All kinds of air compressors（二）
The Roots type air compressor is a positive displacement rotary compressor which keeps the two rotors engaged by synchronous gears on the shaft end of the rotor. Rotor portion of every sunken into the surface of working volume and the cylinder wall, get away from the suction mouth in the rotor rotation process gas, when moved to vent the attachment and vent connected transient time, because of high pressure gas circumfluence, sudden rise at this time the pressure in the working volume, and then transported to the gas exhaust passage. The two rotors do not contact with each other, by the clearance of tight control to achieve sealing, so the discharged gas is not contaminated by lubricating oil.
The scroll compressor is a compressible volume compressor composed of a fixed involute scroll and an eccentrically rotating involute scroll. The compressible volume compressor is made up of two dynamic and static vortex disks with double function equations. In the process of suction, compression and exhaust, the static disk is fixed on the rack, driven by an eccentric shaft and restricted by an anti-rotation mechanism, and rotates around the center of the static disk base circle with a small radius. The gas is inhaled into the periphery of the stator plate through the air filter element. With the rotation of the eccentric shaft, the gas is gradually compressed in several crescent-shaped compression cavities composed of the rotor and stator plate and then discharged continuously through the axial hole of the central part of the stator plate.
Reciprocating air compressor through the reciprocating motion of the piston or diaphragm in the cylinder makes the rigid body volume change periodically and realizes the gas pressurization and transportation. It belongs to the positive displacement air compressor. According to reciprocating movement of the components are divided into piston type and diaphragm type air compressor.
Reciprocating air compressor has high thermal efficiency, low unit power consumption, convenient processing, low material requirements and low cost. In addition, because of its early design and production, its device is relatively simple, the technology has been mature, the application range is also very wide. But it also has many disadvantages. Its structure is more complex, moving parts, maintenance of the workload is very large. Moreover, the piston ring and cylinder wear speed is faster, the working noise is also very large, the speed is relatively controlled. Most importantly, its control system is backward, unable to adapt to interlocking control and unattended.