Contact Us

Contact us

2020-2-25 17:53:00

How to select the type of air compressor when rent it?


Selection of air compressor is very important for users and air compressor equipment. Too much selection is too wasteful. Too small selection may cause the air compressor to be in loading state for a long time or the air consumption is not enough or the pressure is not up. How to select the type of air compressor? Experts of Fuen air compressor rental have been working in the air compressor industry for decades, and introduced four basic precautions for you.

1. Determination of total exhaust volume

Exhaust volume is one of the main parameters of air compressor. The air volume of air compressor should be selected to match the required exhaust volume. If the air consumption is large and the air compressor exhaust volume is small, when the pneumatic tool is started, the exhaust pressure of air compressor will be greatly reduced, but the pneumatic tool cannot be driven. Of course, it is also wrong to blindly pursue large exhaust volume, because the larger the exhaust volume, the larger the motor equipped with the compressor, not only the higher the price, but also the waste of purchase funds, and the waste of electric energy when using.

In addition, the peak consumption, the normal consumption and the low consumption should be considered when selecting the exhaust volume. If the low consumption is large, but the normal consumption and peak consumption are not large, the common way abroad is to use a small amount of air compressor in parallel to obtain a large amount of exhaust, and start one by one with the increase of air consumption, which is not only good for the power grid, but also can save energy.

Calculation method of design capacity Q2 based on average consumption sum of General Factory


Q2 - design capacity m3 / h

Σ Q0 - total average consumption of gas equipment or workshop m3 / h

K - coefficient of consumption inequality (maximum) 1.2-1.4

Φ 1 - pipeline leakage coefficient. When the total length of the pipeline is less than 1km, 0.1 is taken; when it is less than 1.5km, 0.15 is taken; when it is more than 2km, 0.2 is taken

Φ 2 - wear increment coefficient of gas equipment 0.15-0.2

Φ 3 - unforeseen consumption coefficient is 0.1

This kind of calculation method is often used to determine the design capacity of compressed air station in mechanical factory.

Of course, the above is the reference calculation method, and each industry should select according to its own characteristics, traditional habits and experience (it is better to have a standby machine).

When the regeneration adsorption dryer with or without heat is used in the purification system, the designed capacity should be increased by 8% - 10% or 15% - 20% of regeneration self consumption gas respectively.

1. The average consumption and the calculation method of design capacity Q2 are used in general factories

2. The elimination of the piston machine can be based on the gas volume on the nameplate or the power of the motor, with a margin of 15%.

2. Determination of exhaust pressure

As for the pneumatic tools, the pressure margin is too small, and the gas transmission distance is too far away to be used. First, on the basis of ensuring the highest pressure used, it is necessary to fully consider that when the gas flows in the pipe, friction resistance will be generated in the straight pipe section; local resistance will be generated in the valve, tee, elbow, reducer, etc., which will lead to gas pressure loss. The pressure drop in the length of a section of pipeline can be calculated from the table. According to the experience, the total pressure loss should not exceed 0.4kg/cm2 within 100m of the pipeline length. If it exceeds the above data, the design pressure must be increased.

3. Determination of cooling mode

First of all, the gas field and conditions should be considered. If the gas field is narrow (for ship and vehicle), vertical type shall be selected; if the gas field has a long-distance change (more than 800m), mobile type shall be considered; if the power supply is not available in the use, diesel driven type or field operation shall be selected; if there is no running water in the use (convenient or not), air-cooled type shall be selected.

In air cooling and water cooling, users often have a wrong idea that water cooling is good, but it is not. The stroke cooling type of small compressors at home and abroad accounts for more than 90%. This is because the air cooling is simple in design, no water source is needed when the investment is small, but there is redundant power consumption, high-power units need to have access to hot air, the cooling effect is greatly affected by the environment, the maintenance cycle is short, and the environment is affected.

The fatal disadvantages of water-cooled compressor are as follows: there must be a complete water supply and drainage system with large investment; the service life of water-cooled cooler is short; the cylinder is easy to freeze in winter in the north; a large amount of water will be wasted in normal operation, and the water resources are rich according to the actual situation, which is convenient for adjustment (different seasons have a great impact on air cooling).

4. Precautions for plateau type selection

With the increase of altitude, the intake pressure decreases, the volume flow decreases, the power consumption increases, and the volume efficiency decreases. In order to ensure the same performance as sea level, the compressor is required to select a larger volume flow according to different altitude.

With the increase of altitude, the actual power consumption increases, and the motor also needs special motor to meet the requirements of high altitude.

Table of plateau correction coefficient

Altitude (m) 0 305 610 914 1219 1524 1829 2134 2438 2743

Correction factor 1.0 1.03 1.07 1.10 1.14 1.17 1.20 1.23 1.26 1.29

Fooen rental adheres to the enterprise tenet of "service quality first, long-term mutual benefit " and wholeheartedly provides high-quality services for your production and construction.


Tell us what you need

We'll help you find what's right for you