Many home craftsmen who have inherited an old non-working one refrigeratorare wondering what can be done with its insides. Most often, attention is attracted by motor-compressor, which is a sealed steel ball or cylinder. Disassembling this unit is a labor-intensive process that requires understanding the structure of the unit and compliance with strict safety regulations.
The main difficulty is that the case is sealed at the factory and is not intended for service in domestic conditions. However, if your goal is to gain access to internal mechanisms for studying, recycling non-ferrous metals, or creating a homemade compressor, then cutting is the only method available. It is important to understand that after opening the unit will never be able to perform its direct functions of compressing the refrigerant.
Before you take on grinder or a hacksaw, you need to make sure that the unit is completely safe. There may be oil inside, and in some cases, remnants of freon under pressure. Incorrect actions can lead to injuries or ignition of oil vapors, so the procedure must be approached with maximum responsibility and a prepared workplace.
Preparation of the workplace and necessary tools
For successful work, you will need a spacious, well-ventilated room, ideally a garage or workshop outside. Open flames and sparks in a confined space with oil vapors are not permitted. The main tool for quickly separating metal parts will be angle grinder (grinder) with cutting discs for metal with a thickness of no more than 1-1.5 mm.
In addition to power tools, stock up on a set of plumbing supplies. You will need heavy-duty pliers, a hammer, a chisel, and a set of screwdrivers. To collect leaking technical oil, prepare a wide container with low sides. Don't forget about personal protective equipment: thick gloves, safety glasses and a respirator are required, since sawing produces fine metal dust.
If an angle grinder is not available, you can use a hacksaw, but this process will take much longer and require greater physical effort. In this case, it is recommended to secure the compressor in a vice, having previously placed wooden blocks in order not to damage the housing and ensure stability during operation.
☑️ Preparation for cutting the compressor
Safety precautions and precautions
The main danger when working with hermetic compressors hidden inside. Even if the unit has not been operated for a long time, residual pressure may remain in it. In addition, oil vapors, when mixed with air, form an explosive mixture. That is why it is absolutely forbidden to start sawing the housing without making sure that there is no pressure.
⚠️ Attention! Before starting any work to destroy the housing, it is necessary to carefully grind off or drill the top of one of the copper fittings (pipes). This will relieve possible pressure and make sure that there is no active gas inside.
The second important aspect is heat treatment. During operation grinder the metal becomes very hot. If oil vapor remains inside, heat may cause it to ignite. Work in short bursts, allowing the metal to cool, and keep a fire extinguisher or container of sand handy.
Draining the technical oil from the system
After you have ensured that there is no pressure, you need to remove the technical oil from the system. It can be aggressive and leave stubborn stains on clothes and floors. Turn the compressor over so that the pipes point down and place the prepared container.
For complete emptying, it is recommended to make several holes in different places of the housing or carefully cut off the top cover, if access allows. The oil may take a long time to drain, so be patient. Do not drain used oil down the drain or onto the ground - take it to a special waste collection point.
Some experts advise adding a little solvent or kerosene to the system before draining to wash out any remaining viscous deposits. However, this should only be done if you plan to use the parts for technical needs, and not to study the purity of internal processes.
The process of cutting the compressor housing
The most common method of opening is cutting off the upper part of the housing along the weld seam. Visually inspect compressor: you will see a characteristic circular seam connecting two hemispheres or a cylinder with a lid. It is along this line that you need to cut.
Turn on the grinder and smoothly, without strong pressure, move the disk along the seam. Be careful not to go too deep to avoid damaging the internal parts if you plan to keep them intact. Move in a circle, gradually deepening the cut. If the body is thick, several passes may be required.
What to do if the seam is cut and the cover does not come off?
Sometimes the weld may be uneven or have bridges. In this case, take a chisel and a hammer, carefully insert the chisel into the cut and try to loosen the joint with light blows. Do not use excessive force so as not to deform the inner tubes.
Once the circular cut is completed, the upper part of the housing should be easily removed. If it is stuck, check to see if there are any uncut areas left. Inside you will see an electric motor and a piston group immersed in oil.
Internal structure: what is inside the motor
Inside the sealed casing there is electric motor the compressor mechanism itself. The motor is usually asynchronous, with a squirrel-cage rotor. It is mounted on springs or rubber shock absorbers, which dampen vibrations during operation. These springs are often of interest to craftsmen as ready-made spring elements.
The motor shaft directly or through a connecting rod transmits movement to the piston. Unlike car engines, there is no complex gas distribution mechanism. Suction and discharge occur due to the movement of the piston and the operation of petal valves located in the upper part of the cylinder.
All these parts are immersed in oil, which lubricates the rubbing pairs and removes heat. Copper tubes coming from the cylinders lead to the outlet pipes. Their integrity is important if you plan to use the compressor for inflating tires or airbrushing.
Extraction of copper windings and non-ferrous metals
If your goal is to obtain non-ferrous metal, then the stator of the electric motor is of greatest interest. This is a stacked structure made of metal plates, inside of which is wound copper wire. To remove copper, it is necessary to remove the stator from the base.
The windings can be removed in two ways. The first is mechanical: on one side the coils are cut, and on the other they are pulled out in bundles. The second method is thermal: the stator is calcined in a fire or oven to burn off the varnish and insulation, after which the copper easily spills out. However, when burned, toxic substances are released, so this should only be done in the open air, away from residential buildings.
The weight of copper in a standard household compressor can vary from 0.5 to 1.5 kg, depending on the power and model. The composition also contains steel, aluminum (in some rotor models) and a small amount of precious metals in the contacts, although extracting them at home is unprofitable.
Table: Characteristics of a typical household compressor
To better understand what equipment you are working with, check out the average parameters. They will help determine the potential for using parts or the approximate yield of non-ferrous metal.
| Parameter | Value | Note |
|---|---|---|
| Engine power | 100 - 200 W | Depends on the volume of the refrigerator |
| Compressor weight | 10 - 15 kg | Together with oil and casing |
| Copper output | 0.5 - 1.2 kg | Stator windings only |
| Working pressure | up to 15-20 atm | In the discharge line |
| Refrigerant type | R134a / R600a | Depends on the year of manufacture |
Recycling: the compressor is your own by hand
A sawn and cleaned compressor often becomes the basis for homemade installations. Because it can create pressure, it is used to inflate tires, work with an airbrush, or in pneumatic systems. To do this, hoses are connected to the inlet and outlet pipes, and the unit itself is equipped with a receiver (air tank).
A cooling system is also necessary, since the body gets very hot during prolonged operation. In a factory refrigerator, it is cooled by freon, but in a homemade design, this function should be performed by a fan.
⚠️ Attention! When using a compressor for airbrushing or painting, be sure to install a high-quality moisture-oil separator. Getting oil on the surface to be painted will ruin the product, and oil vapors are harmful to breathing.
Disposal and environmental aspects
After disassembling the compressor, you will be left with a significant amount of ferrous metal (housing, stator plates), non-ferrous metal (copper, brass) and waste technical oil. All these components must be disposed of separately. Ferrous and non-ferrous metal can be handed over to recycling collection points, receiving a small monetary compensation.
Used oil is classified as hazardous waste. It is prohibited to pour it into the ground or sewer, as one liter of oil can pollute a huge amount of water. Collect it in a sealed canister and take it to a specialized recycling point or to a car service center where they accept the waste.
If during the cutting process you damage the tubes and notice a strong odor, stop work immediately and ventilate the room. Modern refrigerants may be safe for the ozone layer, but in high concentrations they displace oxygen and can cause suffocation.
Can a refrigerator motor be used as a generator?
Theoretically, an asynchronous motor can be converted into a generator by installing permanent magnets on the rotor. However, the power of such a generator will be low and the efficiency will be low. For serious tasks, it is easier to buy a ready-made gasoline generator.
Frequent errors during disassembly
Beginners often rush and start sawing the body without checking the presence of pressure. This may cause a sharp popping sound and flying shards of oil. Always start by checking the fittings. It is also a mistake to use a dull disc for an angle grinder, which heats the metal and “bites”, which is dangerous for the operator.
Another mistake is trying to keep the compressor working after opening. Tightness is the main condition for the operation of a refrigeration unit. After cutting, it is impossible to assemble it back so that it pumps freon at home. Therefore, accept the fact that you will no longer assemble the refrigerator.
Do not ignore the weight of the unit when working. The compressor can weigh 15 kilograms or more. A poor grip in a vice or an unstable position on a workbench will result in a heavy object falling on your feet or damaging the tool.
Is freon inside an old compressor dangerous?
Old Soviet refrigerators used R12 freon, which destroys the ozone layer, but is not toxic in small doses. Modern models use R134a or isobutane (R600a). Isobutane is explosive when mixed with air. Therefore, before cutting, you should always bleed the contents out in the open air.
How long does it take to completely disassemble a compressor?
If you have an angle grinder and experience, the process of cutting and removing the insides takes from 30 to 60 minutes. If you use a hacksaw for metal, the time can increase to 2-3 hours depending on the thickness of the housing walls.
Is it possible to restore the compressor after cutting?
No, restoring the tightness and vacuuming the system require factory equipment. Once opened, the compressor is only suitable for use as an air pump or for scrap metal.
Which tool is best suited for cutting?
The optimal choice is an angle grinder (grinder) with a 1 mm thick disc. It gives an even cut and a minimal heating zone. A hacksaw is safer, but requires a lot of effort, and a reciprocating saw can get stuck in a round body.
What to do with residual oil on parts?
Parts can be washed with Galosh gasoline, diesel fuel or a special carburetor cleaner. Carry out washing with gloves in a well-ventilated place, away from sources of fire.