1. Consider the exhaust pressure and volume
The air volume of the selected air compressor should match the required air volume, with a margin of at least 10%. If the air end is far away from the air compressor, or there is a budget for adding a small amount of new pneumatic tools in the near future, the margin can be increased to 20%.
If the air consumption is large and the air compressor discharge is small, the air tool cannot be driven. If the air consumption is small and the air discharge is large, the air compressor will increase the loading times, or the air compressor will operate at low frequency for a long time, resulting in energy waste.
When selecting the type of air compressor, the formula should be:
Air demand=all tools+mechanical equipment+air consumption of relevant processes+leakage+wear+future gas consumption+service factor (1.1-1.2).
In addition, when selecting the exhaust volume, we should also consider the peak consumption, the normal consumption and the low consumption, and whether the gas consumption in the workshop is stable or fluctuating. For example, if the pressure and gas consumption in workshop A are basically the same, the air compressor needs to be normally open, and the power frequency series or permanent magnet series can be used; The air consumption and pressure fluctuation in workshop B is relatively large. If the air consumption equipment is normally open, the permanent magnet series is more suitable. If the air consumption in multiple workshops is uneven, use multiple air compressors with smaller air displacement and obtain larger air displacement. Start up one by one as the air consumption increases to save energy.
The discharge pressure of the air compressor refers to the gas pressure (gauge pressure) finally discharged from the compressor, with the unit of MPA. The kilogram is commonly used in the industry as the pressure unit, 1 cm=0.1 Mpa.
The exhaust pressure marked on the nameplate of the air compressor becomes the rated exhaust pressure. When selecting the model, you should not only focus on the exhaust pressure of the nameplate, but also evaluate the entire gas consumption system, considering the pressure drop and pressure loss. Generally speaking
The finally determined working pressure=ultimate user+final stage filtration+pipeline system+dust particle filtration+dryer+compressor regulation range.
The operating pressure of various models should also be listed during model selection. If the operating pressure is too different, the air compressor with different pressure must be purchased. The pressure cannot be reduced to increase the cost.
2. Consider energy efficiency and specific power
The energy efficiency grade of the air compressor is evaluated by the specific power value, that is, the power of the air compressor/the air output of the air compressor.
Grade I energy efficiency: the products reach the international advanced level, the most energy-saving and the lowest energy consumption;
Secondary energy efficiency: relatively energy-saving;
Level 3 energy efficiency: the average energy efficiency of our market.
3. Consider the conditions of gas consumption site
The ventilation condition is good, and it is more suitable to install the air cooler in the space; When the gas consumption is large and the water quality is good, the water cooler is more suitable.
4. Consider compressed air quality
The common standard for the quality and purity of compressed air is GB/T13277.1-2008, and the common international standard for oil-free engine is IS08573-1:2010.
The compressed air produced by the oil injection screw air compressor contains micro-oil particles, water, and micro-dust particles. The compressed air can be purified by configuring air storage tanks, cold dryers, precision filters and other post-processors. Some occasions with high gas quality can be equipped with suction dryers for further filtration.
The compressed air of oil-free air compressor can reach very high air quality, and can reach the Class O standard of ISO 8573 standard.
The quality of compressed air required depends on the demand of products, production equipment and pneumatic tools. The compressed air does not meet the standard, which may lead to the decline of commodity quality, or damage to production equipment. However, it is not the higher the purity, the better. Over-purified compressed air, which increases the cost of equipment procurement, and increases the waste of power.
5. Consider the safety of air compressor operation
The air compressor is a kind of machine working under pressure. The air storage tank of more than 1 cubic meter is a special production equipment, and the safety of its operation should be put first.
When selecting the type of air compressor, the user must check the production qualification of the air compressor manufacturer to ensure the product quality of the air compressor.
6. Consider the manufacturer's after-sales service
The maintenance within the warranty period is directly responsible by the manufacturer or service provider, but there are still some unknown factors in the use process. When the air compressor fails, whether the after-sales service is timely and whether the maintenance level is professional is a problem that users must care about.