The old refrigerator is out of order, but don’t rush to throw it away entirely. In the depths of this household appliance lies a real pearl for the home craftsman - compressor. It is this unit, created for circulating freon, that has the unique ability to create high pressure, which makes it an ideal candidate for recycling.
Unlike cheap Chinese analogues, which are often sold in tool stores, Soviet and Russian motors are incredibly durable. They are able to work for years, withstanding significant loads, and at the same time they cost practically nothing if you got them from decommissioned equipment. In this article we will look at how to turn unnecessary metal into useful equipment.
Before proceeding with dismantling, it is worth assessing the condition of the unit. If the engine hums smoothly, does not spark and starts without strong jerks, you can safely put it into action. Tightness The housing also plays a role, but with the right approach, even minor oil leaks can be compensated. The main thing is to properly prepare the device for new tasks.
Preparation and dismantling of the compressor
The process of removing the heart of the refrigerator requires care and compliance with safety precautions. First of all, you need to completely de-energize the device and wait until all the elements have cooled down. Then you should carefully cut the copper tubes going to the condenser and evaporator, leaving enough length for subsequent connection of the hoses.
It is important not to damage the electrical part, especially the start relay and capacitor. Often it is these elements that require replacement or inspection before starting a new project. Dismantling It is better to do it together, since the compressor weighs a lot and is mounted quite rigidly on the frame.
☑️ Preparation for dismantling
After removing the unit, carefully inspect the tube terminals. There are usually three of them: two for refrigerant circulation and one for charging. We need to determine which of them is input (suction) and which is output (discharge). This is easy to do: just briefly apply power and bring your finger to the hole - where it blows, there is an exit.
⚠️ Attention: When sawing the housing or drilling holes to drain old oil, make sure that there is no freon left inside under pressure. Although in older models its quantity is minimal, there is a risk of depressurization with the release of contents.
Necessary tools and materials
To create a full-fledged compressor installation, one motor is not enough. You will need to assemble an entire infrastructure around it to ensure stable operation and security. A basic set of tools can be found in the garage of any self-respecting craftsman.
- 🔧 Metal container (receiver) - an old fire extinguisher, gas cylinder or tank from the brake system of a truck.
- 🛠️ Fittings and adapters - for connecting pipes, hoses and valves without loss of pressure.
- 📏 Pressure gauge —to control the pressure in the system to prevent rupture of connections.
- 🧪 Oil separator —a filter that prevents oil emulsion from entering the painted surface or pneumatic tool.
Particular attention should be paid to the choice of receiver. It is in this tank that compressed air accumulates, the pressure is equalized and the mixture is cooled. The use of plastic canisters is strictly prohibited due to the risk of explosion. Only metal of a certain thickness can withstand cyclic loads.
For assembly you will also need clamps, high-pressure hoses (for example, from a diesel fuel system) and a set of wrenches. Do not forget about the electrical wiring of a sufficient cross-section, since the starting currents of the compressor can be significant.
Assembling a homemade compressor
Assembling the device begins with preparing the receiver. If you are using an old fire extinguisher, it must be thoroughly cleaned of powder, rinsed and dried. It is advisable to provide a drain valve at the bottom of the cylinder to remove condensate, which will inevitably form during operation.
It is best to install the compressor on the receiver through vibration isolators. These can be rubber gaskets or special shock absorbers. Vibration is the main enemy of connections, and if it is not extinguished, the threaded elements will quickly unwind and the metal will get tired.
| Component | Function | Material |
|---|---|---|
| Receiver | Air accumulation, pulsation suppression | Steel (cylinder, fire extinguisher) |
| Compressor | Pressure injection | Cast iron/Steel (from the refrigerator) |
| Pressure switch | Automatic on/off | Plastic/Metal |
| Reverse valve | Protection against reverse air flow | Brass |
All elements are connected in series. Air from the compressor enters the oil separator, then into the receiver, and from there through the reducer (if the pressure needs to be reduced) it goes to the consumer. All joints must be sealed FUM tape or anaerobic sealant.
Nuances of connecting a pressure switch
The pressure switch usually has two groups of contacts. One opens the circuit when the upper pressure limit is reached, the other closes when it drops to the lower limit. It is important to set the delta correctly so that the compressor does not turn on too often.
Setup and first start
Before the first full start of the assembled system, it is necessary to conduct a thorough leak test. Apply slight pressure to the system and generously lubricate all connections with soapy water. The appearance of bubbles will indicate leaks that need to be eliminated.
It is important to configure correctly pressure switch. For painting work, 2-3 atmospheres are usually sufficient, while working with pneumatic tools may require 6-8 atmospheres. You should not turn the regulator to the maximum, since refrigeration compressors are not designed to create pressure above 10-12 bar.
When you turn it on for the first time, carefully monitor the temperature of the motor housing. If it heats up too quickly or makes unnatural sounds (grinding, knocking), the unit should be stopped immediately. Normal operation is accompanied by a smooth hum and moderate heating.
⚠️ Attention: Never leave a working homemade compressor unattended. The automation may fail, which will lead to a critical increase in pressure and a potential rupture of the receiver.
Options for use in the home and garage
A homemade compressor opens up wide possibilities for the master. The most popular application is painting cars and metal structures. An even flow of air without an oil suspension (with a good filter) allows you to obtain an ideal coating without defects.
The device is also indispensable for inflating tires. Unlike electric pumps, a compressor does this instantly. You can assemble an entire pneumatic network in the garage by spreading pipes around the perimeter and installing several air intake points.
- 🎨 Aerography - creating artistic paintings requires clean air under stable pressure.
- 🔨 Pneumatic tools - impact wrenches, grinders and drills are quieter and more powerful than electric ones analogs.
- 🧹 Blowing —cleaning a computer, keyboard or complex engine components from dust with compressed air is most effective.
Some craftsmen go further and create vacuum sealers, using the ability of the compressor to work in the opposite direction (to suction). This allows you to hermetically package products or parts for storage.
Frequent errors and their elimination
During operation, typical problems may arise. One of them is clogging filters. If the air inlet filter becomes dirty, performance will decrease and the engine may overheat. Regular cleaning or replacement of filter elements is mandatory.
Another common mistake is ignoring condensation in the receiver. Water accumulating at the bottom of the tank leads to corrosion from the inside. Over time, this can thin the walls and lead to an accident. Draining Moisture must be carried out after each cycle of intensive work.
If the compressor begins to turn on and off, check the settings of the pressure switch or look for leaks in the pneumatic network. Also, the cause may be wear of the piston group, although this rarely happens in refrigeration units.
How often do you need to change the oil in the compressor?
In hermetic compressors from refrigerators, oil is filled for the entire service life and does not require replacement if the system is sealed. However, if you have remodeled the unit or noticed increased oil carryover into the pneumatic line, you may need to top up or replace it with synthetic compressor oil.
Is it possible to use a compressor in winter in an unheated garage?
It can be used, but there are nuances. At low temperatures, the oil thickens, making starting and lubrication difficult. In addition, condensation may freeze in the receiver. It is recommended to keep the unit warm or use winter grades of oils.
What is the optimal maximum volume of the receiver?
For garage needs, a volume of 50 to 100 liters is considered optimal. A smaller volume will lead to frequent engine starts, while a too large volume will take up a lot of space and will take a long time to fill with a low-power refrigeration compressor.
Following simple operating rules will allow your homemade device to serve for many years. Remember that safety comes first, and regular inspection of components is the key to uninterrupted operation.