Intercooler and Aftercooler in Air Compressor

What is an Intercooler?

An intercooler is a mechanical heat exchanger that removes the heat from the compressed air generated by an air compressor. It is fitted in the intermediate stages of the compressor.

An intercooler permits the supply of more air to the compressor by increasing the air’s density which in turn boosts the overall efficiency of the compressor. An efficient intercooler will restore the temperature of compressed air to near environmental levels.

Why intercooler is fitted in the main air compressor on ships?

1. An Intercooler reduces the air temperature, volume, and increased air density for the next stage.
2. Thereby increasing the volumetric efficiency and compressor efficiency.
3. The reduced temperature gives better lubrication to the cylinder and piston rings.
4. Drain is fitted from which water and excessive oil can be drained out, to prevent air bottle corrosion and starting air explosion and fouling of intercoolers and pipe.
5. Save the work done.

What are the Advantages of inter-cooling of the air compressor?

1. To avoid excessive temperature rise associated with higher compression ratios, and to approach isothermal compression.
2. Saving in power.
3. Volumetric efficiency is increased.
4. Reduced the volume of air delivered and also reduced the compressor size.
5. It can reduce the air temperature.
6. Due to less temperature suction & delivery valves remain cleaner without being fouled with carbonized oil.
7. It can avoid the danger of an explosion taking place in the compressor cylinder.
8. It allows good lubrication of the compressor piston.
9. Moisture separation is easier through intercooler drains.
10. It also enables to deal with a greater weight of air for the same energy expended.

What is an aftercooler?

An aftercooler is also similar to an intercooler but it is fitted in the final stages of compression. It reduces the final discharged air temperature and thus helps in reducing air bottle size.

What are the types of intercooler and aftercooler?

• An intercooler is a single-pass type
• An aftercooler is a double-pass U-tube type