Heating bodies using electricity magnetic field arising from exposure to induced current is called induction heating. Electrothermal equipment, or induction furnace, has different models, designed to perform tasks for various purposes.

Design and principle of operation

By technical specifications The device is part of a plant used in the metallurgical industry. The operating principle of an induction furnace depends on alternating current , the power of the installation is determined by the purpose of the device, the design of which includes:

1. inductor;
2. frame;
3. melting chamber;
4. vacuum system;
5. mechanisms for moving the heating object and other devices.

The modern consumer market has a large number of models of devices that operate according to the scheme of formation of eddy currents. The operating principle and design features of an industrial induction furnace make it possible to perform a number of specific operations related to the melting of non-ferrous metals, heat treatment metal products, sintering synthetic materials, cleaning precious and semi-precious stones. Appliances used for disinfection of household items and heating of premises.

The work of an induction furnace is to heat objects placed in the chamber with eddy currents emitted by an inductor, which is an inductor coil made in the shape of a spiral, figure eight or trefoil with a large wire wound around it. cross section. An inductor operating from alternating current creates a pulsed magnetic field, the power of which varies in accordance with the frequency of the current. An object placed in a magnetic field is heated to the point of boiling (liquid) or melting (metal).

Installations operating using a magnetic field are produced in two types: with magnetic conductor and without a magnetic circuit. The first type of device has an inductor in its design, enclosed in a metal case, which ensures a rapid increase in temperature inside the processed object. In furnaces of the second type, the magnetotron is located outside the installation.

Features of induction devices

The master also requires skills in the design and installation of electrical appliances. The safety of a custom-assembled device lies in a number of features:

1. equipment capacity;
2. operating pulse frequency;
3. generator power;
4. eddy losses;
5. hysteresis losses;
6. heat output intensity;
7. lining method.

Channel furnaces got their name from the presence in the space of the unit of two holes with a channel forming a closed loop. Due to its design features, the device cannot operate without a circuit, thanks to which liquid aluminum is in continuous motion. If the manufacturer's recommendations are not followed, the equipment switches off spontaneously, interrupting the melting process.

According to the location of the channels, induction melting units are vertical and horizontal with drum or cylindrical shape cameras. The drum furnace in which cast iron can be melted is made of sheet steel. Swivel mechanism equipped with drive rollers, a two-speed electric motor and a chain drive.

Liquid bronze is poured through a siphon located on the end wall, additives and slags are loaded and removed through special holes. Issue finished products carried out through a V-shaped drain channel made in the lining according to a template, which melts during the working process. Cooling of the winding and core is carried out by air mass, the temperature of the housing is regulated using water.

Vacuum units are indispensable equipment in industries where it is necessary to smelt metals and alloys, providing them with a high degree of purification. The sealed vacuum chamber prevents the penetration of contaminants and foreign gases. This allows you to obtain products without impurities or oxidations. If you need to buy a vacuum induction furnace in Moscow, you can order it from our company.

Working principle of vacuum induction furnace

An induction type vacuum furnace is equipped with a crucible in which metal is melted. Based on the operating principle, these products are divided into semi-continuous and periodic. The semi-continuous vacuum unit allows multiple heats to be performed without opening the housing. For batch-type equipment, the chamber depressurizes after each melting process.

The vacuum chamber in which the melting process takes place is sealed, which makes it possible to obtain absolutely pure products. The metal does not oxidize during processing, due to the absence of oxygen, foreign particles do not enter it. The vacuum pump equipped with the device maintains the required pressure and pumps out the air.

Infrared ovens have a number of differences from other types of units:

• It is allowed to use any material: scrap, pieces, briquettes;
• liquid metal can be in a vacuum for a long time;
• during the smelting process it is possible to control and change the chemical composition and temperature of the alloy;
• can be used different ways refining and deoxidation during smelting.

This vacuum installation can be used for smelting heat-resistant, precision heat-resistant alloys, stainless steel.

Advantages of Dana Engineering

Purchasing ready-made vacuum induction furnaces or ordering their manufacture according to an exclusive project from Dana Engineering in Moscow provides several advantages:

• impeccable quality and durability of equipment;
• prompt order fulfillment;
• moderate cost of production.

Our company employs experienced, highly qualified specialists. They own a number of innovations that have made it possible to increase the efficiency and cost-effectiveness of installations. During our work, we have established reliable relationships with the best manufacturers components. The design bureau is located on the territory of the enterprise, which allows you to quickly develop and implement projects.

Sales and prices of vacuum induction furnaces

For those wishing to determine in advance the future costs that a vacuum induction furnace will require, price standard designs indicated in the price list. The cost of equipment produced according to exclusive customer designs is calculated individually. It consists of several factors: the type of furnace, its dimensions, the material used to make the chamber and crucible, and additional devices.

Production and supply of vacuum induction furnaces in Russia and CIS countries

Currently, the demand for steel and alloys special purpose for the aerospace, aviation, nuclear and energy industries is growing rapidly. These industries often require more and more high values on strength, purity and other properties of the metal.

In order to solve the problem of improving the quality properties of smelted metals, the MetaCube company is ready to offer technologies based on innovative smelting methods for producing steel and alloys with special technological properties. These methods include vacuum induction melting.

The need to create vacuum induction furnaces arose in connection with the need to introduce industrial production highly reactive and refractory metals, such as zirconium, titanium, niobium, beryllium and molybdenum, as well as tantalum, tungsten, uranium and a number of others. A peculiarity of such metals is that they oxidize intensively when heated in air, and therefore melting must be carried out in a vacuum.

Features of vacuum induction furnaces

Vacuum induction melting technology makes it possible to obtain highly purified metals in an oxygen-free atmosphere. When using vacuum induction furnaces, it is possible to produce heat-resistant and high-alloy steels and precision alloys. Also, in vacuum induction furnaces, it is possible to carry out heat treatment and melting of precious and rare earth metals, as well as melting high-grade special glass and use them to obtain single crystals. In all cases, the material obtained in vacuum furnaces is distinguished by increased purity and minimal waste.

An important role during refining in a vacuum induction furnace is played by the process of evaporation of low-melting impurities - lead, arsenic, tin and bismuth. The high qualities of the vacuum metal are partly ensured by the purification of the alloy from these impurities, which are contained in very small quantities, which makes it impossible to determine them even with advanced analytical methods. This is necessary when the requirements for the material are quite high and the resulting special alloy must meet certain properties.

Another advantage of vacuum furnaces is the ability to obtain single-crystalline and fine-grained metal structures. In this case, the properties of the resulting material can be predicted.

The operating temperature of the furnaces is up to 2200 degrees.

• Possibility of long-term exposure of liquid metal in a deep vacuum;
• High degree of metal degassing;
• Possibility to reload the furnace during the melting process;
• The ability to actively influence the intensification of deoxidation and refining processes at any time during smelting;
• The ability to effectively control and regulate the state of the melt based on its temperature and chemical composition throughout the entire process;
• Particular purity of the resulting castings due to the absence of any non-metallic inclusions;
• The ability to produce rapid heating (direct heating due to the heat generated in the melt), thereby increasing productivity;
• High homogeneity of the melt due to active mixing of the metal;
• Any form of raw materials (lumpy materials, briquettes, powder, etc.)
• High efficiency and environmental friendliness.

Design of vacuum furnaces

is a high-frequency furnace made of a refractory crucible, placed inside an inductor, which in turn is located inside a sealed housing, from which vacuum pumps gases are pumped out. The crucible of vacuum furnaces is made from powdered highly refractory materials by packing in an inductor according to a template. Vacuum induction furnaces are mechanized units. Metal pouring can occur either by rotating the furnace inside the chamber, or by rotating the chamber itself as a whole. A vacuum induction melting furnace allows you to independently perform the following operations: adjust the temperature of the melt, change the pressure inside the chamber, mix the melt, and also add other elements to the melt.

The modular principle of constructing vacuum furnaces makes it possible to achieve increased compactness of the furnace, as well as the possibility of connecting additional modules - a chamber for unloading, pouring, and also removing the resulting products.

The design of modern vacuum induction furnaces makes it possible to install molds and unload ingots from them without breaking the vacuum in the furnace. Vacuum induction furnaces are most often automated devices. Loading of the charge, introduction of additives and additives, and casting of metal are carried out using an electric or hydraulic drive.

Buy a vacuum induction furnace at a low price - MetaCube Company

The MetaCube company is ready to offer you wide choose vacuum induction furnaces for low prices with delivery and commissioning throughout Russia and the CIS countries. Our company has extensive experience in supplying various metallurgical equipment to enterprises in Russia, Kazakhstan, Belarus and other CIS countries.

Vacuum melting furnaces are used to produce the highest quality metals and alloys. Low pressure in the space of the working chamber allows you to sharply reduce the gas content in the ingot without the use of protective environments.

Scope of application of induction furnaces

Vacuum furnaces are used in many technological processes:

melting of metals and alloys: refractory, heat-resistant, high-alloy;

sintering of products from easily oxidizing metals;

degassing of liquid metals and other materials;

heat treatment of metals (quenching, tempering, annealing);

coating by deposition of evaporated metals, etc.

Main types of vacuum furnaces

The most common types of vacuum furnaces are:

arc: used for smelting stainless, electrical and other high-quality steels, refractory metals (titanium, zirconium, tantalum, etc.);

plasma: designed for melting highly reactive and refractory metals;

induction: they can be classified as widely used equipment. The most widespread vacuum melting induction furnaces with tilting crucible. They are used in large metallurgical plants for melting high-quality and high-alloy steels and casting them into molds.

Standard sizes of melting furnaces

Based on their dimensions, vacuum melting furnaces are divided into laboratory (capacity up to 50-100 kg) and industrial. However, such a classification is very arbitrary: there are many models of industrial importance with a working volume of only 10-20 kg.

Operating principle of induction industrial furnaces

Despite design features different types vacuum melting furnaces, they operate on the same principle: in a refractory crucible placed in vacuum chamber, with the help of a heating element, the metal is melted (or liquid is heated), refined and alloyed. The process ends with casting shaped products or simple ingots.

According to the principle of operation, vacuum melting furnaces are divided into three groups:

semi-continuous;

continuous action;

periodic action.

Semi-continuous industrial melting furnaces do not require systematic depressurization. Molds are changed in them using chambers separated from the main one by gates. The same sluice devices are used to load the furnace. Semi-continuous devices are used in industry. Thanks to their design features:

the refractory lining of the crucibles is in favorable conditions, since it is not subject to temperature changes;

there is no need to pump out air before starting a new melt, which has a very positive effect on the productivity of the furnace;

in the chamber the formation of metal oxides is reduced to a minimum, and, consequently, the contamination of subsequent melting is reduced.

In batch melting industrial furnaces, sluices are not provided. To remove the mold or load the charge, you have to depressurize the housing each time and open the vacuum chamber. Laboratory ovens operate on this principle.

The main advantages of vacuum furnaces are:

economic benefit: instead of expensive inert gases, low pressure in the chamber is used;

high degree of metal purification;

the ability to strictly control the chemical composition and temperature of the melt at any stage of the technological process;

protection heating elements from oxidation, which allows you to increase the operating temperature.

The cost of vacuum melting induction furnaces and other models is quite high, but the costs quickly pay off during their operation.

An induction furnace is used for melting non-ferrous and ferrous metals. Units of this operating principle are used in the following areas: from the finest jewelry making to large-scale industrial smelting of metals. This article will discuss the features of various induction furnaces.

Induction furnaces for metal melting

Principle of operation

Induction heating is the basis for the operation of the furnace. In other words, electricity creates an electromagnetic field and heat is obtained, which is used on an industrial scale. This law of physics is studied in the last grades secondary school. But the concept of an electric unit and electromagnetic induction boilers should not be confused. Although the basis of work here and there is electricity.

How does this happen

The generator is connected to an alternating current source, which enters it through an inductor located inside. The capacitor is used to create an oscillation circuit, which is based on a constant operating frequency to which the system is tuned. When the voltage in the generator increases to a limit of 200 V, the inductor creates an alternating magnetic field.

The circuit is closed, most often, through a ferromagnetic alloy core. The alternating magnetic field begins to interact with the workpiece material and creates a powerful flow of electrons. After the electrically conductive element enters into inductive action, the system experiences occurrence of residual stress, which in the capacitor contributes to the occurrence of eddy current. Eddy current energy is converted into thermal energy inductor and heats up to high temperatures melting the desired metal.

The heat produced by the inductor is used:

• for melting soft and hard metals;
• for hardening the surface of metal parts (for example, tools);
• for thermal treatment of already produced parts;
• household needs (heating and cooking).

Brief characteristics of various furnaces

Types of devices

Induction crucible furnaces

Is the most common type of stove induction heating. Distinctive feature, different from other types is that in it an alternating magnetic field appears in the absence of a standard core. Cylinder shaped crucible located inside the inductor cavity. The furnace, or crucible, is made of a material that perfectly resists fire and is connected to alternating electric current.

Positive aspects

Crucible units include to environmentally friendly heat sources, environment not polluted by metal melting.

In progress crucible furnaces there are disadvantages:

• during technological processing, slags at low temperatures are used;
• The produced lining of crucible furnaces has low resistance to destruction, this is most noticeable during sudden temperature changes.

The existing disadvantages do not pose any particular difficulties; the advantages of a crucible induction unit for melting metal are obvious and have made this type of device popular and in demand among a wide range of consumers.

Channel induction melting furnaces

This type is widely used in the smelting of non-ferrous metals. Effectively used for copper and copper alloys based on brass, cupronickel, bronze. Aluminum, zinc and alloys containing these metals are actively melted in channel units. The widespread use of furnaces of this type is limited due to the inability to provide a fracture-resistant lining on the inner walls of the chamber.

Molten metal in channel induction furnaces undergoes thermal and electrodynamic movement, which ensures constant homogeneity of mixing of alloy components in the furnace bath. Using duct furnaces inductive principle justified in cases where special requirements are imposed on the molten metal and manufactured ingots. The alloys are of high quality in terms of gas saturation coefficient and the presence of organic and synthetic impurities in the metal.

Channel induction furnaces operate like a mixer and are designed to level the composition, maintain a constant process temperature, and select the pouring speed into crystallizers or molds. For each alloy and casting composition, there are parameters for a special charge.

Advantages

• the alloy is heated in the lower part, to which there is no air access, which reduces evaporation from the upper surface, heated to a minimum temperature;
• channel furnaces are classified as economical induction furnaces, since the melting that occurs is ensured by a low consumption of electrical energy;
• the oven has high coefficient useful action thanks to the use in work closed loop magnetic wire;
• Constant circulation of molten metal in the furnace accelerates the melting process and promotes uniform mixing of alloy components.

Flaws

• the durability of the stone internal lining decreases when high temperatures are used;
• the lining is destroyed when melting chemically aggressive alloys of bronze, tin and lead.
• when melting contaminated low-grade charge, the channels become clogged;
• the surface slag in the bath does not heat up to a high temperature, which does not allow operations to be carried out in the gap between the metal and the shelter and to melt chips and scrap;
• channel units do not tolerate interruptions in operation, which forces them to be constantly stored in the furnace mouth significant amount liquid alloy.

Complete removal of molten metal from the furnace leads to its rapid cracking. For the same reason, it is impossible to perform a quick conversion from one alloy to another, you have to make several intermediate melts, called ballast.

Vacuum induction furnaces

This type is widely used for melting steels High Quality and nickel, cobalt and iron alloys of heat-resistant quality. The unit successfully copes with the melting of non-ferrous metals. Glass is boiled in vacuum units, parts are treated with high temperature, produce single crystals.

The furnace is classified as a high-frequency generator located in an inductor isolated from the external environment that passes current high frequency. To create a vacuum, pumps are used to evacuate it. air masses. All operations for introducing additives, loading the charge, and dispensing metal are carried out automatic mechanisms with electric or hydraulic control. Alloys with small admixtures of oxygen, hydrogen, nitrogen, and organics are obtained from vacuum furnaces. The result is far superior to open induction ovens.

Heat-resistant steel from vacuum furnaces used in tool and weapons production. Some nickel alloys containing nickel and titanium are chemically active, and it is problematic to obtain them in other types of furnaces. Vacuum furnaces perform metal pouring by turning the crucible in internal space casing or rotation of the chamber with a fixed furnace. Some models have an opening hole in the bottom to drain metal into an installed container.

Crucible furnaces with transistor converter

Used for limited weight non-ferrous metals. They are mobile, light in weight and can be easily moved from place to place. The furnace package includes a high-voltage transistor converter universal action . Allows you to select the power recommended for connecting to the network, and, accordingly, the type of converter that is needed in this case with changing the weight parameters of the alloy.

Transistor Induction Furnace Widely used for metallurgical processing. It is used to heat up parts in blacksmithing and harden metal objects. Crucibles in transistor furnaces are made of ceramics or graphite; the former are designed to melt ferromagnetic metals such as cast iron or steel. Graphite is installed to melt brass, copper, silver, bronze and gold. They melt glass and silicon. Aluminum melts well using cast iron or steel crucibles.

What is the lining of induction furnaces

Its purpose is to protect the furnace casing from the destructive effects of high temperatures. Side effects is heat conservation, therefore process efficiency increases.

The crucible in the design of an induction furnace is made in one of the following ways:

• by the method of excavation in small-volume ovens;
• by the printed method from refractory material in the form of masonry;
• combined, combining ceramics and a buffer layer between the masonry and the indicator.

The lining is made of quartzite, corundum, graphite, fireclay graphite, magnesite. Additives are added to all these materials to improve the characteristics of the lining, reduce volume changes, improve sintering, and increase the resistance of the layer to aggressive materials.

To select a particular material for lining take into account a number of accompanying conditions, namely, the type of metal, the price and refractory properties of the crucible, the service life of the composition. A properly selected lining composition should provide technical requirements to carry out the process:

• obtaining high quality ingots;
• the largest amount of full melting without repair work;
• safe work of specialists;
• stability and continuity of the smelting process;
• receiving quality material when using an economical amount of resources;
• use of common materials for lining at a low price;
• minimal impact on the surrounding space.

The use of induction furnaces allows you to obtain alloys and metals of excellent quality with a minimum content of various impurities and oxygen, which increases their use in complex areas of production.

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