29. What are The Basic Standards for Selecting an Air Compressor? And What are The Main Issues to Pay Attention to?
- The basic standards for selecting an air compressor are economy, reliability and safety.
- When choosing an air compressor, pay attention to the following issues:
2.1. Consider the exhaust pressure and the air delivery volume. For general-purpose applications, the air dynamic pressure is typically 0.7MPa. Currently, there is a type of air compressor with an exhaust pressure of 0.5MPa available in the market. From a usage perspective, this is not advisable because it provides insufficient pressure margin for pneumatic tools, making them unusable when the transmission distance is slightly longer. If a user requires a compressor with a pressure more than 0.8MPa, it generally needs to be custom-made and should not be forcibly pressurized to avoid potential accidents.
2.2. Air delivery volume is one of the main parameters of an air compressor. Selecting an air compressor with the right air delivery volume is crucial, and it should have approximately a 10% margin. If the air consumption is high and the compressor’s air delivery volume is low, starting pneumatic tools can significantly reduce the compressor’s exhaust pressure, rendering it unable to drive the tools. However, blindly pursuing a large air delivery volume is also a mistake because larger air delivery requires a bigger motor, which not only increases the cost but also wastes capital during procurement and electricity during operation.
2.3. When selecting the air delivery volume, it’s also important to consider peak, normal, and off-peak usage. If the off-peak usage is significant while normal and peak usage are relatively low, a common practice abroad is to parallel multiple smaller air compressors with smaller air delivery volumes to achieve a larger total air delivery capacity. As air demand increases, these compressors can be sequentially activated. This approach benefits the electrical grid and helps conserve energy.
2.4. It is important to consider the usage environment and conditions. For instance, in confined spaces like ships or vehicles, a vertical compressor should be chosen. In cases where there are long variations in distance (exceeding 500m) in the usage environment, a mobile compressor should be considered. If the usage location lacks access to electrical power, a diesel engine-driven compressor should be selected. If there is no access to tap water at the usage site, an air-cooled compressor must be chosen.
2.5. In the choice between air-cooling and water-cooling methods, each has its own distinct characteristics. In both domestic and international markets, air-cooled compressors make up over 90% of small compressors. This is primarily because air-cooling is simpler in design and doesn’t require a water source during operation.On the other hand, water-cooled compressors have certain disadvantages:
① They require a complete water supply and drainage system, which involves significant investment.
② The service life of water-cooled coolers is relatively short.
③ In northern winter, it is easy to freeze the cylinder.
④ A large amount of water is wasted during normal operation.
2.6. Consider compressed air quality. Generally, the compressed air generated by an air compressor contains a certain amount of lubricating oil and water. In some cases, oil and water are prohibited. At this time, not only should you pay attention to the selection of the air compressor, but also add additional spare parts if necessary.
2.7. Consider the safety of air compressor operation. The air compressor is a machine that works under pressure, and its operation involves temperature and pressure changes. Therefore, when purchasing air compressor products, it is essential to rigorously review the manufacturer’s production license and the air tank license.