If you want to choose the right air compressor, you must know these issues
The basic criteria for choosing an air compressor are economy, reliability and safety.
- The level of exhaust pressure and exhaust volume should be considered.
- The exhaust pressure of general-purpose aerodynamic compressors is 0.7MPa, and the old standard is 0.8MPa. At present, there is an air compressor with an exhaust pressure of 0.5MPa, which is unreasonable from the perspective of use, because the pressure margin is too small for pneumatic tools, and it cannot be used if the air transmission distance is slightly longer. In addition, from a design point of view, this compressor is designed as a one-stage compression, and the pressure ratio is too large, which can easily cause the exhaust temperature to be too high, resulting in carbon deposits in the cylinder, leading to accidents. If the compressor used by the user is greater than 0.8MPa, it generally needs to be specially manufactured, and the method of forced pressurization cannot be adopted to avoid accidents!
- The exhaust volume is one of the main parameters of the air compressor. The air volume of the air compressor should be selected to match the required exhaust volume, and a 10% margin should be left. If the air consumption is large and the air compressor exhaust volume is small, once the pneumatic tool is started, the exhaust pressure of the air compressor will be greatly reduced, and the pneumatic tool cannot be driven. Of course, it is also wrong to blindly pursue a large displacement, because the larger the displacement, the larger the motor that the compressor is equipped with, which not only increases the price, but also wastes purchase funds and wastes power energy during use. In addition, peak usage, normal usage and trough usage should also be considered when selecting the exhaust volume. If the consumption in the low valley is large, but the normal consumption and the peak consumption are not large, the usual way abroad is to obtain a larger displacement by connecting air compressors with a smaller displacement in parallel, and start them up one by one as the gas consumption increases, so that Not only is it good for the power grid, but it can also save energy.
- The occasion and condition of gas use should be considered.
- If the gas use site is narrow (for ships, vehicles), you should choose the vertical type; if the gas use site has a long distance change (more than 500 meters), you should consider the mobile type; if the use site cannot supply power, you should choose the diesel engine drive type ; If there is no tap water in the use occasion, you must choose the air-cooled type. Regarding the two cooling methods of air cooling and water cooling, users often have a wrong understanding, thinking that water cooling is better, but it is not. The air-cooled type accounts for more than 90% of the small compressors at home and abroad. This is because the air-cooled type is simple in design and does not require water when used.
- There are four fatal shortcomings of water-cooled compressors: it must have a complete water-cooling system, which requires a large investment; the life of the water-cooled cooler is short; it is easy to freeze the cylinder in winter in the north; and it will waste a lot of water during normal operation.
- Consider the compressed air quality.
- Generally, the compressed air produced by an air compressor contains a certain amount of lubricating oil and a certain amount of water. In some occasions, oil and water are prohibited. At this time, not only attention should be paid to the selection of the compressor, but additional accessories should be added if necessary.
- The solution: (1) Use a non-lubricated compressor. The compressor cylinder basically does not contain oil, and its piston rings and packing are generally polytetrafluoroethylene. But this kind of machine also has disadvantages, such as poor lubrication and high failure rate; polytetrafluoroethylene is also a harmful substance, which cannot be used in food and pharmaceutical industries; non-lubricated compressors can only transmit gas without oil, but not without water. (2) Add the air compressor (no matter what kind) to a primary or secondary purification device or dryer. This device can make the air of the compressor free of oil and water, and keep the oil and water content in the compressed air below 5ppm, which can meet the process requirements.
- Consider the safety of compressor operation.
- The air compressor is a machine that works under pressure. It is accompanied by temperature rise and pressure when working. The safety of its operation should be given priority. The state implements a standardized “two certificates” system for the production of compressors, namely the compressor production license and the pressure vessel production license (gas storage tank). Therefore, when purchasing compressor products, the “two certificates” must be strictly examined. Usually, the product quality assurance system of certified manufacturers is perfect, and there will be no major quality problems. Even if there are some problems, the manufacturers will be responsible for the three guarantees.
Sollant Group-Professional Compressed Gas Solutions Provider