Working principle of screw air compressor

Screw type air compressor is the same as piston type compressor in terms of compression principle, belonging to volumetric type; In terms of movement form, screw type and turbine type do high-speed rotational movement; Therefore, screw air compressor has both characteristics. There are no vulnerable parts such as air valves and piston rings, so it is reliable in operation, long in service life and easy to realize remote monitoring. High speed and compact structure; The volume, weight and floor area per unit exhaust volume are far smaller than those of piston machines. The oil injection screw air compressor can obtain high single-stage pressure ratio and low exhaust temperature. When the operating point changes in a large range, the machine efficiency does not change much, and there is no surge phenomenon of the speed type compressor when the exhaust volume is small.

The screw air compressor uses the high-speed rotating impeller to make the air subject to centrifugal force to generate pressure and obtain speed at the same time. After leaving the impeller, the air gradually converts kinetic energy into pressure energy through expansion channels such as diffuser, so that the pressure is increased. After one stage of compression is completed, it enters the next stage of compression and is discharged after reaching the rated pressure. The centrifugal air compressor is generally composed of multiple stages. The higher the exhaust pressure, the more stages are required, It is divided into multiple sections, and there is an intermediate gas cooler between the sections.

Basic principle and characteristics of screw air compressor "∞" type, in which two male and female screw rotors that rotate reversely and mesh with each other according to a certain transmission ratio are arranged in parallel. When the screw air compressor works, the gas enters the inter tooth cavity of the male and female screws through the suction port. With the continuous rotation of the screw, the volume between the teeth of each screw also increases. When the volume between the teeth reaches a large value, it is disconnected from the suction port, and the suction process ends. The compression process is followed closely, and the male and female screws mesh with each other Closing the teeth makes the volume between teeth decrease continuously and the pressure of gas increases continuously. When the volume between teeth is communicated with the exhaust port, the compression process ends and enters the exhaust process; During the exhaust process, the continuous rotation of the screw continuously sends compressed air to the exhaust pipe.