Put under a lot of pressure, air is an alternative to electricity, to power tools. It is also ideal for many other tasks in the workshop or on the construction site.
To power tools with compressed air, you need a compressor, which compresses and stores the required air. The air then flows to the tool via a hose. Air tools tend to be cheaper and lighter, in some cases also more powerful and more durable than electrically operated relatives. The most important criteria for choosing the right compressor are the pressure required for the application and, above all, the air requirement of the tools.
tools
In the manufacturer's brochures you will find information about the air consumption and the required pressure. A stapler, for example, gets by with less than one liter of air per stroke. For a chisel hammer you have to counter it 150 to 550 Calculate liters of air per minute.
While for airbrushing, tire filling and stapling a small compressor with a filling capacity of 50 liters per minute is perfectly adequate, you need a lot of compressed air to chisel. It is best to choose a compressor, which offers some reserve. So he always has time to cool down during longer work, and you don't have to take forced breaks.
filling performance
The performance data in the brochures are confusing. The intake power is a purely theoretical value. It is calculated from displacement x speed in liters per minute. Since the compressor has to work against the increasing pressure, this value says nothing about the actual performance. The filling capacity is more important. she says, how much air the compressor can actually deliver. This value is between 50 and 66 Percent of intake power. However, the measurement is not standardized, and some manufacturers even conceal them or calculate them nicely. You can determine the filling performance yourself and compare devices. How to do it:
1. Lassen Sie den Behälterdruck bei 10-bar-Kompressoren zum Beispiel auf 6 bar ab.
2. Schalten Sie den Kompressor ein und stoppen Sie die Zeit, that the compressor needs, around the air of 6 up again 10 to bring cash, i.e. to generate a 4-bar differential pressure.
3. Jetzt berechnen Sie die Füllleistung nach der folgenden Formel:
container content (Liter) x 4 bar x 60 stopped time (Sek.)
Depending on the accuracy of the pressure gauge and the specification for the tank size, you can compare the values of different compressors with an accuracy of about ±10 percent.
compressor
A compressor mainly consists of a compressor and the compressed air tank. The electrically driven compressor draws in air and compresses it. In , Heimwerkergeräten kommen Kolbenkompressoren zum Einsatz. They have one or two cylinders and different stroke volumes. Devices with a large stroke volume and low speed are usually more robust than high-speed ones with a low stroke. For devices with several cylinders, you should prefer those with a V-arrangement of the cylinders. They are cooled more evenly than in-line cylinders. The compressor, where the electric motor drives the compressor directly are more efficient and require less maintenance than those with V-belt drive.
pressure vessel
The size of the pressure vessel determines the air reserve, which is available, until the compressor starts again. A large container is, when devices are used in interval operation, sensible. But the performance of the compressor must also be right. A low power compressor, which takes forever until the huge container is under pressure, doesn't make sense. handyman, who only occasionally work with compressed air, come with a small compressed air tank, but stronger compressor better off. This is ready to use faster. For long-term jobs like chiseling, the container size is secondary.
The air that is heated during compression cools down in the pressure vessel, and condensation forms. This must be drained regularly after work, otherwise the container will rust. Be sure to, that the drain plug is easy to reach. Only a few expensive professional compressors have a rust-proof inner coating.
The measure of air pressure is bar. The pressure can usually be read off a manometer on the compressor. The pressure generated must be at least as high, as the operating pressure required for the application. A pressure reducer regulates a higher container pressure. A filter pressure regulator is better, which also filters most of the condensate from the air and protects the tools.
air quality
Most air tools require lubrication from pneumatic oil. With a combined maintenance unit with filter pressure reducer and mist lubricator, both a paint spray gun, the condensate- and needs oil-free air, as well as a chisel hammer or stapler with condensate-free, but operate with oil-mist compressed air. Most wearable- and mobile compressors are already equipped with it. Otherwise they are also available as accessories.
Some manufacturers offer compressors, that work without oil lubrication. These devices are cheaper and the compressed air produced can also be used without a filter for oil-free operation. Such compressors are more suitable for occasional use. Due to the lack of oil lubrication, cooling is poorer in continuous operation and the service life is shorter.
quick couplings
Also pay attention to the couplings for connecting the pressure lines. They are designed as quick couplings, however not standardized. Couplings with large internal cross-sections offer less resistance to air than those with small ones.
weight + landing gear
The weight and the chassis are also important for mobile compressors. Small portable compressors up to approx 25 kg can be quickly transported to different locations, because they find enough space in every trunk.
Larger devices usually have their own chassis. They are easier and more comfortable to move with pneumatic wheels. However, most of the time the compressor is in a fixed place in the workshop, hard rubber wheels suffice.