What are the criteria for the selection of air compressors

What are the criteria for the selection of air compressors

What are the criteria for the selection of air compressors?

When choosing an air compressor, we actually need to pay attention to some principles, so that we can compare and choose the one that is more suitable for us. Today, the company will give the company that needs an air compressor, etc., let’s talk about what we should pay attention to when choosing an air compressor. matter.

　　 1. The safety of compressor operation must be considered.

　　 Air compressor is a kind of machine that works under pressure. It is accompanied by temperature rise and pressure during work. The safety of its operation must be put first. The state implements a standardized "two certificates" system for compressor production, namely compressor production license and pressure vessel production license (gas storage tank). Therefore, when purchasing compressor products, the "two certificates" must be strictly reviewed. Usually the product quality assurance system of the certified manufacturer is complete, and there will be no major quality problems. Even if there are some problems, the manufacturer will be responsible for the three guarantees.

　　2. The occasion and conditions of gas use must be considered.

If the gas space is narrow (for boats, vehicles), vertical type should be selected; if there is a long-distance change (over 500 meters) in the gas usage occasion, mobile type should be considered; if the location cannot be powered, diesel-driven type should be selected ; If there is no tap water in the application, the air-cooled type must be selected.

　　In the two cooling methods of air cooling and water cooling, users often have the wrong understanding that water cooling is good, but it is not. Air-cooled compressors account for more than 90% of small compressors at home and abroad. This is because air-cooling is simple in design and no water source is required for use. There are four fatal shortcomings of water-cooled compressors: it must have a complete water supply system and large investment; water-cooled coolers have a short life; in the northern winter, it is easy to freeze the cylinder; in normal operation, a lot of water will be wasted.

　　 3. Consider the quality of compressed air.

　　Compressed air produced by general air compressors contains a certain amount of lubricating oil and a certain amount of water. In some cases, oil and water are forbidden. At this time, not only should pay attention to the selection of the compressor, but also add auxiliary devices if necessary.

　　The solution: One is to use a non-lubricated compressor. This kind of compressor cylinder basically does not contain oil, and its piston ring and packing are generally polytetrafluoroethylene. But this kind of machine also has shortcomings, poor lubrication, and high failure rate; PTFE is also a harmful substance, which cannot be used in the food and pharmaceutical industries; non-lubricated compressors can only deliver gas without oil, not water. The second and commonly used method is to add a primary or secondary purification device or dryer to the air compressor (no matter which type). This device can make the compressor air contain neither oil nor water, so that the oily water content in the compressed air is below 5ppm, which can meet the process requirements.

　　4. The level of exhaust pressure and the amount of exhaust should be considered.

　　The discharge pressure of the general-purpose aerodynamic compressor is 0.7MPa, and the old standard is 0.8MPa. At present, there is an air compressor with an exhaust pressure of 0.5 MPa, which is unreasonable from the perspective of use, because the pressure margin is too small for the pneumatic tool, and the air delivery distance is slightly longer and cannot be used. In addition, from a design point of view, this compressor is designed for one-stage compression, and the pressure ratio is too large, which can easily cause excessive exhaust temperature, causing carbon deposits in the cylinder and causing accidents. If the compressor used by the user is larger than 0.8MPa, it should be specially manufactured, and the method of forced pressure increase cannot be adopted to avoid accidents.

　　The air displacement is one of the main parameters of the air compressor. The air volume of the air compressor should be selected to match the required air displacement, and a 10% margin should be left. If the air consumption is large and the air compressor has a small exhaust volume, the air-driven tool will greatly reduce the exhaust pressure of the air compressor when the air-driven tool is activated, and the air-driven tool cannot be driven. Of course, blindly pursuing a large displacement is also wrong, because the larger the displacement, the larger the motor equipped with the compressor, not only the price is high, but also a waste of purchase funds, as well as a waste of electricity when used.