Now furnaces with an induction system are widely used in the process of smelting metals. The current produced in the inductor field contributes to the heating of the substance, and this feature of such devices is not only basic, but also most important. Processing leads to the fact that the substance undergoes several transformations. The first stage of conversion is the electromagnetic stage, after it is electric, and then thermal. The temperature that the stove emits is used with almost no residue, so this solution is the best among all others. Many may be interested in an induction furnace , made with their own hands . Next, we will talk about the possibilities of implementing such a solution.
Types of furnaces for smelting metals
This type of equipment can be divided into main categories. At the first, the heart channel acts as the base, and the metal is placed in such furnaces in an annular manner around the inductor. The second category does not have such an element. This species has the name of a crucible, and the metal here is placed inside the inductor itself. In this case, it is technically impossible to use a closed core.
In this case, the melting furnace operates on the basis of the phenomenon of magnetic induction. And there are several components. The inductor is the most important component of this device. It is a coil, in which the conductors are not ordinary wires, but copper tubes. The design of the melting furnaces sets this requirement. The current that flows in the inductor generates a magnetic field that affects the crucible inside which the metal is located. In this case, the material is assigned the role of a secondary transformer winding, that is, through it passes the current heating it. So melting is carried out, even if an induction furnace is made with one's own hands. How to build this type of furnace and increase its efficiency? This is an important question that has an answer. The use of high frequency currents can significantly increase the degree of efficiency of the equipment. For this, it is appropriate to use special power supplies.
Features of induction furnaces
This type of equipment has certain characteristics that are both advantages and disadvantages.
Since the distribution of the metal must be uniform, the resulting material is characterized by a good homogeneous mass. This type of furnace works by transporting energy through zones, and the function of focusing energy is also presented. For use, such parameters as capacitance, operating frequency and lining method are available, as well as temperature control at which the metal melts, which significantly facilitates the work process. The technological potential of the furnace creates a high melting rate, the devices are environmentally friendly, completely safe for humans and ready to work at any time.
The most noticeable drawback of such equipment is the difficulty of cleaning it. Since the heating of the slag occurs solely due to the heat generated by the metal, this temperature is not enough to ensure its full use. The high difference in the temperature of the metal and slag does not allow to make the process of waste disposal as simple as possible. As another drawback, it is customary to single out a gap, because of which it is always necessary to reduce the thickness of the lining. Due to such actions, it may turn out to be malfunctioning after a while.
Industrial use of induction furnaces
In industry, crucible and channel induction furnaces are most often found. First, any metals are melted in arbitrary quantities. Tanks for metal in such cases are capable of holding up to several tons of metal. Of course, in this case it is impossible to do induction melting furnaces with your own hands. Channel furnaces are designed for the smelting of non-ferrous metals of various types, as well as cast iron.
DIY induction ovens
This topic is often of interest to lovers of radio design and radio technology. Now it is becoming clear that it is quite possible to create induction furnaces with your own hands, and very many have managed to do this. However, to create such equipment, it is required to implement the action of an electrical circuit that would contain the prescribed actions of the furnace itself. Such solutions require the use of high-frequency generators capable of producing wave oscillations. A simple do-it-yourself induction furnace according to the scheme can be built using four electronic tubes in combination with one neon lamp, which signals that the system is ready for operation.
In this case, the handle of the AC capacitor is not located inside the device. Thanks to this, an induction furnace can be created with your own hands. The device diagram describes in detail the location of each individual element. You can make sure that the device turned out to be powerful enough if you use a screwdriver, which should reach a hot state in just a few seconds.
If you create an induction furnace with your own hands, the principle of operation and assembly of which is studied and performed according to the corresponding scheme, you should know that in this case one or several factors can influence the melting speed, listed below:
- pulse frequency;
- hysteresis losses;
- generator power;
- period of heat release to the outside;
- losses associated with the occurrence of eddy currents.
If you are going to do an induction oven with your own hands, then when using lamps, you need to remember that their power must be distributed so that four pieces are enough. Using a rectifier results in a network of approximately 220 V.
Domestic use of stoves
In everyday life, such devices are rarely used, although similar technologies can be found in heating systems. They can be seen in the form of microwave ovens, electric ovens and induction hobs. In the environment of new technologies, this development has found wide application. For example, the use of eddy currents in induction cookers allows you to cook a huge variety of dishes. Since they require very little time to warm up, the hob cannot be turned on if nothing is on it. However, special utensils are required to use such special and healthy cookers.
A self-made induction crucible furnace consists of an inductor, which is a solenoid made of a water-cooled copper tube and a crucible, which can be made of ceramic materials, and sometimes steel, graphite and others. In such a device, cast iron, steel, precious metals, aluminum, copper, magnesium can be smelted. Do-it-yourself induction furnaces are manufactured with a crucible capacity from a couple of kilograms to several tons. They can be vacuum, gas-filled, open and compressor. The furnaces are fed with currents of high, medium and low frequency.
So, if you are interested in an induction furnace with your own hands, the scheme involves the use of such basic components: a melting bath and an induction unit, which includes a hearth stone, an inductor and a magnetic core. A channel furnace differs from a crucible in that electromagnetic energy is converted into heat in the heat release channel, in which there must constantly be an electrically conductive body. To make the initial start-up of the channel furnace, molten metal is poured into it or a template is inserted from a material capable of cracking in the furnace. When the smelting is completed, the metal does not merge completely, and there remains a “swamp” intended to fill the heat-release channel for future start-up. If you intend to do the induction oven with your own hands, then to facilitate the replacement of the hearth for equipment, it is made detachable.
So, if you are interested in the do-it-yourself mini-oven, it is important to know that its main element is a heating coil. In the case of a homemade version, it is enough to use an inductor made of a bare copper tube, the diameter of which is 10 mm. For the inductor, an internal diameter of 80-150 mm is used, and the number of turns is 8-10. It is important that the turns are not in contact, and the distance between them is 5-7 mm. Parts of the inductor must not come into contact with its screen, the minimum clearance should be 50 mm.
If you are going to do an induction oven with your own hands, then you should know that on an industrial scale, water or antifreeze is engaged in cooling inductors. In the case of low power and short operation of the created device, you can do without cooling. But during operation, the inductor is very hot, and the scale on copper can not only dramatically reduce the efficiency of the device, but also lead to a complete loss of its performance. It is impossible to make an inductor with cooling on its own, so regular replacement is required. It is impossible to use forced air cooling, since the case of a fan located near the coil will “attract” EMF to itself, which will lead to overheating and a drop in the efficiency of the furnace.
When an induction furnace is assembled with your own hands, the circuit involves the use of such an important element as an alternator. You should not try to make a furnace if you do not own the basics of radio electronics at least at the level of a medium-skilled radio amateur. The choice of the generator circuit should be such that it does not give a hard current spectrum.
Use of induction furnaces
This type of equipment has become widespread in areas such as foundry, where the metal has already been cleaned and you need to give it some specific shape. You can also get some alloys. In jewelry production, they also gained distribution. The simple principle of operation and the possibility that the induction furnace was assembled with your own hands, can increase the profitability of its use. For this area, you can use devices with a crucible capacity of up to 5 kilograms. For small industries, this option will be optimal.