven a versatile unit in numerous metallurgical. There are two methods for the manufacturing of steel which are as follows. 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. 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. Design and prototype development of a minielectric arc furnace. Electric arc furnace an overview sciencedirect topics. It may produce an intermediate product that is subsequently used in additional processing methods. The furnace operating on this principle is known as direct arc furnace. Used worldwide, these furnaces are featured in minimills that recycle iron scrap for reuse.
Design and prototype development of a minielectric arc. Direct reduction scrap ladle refining electric arc furnace steelmaking iron ore pellets electric arc furnace steelmaking continuous casting design by cover photo. The charge is collected directly from an open hearth furnace. 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. At the same time, minimum network disturbance must always be guaranteed. Pdf modeling and simulation of an electric arc furnace. Main melting period these furnaces use a tremendous quantity of power.
1126 1463 1585 812 970 1367 892 738 62 812 1275 451 431 530 269 1238 33 575 726 219 358 677 1034 242 241 939 739 117 577 58 741 623 1370 1442 1044 1143