Dismantling an old refrigeration compressor to obtain non-ferrous metal is a common practice among those involved in the collection and delivery of scrap. The main interest in this unit is the copper stator winding, which has a high cost at collection points. However, the extraction process requires not only physical strength, but also compliance with strict safety rules, since there is oil under pressure and specific gases inside.
Before starting work, you must clearly understand that you cannot simply “pull out” the copper. Sealed case The compressor is designed to withstand high pressure, and opening it is a complex technical process. In this article, we will analyze in detail the stages of preparation, methods of opening the case and methods of extracting valuable contents, based on the experience of professional recyclers.
It is worth noting that the copper yield depends on the model and year of manufacture of the unit. Old Soviet models often contain more non-ferrous metal compared to modern inverter compressors, where manufacturers strive to minimize weight. Below are detailed instructions that will help you carry out dismantling work as efficiently and safely as possible.
Preparation of the workplace and the necessary tools
High-quality disassembly is impossible without a properly organized space. You will need a sturdy workbench or a stable surface that is resistant to oil stains. The first step is to disconnect the compressor from the refrigeration system by cutting the copper tubes at a distance of 10-15 cm from the housing. This will prevent chips from getting inside the system if you plan to reuse some parts, although this is not critical when scrapping.
You will need a specific set of tools for the job. The main weapon will be angle grinder (grinder) with a metal disk 1-1.2 mm thick. Also needed:
- 🔨 A heavy hammer and chisel for opening the case and knocking out the core.
- 🔧 A set of wrenches for dismantling the start relay and terminals.
- 🧤 Thick protective gloves and goggles to protect against sparks and metal shavings.
- 🪣 Container for draining used compressor oil.
⚠️ Attention: It is strictly forbidden to open the compressor without first draining the oil and making sure there is no pressure inside. Residual pressure may spray toxic oil throughout the room.
Remember to prepare a waste disposal area. During the work, a lot of scrap metal is generated, which will need to be stored separately. Also have a rag on hand to remove oil stains, since compressor oil has a high viscosity and is difficult to wipe off the floor.
Draining technical fluids and dismantling attachments
The first stage of direct work with the compressor is removing the contents. Inside there is technical oil, which must be drained before cutting metal. To do this, turn the compressor upside down and wait until the liquid drains into the prepared container. The process may take from 15 to 30 minutes, since the oil is thick.
In parallel with draining the oil, the starting relay and the safety thermostat should be removed. These elements are attached to the side of the housing and connected to the contact group. Carefully remove the plastic casing, note the connection diagram (or take a photo of it), and disconnect the wires. Start relay Often contains copper in the coil, but in smaller quantities, so it can be set aside for separate disassembly.
It is important to understand that in older models refrigerators manufactured before the 2000s could use R12 (freon) refrigerant in the system. Although it may have evaporated long ago during disposal, when cutting a sealed case there is always a risk of releasing gas residues. Work should be carried out in a well-ventilated area or in the open air.
Methods of opening a sealed compressor casing
The most labor-intensive stage is violating the integrity of the steel casing. There are two main methods: mechanical (breaking) and thermal (cutting). The mechanical method involves the use of a chisel and a hammer. Notches are made along the perimeter of the weld, where the two hemispheres of the body are connected. Then they try to split the seam with strong blows. This method requires significant physical effort.
A more effective and modern method is to use grinders. With its help, the top cover of the case is cut off in a circle. This must be done carefully, trying not to damage the internal stator winding, although with complete recycling of copper this is not as critical as during repair. Cutting is done in the upper part, retreating a few centimeters from the weld.
After removing the cover, the internal structure will open in front of you: a stator with a winding, a rotor and a valve group. Often the rotor and stator are pressed or welded to the internal elements. To extract copper, most often it is necessary to completely remove the electric motor from the lower bowl. To do this, sometimes you have to saw through the motor shaft or cut off the mounting points.
⚠️ Attention: When cutting with a grinder, use only thin disks. Thick blades can jam in the metal, causing tool failure or injury. Hold the tool firmly with both hands.
Inside you will see that the space is filled with oil. Even after draining there is quite a lot of it left. Be prepared for the possibility of splashes when cutting. Use safety glasses with a tight fit to your face.
Why is the compressor housing so durable?
The housing is made of two stamped hemispheres, welded in an inert gas environment. This design can withstand pressures of up to 20-30 atmospheres, which is necessary for refrigerant circulation. That is why it is extremely difficult to just break it with a hammer.
Removing the copper winding from the stator
Once access to the insides is obtained, the main goal becomes copper winding. It is wound on the stator core. Depending on the condition of the compressor, the winding can be easily removed or tightly stuck to the iron. In most cases, to speed up the process, the winding is simply cut with an ax on one side and pulled out in bundles on the other.
If your goal is to get copper as pure as possible, without iron, you will have to work hard. The winding consists of many thin wires. To separate copper from electrical steel the core, a burning or chemical etching method is often used, but at home it is safer to use mechanical separation. You can use powerful wire cutters or a hacksaw to cut through the frontal parts of the coils.
Some craftsmen use a hydraulic puller or press to squeeze copper out of the stator grooves. This allows you to maintain the length of the wire and its integrity, which is more valuable when handing over. However, if the copper is being melted down, the integrity of the wire does not matter, the main thing is the weight.
- 🔥 Burning method: Dangerous and not environmentally friendly, burns the insulation, but leaves pure copper. Requires permission from the fire department.
- ⚔️ Mechanical sawing: The core is sawn together with the copper, then the copper is removed. Labor-intensive.
- 🪓 Chopping: The blades are chopped with an ax, the copper is pulled out. Fast, but the copper remains with pieces of insulation.
It is worth considering that the insulation on the wire (varnish) makes up a significant part of the weight. When handing over scrap, you may be deducted a percentage for “shrinkage” or contamination if the wire is not completely cleared of varnish.
Disassembling the rotor and recycling ferrous metal
In addition to the stator, the compressor contains a rotor - the rotating part of the engine. It is also of interest, but as black scrap or, in some cases, contains rare earth magnets (in modern models). The rotor usually sits tightly on the shaft. To dismantle it, a puller or strong physical impact is often required.
The rest of the compressor housing, valve group and casings are classified as black scrap. They should be collected and returned separately. Ferrous metal costs significantly less than copper, but its volumes during mass recycling of refrigerators can be significant. Do not mix copper and steel when weighing to get maximum profit.
Modern compressors may contain additional filter driers inside, which also contain non-ferrous metals, but in minute quantities. The main attention should be paid to the motor winding. After removing all valuable components, the workplace must be thoroughly cleaned.
| Compressor type | Approximate weight of copper (kg) | Weight of ferrous metal (kg) | Disassembly difficulty |
|---|---|---|---|
| Soviet (household, farm) | 1.2 - 1.8 | 8 - 10 | High (thick walls) |
| Imported (old) | 0.9 - 1.4 | 7 - 9 | Average |
| Modern (inverter) | 0.5 - 0.8 | 5 - 7 | Low (thin metal) |
Safety and environmental aspects
Working with the disposal of electrical appliances is fraught with risks. In addition to mechanical injuries from the tool, there is a danger of chemical poisoning. The fumes from burnt wire insulation are toxic. If you use the heat treatment method to remove nail polish, make sure you are outdoors and downwind.
The oil from the compressor should not be poured down a drain or onto the ground. It contains wear products and chemical additives. Collect it in a sealed container and take it to a special waste oil collection point. This rule also applies to refrigerants, although in a disassembled household refrigerator their concentration in the air usually does not reach critical values.
Use a respirator when working with an angle grinder, as metal dust is harmful to the lungs. Glasses should protect your eyes not only from the front, but also from the sides. Do not neglect personal protective equipment, even if the work takes only a few minutes.
⚠️ Attention: Waste disposal laws are subject to change. Check with local scrap collection points for current requirements for the preparation of non-ferrous metal (presence of tags, degree of purification) before handing over the batch.
Following these simple rules will allow you not only to make money from handing over metal, but also to preserve the health and cleanliness of the environment. Remember that proper disposal is an investment in the future.
☑️ Ready for disassembly
Frequently asked questions (FAQ)
How much copper can be obtained from one compressor?
The amount of copper varies from 0.5 to 1.8 kg depending on the model, year of manufacture and power of the refrigerator. Old Soviet units are the richest in non-ferrous metal.
Is it possible to burn the winding on a fire for cleaning?
Technically this is possible, but it is highly not recommended due to the release of toxic substances during the combustion of varnish insulation and violation of environmental standards. It is better to hand it over in a cleaned mechanical form.
Is the gas inside the compressor dangerous when sawing?
In old, serviceable compressors, the pressure can be high. Before cutting, be sure to check that the hoses are open and the pressure has been released. In most used compressors, gas has long escaped through microcracks.
Does it make sense to disassemble the compressor for magnets?
Modern compressors can use powerful neodymium magnets, which are valued by radio amateurs. However, their extraction is labor-intensive and their weight is light compared to copper. The main profit is the copper winding.