A home induction furnace copes with the melting of relatively small portions of metal. However, such a hearth does not need a chimney or bellows that pump air into the melting zone. And the whole design of such a furnace can be placed on a desk. Therefore, heating by electrical induction is the best way to melt metals at home. And in this article we will consider the designs and assembly schemes of such furnaces.
How an induction furnace works - generator, inductor and crucible
In factory workshops, you can find channel induction furnaces for melting non-ferrous and ferrous metals. These installations have a very high power, which is set by the internal magnetic circuit, which increases the density of the electromagnetic field and the temperature in the crucible of the furnace.
However, channel structures consume large portions of energy and take up a lot of space, therefore, at home and in small workshops, an installation without a magnetic circuit is used - a crucible furnace for melting non-ferrous / ferrous metal. Such a design can be assembled even with your own hands, because the crucible installation consists of three main components:
- A generator that produces alternating current with high frequencies, which are necessary to increase the density of the electromagnetic field in the crucible. Moreover, if the diameter of the crucible can be compared with the long wave frequency of the alternating current, then such a design will make it possible to transform up to 75 percent of the electricity consumed by the installation into thermal energy.
- The inductor is a copper spiral created on the basis of an accurate calculation of not only the diameter and number of turns, but also the geometry of the wire used in this process. The inductor circuit must be tuned to gain power as a result of resonance with the generator, or rather with the frequency of the supply current.
- The crucible is a refractory container, in which all the melting work takes place, initiated due to the occurrence of eddy currents in the metal structure. In this case, the diameter of the crucible and other dimensions of this container are determined strictly according to the characteristics of the generator and inductor.
Any radio amateur can assemble such an oven. To do this, he needs to find the right scheme and stock up on materials and parts. You can find a list of all this below.
What furnaces are assembled from - we select materials and parts
The design of a home-made crucible furnace is based on the simplest laboratory inverter Kukhtetsky. The scheme of this installation on transistors is as follows:
Based on this diagram, you will be able to assemble an induction furnace using the following components:
- two transistors - preferably field type and brand IRFZ44V;
- copper wire with a diameter of 2 mm;
- two diodes brand UF4001, even better - UF4007;
- two throttle rings - they can be removed from the old power supply from the desktop;
- three capacitors with a capacity of 1 microfarad each;
- four capacitors with a capacity of 220nF each;
- one capacitor with a capacitance of 470 nF;
- one capacitor with a capacitance of 330 nF;
- one 1 watt resistor (or 2 resistors of 0.5 watts each), designed for a resistance of 470 ohms;
- copper wire with a diameter of 1.2 mm.
In addition, you will need a couple of heatsinks - they can be removed from old motherboards or CPU coolers, and a rechargeable battery with a capacity of at least 7200 mAh from an old 12 V uninterruptible power supply. The furnace will melt bar metal, which can be held by the cold end.
Step-by-step instructions for assembly - simple operations
Print and hang a drawing of Kukhtetsky's laboratory inverter over your desktop. After that, lay out all the radio components by grades and brands and heat up the soldering iron. Attach the two transistors to the heatsinks. And if you work with the stove for more than 10-15 minutes in a row, fix coolers from the computer on the radiators by connecting them to a working power supply. The pinout diagram for transistors from the IRFZ44V series is as follows:
Take a 1.2 mm copper wire and wind it around the ferrite rings, making 9-10 turns. As a result, you will get chokes. The distance between the turns is determined by the diameter of the ring, based on the uniformity of the pitch. In principle, everything can be done "by eye", varying the number of turns in the range from 7 to 15 turns. Assemble a battery of capacitors by connecting all the parts in parallel. As a result, you should get a 4.7 microfarad battery.
Now make an inductor out of 2mm copper wire. The diameter of the turns in this case can be equal to the diameter of a porcelain crucible or 8-10 centimeters. The number of turns should not exceed 7-8 pieces. If during the testing process the power of the furnace seems insufficient to you, redo the design of the inductor by changing the diameter and number of turns. Therefore, in the first pair, it is better to make the inductor contacts not soldered, but detachable. Next, assemble all the elements on the PCB board, based on the drawing of Kukhtetsky's laboratory inverter. And connect a 7200 mAh battery to the power contacts. That's all.
Induction heaters work on the principle of “getting current from magnetism”. In a special coil, a high-power alternating magnetic field is generated, which generates eddy electric currents in a closed conductor.
A closed conductor in induction cookers is metal utensils, which are heated by eddy electric currents. In general, the principle of operation of such devices is not complicated, and with little knowledge in physics and electrical engineering, it will not be difficult to assemble an induction heater with your own hands.
The following devices can be made independently:
- Devices for heating the coolant in the heating boiler.
- Mini ovens for melting metals.
- Plates for cooking food.
Do-it-yourself induction cooker must be made in compliance with all norms and rules for the operation of these devices. If electromagnetic radiation dangerous for humans is emitted outside the case in the lateral directions, then it is strictly forbidden to use such a device.
In addition, a great difficulty in the design of the stove lies in the selection of material for the base of the hob, which must meet the following requirements:
- Ideal for conducting electromagnetic radiation.
- Not conductive.
- Withstand high temperature stress.
In household induction hobs, expensive ceramics are used; in the manufacture of an induction cooker at home, it is rather difficult to find a worthy alternative to such material. Therefore, to begin with, you should design something simpler, for example, an induction furnace for hardening metals.
Blueprints
Figure 1. Electrical diagram of an induction heater. Figure 2. Device. Figure 3. Diagram of a simple induction heater.
For the manufacture of the furnace you will need the following materials and tools:
- soldering iron;
- solder;
- textolite board.
- mini drill.
- radioelements.
- thermal paste.
- chemical reagents for board etching.
Additional materials and their features:
- To make a coil, which will emit an alternating magnetic field necessary for heating, it is necessary to prepare a piece of copper tube with a diameter of 8 mm and a length of 800 mm.
- Powerful power transistors are the most expensive part of a homemade induction installation. To mount the frequency generator circuit, it is necessary to prepare 2 such elements. For these purposes, transistors of brands are suitable: IRFP-150; IRFP-260; IRFP-460. In the manufacture of the circuit, 2 identical of the listed field-effect transistors are used.
- For the manufacture of an oscillatory circuit you will need ceramic capacitors with a capacity of 0.1 mF and an operating voltage of 1600 V. In order for a high-power alternating current to form in the coil, 7 such capacitors are required.
- During the operation of such an induction device, field-effect transistors will get very hot and if aluminum alloy radiators are not attached to them, then after a few seconds of operation at maximum power, these elements will fail. Transistors should be placed on heat sinks through a thin layer of thermal paste, otherwise the efficiency of such cooling will be minimal.
- Diodes, which are used in an induction heater, must be of ultra-fast action. The most suitable for this circuit, diodes: MUR-460; UV-4007; HER-307.
- Resistors used in circuit 3: 10 kOhm with a power of 0.25 W - 2 pcs. and 440 ohm power - 2 watts. Zener diodes: 2 pcs. with an operating voltage of 15 V. The power of the zener diodes must be at least 2 watts. A choke for connecting to the power outputs of the coil is used with induction.
- To power the entire device, you will need a power supply unit with a capacity of up to 500. W. and voltage 12 - 40 V. You can power this device from a car battery, but you will not be able to get the highest power readings at this voltage.
The very process of manufacturing an electronic generator and coil takes a little time and is carried out in the following sequence:
- From a copper pipe a spiral with a diameter of 4 cm is made. To make a spiral, a copper tube should be wound onto a rod with a flat surface with a diameter of 4 cm. The spiral should have 7 turns that should not touch. Mounting rings are soldered to the 2 ends of the tube for connection to the transistor radiators.
- The printed circuit board is made according to the scheme. If it is possible to supply polypropylene capacitors, then due to the fact that such elements have minimal losses and stable operation at large amplitudes of voltage fluctuations, the device will work much more stable. The capacitors in the circuit are installed in parallel, forming an oscillatory circuit with a copper coil.
- Metal heating occurs inside the coil, after the circuit is connected to a power supply or battery. When heating the metal, it is necessary to ensure that there is no short circuit of the spring windings. If you touch the heated metal 2 turns of the coil at the same time, then the transistors fail instantly.
Nuances
- When conducting experiments on heating and hardening metals, inside the induction coil the temperature can be significant and amounts to 100 degrees Celsius. This heating effect can be used to heat domestic water or to heat a house.
- Scheme of the heater discussed above (Figure 3), at maximum load it is able to provide the radiation of magnetic energy inside the coil equal to 500 watts.
Such power is not enough to heat a large volume of water, and the construction of a high power induction coil will require the manufacture of a circuit in which it will be necessary to use very expensive radio elements.
- A budget solution for organizing induction heating of a liquid, is the use of several devices described above, arranged in series. In this case, the spirals must be on the same line and not have a common metal conductor.
- as a heat exchangera stainless steel pipe with a diameter of 20 mm is used. Several induction spirals are “strung” onto the pipe, so that the heat exchanger is in the middle of the spiral and does not come into contact with its turns.
With the simultaneous inclusion of 4 such devices, the heating power will be about 2 kW, which is already enough for the flow heating of the liquid with a small circulation of water, to values \u200b\u200ballowing the use of this design in supplying warm water to a small house.
- If you connect such a heating element to a well-insulated tank, which will be located above the heater, the result will be a boiler system in which the heating of the liquid will be carried out inside the stainless pipe, the heated water will rise up, and a colder liquid will take its place.
- If the area of the house is significant, the number of induction coils can be increased up to 10 pieces.
- The power of such a boiler can be easily adjusted by turning off or on the spirals. The more sections that are simultaneously turned on, the greater the power of the heating device operating in this way will be.
- To power such a module, you need a powerful power supply. If a DC inverter welding machine is available, then a voltage converter of the required power can be made from it.
- Due to the fact that the system operates on direct electric current, which does not exceed 40 V, the operation of such a device is relatively safe, the main thing is to provide a fuse block in the generator power circuit, which, in the event of a short circuit, will de-energize the system, thereby eliminating the possibility of a fire.
- It is possible to organize “free” heating of the house in this way, provided that batteries are installed to power induction devices, which will be charged using solar and wind energy.
- Batteries should be combined in sections of 2, connected in series. As a result, the supply voltage with such a connection will be at least 24 V., which will ensure the operation of the boiler at high power. In addition, series connection will reduce the current in the circuit and increase the battery life.
- Operation of homemade induction heating devices, does not always make it possible to exclude the spread of electromagnetic radiation harmful to humans, therefore the induction boiler should be installed in a non-residential area and shielded with galvanized steel.
- Mandatory when working with electricitysafety regulations must be followed and, especially for 220 V AC networks.
- As an experimentyou can make a hob for cooking according to the scheme indicated in the article, but it is not recommended to constantly operate this device due to the imperfection of self-manufacturing of the shielding of this device, because of this, the human body may be exposed to harmful electromagnetic radiation that can adversely affect health.
Source: http://housetronic.ru/otoplenie/obogrevateli/elektroobogrevateli/indukcionnye-svoimi-rukami.html
Induction cooker diagram - basic device
The induction cooker is capable of heating metal utensils by means of induced eddy currents from a high-frequency magnetic field.
The standard scheme of an induction cooker, as a rule, is represented by an induction coil and a frequency converter, as well as an electronic control unit equipped with temperature sensors.
Introduction
Induction cookers are relatively new equipment, but already extremely popular with domestic consumers.
A feature of such stoves is the ability to heat only the bottom of the cookware.
In conventional electric stoves, the switched-on burner is initially heated.
Before choosing such equipment, it is important to familiarize yourself with the advantages of operation, as well as take into account some of the design flaws of the induction cooker.
The main advantages are presented:
- a faster heating and cooking process, which takes several times less time than with a traditional electric stove;
- the absence of burning food that can get on the hob during cooking, due to the low temperature of the burner;
- reduction of consumed electrical energy due to the very rapid heating of the used kitchen utensils;
- ease of use due to the ability to adjust the cooking mode on different stoves.
The advantages also include safety of operation, which is especially important for families with small children, pensioners or people with disabilities.
Induction cooker in the kitchen
Disadvantages of operation in such modern equipment are also present and, despite the fact that they are minimal, they should be taken into account when choosing a model:
- turning on induction equipment at full power can create an increased load on the power grid;
- for cooking on this type of stove, only special cookware with a ferromagnetic bottom should be used;
- some models are characterized by the presence of a single high-frequency generator, which adversely affects the power level when all burners are turned on at the same time;
- The hob is fragile, so during the entire period of operation, some care must be taken.
As practice shows, the operation of models belonging to the economy class price category is often accompanied by annoying noise and a peculiar buzz.
It is important to remember that induction cookers are capable of creating a fairly high electromagnetic type of radiation and can have a negative effect on household appliances installed at a short distance.
Scheme of the induction cooker
In accordance with the heating scheme, the electric current that comes from the mains to the coil undergoes a transformation into a magnetic field that generates vortex flows.
As a result of the interaction of the ferromagnetic bottom with the induction current, a circuit is formed, and the resulting thermal energy heats the used kitchen utensils and their contents.
The glass-ceramic surface of the stove covers an induction coil with an electric current flowing at a frequency of 50 kHz.
The standard equipment layout is relatively complex, and can vary greatly depending on the model.
The basis is represented by an oscillator, a driver on transistors of medium power and an output bipolar transistor with an insulated gate and controlling an inductor coil.
The scheme of operation of the induction cooker is reflected in the rules of service and the features of the operation of such equipment, and must also be taken into account when choosing cookware, which must be made of special materials with ferromagnetic properties.
Electrical diagram of the induction cooker
The most complex structural element is the electronic control unit, through which not only turns on, but also regulates the power level of the generator.
Modern models are characterized by the presence of an infrared sensor device that effectively controls the cooking process.
Once the cookware is removed from the hob, the hob will automatically switch off.
Do not use copper, glass, ceramic or aluminum utensils, and cleaning the surface of the induction cooker is carried out only with special products that do not have abrasive effects.
The power circuit of a standard induction cooker can vary significantly depending on the design features of the modification, but is most often represented by:
- ferrite torus, which is put on the mains wire and suppresses common-mode interference;
- standard fuse;
- a capacitor that filters impulse noise that occurs during operation;
- a resistor that operates after the mains power is turned off;
- a rectifier designed for power indicators and effectively protecting the device from overvoltage;
- wire shunt;
- filtering system for impulse noise;
- a capacitor that allows you to return energy from the oscillatory-inductor circuit to the intermediate part with constant current indicators;
- a resonant capacitor that provides continuous current after the transistor is locked;
- an induction device, which is focused on the transfer of heat from the surface to the bottom of the used kitchen utensils;
- a transistor that converts direct current into variable indicators;
- resistor to fix the transistor after shutdown;
- a resistor to suppress high-frequency current indicators;
- rectifier for voltage in the electrical network;
- current controller, which prevents the possible occurrence of overload;
- collector voltage controller.
In budget models, there are only basic structural elements, which affects the functionality of such a device.
Self-production of a simple induction cooker involves strict adherence to all standards, which will make the operation of such a device completely safe. Significant complexity in the process of designing a stove arises at the stage of selecting high-quality material to create the base of the hob.
Do-it-yourself induction cooker - diagram
Such a material must necessarily be distinguished by the ability to correctly conduct electromagnetic radiation, not conduct current and withstand high-temperature conditions.
Factory-made household cooking equipment, which includes all modern induction cookers, is made using quite expensive ceramics.
It is for this reason that the independent manufacture of an induction hob at home is associated with certain problems in choosing a worthy alternative to a ceramic surface.
Conclusion
Modern household induction hobs, as a rule, have a standard scheme, according to which the installed magnetic coils, in the process of contact with the ferromagnetic bottom of the cookware, carry out stable heating of the cooked food.
The control of such household equipment can be carried out by means of mechanical switches and touch buttons, which makes the operation of the induction cooker very convenient.
Source: https://microklimat.pro/otopitelnoe-oborudovanie/otopitelnye-pribory/cxema-indukcionnoj-plity.html
Do-it-yourself induction furnace - instructions!
Induction furnaces are used for smelting metals and are distinguished by the fact that they are heated by means of electric current. The excitation of the current occurs in the inductor, or rather in a non-variable field.
DIY induction oven
In such constructions, energy is converted several times (in this sequence):
- into the electromagnetic
- electrical;
- thermal.
Such stoves allow you to use heat with maximum efficiency, which is not surprising, because they are the most advanced of all existing models that run on electricity.
Note! Induction designs are of two types - with or without a core. In the first case, the metal is placed in a tubular chute, which is located around the inductor. The core is located in the inductor itself. The second option is called the crucible, because in it the metal with the crucible is already inside the indicator. Of course, there can be no talk of any core in this case.
In today's article, we will talk about how to make an induction furnace with your own hands.
Pros and cons of induction designs
Among the many benefits are the following:
- environmental cleanliness and safety;
- increased homogeneity of the melt due to the active movement of the metal;
- speed - the oven can be used almost immediately after switching on;
- zone and focused orientation of energy;
- high melting rate;
- lack of waste from alloying substances;
- the ability to adjust the temperature;
- numerous technical possibilities.
But there are also disadvantages.
- The slag is heated by the metal, as a result of which it has a low temperature.
- If the slag is cold, then it is very difficult to remove phosphorus and sulfur from the metal.
- Between the coil and the melting metal, the magnetic field dissipates, so a reduction in lining thickness will be required. This will soon lead to the fact that the lining itself will fail.
Industrial Application
Both design options are used in the smelting of iron, aluminium, steel, magnesium, copper and precious metals. The useful volume of such structures can range from several kilograms to several hundred tons.
Furnaces for industrial use are divided into several types.
- Medium frequency designs are commonly used in mechanical engineering and metallurgy. With their help, steel is melted, and when using graphite crucibles, non-ferrous metals are also melted.
- Industrial frequency designs are used in iron smelting.
- Resistance structures are intended for melting aluminum, aluminum alloys, zinc.
Note! It was induction technology that formed the basis of more popular devices - microwave ovens.
domestic use
Scheme of the induction furnace
For obvious reasons, the induction melting furnace is rarely used in the home. But the technology described in the article is found in almost all modern houses and apartments. These are the microwaves mentioned above, and induction cookers, and electric ovens.
Consider, for example, plates. They heat the dishes due to inductive eddy currents, as a result of which the heating occurs almost instantly. It is characteristic that it is impossible to turn on the burner on which there are no dishes.
The efficiency of induction cookers reaches 90%. For comparison: for electric stoves it is about 55-65%, and for gas stoves - no more than 30-50%. But in fairness, it is worth noting that the operation of the described stoves requires special dishes.
Homemade induction oven
Scheme for the design of the generator
Not so long ago, domestic radio amateurs clearly demonstrated that you can make an induction furnace yourself. Today, there are a lot of different schemes and manufacturing technologies, but we have given only the most popular of them, which means the most effective and easy to implement.
Induction furnace from high frequency generator
Below is an electrical circuit for making a homemade device from a high-frequency (27.22 megahertz) generator.
In addition to the generator, the assembly will require four high-power light bulbs and a heavy lamp for the ready-to-work indicator.
Note! The main difference between the furnace, made according to this scheme, is the condenser handle - in this case, it is located outside.
In addition, the metal in the coil (inductor) will melt in the device of the smallest power.
When manufacturing, it is necessary to remember some important points that affect the speed of metal boarding. It:
- power;
- frequency;
- eddy losses;
- heat transfer intensity;
- hysteresis loss.
The device will be powered by a standard 220 V network, but with a pre-installed rectifier. If the furnace is intended for heating a room, then it is recommended to use a nichrome spiral, and if for melting, then graphite brushes. Let's get acquainted with each of the structures in more detail.
Graphite brush design
The essence of the design is as follows: a pair of graphite brushes is installed, and powdered granite is poured between them, after which a step-down transformer is connected. It is characteristic that when smelting, one can not be afraid of electric shock, since there is no need to use 220 V.
Making an induction furnace
Assembly technology
Step 1. The base is assembled - a box of fireclay bricks measuring 10x10x18 cm, laid on a refractory tile.
Step 2. Boxing is finished with asbestos cardboard. After wetting with water, the material softens, which allows you to give it any shape. If desired, the structure can be wrapped with steel wire.
Note! The dimensions of the box may vary depending on the power of the transformer.
Step 3. The best option for a graphite furnace is a transformer from a 0.63 kW welding machine. If the transformer is designed for 380 V, then it can be rewound, although many experienced electricians say that you can leave everything as it is.
Step 4. The transformer is wrapped with thin aluminum - so the structure will not get very hot during operation.
Step 5. Graphite brushes are installed, a clay substrate is installed on the bottom of the box - so the molten metal will not spread.
Graphite brush design
The main advantage of such a furnace is the high temperature, which is suitable even for melting platinum or palladium. But among the minuses is the rapid heating of the transformer, a small volume (no more than 10 g can be smelted at a time). For this reason, a different design will be required for melting large volumes.
Device with nichrome spiral
Device with nichrome spiral
So, for the smelting of large volumes of metal, a furnace with nichrome wire is required. The principle of operation of the design is quite simple: an electric current is applied to a nichrome spiral, which heats up and melts the metal. There are a lot of different formulas on the Web for calculating the length of the wire, but they are all, in principle, the same.
Step 1. For the spiral, nichrome ø0.3 mm is used, about 11 m long.
Step 2. The wire must be wound. To do this, you need a straight copper tube ø5 mm - a spiral is wound on it.
Step 3. A small ceramic pipe ø1.6 cm and 15 cm long is used as a crucible. One end of the pipe is plugged with asbestos thread - so the molten metal will not flow out.
Step 4. After checking the performance, the spiral is laid around the pipe. At the same time, the same asbestos thread is placed between the turns - it will prevent a short circuit and limit the access of oxygen.
Step 5. The finished coil is placed in a cartridge from a high power lamp. Such cartridges are usually ceramic and have the required size.
Finished construction
The advantages of such a design:
- high productivity (up to 30 g per run);
- fast heating (about five minutes) and long cooling;
- ease of use - it is convenient to pour metal into molds;
- prompt replacement of the spiral in case of burnout.
But there are, of course, downsides:
- nichrome burns out, especially if the spiral is poorly insulated;
- insecurity - the device is connected to the mains 220 V.
Note! You can not add metal to the stove if the previous portion is already melted there. Otherwise, all the material will scatter around the room, moreover, it may injure the eyes.
As a conclusion
Induction cooker
As you can see, you can still make an induction furnace on your own. But to be frank, the described design (like everything available on the Internet) is not quite a furnace, but a Kukhtetsky laboratory inverter. It is simply impossible to assemble a full-fledged induction structure at home.
Source: https://svoimi-rykami.ru/stroitelstvo-doma/pechi_i_mangaly/indukcionnaya-pech-svoimi-rukami.html
How to make an induction boiler with your own hands
Induction heating boilers appeared on sale recently and immediately competed with the usual electric boilers with heating elements.
With similar size and power consumption, induction heaters are able to warm up the system much faster, in addition, they can work in systems with poor quality of the coolant and require less maintenance.
Applying knowledge in electrical engineering and ingenuity, you can make an induction heating boiler with your own hands.
Operating principle
The operation of induction boilers and other heating devices of this type is based on the ability of conductive materials to heat up under the action of eddy currents created as a result of electromagnetic induction.
The source of induction is a high-frequency alternating current passing through the primary winding of the heating device, made in the form of a coil. The heating element placed inside the coil plays the role of a secondary short-circuited winding. It converts electromagnetic energy into thermal energy.
Eddy currents also occur at an industrial frequency of 50 Hz, but the efficiency of the heater will be low, and the operation of the device will be accompanied by a strong hum and vibration. When the frequency is increased to 10 kHz and above, the noise disappears, the vibration becomes imperceptible, and the heating increases.
Device
An industrial induction boiler consists of a core, the role of which is played by a heat exchanger, around which a toroidal winding is wound, connected to a high-frequency converter. When current passes through the winding, an alternating electromagnetic field is created, which results in eddy currents passing through the core.
The winding is connected to a high-frequency converter, in which a signal from the control unit creates a current of the required frequency. Modern boilers have a high level of automation, which allows not only to create the optimal mode for heating the coolant, but also to turn off the device in case of an emergency.
Inside the core-heat exchanger is a coolant. Under the influence of eddy currents, it heats up to high temperatures.
Due to the difference between the temperature of the coolant at the inlet and outlet, the circulation of the coolant through the system from the boiler occurs continuously, even without connecting the pump.
Therefore, induction boilers can be used in systems with forced and natural circulation.
The coolant can be either water or antifreeze, antifreeze, oil. In this case, the quality of the liquid does not matter: the constant vibration of the system, which is imperceptible by a person, makes it impossible for scale and other impurities to settle on the walls of the heating circuit.
Outer shell- a metal case equipped with a system of thermal and electrical protection insulation.
Boiler shape it can be any, as well as the method of its installation: due to the absence of a tank inside the boiler, its dimensions are usually small, and its weight does not exceed 50 kg.
The induction boiler must not even be put into operation for a short time without filling the system with coolant! Overheating of the boiler and failure of its elements may occur!
Advantages:
- High efficiency. Most manufacturers give figures of 95-98%;
- Large selection of models of different power for single-phase voltage ~ 220 V or three-phase ~ 380 V;
- Rapid heating of the heating system at startup;
- Can work with any coolant;
- The circuit through which the coolant passes inside the boiler is absolutely hermetic, which eliminates leaks and related malfunctions;
- Long work without formation of a scum and deposits. It is this phenomenon that over time reduces the efficiency of boilers with heating elements and is a common cause of their breakdown due to overheating of the heating elements;
- The service life declared by manufacturers is from 25 to 30 years.
Not without heaters and disadvantages, the most significant of which is the high price.
This factor usually prompts a prudent owner to assemble a home-made induction boiler from improvised materials and appliances.
Despite the complexity of the processes occurring in boilers of this type, it is possible to create a design that does not lag behind an industrial boiler in terms of basic parameters, and make an induction boiler with your own hands.
Boiler powered by a welding inverter
The design of such a homemade boiler is quite simple. The most difficult block for independent implementation, which requires knowledge of the basics of electronics and electrical engineering, is a high-frequency converter. Its function is perfectly performed by a modern-type welding inverter capable of delivering an output signal with a frequency of 20-50 kHz.
In addition, for installation you will need:
- copper wire in enamel insulation with a diameter of 1-1.5 mm;
- insulated wire with terminals for connecting the winding to the inverter;
- cuttings of stainless steel wire with a diameter of 3-5 mm, 5 cm long;
- fine stainless steel mesh;
- a section of a water pipe made of sewn polyethylene or polypropylene for hot water and heating systems with a diameter of 50 mm and a wall thickness of 8.4 mm, length - 1 m;
- adapters from a 50 mm pipe to pipes used in an existing or planned heating system, a tee for connecting an emergency valve and two ball valves;
- strips of textolite for fastening the winding;
- epoxy adhesive for winding insulation;
- the body of a homemade boiler, it can be made from a metal or plastic distribution cabinet, in which you can install an inverter and fix the heating element.
The sequence of assembly and installation of elements:
- On a segment of a polypropylene pipe with a diameter of 50 mm, using epoxy glue, 4 strips of textolite 8-10 mm wide are attached, stepping back from the ends of the pipe by 70-100 mm. A winding will be wound on them. To fix the extreme turns of the winding in the textolite, grooves can be made.
- 50-100 turns of copper wire are wound in enamel insulation. The turns should be approximately 0.3-0.6 mm apart at an equal distance. The exact number of turns depends on the diameter of the wire used and its resistivity, as well as the output parameters of the inverter.
- When installing a homemade boiler in a residential area, it is recommended to perform a toroidal winding to reduce the external electromagnetic field. The toroidal winding consists of the same number of oppositely directed turns, while the electromagnetic fluxes are mutually compensated and pass only along the inner loop.
- A stainless steel mesh is inserted into the pipe from one end of it and tightly packed on the other side with pieces of stainless wire - it will heat up under the influence of eddy currents. It is recommended to use stainless steel so that corrosion damage of the wire does not occur over time, but theoretically any conductive metal, including wire rod, will do. The other end of the pipe is also closed with a mesh.
- Polypropylene adapters are soldered to both ends of the pipes to the diameter used in the heating system. Ball valves are installed on them to shut off the circulation and remove the heat exchanger for revision.
- An emergency valve is installed on the side of the upper outlet adapter to relieve pressure.
The winding is coated with epoxy glue to ensure high-quality electrical insulation of the winding. The manufacture of glue is recommended to be carried out with a slight deviation from the instructions, adding 10-15% less hardener. This will make the insulation less brittle. - They are attached to the terminals of the winding wires in insulation using crimp terminals. The other end of the wire must be equipped with terminals for connection to the inverter. The diameter of the wires must be able to withstand the maximum output current of the inverter.
- Install the heat exchanger in the cabinet, fixing it on brackets made of heat-resistant non-conductive material. Textolite can be used.
- Connect the heater to the system and fill it with water.
- An inverter is placed at the bottom of the cabinet. Connect the terminals to it and turn it on to the network. The boiler is started and the mode is set.
The cabinet body made of metal must be grounded!
From induction hob
An induction boiler can also be made on the basis of an induction hob. To do this, the heating element of the tile is disassembled and a copper wire is used for winding on a core made in the above way.
The tile control unit is used to power the resulting winding, setting the required power on the touch control panel.
However, this method has significant disadvantages:
- For the successful operation of such a home-made boiler, it is necessary to calculate the parameters of the inductance of the newly assembled coil. They may not match those for which the tile electronics are designed, as a result of which the control unit may fail. For calculations, you need to have good knowledge in the field of electrical engineering and be able to understand the connection diagram;
- Most stove models are equipped with an automatic shutdown after 2-3 hours after the start of the burner. This will lead to a regular shutdown of the boiler;
- Induction type stoves usually have a power of no more than 2.5 kW, therefore they are only suitable for conversion to a low power boiler.
Errors in the device of an induction tile boiler are shown in the video:
An easier way to use an induction hob, excluding disassembly of the device and installation of a new circuit - install a sealed stainless steel tank of a suitable size on it with an inlet and outlet fitting and connecting it as a boiler to the heating system. Almost everyone can cope with such a connection scheme.
If you have the necessary knowledge and ability to understand the circuits, you can follow the example of the author of the video and assemble a functional induction boiler from tiles, finalizing its circuit.
Dry type heater
The principle of operation of an induction boiler involves the use of water or other liquid not only as a heat carrier, but also to cool the core.
But the heating of the secondary winding, the role of which in this device is played by a pipe with water, will also occur if it consists only of metal.
The degree of heating in this case depends on the ratio of the strength of the electromagnetic field created by the winding and the mass of the core metal.
After making the calculations, you can create a dry induction heater with your own hands from metal pipes and copper winding, as shown in the video.
The use of an induction boiler is cheaper than a conventional electric boiler with heating elements, and a home-made design will significantly reduce the cost of its installation. Similarly, you can assemble a flow-type water heater for installation in the country, choosing a device of the required power.
The induction furnace is no longer a novelty - this invention has existed since the 19th century, but only in our time, with the development of technology and the element base, it finally begins to enter everyday life everywhere. Previously, there were many questions in the intricacies of the operation of induction furnaces, not all physical processes were fully understood, and the units themselves had a lot of shortcomings and were used only in industry, mainly for melting metals.
Now, with the advent of powerful high-frequency transistors and cheap microcontrollers that have made a breakthrough in all areas of science and technology, truly efficient induction furnaces have appeared that can be freely used for domestic needs (cooking, heating water, heating) and even assemble hands.
Physical basis and principle of operation of the furnace
Fig.1. Scheme of the induction furnaceBefore choosing or making an inductor heater, you should understand what it is. Recently, there has been an outbreak of interest in this topic, but few people have a complete understanding of the physics of magnetic waves. This gave rise to many misconceptions, myths and a lot of inefficient or unsafe homemade products. You can make an induction furnace with your own hands, but before that you should get at least basic knowledge.
The induction stove is based on the principle of electromagnetic induction. The key element here is the inductor, which is a high quality inductor. Induction furnaces are widely used for heating or melting electrically conductive materials, most often metals, due to the thermal effect of inducing an eddy electric current in them. The above diagram illustrates the design of this furnace (Fig. 1).
Generator G produces a variable frequency voltage. Under the action of its electromotive force, an alternating current I 1 flows in the inductor coil L. The inductor L together with the capacitor C is an oscillatory circuit tuned to resonance with the frequency of the source G, due to which the efficiency of the furnace is significantly increased.
In accordance with physical laws, an alternating magnetic field H arises in the space around the inductor L. This field can also exist in the air, but special ferromagnetic cores are sometimes used to improve performance, which have better magnetic conductivity compared to air.
The lines of force of the magnetic field pass through an object W placed inside the inductor and induce a magnetic flux F in it. If the material from which the workpiece W is made is electrically conductive, an induced current I 2 appears in it, closing inside and forming eddy induction flows. In accordance with the law of the thermal effect of electricity, eddy currents heat up the object W.
Making an inductive heater
An induction furnace consists of two main functional blocks: an inductor (a heating induction coil) and a generator (an alternating voltage source). The inductor is a bare copper tube coiled into a spiral (Fig. 2).
To make a do-it-yourself furnace with a power of not more than 3 kW, the inductor must be made with the following parameters:
- tube diameter - 10 mm;
- spiral diameter - 8-15 cm;
- the number of turns of the coil - 8-10;
- the distance between the turns is 5-7 mm;
- the minimum gap in the screen is 5 cm.
Adjacent turns of the coil must not be allowed to touch, keep the specified distance. The inductor must not come into contact with the protective screen of the furnace in any way, the gap between them must not be less than the specified one.
Generator manufacturing
Fig.3. Scheme on lamps
It is worth noting that an induction furnace for its manufacture requires at least average radio engineering skills and abilities. It is especially important to have them to create the second key element - a high-frequency current generator. Neither assembling nor using a do-it-yourself oven will work without this knowledge. Moreover, it can be life-threatening.
For those who take up this business with knowledge and understanding of the process, there are various ways and schemes by which an induction furnace can be assembled. When choosing a suitable generator circuit, it is recommended to abandon options with a hard emission spectrum. These include the widespread scheme using a thyristor key. High-frequency radiation from such a generator is capable of creating powerful interference for all surrounding radio devices.
Since the middle of the 20th century, an induction furnace assembled on 4 lamps has enjoyed great success among radio amateurs. Its quality and efficiency are far from the best, and radio tubes are difficult to access nowadays, however, many continue to assemble generators according to this scheme, since it has a great advantage: a soft, narrow-band spectrum of the generated current, due to which such a furnace emits a minimum of interference and as safe as possible (Fig. 3).
The operating mode of this generator is set using a variable capacitor C. The capacitor must be with an air dielectric, the gap between its plates must be at least 3 mm. The diagram also contains a neon lamp L, which serves as an indicator.
Scheme of a universal generator
Modern induction furnaces operate on more advanced elements - microcircuits and transistors. The universal scheme of a push-pull generator, which develops power up to 1 kW, is enjoying great success. The principle of operation is based on an independent excitation generator, while the inductor is switched on in the bridge mode (Fig. 4).
Advantages of a push-pull generator assembled according to this scheme:
- The ability to work on the 2nd and 3rd mode in addition to the main one.
- There is a surface heating mode.
- Control range 10-10000 kHz.
- Soft spectrum of radiation in the entire range.
- Does not need additional protection.
Frequency tuning is carried out using a variable resistor R 2 . The operating frequency range is set by capacitors C 1 and C 2 . The interstage matching transformer must be with a ring ferrite core with a cross section of at least 2 sq.cm. The winding of the transformer is made of enameled wire with a cross section of 0.8-1.2 mm. Transistors must be seated on a common radiator with an area of \u200b\u200b400 sq. Cm.
Conclusion on the topic
The electromagnetic field (EMF) emitted by the induction furnace affects all the conductors around. It also affects the human body. The internal organs under the action of EMF are evenly warmed up, the overall body temperature rises throughout the entire volume.
Therefore, when working with the oven, it is important to observe certain precautions in order to avoid negative consequences.
First of all, the generator housing must be shielded with a casing made of galvanized iron sheets or fine mesh. This will reduce the radiation intensity by 30-50 times.
It should also be borne in mind that in the immediate vicinity of the inductor, the energy flux density will be higher, especially along the winding axis. Therefore, the induction coil must be placed vertically, and it is better to observe the heating from afar.
Induction furnaces are used for smelting metals and are distinguished by the fact that they are heated by means of electric current. The excitation of the current occurs in the inductor, or rather in a non-variable field.
In such constructions, energy is converted several times (in this sequence):
- into the electromagnetic
- electrical;
- thermal.
Such stoves allow you to use heat with maximum efficiency, which is not surprising, because they are the most advanced of all existing models that run on electricity.
Note! Induction designs are of two types - with or without a core. In the first case, the metal is placed in a tubular chute, which is located around the inductor. The core is located in the inductor itself. The second option is called the crucible, because in it the metal with the crucible is already inside the indicator. Of course, there can be no talk of any core in this case.
In today's article we will talk about how to makeDIY induction oven.
Among the many benefits are the following:
- environmental cleanliness and safety;
- increased homogeneity of the melt due to the active movement of the metal;
- speed - the oven can be used almost immediately after switching on;
- zone and focused orientation of energy;
- high melting rate;
- lack of waste from alloying substances;
- the ability to adjust the temperature;
- numerous technical possibilities.
But there are also disadvantages.
- The slag is heated by the metal, as a result of which it has a low temperature.
- If the slag is cold, then it is very difficult to remove phosphorus and sulfur from the metal.
- Between the coil and the melting metal, the magnetic field dissipates, so a reduction in lining thickness will be required. This will soon lead to the fact that the lining itself will fail.
Video - Induction furnace
Industrial Application
Both design options are used in the smelting of iron, aluminium, steel, magnesium, copper and precious metals. The useful volume of such structures can range from several kilograms to several hundred tons.
Furnaces for industrial use are divided into several types.
- Medium frequency designs are commonly used in mechanical engineering and metallurgy. With their help, steel is melted, and when using graphite crucibles, non-ferrous metals are also melted.
- Industrial frequency designs are used in iron smelting.
- Resistance structures are intended for melting aluminum, aluminum alloys, zinc.
Note! It was induction technology that formed the basis of more popular devices - microwave ovens.
domestic use
For obvious reasons, the induction melting furnace is rarely used in the home. But the technology described in the article is found in almost all modern houses and apartments. These are the microwaves mentioned above, and induction cookers, and electric ovens.
Consider, for example, plates. They heat the dishes due to inductive eddy currents, as a result of which the heating occurs almost instantly. It is characteristic that it is impossible to turn on the burner on which there are no dishes.
The efficiency of induction cookers reaches 90%. For comparison: for electric stoves it is about 55-65%, and for gas stoves - no more than 30-50%. But in fairness, it is worth noting that the operation of the described stoves requires special dishes.
Homemade induction oven
Not so long ago, domestic radio amateurs clearly demonstrated that you can make an induction furnace yourself. Today, there are a lot of different schemes and manufacturing technologies, but we have given only the most popular of them, which means the most effective and easy to implement.
Induction furnace from high frequency generator
Below is an electrical circuit for making a homemade device from a high-frequency (27.22 megahertz) generator.
In addition to the generator, the assembly will require four high-power light bulbs and a heavy lamp for the ready-to-work indicator.
Note! The main difference between the furnace, made according to this scheme, is the condenser handle - in this case, it is located outside.
In addition, the metal in the coil (inductor) will melt in the device of the smallest power.
When manufacturing, it is necessary to remember some important points that affect the speed of metal boarding. It:
- power;
- frequency;
- eddy losses;
- heat transfer intensity;
- hysteresis loss.
The device will be powered by a standard 220 V network, but with a pre-installed rectifier. If the furnace is intended for heating a room, then it is recommended to use a nichrome spiral, and if for melting, then graphite brushes. Let's get acquainted with each of the structures in more detail.
Video - Welding inverter design
The essence of the design is as follows: a pair of graphite brushes is installed, and powdered granite is poured between them, after which a step-down transformer is connected. It is characteristic that when smelting, one can not be afraid of electric shock, since there is no need to use 220 V.
Assembly technology
Step 1. The base is assembled - a box of fireclay bricks measuring 10x10x18 cm, laid on a refractory tile.
Step 2. Boxing is finished with asbestos cardboard. After wetting with water, the material softens, which allows you to give it any shape. If desired, the structure can be wrapped with steel wire.
Note! The dimensions of the box may vary depending on the power of the transformer.
Step 3. The best option for a graphite furnace is a transformer from a 0.63 kW welding machine. If the transformer is designed for 380 V, then it can be rewound, although many experienced electricians say that you can leave everything as it is.
Step 4. The transformer is wrapped with thin aluminum - so the structure will not get very hot during operation.
Step 5. Graphite brushes are installed, a clay substrate is installed on the bottom of the box - so the molten metal will not spread.
The main advantage of such a furnace is the high temperature, which is suitable even for melting platinum or palladium. But among the minuses is the rapid heating of the transformer, a small volume (no more than 10 g can be smelted at a time). For this reason, a different design will be required for melting large volumes.
So, for the smelting of large volumes of metal, a furnace with nichrome wire is required. The principle of operation of the design is quite simple: an electric current is applied to a nichrome spiral, which heats up and melts the metal. There are a lot of different formulas on the Web for calculating the length of the wire, but they are all, in principle, the same.
Step 1. For the spiral, nichrome ø0.3 mm is used, about 11 m long.
Step 2. The wire must be wound. To do this, you need a straight copper tube ø5 mm - a spiral is wound on it.
Step 3. A small ceramic pipe ø1.6 cm and 15 cm long is used as a crucible. One end of the pipe is plugged with asbestos thread - so the molten metal will not flow out.
Step 4. After checking the performance and the spiral is laid around the pipe. At the same time, the same asbestos thread is placed between the turns - it will prevent a short circuit and limit the access of oxygen.
Step 5. The finished coil is placed in a cartridge from a high power lamp. Such cartridges are usually ceramic and have the required size.
The advantages of such a design:
- high productivity (up to 30 g per run);
- fast heating (about five minutes) and long cooling;
- ease of use - it is convenient to pour metal into molds;
- prompt replacement of the spiral in case of burnout.
But there are, of course, downsides:
- nichrome burns out, especially if the spiral is poorly insulated;
- insecurity - the device is connected to the mains 220 V.
Note! You can not add metal to the stove if the previous portion is already melted there. Otherwise, all the material will scatter around the room, moreover, it may injure the eyes.
As a conclusion
As you can see, you can still make an induction furnace on your own. But to be frank, the described design (like everything available on the Internet) is not quite a furnace, but a Kukhtetsky laboratory inverter. It is simply impossible to assemble a full-fledged induction structure at home.
Melting metal by induction is widely used in various industries: metallurgy, engineering, jewelry. A simple induction type furnace for melting metal at home can be assembled with your own hands.
Heating and melting of metals in induction furnaces occur due to internal heating and changes in the crystal lattice of the metal when high-frequency eddy currents pass through them. This process is based on the phenomenon of resonance, in which eddy currents have a maximum value.
To cause the flow of eddy currents through the melted metal, it is placed in the zone of action of the electromagnetic field of the inductor - the coil. It can be in the form of a spiral, figure eight or trefoil. The shape of the inductor depends on the size and shape of the heated workpiece.
The inductor coil is connected to an alternating current source. In industrial melting furnaces, industrial frequency currents of 50 Hz are used; for melting small volumes of metals in jewelry, high-frequency generators are used, as they are more efficient.
Kinds
Eddy currents are closed along a circuit limited by the magnetic field of the inductor. Therefore, heating of conductive elements is possible both inside the coil and from its outer side.
- Therefore, induction furnaces are of two types:
- channel, in which the channels located around the inductor are the container for melting metals, and the core is located inside it;
- crucible, they use a special container - a crucible made of heat-resistant material, usually removable.
channel furnace too overall and designed for industrial volumes of metal melting. It is used in the smelting of cast iron, aluminum and other non-ferrous metals.
crucible furnace quite compact, it is used by jewelers, radio amateurs, such an oven can be assembled with your own hands and used at home.
Device
- A home-made furnace for melting metals has a fairly simple design and consists of three main blocks placed in a common housing:
- high frequency alternator;
- inductor - do-it-yourself spiral winding of copper wire or tube;
- crucible.
The crucible is placed in an inductor, the ends of the winding are connected to a current source. When current flows through the winding, an electromagnetic field with a variable vector arises around it. In a magnetic field, eddy currents arise, directed perpendicular to its vector and passing through a closed loop inside the winding. They pass through the metal placed in the crucible, while heating it to the melting point.
Advantages of the induction furnace:
- fast and uniform heating of the metal immediately after switching on the installation;
- directivity of heating - only the metal is heated, and not the entire installation;
- high melting rate and homogeneity of the melt;
- there is no evaporation of the alloying components of the metal;
- the installation is environmentally friendly and safe.
A welding inverter can be used as a generator of an induction furnace for melting metal. You can also assemble the generator according to the diagrams below with your own hands.
Furnace for melting metal on a welding inverter
This design is simple and safe as all inverters are equipped with internal overload protection. The entire assembly of the furnace in this case comes down to making an inductor with your own hands.
It is usually performed in the form of a spiral from a copper thin-walled tube with a diameter of 8-10 mm. It is bent according to a template of the desired diameter, placing the turns at a distance of 5-8 mm. The number of turns is from 7 to 12, depending on the diameter and characteristics of the inverter. The total resistance of the inductor must be such that it does not cause an overcurrent in the inverter, otherwise it will be tripped by the internal protection.
The inductor can be mounted in a housing made of graphite or textolite and a crucible can be installed inside. You can simply put the inductor on a heat-resistant surface. The housing must not conduct current, otherwise the eddy current circuit will pass through it and the power of the installation will be reduced. For the same reason, it is not recommended to place foreign objects in the melting zone.
When working from a welding inverter, its housing must be grounded! The socket and wiring must be rated for the current drawn by the inverter.
The heating system of a private house is based on the operation of a furnace or boiler, the high performance and long uninterrupted service life of which depends both on the brand and installation of the heating devices themselves, and on the correct installation of the chimney.
you will find recommendations for choosing a solid fuel boiler, and in the following you will get acquainted with the types and rules:
Transistor induction furnace: circuit
There are many different ways to assemble an induction heater with your own hands. A fairly simple and proven scheme of a furnace for melting metal is shown in the figure:
- To assemble the installation with your own hands, you will need the following parts and materials:
- two field-effect transistors of the IRFZ44V type;
- two diodes UF4007 (you can also use UF4001);
- resistor 470 Ohm, 1 W (you can take two series-connected 0.5 W each);
- film capacitors for 250 V: 3 pieces with a capacity of 1 microfarad; 4 pieces - 220 nF; 1 piece - 470 nF; 1 piece - 330 nF;
- copper winding wire in enamel insulation Ø1.2 mm;
- copper winding wire in enamel insulation Ø2 mm;
- two rings from chokes taken from a computer power supply.
Do-it-yourself assembly sequence:
- Field-effect transistors are mounted on radiators. Since the circuit gets very hot during operation, the radiator must be large enough. You can also install them on one radiator, but then you need to isolate the transistors from the metal using gaskets and washers made of rubber and plastic. The pinout of field effect transistors is shown in the figure.
- It is necessary to make two chokes. For their manufacture, copper wire with a diameter of 1.2 mm is wound around rings taken from the power supply of any computer. These rings are made of powdered ferromagnetic iron. They need to be wound from 7 to 15 turns of wire, trying to maintain the distance between the turns.
- The capacitors listed above are assembled into a battery with a total capacity of 4.7 microfarads. Connection of capacitors - parallel.
- The inductor winding is made of copper wire with a diameter of 2 mm. 7-8 turns of winding are wound on a cylindrical object suitable for the diameter of the crucible, leaving long enough ends to connect to the circuit.
- Connect the elements on the board in accordance with the diagram. A 12 V, 7.2 A/h battery is used as a power source. The current consumed in operation is about 10 A, the battery capacity in this case is enough for about 40 minutes. If necessary, the furnace body is made of heat-resistant material, for example, textolite. The power of the device can be changed by changing the number of turns of the inductor winding and their diameter.
Induction heater for melting metal: video
Lamp induction oven
A more powerful induction furnace for melting metals can be assembled by hand on vacuum tubes. The diagram of the device is shown in the figure.
To generate high-frequency current, 4 beam lamps connected in parallel are used. A copper tube with a diameter of 10 mm is used as an inductor. The unit is equipped with a trimmer capacitor for power adjustment. The output frequency is 27.12 MHz.
To assemble the circuit you need:
- 4 vacuum tubes - tetrodes, you can use 6L6, 6P3 or G807;
- 4 chokes for 100 ... 1000 μH;
- 4 capacitors at 0.01 uF;
- neon indicator lamp;
- tuning capacitor.
Assembling the device with your own hands:
- An inductor is made from a copper tube, bending it in the form of a spiral. The diameter of the turns is 8-15 cm, the distance between the turns is at least 5 mm. The ends are tinned for soldering to the circuit. The diameter of the inductor must be 10 mm larger than the diameter of the crucible placed inside.
- Place the inductor in the housing. It can be made from a heat-resistant non-conductive material, or from metal, providing thermal and electrical insulation from the circuit elements.
- Cascades of lamps are assembled according to the scheme with capacitors and chokes. Cascades are connected in parallel.
- Connect a neon indicator lamp - it will signal the readiness of the circuit for operation. The lamp is brought to the installation housing.
- A tuning capacitor of variable capacitance is included in the circuit, its handle is also displayed on the case.
For all lovers of cold-smoked delicacies, we suggest you learn how to quickly and easily make a smokehouse with your own hands, and get acquainted with the photo and video instructions for making a cold-smoked smoke generator.
Circuit cooling
Industrial melting plants are equipped with a forced cooling system using water or antifreeze. Water cooling at home will require additional costs, comparable in price to the cost of the metal melting plant itself.
Air-cooling with a fan is possible provided that the fan is sufficiently remote. Otherwise, the metal winding and other elements of the fan will serve as an additional circuit for closing eddy currents, which will reduce the efficiency of the installation.
Elements of the electronic and lamp circuits are also able to actively heat up. For their cooling, heat-removing radiators are provided.Work Safety Measures
- The main danger during operation is the risk of burns from the heated elements of the installation and molten metal.
- The lamp circuit includes elements with high voltage, so it must be placed in a closed case, eliminating accidental contact with the elements.
- The electromagnetic field can affect objects that are outside the device case. Therefore, before work, it is better to put on clothes without metal elements, remove complex devices from the coverage area: phones, digital cameras.
A domestic metal melting furnace can also be used to quickly heat up metal elements, for example, when they are tinned or shaped. The characteristics of the operation of the presented installations can be adjusted to a specific task by changing the parameters of the inductor and the output signal of the generator sets - this way you can achieve their maximum efficiency.