Classification of air compressors 1. According to the working principle, it can be divided into three categories: volumetric, dynamic (speed or turbine), and thermal compressors. 2. According to the lubrication method, it can be divided into oil-free air compressors and oil-lubricated air compressors. 3. According to the performance, it can be divided into: low noise, variable frequency, explosion-proof and other air compressors. 4. According to the purpose, it can be divided into: refrigerator compressor, air conditioner compressor, refrigeration compressor, oil field compressor, natural gas filling station, rock drill, pneumatic tool, vehicle braking, door and window opening and closing, textile machinery Used for tire inflation, plastic machinery compressors, mining compressors, marine compressors, medical compressors, sandblasting and painting. 5. According to the type, it can be divided into: fixed type, mobile type and closed type [1]. Positive Displacement Compressors - Compressors that rely directly on changing the volume of the gas to increase the pressure of the gas. Piston compressor - is a positive displacement compressor, and its compression element is a piston, which reciprocates in the cylinder. Rotary Compressor - is a positive displacement compressor where compression is achieved by forced movement of a rotating element. Sliding vane compressor - is a rotary variable capacity compressor whose axial vanes slide radially on the eccentric rotor of the same cylinder. The air trapped between the sliding vanes is compressed and discharged. Liquid-piston compressors - are rotary positive displacement compressors in which water or other liquid acts as a piston to compress gas and then discharge the gas. Roots double-rotor compressor - is a rotary positive displacement compressor, in which two Roots rotors mesh with each other to intercept the gas and send it from the intake port to the exhaust port. There is no internal compression. Screw compressor - is a rotary positive displacement compressor, in which two rotors with helical gears mesh with each other, so that the volume of the meshing place between the two rotors changes from large to small, so as to compress and discharge the gas. The screw compression components in screw air compressors are manufactured in-house using the latest CNC grinding machines, and combined with in-line laser technology to ensure extremely precise manufacturing tolerances. Its reliability and performance ensure that the compressor's operating costs remain extremely low over its lifetime. The Adjustment Compressor, Integrated Compressor and Dryer series are all new to the L/LS series of compressors. Velocity Compressor - is a rotary continuous air compressor in which high-speed rotating blades accelerate the gas passing through it, thereby converting velocity energy into pressure. This conversion takes place partly on the rotating vanes and partly on the fixed diffuser or recirculator baffles. Centrifugal Compressor - is a speed compressor in which one or more rotating impellers (the blades are usually on the sides) accelerate the gas. The main air flow is radial. Axial Compressor - is a speed compressor in which gas is accelerated by a vaned rotor. The main air flow is axial. Mixed flow compressor - also a speed compressor. The shape of its rotor combines some features of both centrifugal and axial flow. Jet Compressor - Uses high velocity gas or steam jets to carry away the gas that is drawn in and then converts the velocity of the mixture to pressure on a diffuser. Permanent magnet variable frequency compressor - because the variable frequency screw air compressor utilizes the stepless speed regulation characteristics of the frequency converter, it can start smoothly through the controller or the PID regulator inside the frequency converter; for occasions where the air consumption fluctuates greatly , and can quickly adjust the response. Unipolar compression screw air compressor - the head is a screw air compressor composed of a pair of yin and yang rotors. This model is a widely used screw air compressor. Bipolar compression screw air compressor - the head is composed of two pairs of yin and yang rotors. After the first stage compression, the gas enters the second stage compression. The compression ratio is high, and the power is one gear lower than that of the first stage compressor. . Bipolar permanent magnet variable frequency air compressor - a new energy-saving product developed after 2014, combined with permanent magnet frequency conversion and bipolar compression technology, with high energy saving efficiency.