In axial flow compressor, a massive rotor with several rows of blades rotating in a casing containing rows of stationary blades. Gas is drawn into an intake nozzle and passed in an axial direction through a series of moving and stationary rows of blades and is fully discharged through a discharge nozzle.
Axial compressors are generally driven by electric motors, steam and gas turbines.
Axial compressors are large volume compressors that are characterized by the axial direction of the flow passing through the machine. The energy from the rotor is transferred to the gas by blades. One common arrangement has the energy transfer arranged to provide 50 % of the pressure rise in the rotating row and the other 50 % of the pressure rise in the stationary rows. This type of design is referred to as 50 % reaction.
Axial compressors are most suited for higher capacity and comparatively lowpressure applications. These offer higher efficiency, smaller foundation requirements in weight and space and more efficient drive selection because of its higher speed and lower power requirements. The axial compressor is
usually a single inlet, uncooled machine consisting essentially of blades mounted on the horizontally split casing. The stationary blades can be either fixed or movable. The movable allows for better control of and increased flexibility in operations. Most units have inlet guide vanes for at least the first
rows of blades and have exit vanes also. The general size of these machines is often much larger than centrifugal compressors, although this is not necessary a firm condition. The casing require extremely precision casting to obtain the shapes usually associated with the arrangement of these machines. The sealing systems for the shaft are quite similar to those for the centrifugal; however internal shaft seals are not necessary between stages. The material of construction is similar to those for centrifugal compressors.
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