Air compressor is a compressor that takes in air at atmospheric pressure and delivers it at a higher pressure.
An air compressor is not very efficient if you attempt to compress the air from atmospheric pressure to 7 barg in one go. It is better to compress the air in four goes or stages, cooling the hot air between the stages. A compressor which reaches the final working pressure using four stages of compression is called a four-stage compressor. Four stage compression is most efficient.
Four stage compressor unit comprises four different compressor elements and four separate electric motors with an adjustable speed. It also comprises pistons in series. The outlet of a compressor element of one lower stage is connected to the inlet of a successive compressor element of a successive higher stage. The mass flow rate is constant in each of the stage. The optimum efficiency of the compressor unit is obtained by optimizing the speed of each stage and, therefore, the pressure ratio over each stage.
Features of Four Stage Air Compressor
- Oil free operation.
- Air cooled.
- Low and easy maintenance.
- Less wear due to no moving parts in contact.
- Long service life.
- No contamination of gas with ambient air.
- Neutral room between compression room and mechanical drive.
- Compact and lightweight design.