The maintenance of induction furnace continuous smelting. Channel induction furnaces consist of a refractorylined steel shell that contains molten metal. The molten metal in an induction furnace is circulated automatically by electromagnetic action so that when alloy additions are made, a homogeneous product is ensured in minimum time. New generation refractory lining for coreless induction. Channel induction furnaces are commonly used for melting lowmeltingpoint alloys andor as a holding and superheating unit. Induction furnace capacities range from less than one kilogram to one hundred tonnes, and are used to melt iron and steel, copper, aluminium, and precious metals. Recent advances in lowertemperature aluminum braze materials have allowed induction to effectively replace flame and furnace heating in highvolume brazing of aluminum assemblies.
Steel scrap is the most important rawmaterial in secondary steel making shop. Induction furnace can melt relatively small quantities of a wide variety of metals and alloys quickly, conveniently and cleanly. Sep 24, 1974 a method of lining a metallurgical furnace particularly induction furnaces using a form which is placed at a spaced location from the furnace wall comprises filling the hollow space between the furnace wall and the form with a granular and dry refractory material, compacting the material, subjecting the compacted material to a ceramic sintering process by heating it to an intermediate. Routine operational maintenance of furnace is undertaken to standard operating procedures. Running a powerful alternating current through the coil creates a magnetic field that induces electric currents inside the metal and quickly melts the charge inside. Inadequate stack height leads to lower heat exchange and higher coke consumption. It normally consists of high purity silica ramming mass. Invented by gradmatic equipments founder, ayton grady, the gradmatic refractory installation and vibration system is a mechanism designed to eliminate problems associated with. Studies established that the lining body made from karelsk quartzites is not inferior to the swedish material used for lining induction furnaces by many foreign companies. Introduction for airoperated ramming machine for induction furnace lining building introduction of airoperated ramming machine airoperated ramming machine is composed of the wall vibrator, pneumatic hammer head, the length adjustment lever and pendant chain. The purpose of this article is to provide an understanding of the entire induction. Keeping furnace lining free of slag slag generated during melting has tendency to stick on the furnace wall. The working principle of induction furnace medium frequency induction furnace is mainly constituted by the furnace, inverter system, electrical control system, cooling system and etc.
In a coreless induction furnace, an essentially monolithic refractory cement lining, the thickness of said lining consisting of. Replacement of the lining increases furnace downtime. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Refractory for lining induction furnaces springerlink. Induction furnace refractory lining with silica ramming. Pneumatic furnace lining building process furnace lining building for induction furnace description. Post mortem study on al2o3mgo induction furnace ozan uylas. The low melting temperature of aluminum requires that the induction brazing process apply the energy to the part correctly, to raise both part surfaces to the braze flow temperature at the. For side wall lining a suitable cylindrical former is essential. Development of charge calculation program for target steel in induction furnace. A stack height between 16 ft to 22 ft depending upon its diameter is necessary for heat exchange. Furnace is started up to standard operating procedures. Superheating of metal is done at higher temperature and held for few minutes. Steel making by induction furnace basai steels pvt ltd.
The launder or spout of the furnace either is rammed or lined with refractory bricks. Inter national journal of engineering and technology vol. Energy efficiency best operating practices guide for foundries 2 1. Sophisticated software running on personal computers is capable of making calculations in seconds, minutes, or hours that would have taken days, weeks, or months to solve manually. The former can be made either removable or consumable type.
Preformed highly insulating refractory lining for aluminium furnace. Melting furnace there are two type of the furnace structure. The efficiency of an induction heating machine for a specific application depends on several factors. Innovative refractory technology for coreless induction. Depending on the size of the furnace, this activity can be lengthy, exceeding one hour, exposing workers to airborne dust and repetitivestrain injury. If the procedure is unsuccessful in removing the deposits, the bath should be allowed to cool or should be charged with returns sufficient to cool it back to normal operating temperature. Experimental procedure the samples of neutral lining and those of slag were obtained from an induction furnace of bilecik demir celik inc. To better understand the stress imparted on the lining during service a finite element analysis fea was performed on this model. Refractory material for copper melting furnace requirements for the use of refractory materials in the induction furnace for melting copper 1, the damage mechanism of refractory material in induction furnace the channel refractory damage is mainly caused by the molten metal, metal oxide, slag penetration and thermal stresses. Innovative refractory technology for coreless induction furnaces. Refractory systems iron and steel industry steulerkch. Development of charge calculation program for target steel in.
Theory of heating by induction 7 tromagnetic, or flux around it. An iron foundry can use electric arc, induction or cupola furnace. The ramming mass of the lining was provided by kuma, the specific brand being coded as nh22. Special furnace design 1500kw 2x3000kg melting furnace at the time of casting norway 5m design coreless induction melting furnace with all accessories safety back and side barriers back tilting, capture hood and easy lining removal system hydraulic furnace lid gas vacuuming system demountable top cassette design high insulated shielding system. Refractory material lining requires two steps for induction furnaces. As far as cast iron is concerned, available are models with a total capacity of 2 900 kg to 25 000 kg and an inductor power of kw to 500 kw. Induction furnaces produce their heat cleanly, without combustion. Furnace lining building for induction furnace description. An engineered method for when a coreless induction. A method of lining a metallurgical furnace particularly induction furnaces. Temperature estimation of liquid steel in induction furnace. This bottom lining is compacted first, then, when complete, the bottom plate assembly is removed.
Induction melting brings together three thingswater, molten metal and electricitythat have the potential for concern if your furnace is not properly working. For more than twenty years, gradmatic equipment has significantly influenced the foundry industry by introducing innovative technology to line coreless induction furnaces with dry, refractory materials. This reduces volume of furnace hence reduces metal out put per heat. Faults are reported according to standard operating procedures.
Induction furnaces must have a water cooling system built into the coil itself. Business metals, metalworking and machinery casting metal equipment and supplies founding induction furnaces maintenance and repair metallurgical furnaces. This inhibits slag to deposit on the furnace lining keeping furnace clean with full volume. As it is noncontact heating process, it does not pollute the material being heated. The great reserves and favorable mining conditions for obtaining these materials enable us to examine quartzite from the central karelsk area as raw materials for producing the lining. The bottom plate with the vibrator bolted at its center, as shown to the right, is lowered and placed on the dry refractory material previously poured into the bottom of the furnace. Otherwise, the deposit may slump when the furnace is poured, filling the lower part of the crucible with a difficulttoremove material. For example, furnace lining is a protective and insulating layer that serves to protect the furnace parts from the extreme heat developed during smelting operations. The melting process is the procedure from the first charging to the tapping of the finished melt. Design and fabrication of inductors for induction heat treating. The time between tap and charge, the charging time, power delays etc. Life of refractory lining is low as compared to eaf.
An induction furnace is an electrical furnace in which the heat is applied by induction heating of metal. Induction furnace handbook in english, and including in it advertise ments for the products. Design analysis of an electric induction furnace for melting. Photo a to the right shows the wec hydraulic model 800 with vibrator attached, fully contracted shoes and battens are shown in place. The furnace coil shown in figure 14, during the heating process.
Normally, the selection of refractory is based on the type of slag generated during melting. Induction furnace definition is an electric furnace heated by a current which is caused to flow through the charge by electromagnetic induction. Power and frequency control of induction furnace using. Induction furnace capacities range from less than one kilogram to one hundred tonnes, and are used to melt iron and steel, copper, aluminium, and precious metals the advantage of the induction furnace is a clean, energyefficient and wellcontrollable melting process compared.
If the slag contains high amount of acidic components then a silica lining is used. Aug 07, 1973 in a coreless induction furnace, an essentially monolithic refractory cement lining, the thickness of said lining consisting of. The most commonly used lining material for induction furnace is acidic lining. The great reserves and favorable mining conditions for obtaining these materials enable us to examine quartzite from the central karelsk area as raw materials for producing the lining bodies of induction furnaces. Improvement in energy efficiency of melting furnace. It is mainly used for ramming the dry vibration materials for the induction furnace. Lets now investigate the various stresses that are created in lining of this furnace system, and how the different lining structures handle them. A silica lining with algt has been used for the complete lining, resulting in a record campaign of 675 heats with one minor patch of the floor and taper area. Induction furnace lining and industrial vibrator design.
The burning fuel brings the interior temperature of the furnace above the melting point of the charge material placed inside. Induction and arc furnaces use electricity to melt steel and cast iron. The roof is lined with a suitable castable generally of high alumina base and low cement castablelcc. It is incorrect procedure to install the spout above the working lining reference figure 4 which inhibits the free. Refractory failure in induction furnaces can be limited. Introduction induction furnaces are used for melting cast iron, mild steel and various alloy steels in foundries. If there is leakage of furnace, first close the igbt power supply immediately, evacuate the surrounding people, then pour out the liquid metal in the furnace body to prevent the metal liquid water explosion. The induction coil actually functions as a transformer primary, with the workpiece to be heated becoming the transformer secondary. Induction furnaces basics of foundry melting furnaces.
In many cases, no analytical formula exists for complex coils, and the only way to make calculations prior to tests is with a computer modeling program. When the induction coil is placed next to or around a workpiece, the lines of force concentrate in the air gap between the coil and the workpiece. The advantage of the induction furnace is a clean, energyefficient and wellcontrollable melting process compared to most other means of metal melting. The length of the asbesto cloth must be 300mm higher than furnace mouth top level and pressed. Induction furnace definition of induction furnace by. Refining in induction furnace is not as intensive or effective as in electric arc furnace eaf.
Figure 1 iron melting coreless furnace with silica lining. The refractory cement lining of claim 1 consisting essentially of from 80 to 97 percent by weight of fused or dead burned magnesia made up of graded particle sizes, the coarsest being approximately 0. This heats the surface of the charge material, causing it to melt. Regularly inspect furnace lining to minimize the possibility of a dangerous run through occurring. Design analysis of an electric induction furnace for. The pouring furnace with its pressuretight cover has a cylindrical shape. An engineered method for when a coreless induction furnace. Development of charge calculation program for target steel. Induction furnace lining building toolscooldo industrial. Discusses various aspects of using an induction furnace in founding. Energy efficiency best operating practices guide for foundries. Our personnel work directly with the customer to develop comprehensive coil maintenance programs. That it is why is used on induction furnaces lining and also because quartz is stable. Thermal and thermomechanical evaluations of channel.
Oilfired furnaces mostly use furnace oil, especially for reheating and heat treatment of materials. A process for refining steel in induction furnace comprising steps of. Melting furnaces for nonferrous materials use fuel oil. It also prevents excessive heat loss from the external furnace surfaces, making the process more efficient. Most furnaces use liquid fuel, gaseous fuel or electricity as energy input. It contributes between 60% and 80% of the total production costs 1. New generation refractory lining for coreless induction furnace. Magnetic stirring of the melt produces excellent uniformity of the melt composition. Nov 28, 2014 types of induction furnace there are two main types of induction furnace, coreless and channel. They are chosen by the alloy system quantities produced. The channel induction furnace consists of a refractory lined steel shell which contains the molten metal. Post mortem study on al2o3mgo induction furnace ozan.
Attached to the steel shell and connected by a throat is an induction unit which forms the melting component of the furnace. A method of lining a metallurgical furnace particularly induction furnaces using a form which is placed at a spaced location from the furnace wall comprises filling the hollow space between the furnace wall and the form with a granular and dry refractory material, compacting the material, subjecting the compacted material to a ceramic sintering process by. Effects and analysis of thermal stresses on large induction. Continuous furnace to reduce the repeated heat that caused by quenching furnace lining cracking, continuous furnace for the extension of lining life is very important, it has caused enough attention of many users. Then furnace heating schedule is to be followed carefully which will depend up thickness, nature of on the furnace lining ramming mass etc. The main circuit topology of induction heating based on fuzzy control system is shown in fig. Induction smelting furnace safety notes superbmelt. Specializing in refractory installation, our product primarily focuses on improving the industrial furnace lining process for worker safety and efficiency. Design and fabrication of inductors for induction heat. Design and implementation of an induction furnace diyala journal of engineering sciences, vol. Water picks up the heat caused by the current, as well as heat. Refractories are heat resistant materials used in all processes that work at. Furnace lining materials are typically ceramics or combination metal. Traditional furnace lining systems involving the application.
All furnace linings have been successfully converted to take advantage of the extended campaign life. When a certain amount of damage occurs, induction furnace operation must be interrupted to repair or replace refractory lining. The induction unit consists of an iron core in the form of a ring around which a primary. In this report induction furnaces will be mentioned which are used for ferrous materials. The form supports the refractory until the lining has attained enough strength during the. Before starting up the induction smelting furnace, must check whether the lining material has crack and other defects. Refractory furnace installation equipment gradmatic. The furnace lid where one is used should be closed before the furnace is tilted. For the direct reduction process, steulerkch supplies individual solutions for. The following manual is no longer available in its.
Channel induction furnaces harbisonwalker international. Photo b shows the wec 800 fully expanded, and photo c shows the smallest. The maintenance of induction furnace continuous smelting and repair. Power and frequency control of induction furnace using fuzzy. With this lining the furnace was used to melt numerous. A coreless induction furnace consists of a nonconductive refractory crucible, surrounded by a coil of copper tubes. New, repair andor rebuild phoenix induction has many years of induction coil, melting furnace and sintering coil design, build and repair experience. Silica ramming mass is used for melting carbon steels with carbon content higher than 0.
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