Aluminum alloys have low melting point and good workability details. And there is always a lot of aluminum scrap on the farm.
That's why aluminum is often melted at home to replace non-standard or small parts of mechanisms: a blank is cast, and then processed lathe. Sometimes souvenirs and small interior items are made from aluminum with their own hands.
Melting furnace structure
Homemade furnaces for melting aluminum consist of a body - metal cylinder (2), lined with refractory (clamotte with sand or concrete). Inside the mine is charcoal (8) , serving as fuel. It is installed crucible (3)- a container in which the metal will melt. The crucible can be a thick tin can, a teapot or any stainless steel container.
At the bottom of the shaft (6) made air injection hole (7) through lattice base (4), which allows you to maintain combustion and regulate the temperature in the furnace.
A hair dryer or a vacuum cleaner pipe is used as a blower. Damper (5) necessary to remove excess air.
For ovens with a capacity of several tens of kilograms, you need cover (1) for quick and uniform heating of the metal. In small ovens you can do without it.
Furnace elements should not deform or melt when heated. Therefore, the use of aluminum bodies, tubes and crucibles is unacceptable. It is best to take steel or cast iron details.
Reference. Also used as fuel for smelting aluminum natural gas or electricity.
How to make a furnace for melting metal?
Creating a small unit that can melt several kilograms of aluminum scrap is not a difficult task. To lay out the oven on garden plot will be required following materials:
- red bricks - 20-25 pcs.;
- high tin can - 1 pc.;
- grill grate - 1 pc.;
- drying hair dryer - 1 pc.;
- piece of pipe, with a diameter suitable for the outlet of the hair dryer - 1 PC.;
- roll of electrical tape;
- line segment steel wire length 30-50 cm;
- coal for ignition (the quantity depends on how much aluminum needs to be melted).
The bricks will appear simultaneously and body and fireproof coating oven, a tin can will act as a crucible. At the top of the can are being done two holes opposite each other, and through them the wire is threaded. It will be possible to lift and remove the crucible with the melt from the furnace. The air will be supplied from the hairdryer turned on in cold air mode. Tape or tape to the outlet of the hair dryer attach a piece of pipe- this will be the air duct.
Such simple circuit The furnace is convenient in that no tools are actually required to create it; everything is done by hand.
Important! Do not use oven elements with zinc coating, because when aluminum is melted, toxic zinc fumes will be released.
Brick well installation plan
- Gives his all one row bricks in the form of a rectangular well. The internal dimensions of the hole should be approximately length and width of one brick. On one side two bricks laid out so as to form a corridor for the air duct. The width of the corridor is tube diameter for air supply.
- On the laid out row grating is installed. Instead of a grill grate, you can use any metal lid or plate with holes for air supply.
- Placed on the grill second row bricks, without any gap for the air duct.
Photo 1. Finished brick well for the melting furnace. The edges are reinforced with metal strips, the air duct opening is visible.
- Created air duct. Tape or tape to the hairdryer a piece of pipe is wound. To ensure structural strength, the connection point wrapped in thick paper, and then connects duct tape. Electrical tape is a more elastic material compared to adhesive tape, so it is more convenient to work with. The cold air supply button is also secured with tape on the hairdryer. Ready the mechanism is brought to the bottom row bricks.
- In the stove well on the grate coal is poured and melted for ignition. The hair dryer turns on, which activates the combustion process.
Advice. The air supply intensity can be adjusted by changing hair dryer operating mode, and distance between pipe and window for the air duct.
- Tin is installed to the top row bricks for the wire threaded into it. Like a pot over a fire, it hangs over the grate.
- After lighting the furnace and installing the crucible third row are placed two more bricks so that from a rectangular hole you get a square one. This will fix the can inside the housing and heat up the oven space faster.
After heating the jar into it scrap can be loaded for remelting. A sign that the jar is warming up is its redness.
The principle of the design and operation of such a furnace is very simple and does not cause difficulties. However, it is always worth remembering safety precautions:
- work in fire-resistant gloves;
- avoid water getting into the melt;
- do not use materials containing toxic substances.
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Two-can design
Another variety homemade stove for melting aluminum is a design made of two large cans. One of them serves body, in which a hole is cut for air supply, and bottom of the second jars with holes serves as a divider.
A crucible is installed inside the jars.
Such a device very compact, and small volumes of metal can be melted even in a ventilated garage. However, the design is not resistant or fire resistant, and will only last a few cycles.
Possible problems and their solutions
Carelessly assembled device causes the oven to operate inefficiently and makes it dangerous to use. Here are a few points to pay attention to:
- Slots and gaps in a brick building. They can be caused by chips on bricks or loose fit of refractories to each other. Gaps reduce fuel efficiency and reduce combustion intensity and temperature. Aluminum in a crucible may simply not melt.
Therefore, after laying out each row, a visual check is carried out for the presence of holes. Holes covered with a sand-clay mixture or closed fireproof material .
It is recommended to use concrete mortar only in the case of a stationary unit that is not planned to be disassembled. But Asbestos sheets and chips should not be used in places where the stove is heated, because this material is a carcinogen.
- Violation of the horizontal level the buildings. Misalignment reduces the stability of the structure and creates conditions for uneven distribution of coal. The result is uneven heating of the crucible and the metal in it.
Laying out each, especially the bottom row of bricks controlled by level. You can also check horizontality placing a jar of water on the grill. On a flat surface, the top edge of the water will be parallel to the edge of the can.
For melting metal on a small scale, some kind of device is sometimes necessary. This is especially acute in a workshop or in small-scale production. The most efficient furnace at the moment is a metal melting furnace with an electric heater, namely an induction furnace. Due to the peculiarities of its structure, it can be effectively used in blacksmithing and become an irreplaceable tool in the forge.
Induction furnace structure
The oven consists of 3 elements:
- 1. Electronic and electrical part.
- 2. Inductor and crucible.
- 3. inductor cooling system.
In order to assemble a working furnace for melting metal, it is enough to assemble a working electrical circuit and an inductor cooling system. The simplest version of metal melting is shown in the video below. Melting is carried out in the counter electromagnetic field of the inductor, which interacts with induced electro-eddy currents in the metal, which holds a piece of aluminum in the space of the inductor.
In order to effectively melt metal, large currents and high frequencies of the order of 400-600 Hz are required. The voltage from a regular 220V home socket is sufficient to melt metals. It is only necessary to turn 50 Hz into 400-600 Hz.
Any circuit for creating a Tesla coil is suitable for this. I liked the following 2 circuits on the GU 80, GU 81(M) lamp the most. And the lamp is powered by an MOT transformer from a microwave oven.
These circuits are intended for a Tesla coil, but they make an excellent induction furnace; instead of the secondary coil L2, it is enough to place a piece of iron in the internal space of the primary winding L1.
The primary coil L1 or inductor consists of a copper tube rolled into 5-6 turns, the ends of which are threaded to connect the cooling system. For levitation melting, the last turn should be done in the opposite direction.
Capacitor C2 in the first circuit and an identical one in the second sets the frequency of the generator. At a value of 1000 picoFarads, the frequency is about 400 kHz. This capacitor must be a high-frequency ceramic capacitor and designed for high voltage of about 10 kV (KVI-2, KVI-3, K15U-1), other types are not suitable! It's better to use K15U. Capacitors can be connected in parallel. It is also worth taking into account the power for which the capacitors are designed (this is written on their case), take it with a reserve. the other two capacitors KVI-3 and KVI-2 heat up during prolonged operation. All other capacitors are also taken from the KVI-2, KVI-3, K15U-1 series; only the capacitance changes in the characteristics of the capacitors.
Here is a schematic diagram of what should happen. I circled 3 blocks in frames. 
The cooling system is made of a pump with a flow of 60 l/min, a radiator from any VAZ car, and I placed a regular home cooling fan opposite the radiator.
Metal smelting by induction is actively used in various industries, such as mechanical engineering, metallurgical and jewelry production. The material heats up under the influence electric current, which allows you to use heat with maximum efficiency. Large factories have special industrial units for this, while at home you can assemble a simple and small induction furnace with your own hands.
Such furnaces are popular in production
Self-assembly of the stove
There are many technologies and schematic descriptions of this process presented on the Internet and magazines, but when choosing, it is worth choosing one model that is most effective in operation, as well as affordable and easy to implement.
Homemade melting furnaces have quite simple design and usually consist of only three main parts, placed in a sturdy case. These include:
- element generating high frequency alternating current;
- a spiral-shaped part created from a copper tube or thick wire, called an inductor;
- crucible - a container in which calcination or melting will be carried out, made of refractory material.
Of course, such equipment is not often used in everyday life, because not all craftsmen need such units. But the technologies found in these devices are found in household appliances that many people deal with almost every day. This includes microwaves, electric ovens and induction cookers. You can make various equipment using diagrams with your own hands if you have the necessary knowledge and skills.
In this video you will learn what this oven consists of
Heating in this technique is carried out thanks to induction eddy currents. The temperature rise occurs instantly, unlike other devices of a similar purpose.
For example, induction cookers have an efficiency of 90%, but gas and electric cookers cannot boast of this value, it is only 30-40% and 55-65%, respectively. However, HDTV cookers have a drawback: to use them you will have to prepare special dishes.
Transistor design
There are many various schemes for assembling induction smelters at home. A simple and proven furnace made from field-effect transistors is quite easy to assemble; many craftsmen familiar with the basics of radio engineering can handle its manufacture according to the diagram shown in the figure. To create an installation You need to prepare the following materials and parts:
- two IRFZ44V transistors;
- copper wires (for winding) in enamel insulation, 1.2 and 2 mm thick (one piece each);
- two rings from chokes, they can be removed from the power supply of an old computer;
- one 470 Ohm resistor per 1 W (you can connect two 0.5 W each in series);
- two UF4007 diodes (can easily be replaced with the UF4001 model);
- 250 W film capacitors - one piece with a capacity of 330 nF, four - 220 nF, three - 1 µF, 1 piece - 470 nF.
Before assembling such a stove, do not forget about the tools Assembly takes place according to the schematic drawing; it is also recommended to check step by step instructions, this will protect you from errors and damage to elements. Creating an induction melting furnace with your own hands is carried out according to the following algorithm:
- Transistors are placed on fairly large heatsinks. The fact is that circuits can get very hot during operation, which is why it is so important to select parts of the appropriate size. All transistors can be placed on one radiator, but in this case you will have to insulate them, preventing them from coming into contact with metal. Washers and gaskets made of plastic and rubber will help with this. The correct pinout of transistors is shown in the picture.
- Then they start making chokes; you will need two of them. To do this, take copper wire 1.2 millimeters in diameter and wrap it around rings taken from the power supply. These elements contain ferromagnetic iron in powder form, so it is necessary to make at least 7-15 turns, leaving a small distance between them.
- The resulting modules are assembled into one battery with a capacity of 4.6 μF, and the capacitors are connected in parallel.
- Copper wire 2 mm thick is used to wind the inductor. It is wrapped 7-8 times around any cylindrical object, its diameter should correspond to the size of the crucible. The excess wire is cut off, but rather long ends are left: they will be needed for connecting to other parts.
- All elements are connected on the board, as shown in the figure.
If necessary, you can build a housing for the unit; for this purpose, only heat-resistant materials, such as textolite, are used. The power of the device can be adjusted, for which it is enough to change the number of turns of wire on the inductor and their diameter.
There are several variations of the induction furnace that can be assembled With graphite brushes
The main element of this design is assembled from graphite brushes, the space between which is filled with granite, crushed to a powder state. Then the finished module is connected to a step-down transformer. When working with such equipment, you do not have to worry about electric shock, since it does not need to use 220 volts.
Manufacturing technology of an induction furnace from graphite brushes:
- First, the body is assembled; for this, fire-resistant (fireclay) bricks measuring 10 × 10 × 18 cm are laid on tiles that can withstand high temperatures. The finished box is wrapped in asbestos cardboard. To give this material the desired shape, it is enough to moisten it with a small amount of water. The size of the base directly depends on the power of the transformer used in the design. If desired, the box can be covered with steel wire.
- An excellent option for graphite furnaces would be a transformer with a power of 0.063 kW, taken from welding machine. If it is designed for 380 V, then for safety reasons it can be subjected to winding, although many experienced radio technicians believe that this procedure can be abandoned without any risk. However, it is recommended to wrap the transformer with thin aluminum so that the finished device does not heat up during operation.
- A clay substrate is placed at the bottom of the box so that the liquid metal does not spread, after which graphite brushes and granite sand are placed in the box.
The main advantage of such devices is considered to be the high melting point, which can change the state of aggregation of even palladium and platinum. The disadvantages include too rapid heating of the transformer, as well as small area a furnace that will not allow smelting more than 10 g of metal at a time. Therefore, every master should understand that if the device is assembled to process large volumes, then it is better to make a furnace of a different design.
Lamp-based device
A powerful melting stove can be assembled from electronic light bulbs. As can be seen in the diagram, to obtain high-frequency current, beam lamps must be connected in parallel. Instead of an inductor, this device uses a copper tube with a diameter of 10 mm. The design is also equipped with a tuning capacitor in order to be able to regulate the power of the furnace. For assembly you need to prepare:
- four lamps (tetrodes) L6, 6P3 or G807;
- trimmer capacitor;
- 4 chokes at 100-1000 µH;
- neon indicator light;
- four 0.01 µF capacitors.
To begin with, the copper tube is shaped into a spiral - this will be the inductor of the device. In this case, a distance of at least 5 mm is left between the turns, and their diameter should be 8-15 cm. The ends of the spiral are processed for attachment to the circuit. The thickness of the resulting inductor should be 10 mm greater than that of the crucible (it is placed inside).
The finished part is placed in the housing. For its manufacture, you should use a material that will provide electrical and thermal insulation for the filling of the device. Then a cascade is assembled from lamps, chokes and capacitors, as shown in the figure, the latter being connected in a straight line.
It's time to connect the neon indicator: it is needed so that the master can find out when the device is ready for work. This light bulb is connected to the furnace body along with the handle of the variable capacitor.
Cooling system equipment
Industrial units for melting metal are equipped with special cooling systems using antifreeze or water. Equipping these important installations in homemade HDTV stoves will require additional costs, which is why the assembly can put a significant dent in your wallet. Therefore, it is better to provide a household unit with a cheaper system consisting of fans.
Air cooling with these devices is possible when they are located remotely from the furnace. Otherwise, the metal windings and fan parts can serve as a loop for short-circuiting eddy currents, which will significantly reduce the efficiency of the equipment.
Lamp and electronic circuits also tend to actively heat up during operation of the unit. Heat sinks are usually used to cool them.
Terms of use
For experienced radio technicians, assembling an induction furnace according to the diagrams with your own hands may seem like an easy task, so the device will be ready quite quickly, and the master will want to try his creation in action. It is worth remembering that when working with a homemade installation, it is important to follow safety precautions and not forget about the main threats that may arise during operation of an inertial furnace:
- Liquid metal and heating elements of the device can cause severe burns.
- Lamp circuits consist of high-voltage parts, so during assembly of the unit they must be placed in a closed box, thus eliminating the possibility of accidental touching of these elements.
- The electromagnetic field can influence even those things that are outside the installation box. Therefore, before turning on the device, you need to put away all complex technical devices, such as mobile phones, digital cameras, MP3 players, and also remove all metal jewelry. People with pacemakers are also at risk: they should never use such equipment.
These furnaces can be used not only for smelting, but also for quickly heating metal objects during forming and tinning. By changing the output signal of the installation and the parameters of the inductor, you can configure the device for a specific task.
For melting small volumes of iron, homemade stoves are used; these effective devices can operate from ordinary sockets. The device does not take up much space, it can be placed on a desktop in a workshop or garage. If a person knows how to read simple electrical diagrams, then he does not need to purchase such equipment in a store, because he can assemble a small stove with his own hands in just a few hours.
Radio amateurs have long discovered that they can make induction furnaces for melting metal with their own hands. These simple circuits will help you make a HDTV installation for home use. However, it would be more correct to call all the described designs “Kukhtetsky’s laboratory inverters,” since it is simply impossible to independently assemble a full-fledged stove of this type.
Well-established metal and steel production technologies have already been formed in the world, which metallurgical enterprises still use today. These include: the converter method of producing metal, rolling, drawing, casting, stamping, forging, pressing, etc. However, the most common under modern conditions is the remelting of metal and steel in convectors, open-hearth furnaces and electric furnaces. Each of these technologies has a number of disadvantages and advantages. However, the most perfect and the latest technology today is the production of steel in electric furnaces. The main advantages of the latter over other technologies are high productivity and environmental friendliness. Let's consider how to assemble a device where metal will be melted at home with your own hands.
Small-sized induction electric furnace for melting metals at home
Melting metals at home is possible if you have an electric furnace that you can make yourself. Let's consider the creation of an inductive small-sized electric oven to obtain homogeneous alloys (OS). Compared to analogues, the created installation will differ in the following features:
- low cost (up to 10,000 rubles), while the cost of analogues is from 150,000 rubles;
- possibility of temperature control;
- the possibility of high-speed melting of metals in small volumes, which allows the installation to be used not only in the scientific field, but also, for example, in the jewelry, dental fields, etc.
- uniformity and heating rate;
- the possibility of placing the working body in a furnace in a vacuum;
- relatively small dimensions;
- low noise level, almost complete absence of smoke, which will increase labor productivity when working with the installation;
- possibility of operation from both single-phase and three-phase networks.
Choosing a schema type
Most often, when constructing induction heaters, three main types of circuits are used: half bridge, asymmetric bridge and full bridge. When designing this installation, two types of circuits were used - a half-bridge and a full bridge with frequency regulation. This choice was driven by the need to regulate power factor. The problem arose of maintaining the resonance mode in the circuit, since it is with its help that the required power value can be adjusted. There are two ways to regulate resonance:
- by changing the capacity;
- by changing the frequency.
In our case, resonance is supported by adjusting the frequency. It was this feature that caused the choice of the type of frequency-controlled circuit.
Analysis of circuit components
Analyzing the operation of an induction furnace for melting metal at home (IP), we can distinguish its three main parts: a generator, a power supply unit, and a power unit. To provide the required frequency during operation of the installation, a generator is used, which, to avoid interference from other units of the installation, is connected to them through a galvanic solution in the form of a transformer. To provide the power voltage circuit, a power supply unit is required, which ensures safe and reliable operation of the power elements of the structure. Actually, it is the power unit that generates the necessary powerful signals to create the required power factor at the output of the circuit.
Figure 1 shows the general circuit diagram induction installation.
Creating a Wiring Diagram
The connection diagram (installation diagram) shows the connections of the component parts of the product and determines the wires, cables that make these connections, as well as their connection points.
For the convenience of further installation of the installation, a connection diagram was developed that reflects the main contacts between the functional blocks of the furnace (Fig. 2).
Frequency generator
The most complex IP block is the generator. It provides the required operating frequency of the installation and creates the initial conditions for obtaining a resonant circuit. A specialized electronic pulse controller of the KR1211EU1 type is used as a source of oscillations (Fig. 3). This choice was caused by the ability of this microcircuit to operate in a fairly wide frequency range (up to 5 MHz), which makes it possible to obtain a high power value at the output of the power unit of the circuit.
Figures 4 and 5 show a schematic diagram of the frequency generator and a diagram of the electrical board.
The KR1211EU1 microcircuit generates signals of a given frequency, which can be changed using a control resistor installed outside the microcircuit. Next, the signals go to transistors operating in switching mode. In our case, silicon field-effect transistors with an insulated gate of the KP727 type are used. Their advantages are as follows: the maximum permissible pulse current that they can withstand is 56 A; maximum voltage is 50 V. We are completely satisfied with the range of these indicators. But, in connection with this, the problem of significant overheating arose. It is to solve this issue that a key mode is needed, which will reduce the time the transistors are in working condition.
power unit
This block provides power supply to the executive units of the installation. Its main feature is the ability to operate from single-phase and three-phase networks. A 380V power supply is used to improve the power factor generated in the inductor.
The input voltage is supplied to a rectifying bridge, which converts AC voltage 220V constant pulsating. Storage capacitors are connected to the bridge outputs, which maintain a constant voltage level after removing the load from the installation. To ensure reliable operation of the installation, the unit is equipped with an automatic switch.
Power block
This block provides direct signal amplification and the creation of a resonant circuit by changing the capacitance of the circle. Signals from the generator go to transistors, which operate in amplification mode. Thus, they, opening at different times, excite the corresponding electrical circuits passing through the step-up transformer and pass power current through it in different directions. As a result, at the output of the transformer (Tr1) we receive an increased signal with a given frequency. This signal is supplied to the installation with an inductor. An installation with an inductor (Tr2 in the diagram) consists of an inductor and a set of capacitors (C13 - Sp). Capacitors have a specially selected capacitance and create an oscillating circuit that allows you to adjust the level of inductance. This circuit must operate in resonance mode, which causes a rapid increase in the frequency of the signal in the inductor, and an increase in induction currents, due to which heating actually occurs. Figure 7 shows electrical diagram power unit of an induction furnace.
Inductor and features of its operation
An inductor is a special device for transferring energy from a power source to a product; it heats up. Inductors are usually made from copper tubes. During operation, it is cooled by running water.
Melting non-ferrous metals at home using an induction furnace involves the penetration of induction currents into the middle of the metals, which arise due to the high frequency of voltage changes applied to the inductor terminals. The power of the installation depends on the magnitude of the applied voltage and its frequency. Frequency affects the intensity of induction currents and, accordingly, the temperature in the middle of the inductor. The greater the frequency and operating time of the installation, the better the metals are mixed. The inductor itself and the directions of flow of induction currents are shown in Figure 8.
To ensure uniform mixing and avoid contamination of the alloy with foreign elements, for example, electrodes from a tank with an alloy, an inductor with a reverse turn is used as shown in Figure 9. It is thanks to this turn that an electromagnetic field is created that holds the metal in the air, exceeding the force of gravity of the Earth.
Final installation of the installation
Each of the blocks is attached to the body of the induction furnace using special racks. This is done in order to avoid unwanted contacts of live parts with the metal coating of the housing itself (Fig. 10).
For safe work Once installed, it is completely covered with a durable casing (Fig. 11), thus creating a barrier between dangerous structural elements and the body of the person working with it.
For the convenience of setting up the induction installation as a whole, an indication panel was made to accommodate metrological devices, with the help of which all parameters of the installation are monitored. Such metrological devices include: an ammeter that shows the current in the inductor, a voltmeter connected to the output of the inductor, a temperature indicator, and a signal generation frequency controller. All of the above parameters make it possible to regulate the operating modes of the induction unit. The design is also equipped with a manual activation system and an indication system for heating processes. With the help of displays on devices, the operation of the installation as a whole is actually monitored.
Designing a small-sized induction installation is quite complex technological process, since it must ensure compliance with a large number of criteria, such as: ease of design, small size, portability, etc. This installation operates on the principle of contactless energy transfer into an object and heats it up. As a result of the targeted movement of induction currents in the inductor, the melting process itself occurs directly, the duration of which is several minutes.
The creation of this installation is quite profitable, since its scope of application is limitless, starting with use for ordinary laboratory work and ending with the production of complex homogeneous alloys from refractory metals.
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Unlike industrial equipment, a homemade furnace for melting metal is a compact device. Such portable equipment can be used to smelt, harden or smelt non-ferrous metals.
A furnace for melting metal is a body made of fireclay bricks. The binding element is clay. The firebox is designed to burn coal. There is a hole at the bottom through which the air is blown into the inferno. Below is located cast iron grate, which is called the grate. Coke or coal is laid out on it. It can be removed from old stove. Sometimes refractory bricks are laid on edge when forming the body. The finished structure is fastened from the outside with a metal belt.
A furnace for melting metals must have a crucible. It can be an enameled or cast iron cauldron. The location of the crucible is next to the burning coke. To improve airflow, a fan is installed nearby. The equipment is used for steel smelting, but can be used as a furnace for cast iron smelting.
Electric furnaces for melting metal
The basis of such a stove is asbestos, which can be replaced with tiles. Electrodes installed in a melting furnace with your own hands must have a voltage of 25 V.
They are made in the following order:
- They are machined from the brushes of an electric motor.
- 6 mm holes are drilled into the assembly.
- A wire with a cross section of 5 mm is passed through them.
- A nail is driven in to secure the wiring.
- In order to improve contact with graphite, the file makes notches.
Mica is placed inside the furnace as a heat insulator. When connecting to the network, you need to use a step-down transformer. After production, the oven turns on and runs for some time in idle mode.
Muffle furnace
Muffle furnaces are often used for heat treatment of parts. Such equipment is characterized by a wide temperature range, from 20 to 1000 degrees.
Muffle furnace for metal hardening works at different types energy. However, at home it is better to use a unit that runs on electricity. Hardening is carried out in the furnace muffle.
A muffle furnace is made with your own hands in several stages:
- The muffle is made from fireclay bricks. Due to the round shape of the oven body, their corners are beveled. In each brick, grooves are selected where the spiral is laid.
- If the muffle furnace for melting is made from an oven, then the inside is lined with fire-resistant bricks. Grooves for the spiral are cut into the masonry.
- The chamber, made of refractory brick, is placed in a housing made of steel. Insulation is placed on the bottom. The gap between the side walls of the chamber and the housing is 4 cm, where the insulation is inserted. The top consists of 2 layers of metal and insulation.
- Holes are drilled in the housing, and the ends of the spiral are brought out through them, which are connected to the network cable.
- When using an oven, no insulation is required. It is already provided for in it.
Aluminum smelting
Making a furnace for melting aluminum with your own hands is a real thing. In industrial production, units with the name - rotary-type ovens - are very expensive.
To understand how to make a furnace for melting aluminum, you need to understand their operating principle. There are several types where non-ferrous metal is melted.
Mini oven
Take a car wheel and bury it in the ground so that the top cut does not protrude outward. A hole is made in the middle for the pipe. One end is passed into the hole, and the other is brought out. A cooler is placed on it to pump air. The smelter is filled with coals and aluminum scrap. Air is supplied and the temperature rises.
Metal tank
You can make a furnace for aluminum from a metal tank. For example, cases washing machine with vertical loading. The interior of the structure is lined with refractory bricks. A pipe for air supply is mounted below. Thus, portable equipment is obtained.
From the bottle
One of unusual ways how aluminum is melted. Nichrome wire is wound around the bottle. The surface of the bottle is first lubricated with oil. The mixture is applied on top liquid glass and clay. Drying is carried out for a week. Then another layer of wire is wound and clay is applied. After 7 days, the bottle is removed and only the heat-resistant shell remains. Voltage is connected to the ends of the wire to glow the nichrome, and raw materials are loaded into the hearth.
Lead smelting
An electric furnace for melting lead consists of the following elements:
- A round casing made of stainless steel, inside of which there is insulation. It is attached with brackets to the wall.
- An industrial heating element is supplied from below.
- There is a rotary type valve on top.
- A sensor that is located 3 cm from the bottom.
- There is a temperature regulator on the side.
By setting the regulator to a certain temperature, we warm up the device. The lead inside melts. At the end of the melt, a mold is placed underneath and the valve opens. Molten lead fills the interior of the mold.
Copper smelting
At home, you can use foam concrete material to melt copper. 2 cylinders with a diameter of 100 mm are cut from such material. The height of one is 100 mm, and the second is 15. Laying one on top of the other, a hole with a diameter of 15 mm is drilled in the middle. In the larger cylinder, in the middle, a funnel-shaped hole is made to a depth of 85 mm. In the middle of the cylinder, on the outside, a groove is cut and tied with wire. It is needed to ensure that the part does not fall apart due to temperature.
An adapter is placed on the gas stove. A larger cylinder is placed on top so that the conical funnel is directed upward. The top is covered with a small cylinder with a hole. When lighting the burner, lower a piece of copper rod into a small hole until it touches the wall of the funnel. After a minute the rod will melt.
Melting gold and silver
A gold smelting furnace is easy to make at home. It is also applicable for smelting silver.
The operating procedure is as follows:
- A fireclay brick is taken and cut into 2 parts. Using a Pobedit drill with a diameter of 48 mm, a through hole is made in one half, in the middle. And in the second hole is drilled to half the height.
- A spiral is drawn through the hole and both halves are tightened with bolts, holes for which are drilled from the sides.
- A graphite crucible is installed on top.
- In production metal carcass and both halves are inserted into it.
- All side gaps are covered with clay.
- Voltage is applied to the removed ends of the spiral.
- Pieces of gold or silver are thrown into the crucible.
- During the heating process, the non-ferrous metal melts.
Making furnaces for melting metal with your own hands is a complex process, but doable. To do this, you need to study the characteristics of the types of equipment. Decide which one is most preferable to the given conditions. Manufacturing costs will quickly pay for themselves.