When you need to use pneumatic tools, it means that the need to buy a compressor immediately appears. This is a special device for compressing air and forcing it into the tool. It can be used to paint, inflate tires or other materials. The devices themselves are complex from a technical point of view, but there are many manufacturers that offer products of different design types. During the purchase, customers do not understand which compressor to choose for painting, because the range is very large. The article will help you find out the main types, as well as selection rules that help eliminate mistakes and rash waste of funds.
Content
The principle of operation and the device of the compressor
An installation such as a compressor works on the principle of sucking and compressing air or gas, and after that, high pressure injection into the tool begins. Experts divide devices into volumetric and dynamic. They differ in their constructive and operating principle.
During the operation of the first type, air is compressed after entering a special compartment, where it is forced to decrease. The delivery of the required air is carried out using valves, which will open and close in turn. The latter work differently, the essence lies in the effect on the gas of the rotor blades. This gives more accurate work, which depends on the modification and features of the device.
What is important to know about the compressor when choosing
Visually, almost all compressors appear to be the same, but looking at the cost of the equipment, you can see a great difference. The price is formed as a result of many elements and factors, and is also determined by the scope of use, purpose. Buyers should remember that it does not always make sense to take the most powerful and expensive device, especially if the work is planned periodically. Among the specific characteristics that affect the cost, one should highlight:
- The volume of the drive (receiver). Many models on the market have an indicator of 5 liters, but there are also the largest ones at 500 liters. The size can affect the activity of using the device. The more compressed air is used, the more volumetric the receiver needs to be selected. This makes it possible to reduce the load on the motor.
- Number of cylinders. Depending on the design and type of compressor, 1-4 cylinders are installed, the more there are, the sooner air is pumped into the tank. Often 4 cylinders are used in industry, and 1-2 cylinder models are sufficient for heavy and intense loads and trouble-free operation.
- Motor power. All household options operate from an outlet, so another connection is excluded. Motor power is 0.5-3 kW, and the choice depends on the frequency of application of the device, as well as the degree of load.
- Operating pressure. Based on the design and the specific model of household equipment, the value will be in the range of 2-12 bar. If the technique is chosen for painting surfaces, then the indicator depends on the type of paint used. A liquid mixture requires a minimum of pressure to spray properly.For example, for water-based paints, even 2 bar is enough, and for hammer mixtures it is better to use from 8 bar.
- Mobility. This parameter will be important for a person who uses equipment in everyday life. The compressors, which are small in weight and size, can be carried by hand, but the rest of the devices need stationary installation. Mobility is provided by small wheels making it easy to carry.
Top compressor manufacturers
The compressor for car painting is produced by many companies. The device itself is complex and expensive, so you need to choose it from trusted manufacturers. There are many important characteristics that are important to familiarize yourself with, and one of them is the manufacturer. The best and most popular at the moment are as follows:
- Fubag;
- Abac;
- Metabo;
- Elitech.
They all make reliable and high quality compressors that can last for years.
Compressor types
To understand how to choose a compressor for painting, you need to understand the possible types of such equipment.
Reciprocating compressors
Such models can be used in a domestic environment or in professional activities. Using the device, you can paint surfaces, inflate tires or connect a tool for working with nuts, etc.
Main structural elements:
- main unit for work;
- receiver (storage);
- motor.
All devices differ from each other; among the variety, compressors can be distinguished:
- mobile and stationary;
- 1 or more steps;
- for 1 or more cylinders;
- with a different drive;
- with or without oil;
- with different placement of cylinders.
Based on the maximum pressure, it is customary to distinguish between low (up to 12 atm.), Medium (up to 100 atm.) And high pressure (up to 1000 atm.) Options. As a result, the values of the model are divided into tasks for everyday life, professional or industrial activities. To ensure operation, a motor is installed that runs on an electrical network, gasoline or diesel.
Pros:
- A large scope of use, since the device can be used for household work or industrial tasks, including the transportation of gas and air for the tool.
- A wide range of devices with different design configurations.
- There are models that provide clean air, and during operation there will be minimal noise, and they are suitable for use in extreme conditions.
- Relative ease of use.
- High degree of maintainability.
- Optimal pricing policy, which will differ from the purpose of the device.
- High popularity and demand.
Minuses:
- In comparison with other types, there may be less efficiency.
- Some devices are very noisy.
Screw Compressors
In comparison with other types, these devices are more productive and functional, and can also win in other parameters. Their design is much more complex and uses many important details. There are several modes for operation, including start, working, idle, waiting and others. The operation is carried out with or without lubrication, and the drive is direct and belt. Based on the specific model, the device can compress gas or air, expensive devices can function alternately or simultaneously, supplying different mixtures.
Screw devices are more often suitable for industry. This technique is often used in automotive or shipbuilding plants, as well as in the processing industry.
Pros:
- Very high productivity, which gives about 100 cubic meters. in a minute.
- A great resource of work, which reaches 20 years.
- The possibility of autonomous work, since the user does not need constant maintenance.
- A high degree of reliability and repair work due to breakdowns are very rare.
- Quiet operation, so the compressor can stand directly in the workshops.
- Low current consumption.
- Oil consumption is minimal.
- You can connect several devices to one network at once.
- During operation, the machine generates heat, which can be used for additional heating.
Minuses:
- A very large mass, which is in the range of 200-700 kg.
- High pricing policy, you have to pay hundreds of thousands of rubles for a quality product.
- The payback period is very long.
Oil Compressors
The operation of such devices is ensured with the help of a special oil, which makes it possible to reduce the frictional force of different surfaces. This design allows to reduce the force and heating time, and also increases the efficiency, increases the service life and the time of operation without pause. The optimal variant of operation is 20 min / hour.
The oil makes it possible to protect the piston, cylinder and other parts from the effects of corrosion. On the other hand, it is important from time to time to add oil to a certain level, as well as change it over time due to its use. This is a disadvantage and not the most convenient operation. In addition, you need to make sure that the equipment does not get very hot, otherwise the compressor will quickly break down.
The most popular among oil devices are household types. They are often bought for a summer residence, for work in a garage or workshops. Those devices that are characterized by high power are suitable for large service stations, as well as a furniture factory. This compressor is perfect for painting a house or other items.
Pros:
- Great resource of work, which reaches 3000 hours.
- The storage tank can be up to 500 liters.
- The ability to develop pressure up to 80 atm., With a productivity of 80-3400 l / min.
- Slow heating.
- Excellent protection against oil corrosion.
- Optimal cost for many home appliances.
Minuses:
- The need for frequent disconnection
- Loud work.
Oil-free compressors
Such devices work without the use of oil, due to this, there is no need for its addition or complete replacement. As a result of the lack of lubrication elements, manufacturers use materials with a minimum frictional force in order to increase the life of the parts and the unit itself.
Such devices help to get good results, but they are not always sufficient. For 1 hour of operation, continuous use is only 10 minutes. In addition, the user will receive clean air at the outlet, so oil-free installations can be used where oil is not suitable.
As a result of clean air at the outlet, where there are no impurities, the use of devices often falls on the food and medical industry. You can also choose an apparatus for those people who do not know which compressor to choose for painting a car with a spray gun.
Pros:
- The resource is optimal for household purposes, it is about 1000 hours of work.
- Storage capacity up to 500 liters.
- Possibility to develop pressure up to 80 atm. productivity 20-3500 l / min.
- The outlet will have exceptionally clean air.
- Simple maintenance with no need for oil addition.
- Small size and weight.
- The optimal balance of cost, quality and efficiency.
Minuses:
- Must be disconnected frequently.
- Relatively short service life.
Compressor selection parameters
When choosing, you should be guided by several basic parameters that simplify the selection of the optimal equipment.
Pressure
This value indicates the force of compression of air and is not measured in atmospheres, but in bars, since 1 bar = 0.99 atm. With this knowledge, one can understand which pneumatic tool can be connected. For example, 6 bar will be enough for a spray gun. When buying, you should always choose models with a margin, because the pressure during use will gradually decrease by several bars.
Power
Stable value measured in kW. The more powerful the engine is in the device, the more pressure is created and the productivity of the machine increases. To approximately set this value, you need to multiply the current consumption by the efficiency.
Noise
When choosing, it is recommended to focus on the loudness of the operation, the less dB, the better. Often many compressors are 86 dB, but various isolating means can help reduce the value by about 20 points.
Performance
This value helps determine the volumes of air that will be compressed per minute or hour. Manufacturers often indicate the parameter in l / min or cubic meters / min. The indicator is unstable, because a lot depends on the specific compressor model and air temperature. When buying, it is better to leave 1/3 of the stock from the specified company.
Receiver volume
This indicator indicates the volume of the gas or air tank. Manufacturers make it with a volume that is commensurate with other characteristics. The smaller the container, the faster the filling takes place, but the likelihood of pressure instability and pressure surges increases. Large capacities give the opposite situation. For domestic use, it is not recommended to purchase models with a receiver over 50 liters.
Fuel used
Different types of fuel can be used to operate the engine. The main ones are electricity, gasoline and diesel. The last 2 options do not require attention, but working from an outlet requires care, since some models can only operate from a 380 V network, and will not work in a standard 220 V outlet.
In addition to the characteristics described, you should look at the size and weight of the equipment, its price and warranty period.
The most popular models are household ones with the ability to create low pressure. They are the ones that are suitable for pneumatic tools. Among them are oil piston with a starting price of 4.5 thousand rubles, as well as oil-free models for painting surfaces, which cost from 3.5 thousand rubles. Screw devices are best used for commerce or large workshops. The cheapest options are belt ones, they will cost from 28,000 rubles, and oil and oil-free ones are several times more expensive.
The information described in the article and the types of devices will help determine how to choose a compressor for pneumatic tools or painting a house or car.
