How to make an air compressor from an old refrigerator. How to assemble a compressor from a motor from an old refrigerator with your own hands

The refrigerator has a reliable compressor, so you can work with it fearlessly. This is a single piston pump that creates excess pressure. It compresses, moves hot refrigerant vapor when used for its intended purpose.

For this we need old refrigerator, approximately one thousand rubles per Consumables, adjusting devices, a little knowledge and desire.

Advantages and disadvantages of a homemade compressor

Each person decides for himself what he will do: buy ready-made or do it yourself.

1. The factory compressor runs on a belt drive, which allows you to work at high speed, does not require lubrication, has a large size. The belt must be protected from oil. Even under all operating conditions, the belts quickly fail. Home - does not have a belt.
2. A pressure relief system is installed in the factory apparatus, which allows you to work from 4 to 10 hours per day, depending on the class of equipment. The system is capricious, to constantly maintain air pressure, an excess amount of air is required due to the possibility of losing it on the pipeline line or when filters are dirty. The pipeline must be large diameter otherwise the risk of pressure drop increases. This adds bulk to the system.
3. In expensive models, the pressure level, as well as the termination of its supply, is regulated by a pressure switch, in which the pressure difference is already set by the manufacturer. At budget options automation is minimal, so you have to time the clock to turn on and turn off the device.
4. The refrigerator contains a compressor without a regulator, so in home version you have to do it yourself protective relay, which will only be activated if there is a risk of overheating.
5. The cost of self-made equipment is significantly lower, it works much quieter. The versatility of the home device is obvious: tire inflation, painting, airbrushing, connecting pneumatic devices have become available.
6. As experience shows, it is not possible to make changes and additions to the factory equipment. If the device is intended only to pump up tires, then you cannot increase its power. On a homemade one, you can install a large receiver, which will lead to an increase in power, equip it with a handle for ease of transportation, and provide an external fan for cooling.
7. The car pump runs on 12 volts, and the home compressor runs on 220 volts.

Stages of work

To make a compressor from the refrigerator with your own hands means to follow the sequence of steps:

1. Take pliers, a spanner wrench for 12, 2 screwdrivers - for plus and minus. At the bottom of the back panel, bite with pliers the tubes connecting the compressor to the cooling system. Unscrew the starting relay, after marking the top and bottom side. Disconnect the relay from the plug. We take all the fasteners with us.
2. Function test: connect the relay back, provide air access to the compressor through the pipes, connect to the network. If everything is done correctly, then the device works. Air will enter one tube and exit the other. Label these tubes.
3. Attach the compressor with self-tapping screws to a wooden board.
4. We take an old fire extinguisher, 1 hose 600 mm long, 2 others - 100 mm, fuel filter, clamps, pressure gauge, sealant. We already have a drill, screwdriver, pliers.
5. If there is no fire extinguisher, then we will make a plastic container. To do this, you need to take a container with a volume of more than 3 liters. Make 2 holes. Insert the inlet tube into 1 hole at a distance of 2 cm from the bottom of the container. We lower the outlet pipeline 10 cm deep. It is impossible to install a pressure gauge on a plastic tank.
6. If there is an iron tank, then the tubes can be fixed by welding. We install a pressure gauge on the iron receiver.
7. We fasten the receiver and compressor together.
8. Put a filter on a hose 10 cm long, attach the free end of the tube to the inlet of the designed apparatus. Connect the receiver inlet to the compressor outlet with another hose. We fix the docking points with clamps. A diesel filter is attached to the last hose, and its free end is inserted into the outlet of the receiver. Equipment can be put on the remaining end of the tube, if necessary, so that airbrushing and painting become available.

Let's look at the video "How to make a compressor from an old refrigerator with your own hands."

Change of oil

When you create a compressor from a refrigerator for painting with your own hands, you need to take into account all the nuances. The oil needs to be changed. At the factory, mineral water was filled in, which a household refrigerator needs. It doesn't suit us. It has no additives, because the refrigerator is isolated from the outside world. When there is air access, the composition oxidizes, clogs, the equipment overheats and breaks with noise. How is it replaced?

Scheme of actions: find a tube with a sealed hole, open it by removing the sealed end of the hose. Drain the oil into a suitable container, fill in half a liter of new oil with a syringe. At the end of the procedure, the hole must be soldered.

Possible problems

We figured out why we need an old refrigerator, we understand the scheme of actions with our own hands. It is necessary to discuss possible complications and malfunctions in the operation of the unit we have created. Protect the equipment from overheating, as this may harm it.

With a frequency of 1 time per year, it will be necessary to replace filters and oils.

It is contraindicated to load the compressor by more than 75% of its capacity. But it is quite difficult to understand where the line is, which cannot be crossed, to predict what pressure the compressor will show. It depends on when the refrigerator was released, what brand it is. On older models, this figure will be better. Then for comfort quality work we only need to replace the consumable filters.

An old refrigerator will come in handy if you want to make a vacuum pump out of a compressor.

The most important thing to remember is that the equipment must be used for its intended purpose. Piston in 95% modern refrigeration compressors does not have rings, but without freon and closed system after 24 hours it jams. The scheme of its work is such that it can withstand pressure from 12 to 24 bar due to weak valves. But you can use old models of Soviet cast-iron compressors. We must remember about safety.

The idea of ​​making an air compressor for working with an airbrush based on a refrigerator (hereinafter referred to as the “device”) caught fire for a long time, but it took about a year to bring it to life.

The idea is attractive because this device gives a low noise level (noise at the level of a conventional refrigerator), allowing you to work late in the evening (early night), since using an oil-free Chinese compressor, giving 94 dB of noise, somehow became annoying.

First of all, a compressor was needed to implement the idea. This unit was purchased from hand as part of a Biryusa working refrigerator. But then it turned out that the refrigerator itself was larger in volume than the one that stands in the country. Therefore, the “newly acquired” went to the dacha, and the compressor unit itself was mercilessly removed from the “dacha”. Here it is necessary to add that the compressor was attached to the refrigerator by means of suspension on springs to a rigid plate, so I decided to keep this design and fully apply it in the manufacture of the device.

Then an old OU-5 fire extinguisher was found in the garage, which later became a receiver.
Conceptually, it was assumed that this device would be stationary, so I decided to make a rigid spatial structure for it from corners (which I collected in exactly the required amount in the country).

With such a set of basic technical requirements and the actual production of the device began. The length of the device was determined by the size of the compressor carrier plate. The width was selected arbitrarily, taking into account the placement of the receiver, compressor and the rest of the body kit.
The scheme of the device is ordinary: compressor, filter, check valve, receiver, pressure switch, pressure regulator, filter, quick coupling.
After cleaning the corners from rust and dirt, they were welded as carefully as possible by household welding in the country. After I made the frame, I tried on the receiver and outlined the tie-in point for the air inlet and the condensate drain point.

I drilled two holes in the receiver with a diameter of 9.00 mm and welded spurs with a 1/2" thread. Then I roughly figured out how the receiver would be placed and welded supports to fix it. The receiver was placed at an angle of 5-10 degrees, for the accumulation of condensate in one place. I did the same for mounting the compressor. As a result, I got a very heavy (about 25 kg together with the compressor and receiver) and powerful design. But this turned out to be a plus - this is the complete absence of vibration, both on the case and on concrete floor where he stands.

I changed the oil in the compressor, without particularly bothering the bay 250 gr. Lukoil semi-synthetics 10 W-40. To replace, I carefully opened the third (oil) tube in the compressor. He drained it through it and poured honey through it. syringe (volume 20 ml). I screwed a self-tapping screw on the sealant into the tube. Oil poured 300 ml.
The receiver was fixed with two strips cut from scraps of roofing iron. Pieces of a watering hose, cut lengthwise, came up as gaskets.
Next came the turn to the automation system and air supply. I decided not to throw away my native tee (separator) from the fire extinguisher, especially since the fire extinguisher itself uses tapered thread. Having disassembled the tee and removed the shut-off valve from it, the hole of the valve stem was clogged with a bolt, having previously cut the thread with a tap.
Now there are two "live" holes left in the tee - from the safety valve and the CO2 atomizer tube. A pressure switch, such as RDM-5, was very easily screwed onto the safety valve fitting (removing it naturally). But with the hole for the spray tube, I had to toil. Not a single standard pipe thread fit this hole, therefore, after going through all possible options, I had to go to the turner in the taxi depot. For 200 rubles, the turner made an adapter from a steel blank for a standard pipe thread 1/2". Well, then everything flowed like clockwork. Half a day of searching in stores and the necessary adapters, tees, a pressure regulator, a pressure gauge, a check valve, automobile gasoline filters (VAZ 06, 09), and a filter were purchased fine cleaning for air, etc. I bought a pressure gauge with a “clear” scale to make it easier to visually control the presence of air in the receiver. It should be noted that the pressure switch according to the passport is designed to work on water, so I decided to play it safe and, having disassembled the relay, put the working chamber on the sealant. Just in case. The frame was painted with oil paint, which was at hand.

It took a total of two hours to assemble the device. All threaded connections connected with the help of a sanitary thread "Tangit-Unilok". It makes no sense to describe what is screwed to what and in what sequence, because. each device is individually manufactured and the assembly algorithm determines the assembly itself. The pressure switch was adjusted to turn off at 3.5 atm., Turn on 1.5 atm. No matter how I tried to lower the value of the setpoint limits, nothing happened.

After assembling, proceeded to pressing. Here was my first disappointment. The pressure in the receiver decreased by approximately 0.5 kgf/cm2 per minute. Found leaks by washing. It turned out that it was “poisoning” from under the fittings welded to the receiver (however, I am not a professional welder). The solution was found immediately - cold welding. After applying and holding for a day, I tried again. Holds pressure. HOORAY. But, there is still a leak from the pressure regulator. Approximately 0.1 kgf / cm2 “leaves” in 20 minutes. I thought about it and decided not to “treat” the device anymore, since this air loss can be neglected. Such pressure losses during painting are not fundamental for me.

Test painting showed that there is no oil in the air, the paint lays down evenly, both acrylic and enamel. And the most important thing is the silence during the operation of the device. Q.E.D.

The new device organically fit under the table in the workshop. In a few days test trials I decided to check for condensation in the receiver. When opening ball valve, 20 grams of oil spat out with a whistle. This was the second disappointment. I thought about it and went to read literature. After reading various articles and thinking logically, I realized one thing that the compressor will spit out oil anyway, because the system in the refrigerator is closed, but in my device it is not. Therefore, I will periodically pour oil into it, approximately in the proportions “how much I spit out, so much I poured in.” And people write that the compressor is on engine oil won't last long. Well, let's wait and see.
Blew out a new device

Recently, compressors have gained popularity among tinkerers. They are made on the basis of almost any engine, calculating the power of the base unit depending on the number of consumers. For home workshops, do-it-yourself self-made compressor units are in demand.
Compressors from refrigerators often remain operational after the breakdown or obsolescence of the refrigerator itself. They are weak, but unpretentious in work. And many masters make quite worthy of them makeshift installations. Let's see how we can do it ourselves.

Details and materials

• 11 kg propane tank;
• 1/2" Female Coupling with Plug;
• Metal plates, width - 3-4 cm, thickness - 2-4 mm;
• Two wheels with mounting platform;
• Refrigeration compressor from the refrigerator;
• 1/4" adapter;
• Brass check valve connector;
• ¼ inch copper pipe connector - 2 pcs;
• Compressor pressure control equipment;
• Bolts, screws, nuts, fumlenta.

• welding inverter;
• Screwdriver or drill;
• Milling cutters for metal with titanium coating;
• Turbine or drill with abrasive nozzles;
• Metal brush;
• Roller for copper tubes;
• Adjustable wrenches, pliers.

  Assembling the compressor

  Step one - prepare the receiver

  Rinse an empty propane tank thoroughly with water. It is very important to remove all residues of the explosive gas mixture in this way.
  

  

  
  

  

  
  In the end hole of the cylinder, we overlap the adapter by 1/4 inch. We scald it from all sides by welding, and muffle it with a screw.
  

  

  
  

  

  
  

  

  
  We put the receiver on wheels and support. To do this, we take segments metal plates, bend them at an angle and weld them onto the body from the bottom. We weld wheels with a mounting platform to the corners. In front of the receiver we mount the support bracket.
  

  

  
  

  

  
  

  

  Step two - mount the compressor

  On top of the receiver, we expose the mounting frames for the compressor from metal plates. Checking their position bubble level, and boil. We sit the compressor on the clamping bolts through rubber shock-absorbing pads. At of this type compressor, only one outlet will be used, through which air is forced into the receiver. The other two, sucking in air, will remain intact.
  

  

  
  

  

  
  

  

  Step three - we fix the check valve and the adapter to the equipment

  We select a cutter for metal that is suitable for the diameter, and make a hole in the housing for the coupling with a screwdriver or drill. If there are protruding forms on the coupling body, we grind them with a drill (you can use a regular electric emery or a grinder with a grinding disk for this).
  

  

  
  

  

  
  We expose the coupling into the hole and scald it around the circumference. Internal thread it must correspond in pitch and diameter to the seat thread on the check valve.
  

  

  
  

  

  
  We use a brass check valve for small compressors. We plug the pressure relief outlet with a suitable bolt, since a bleed valve is already provided on the adjusting assembly.
  

  

  
  

  

  
  

  

  
  To install a pressure switch or pressure switch with all the control equipment, we mount another 1/4 inch adapter. We make a hole for it in the center of the receiver, not far from the compressor.
  

  

  
  

  

  
  

  

  
  We twist the check valve with an adapter 1/2 inch.
  

  

  
  

  

  
  

  

  
  We connect the outlet of the compressor cylinder and the check valve with a copper tube. For this special tool we flare the ends of the copper tubes, and connect them with brass threaded adapters. We tighten the connection with adjustable wrenches.
  

  

  
  

  

  
  

  

  
  

  

  Step four - install the control equipment

  The control equipment assembly consists of a pressure switch (pressure switch) with a control sensor, a safety valve or a pressure relief valve, an adapter-coupling with external thread and several taps and pressure gauges.
  

  

  
  First of all, we mount the pressure switch. It must be slightly raised to the level of the compressor. We use an extension-coupling with an external thread, and we twist the relay through the sealing tape.
  

  

  
  

  

  
  Through the adapter, we install a pressure control sensor with pressure gauges. We complete the assembly with a pressure relief valve and two taps for the hose outlets.
  

  

  
  

  

  
  

  

  
  

  

  
  

  

  Step five - connect the electrician

  We disassemble the pressure switch housing with a screwdriver, opening access to the contacts. We bring a 3-core cable to the contact group, and distribute each of the wires according to the connection diagram (including grounding).
  

  

  
  

  

  
  

  

  
  

  

  
  

  

  
  Similarly, we make the supply cable, equipped with a plug for a power outlet. Screw the relay cover back into place.
  

  

  
  

  

  Step Six - Refinement and Trial Run

  For carrying compressor unit we attach a special handle to the compressor frames. We make it from scraps of profile square and round pipe. We fasten it to the clamping bolts and paint it in the color of the compressor.
  

  

  
  

  

  
  We connect the installation to a 220 V network, and check its performance. According to the author, to obtain a pressure of 90 psi or 6 atm, this compressor needs 10 minutes. With the help of an adjusting sensor, the inclusion of the compressor after a pressure drop is also regulated from a certain indicator displayed on the pressure gauge. In my case, the author set up the installation so that the compressor turns on again from 60 psi or 4 atm.
  

  

  
  

  

  
  

  

  
  The last step is to change the oil. This is an important part Maintenance such installations, because they do not provide a revision window. And without oil, such machines can work for a very short time.
  We unscrew the drain bolt at the bottom of the compressor, and drain the waste into the bottle. Turning the compressor on its side, fill in a little clean oil, and screw the plug back on. Now everything is in order, you can use our compressor unit!
  

  

No need to talk again about what the compressor is for, because this is already clear. But not everyone can do it from the refrigerator with their own hands. However, with patience essential tool and theoretical knowledge, this task can be dealt with, and quite quickly. You can use such equipment together with an airbrush, spray gun, etc. tool. Its key features are that the operation is almost silent, and the dimensions are small. But such a compressor creates very good pressure.

Why homemade and not professional?

You probably already know the answer to this question. Often it's a matter of price. Professional compressors are expensive. And if you have an old refrigerator that is idle, then why not take yourself a few hours and not make the compressor yourself. As for the design, it is different, but not much. Purchased models have an electric motor that transmits work through a belt drive. In our case, the electric motor and the working chamber will be in the same housing, but there is no belt drive.

less in homemade product and automation. Although here protection against overheating needs to be installed. This relay will save your motor from high temperatures and prevent breakage. As for lubrication, professional compressors can also be dry, that is, without lubrication. Such models work due to graphite rings. In our case, there will be a lot of lubrication, which directly affects the durability of the equipment.

It is worth noting that homemade compressor making it out of the refrigerator with your own hands is not so difficult. But you need to understand that attention to detail is required here. In any case, if everything works out for you, then at the end you will have a functional station that can be adjusted as you like and arranged as you like. All this, unfortunately, cannot be done with purchased equipment.

Dismantling works

Before using the compressor, it must be removed from the refrigerator and equipped accordingly. But more on that later. Now actually about how to perform dismantling work. There is nothing complicated here. You will need a small set of tools: pliers, two screwdrivers (flat and Phillips), a pair of box wrenches. Probably everyone knows where the compressor is located. This is usually the lower back of the refrigerator.

Now you can start removing. You will see copper pipes that lead to the cooling system. With the help of pliers, you need to bite them off. Preferably with maximum vacation. In the future, you can use them for your own purposes. It is worth paying your attention to the fact that you need to bite off the pipes, and not try to saw them with a file. "Why?" - you ask. It's simple, when sawing, small chips are necessarily formed, which, in one size or another, enter the compressor, which can lead to its deterioration. technical condition up to breakage.

This work is not finished, we need to remove an equally important element - the starting relay. Usually it is a white or black small box with wires coming in and out of it. Carefully unscrew the fasteners and bite off the wires leading to the plug. Mark in advance where the relay has the top and where the bottom. This may be indicated on the case, check. are needed in order to remove the carcass of the compressor. So we removed the compressor from the refrigerator with our own hands. Another point, take all the fasteners with you, they will come in handy.

Checking the functionality of the equipment

The first step after removal is to make sure that the compressor is not “dead” and can be used for your own purposes. To do this, flatten the copper tubes with pliers. This is done so that air can freely exit and enter through them. On next step we need to put the starting relay in the position in which it was before removal. This is extremely important. The fact is that the relay works on the principle of heating the plates and gravity. Incorrect orientation will cause it to break. The compressor winding may even burn out, which is not good.

The relay has input wires. To them you need to fasten the wire with a plug. The connection point, in order to avoid electric shock, must be twisted with electrical tape. After that, you can plug the plug into the socket. If the compressor rumbles quietly to itself, and air comes out of the tube, then you did everything right and you can use the equipment. At this stage, it is recommended to mark the tubes so that you know which one is leaving and which one is entering. If, however, problems arise during operation, for example, the compressor does not turn on or turns off after a while, then you will have to dial the relay and find the weak link. This procedure requires minimal knowledge electrical circuits and electrical engineering in general.

Materials required for work

Before you make a compressor from the refrigerator, you need to get everything you need to work. First, it's a compressor. We have already figured out how to remove the engine (compressor) from the refrigerator, so you should have it at hand. By the way, on different models refrigeration technology installed different compressors. Usually they are a cylindrical product or a so-called pot.

In order to make a high-quality compressor that would fulfill its purpose at 100%, it is necessary to acquire a receiver. In fact, this is a container into which the engine will pump air from the refrigerator. In principle, there are no specific requirements for the receiver. An old empty fire extinguisher, a receiver from a truck will do. The volume can be different - from 3 liters and more. Also, before you make a compressor from the refrigerator, you need to find suitable hoses. The length of two of them should be 10 cm or more, the last one should be at least 50-60 cm. It is very convenient to take car hoses here. The fact is that they will be attached to the filters, and their size is perfect for these purposes.

As for consumables, these are two filters - gasoline and diesel, clamps, wire, epoxy resin, pressure gauge. As for the tool, every owner will find it in the workshop. Need a drill, knife, screwdriver and pliers. Once you have all this put together, you can begin to work.

from the refrigerator: step by step instructions

Most compressors have three copper tubes at the outlet. Two of them are open, the ones you bit off with pliers, and one is sealed. It is usually the shortest. Accordingly, the tube from which air blows is the outlet, and the one that sucks in is the inlet. We don’t touch the third yet, but a little later we will figure out what it is for and what to do with it. So, after checking the output and input, make the appropriate marks and disconnect the compressor from the network. Next, we take a pre-prepared board. She will be our foundation. Using self-tapping screws, we attach the compressor to the board. Tubes must be further processed before connection. It is advisable not to use a metal file, it is better to take pliers.

One important point: the compressor must be attached to the base in exactly the same way as it was installed on the refrigerator. Mounting sideways or upside down is not permitted. This is due to the starting relay already familiar to us, which works due to the forces of gravity. Our do-it-yourself compressor from the refrigerator has not yet been made. Now we need to make a receiver. A plastic container will do. In its upper part we drill two holes for tubes of the appropriate diameter. Then we put them in there and fill it all in epoxy resin for sealing. One of the tubes (inlet) should not reach the bottom of the receiver a couple of centimeters. A short tube (outlet) starts about 10 cm. Such manipulations are needed for more convenient air mixing.

iron receiver

"How to make from the refrigerator?" - you ask. Yes, it's very simple, for this you need to use the instructions described above. But there is one thing, for such purposes it is best to take an iron receiver. There is not much difference between plastic and metal, but only on an iron receiver can we install a pressure gauge. In addition, the hoses are soldered or welded, not filled with resin. This provides a better tightness of the container.

To install a pressure gauge, you need to drill a hole of the appropriate diameter, install the device and solder this place. Although it would be more humane to go following way. Drilling a hole in suitable place and in this place we weld a nut. Then it remains only to screw the pressure gauge, and the job is done. In principle, there is not much difference, only replacing a failed pressure gauge is much easier. After everything is done, you can attach the receiver to the base. To do this, use steel tape or wire. In fact, we almost made a compressor from the refrigerator with our own hands. There are a few small details left.

How to make a mini compressor: the last part of the installation

We have already passed most of the way. Now there are a few lines left. First, take a piece of hose (10 cm) and put a gasoline filter on it. If you use a car hose, then there should be no problems with putting on. If the hoses are thin and are not put on the fitting, then as an option they can be heated. The free end of the hose must be put on the compressor inlet. If the connections are strong, then the clamps can not be used, especially since there is practically no pressure here. It is easy to guess that the filter is necessary in order to prevent dust from entering the compressor. The second piece of hose is connected to the outlet of the compressor and the inlet of the receiver. There will already be a lot of pressure, so we put clamps. We put a diesel filter on the third hose, and insert the second end into the outlet of the receiver. The outlet fitting of the filter (diesel) is connected to the working hose of the spray gun, airbrush or other equipment. You will probably decide for yourself how you can use the compressor from the refrigerator and for what purposes.

Equipment specifications and maintenance

As for the pressure created by the compressor, it is difficult to talk about specific figures. Much depends on the model and age of the equipment. By the way, the "ancient" compressors are more powerful. They are able to give about 2-3 bar. Both imported and Soviet models work almost silently, however, there are exceptions.

In terms of maintenance, this is a pretty important point if you don't want your fridge compressor to need to be repaired soon. It is not difficult to take care of such equipment with your own hands. The main rule is that it is necessary to periodically change the gasoline and diesel filters. In addition, it is advisable to drain the oil accumulated in the receiver. decisive role the high frequency of oil changes in the compressor also plays into the durability of the equipment. You need to do this not so much often, but at the appointed time. To drain the mining, it is necessary to cut off a piece of the sealed tube. Remember, we mentioned it at the very beginning of the article. Through it, the old oil is drained and new is poured.

Should the compressor be repaired?

Often the refrigerator motor fails. Oddly enough, but often there is no point in repairing. But when it comes to refrigerant, the issue is resolved by replacing it. As for other cases, such as dust getting inside or winding burning, this is best left unattended. Really easier and cheaper to buy new engine. But with your own hands it makes sense. There is nothing difficult in this. Moreover, you already know how to remove the compressor from the refrigerator. It is installed in reverse order. It is important that the installation is carried out correctly. That is, the joints of the tubes must be sealed, and the wires must be reliable, that is, insulated. In general, the replacement process itself takes no more than 20 minutes. If you still decide to repair the refrigerator compressor with your own hands, then get ready for difficulties. First, ring the relay, perhaps it is in it, and therefore the equipment does not start. Then in the compressor. If this does not help, then the equipment can be thrown away, there is no particular point in messing with it.

Conclusion

So we figured out how to make a compressor from a refrigerator with our own hands. In general, a variety of difficulties may arise during the execution of work. From the fact that the hoses do not fit on the filter, and ending with poor connections or lack of response from the compressor. But most problems can be fixed. In general, such a compressor is a very useful thing. With it, you can do painting and other useful deeds. It matters more what kind of airbrush or spray gun you use than a compressor. The main purpose of such equipment is to provide constant pressure. If there is a need for a large pressure, say 3.5 bar and above, then it will not be difficult to find a suitable compressor. Most likely, this is the Soviet model. This is due to the fact that modern refrigerator engines, although not powerful, are very productive. That's all for this topic now you can get down to business.

Portable air compressor, quiet, consuming relatively little electricity - this is probably the dream of every owner of a private house, cottage, garage, small business. Well, mobile installation compressed air it is quite acceptable to do it yourself, for example, taking part of the equipment of the old household refrigerator. Each refrigeration unit has a built-in compressor. If you remove this part, add equipment, you get an air compressor from a refrigerator compressor,.

Before deciding to implement an idea, it is advisable to determine exactly: is this idea really worth taking on? Let's look at a few important aspects of the topic in order to help future designers to accept the right decision:

1. not designed for air service.
2. The performance of compressors in household refrigerators is low.
3. Refrigeration compressors require special oil to lubricate the mechanism.

From this follow the corresponding conclusions. When working with air environment the device will not function long time without good cooling.

When the refrigeration compressor works with freon, due to other temperature parameters of the refrigerant, the housing is cooled.

The compression of the air mixture by a refrigeration compressor occurs in completely different temperature conditions, which will lead to an increase operating temperature in order. Ultimately, without good cooling, the compressor will simply burn out.

The low performance of home refrigeration units is another factor limiting the use of such equipment for producing compressed air.

For example, in order to pump up a 5-liter receiver to a pressure of 5-7 atm., It will take at least 15-20 minutes of operation of the refrigeration unit.

Meanwhile, this volume of air is not enough even to inflate the wheel of a car in one sitting or paint one wall with a spray gun small room garage.

Finally, one more important factor- compressor oil. To lubricate the mechanism of refrigeration compressors, a special freon oil is used, the properties of which change dramatically in contact with air.

If you do not change the oil to another type of lubricant that is loyal in structure to air, after a certain time the compressor mechanism will simply “close” due to the rapid wear of parts.

DIY construction

So, if, despite all the noted nuances, a decision is made to assemble from the refrigerator, you can proceed directly to action.

The first step is to collect all the necessary details of the project equipment:

1. Air receiver.
2. Oil separator.
3. Differential pressure switch.
4. Copper tube.
5. Inlet air filter.
6. Shut-off regulating and control fittings.

For an air receiver, a compressed air cylinder from a KAMAZ vehicle is optimally suited. The five-liter container has overall dimensions acceptable for the domestic environment and meets the requirements for pressure vessels.

A differential pressure switch (for example, from the PT series) is used from among those used in industrial refrigeration plants.

A sufficient amount of copper tube is available in the design of the condenser of a domestic refrigerator. In diameter, it fits the outlet pipe of the refrigerator compressor.

The air filter at the compressor inlet is easy to make from any suitable plastic container by placing an ordinary foam rubber sponge inside. Shut-off control and control valves - valves, check valve, pressure gauges - can be bought at the store.

Assembly of the air unit

An air receiver (for example, an air tank from a KAMAZ vehicle) is mounted on a chassis made of metal corner. Additionally, it is recommended to install a pair of wheels on the chassis for ease of movement, a supporting “leg” and a handle.

A platform for installing a refrigerator compressor and a bracket for mounting a differential pressure switch are fixed above the upper area of ​​\u200b\u200bthe cylinder. An oil separator is fixed to the side of the receiver, through a clamp and an outlet fitting.

An air filter must be installed on the inlet pipe of the refrigerator compressor. The presence of an air filter is required to reduce the entry of foreign particles present in the air into the system.

It is easy to make an air filter from any plastic container by attaching it through an angled threaded transition to the inlet pipe.

The outlet pipe of the compressor is connected through a compensatory copper tube-heat exchanger with the inlet fitting of the separator (oil separator). The outlet branch pipe of the separator is connected to the receiver through an angle adapter.

A tee is installed at the outlet of the receiver and (compressed air outlet). Through the branches of the tee, the receiver output is additionally reported copper pipes with differential relay and pressure gauge. There is also a safety valve.

Electrical part and principle of operation

The electrical circuit diagram actually remains intact, with the exception of minor changes. That is, the compressor from the refrigerator, as it was powered from the AC mains through the starting relay, so this option is left unchanged.

Another question is that it is possible to modernize the circuit somewhat. For example, supplement it with a switch installed on the case assembled installation. Still, this option is more convenient than periodically plugging and unplugging the plug from the outlet each time the device is used in practice.

Also, the circuit for supplying voltage to the compressor must be configured taking into account the inclusion of the contact group of the differential pressure switch.

Due to this configuration, the device will turn off immediately after reaching the set air pressure limit. Here, in fact, that's all. The air compressor from the refrigerator can be considered done.

Some notes on the project

Often as a receiver for homemade projects fire extinguishers are used. Meanwhile, the containers of powder fire extinguishers have a low limit of the maximum allowable working pressure (8-12 atm.).

In addition, such vessels are subject to mandatory examination after a certain period of time in the relevant authorities. If you still take a fire extinguisher vessel under the receiver, then vessels from under carbon dioxide systems can be considered an acceptable option.

Finally, the most important point. Such structures, in fact, should be registered with the Rostekhnadzor authorities, since the assembly contains a vessel operating under a pressure of more than 0.07 MPa ( operating pressure installation 10 atm.).

Owners of unregistered home-made air compressors may well be held liable (administrative and even criminal), as soon as something extraordinary happens during the operation of the equipment with a threat to human life and health.

So it’s worth thinking a thousand times before trying to assemble an air compressor from a refrigerator compressor with your own hands.

The practice of assembling a compressed air installation