1. Characteristics and application scope of piston air compressor:
Piston air compressor due to large noise and maintenance, has been gradually eliminated, replaced by a stable operation, small noise and maintenance of the screw air compressor. But because of its low cost, and many enterprises have accumulated years of experience in the use and maintenance of its structure and fault has a more comprehensive understanding, some old piston air compressor is still in use.
Piston-type air compressor is easy to maintain, cheap, suitable for small gas users, can adapt to harsh environment, in the field environment, mining, agriculture and portable engineering machinery and other fields.
Application range of single screw and double screw air compressor
Screw air compressor is easy to install, stable gas production, can adapt to long hours of work, can automatically maintain at the set pressure, in small and medium-sized exhaust capacity (single unit within 60 m3/min) is widely used. The choice of screw air compressor can be considered from the following aspects:
(1) compared with technology, twin-screw technology is more mature, with high precision and high price. Well-known foreign manufacturers mainly produce twin-screw air compressor, but most domestic manufacturers do not master the core technology, on the market many twin-screw air compressor is imported (mostly imported assembly) compressor, domestic manufacturing assembly of other parts. Single-screw appeared later, in domestic development is rapid, the reason is mainly for the processing of high precision double screw compressor, domestic production, single screw theory is more complex, but its low requirement to the precision parts processing, domestic enterprises have the capacity for independent production, domestic research institutions also did a lot of theoretical research.
(2) compared with the actual use, the stability of single screw and double screw is good, and the maintenance of double screw is difficult. Screw air compressor as long as proper maintenance, the head part of the fault is very few. Some of the original imported small displacement twin screw compressor can run for a long time when the site environment is good, but because the twin screw compressor is difficult to disassemble and maintain on site and ensure the accuracy, but once the fault needs to return to the factory for repair, in order to ensure the continuous gas often need to add extra spare air compressor (or spare head).
(3) compared with the gas production efficiency and quality, the single screw has a lower efficiency due to the wear of star wheel. The Yin and Yang rotor with double screw has no friction and high efficiency in rotation, but the small clearance in operation cannot be guaranteed under the unstable foundation environment, so the single screw compressor can only be used on ships and submarines. For air pressure station, the efficiency depends more on the unloading of air compressor and the fluctuation of pipe network pressure, both efficiency is equal. Single, double screw air compressor gas production quality, oil, water are more.
Application range of centrifugal air compressor
The centrifugal air compressor works stably and reliably when the gas load is stable. It has the following advantages:
(1) compact structure, light weight, large displacement range;
(2) few wearing parts, reliable operation and long service life;
(3) the exhaust is not polluted by lubricating oil, and the air supply quality is high;
(4) when the displacement is large, the efficiency is high and conducive to energy conservation.
The efficiency advantage of centrifugal air compressor is obvious in the case of stable gas consumption with large discharge capacity (above 60 m3/min per unit). However, the noise is large, the range of stable gas production is small, the regulation is poor, and the change of exhaust volume is easy to lead to surge. Surge not only affects the stability of gas production, but also does great damage to the body. Its technology has improved in recent years, and its own microcomputers have been able to judge the surge and try to protect the mainframe. At present, it is still restricted in the environment where the gas consumption varies greatly. It is worth noting that the gas produced by the centrifuge does not contain oil, and the post-treatment dehydration is relatively easy, and the quality of gas produced is higher than that of the screw air compressor. In the compressed air quality and odor requirements of the environment, such as food, medicine industry is widely used.