Air/Water Aftercoolers
Water-cooled shell and tube aftercoolers can be used to cool compressed air easily and effectively. The counter-current heat exchanger allows the compressed air temperature to be reduced to the required conditions, optimising the downstream process. This is the case for adsorption dryers which prefer moderate inlet temperatures achievable with the CWA. The air temperature obtained is slightly higher than the water temperature. Cooling compressed air, which is in most cases humid, leads to the formation of condensate, which can be separated by a condensate separator installed at the heat exchanger outlet. Separators included in aftercoolers up to CWA350, have an aluminium body and cyclone cartridge and are equipped with an automatic floatcontrolled condensate drain. Separators from A450 onwards have a carbon steel body and a cyclone separator with manual drain. Reductions for connection to the compressed air system are optional.
Design Conditions
- Maximum compressed air inlet temperature: 200°C
- Maximum compressed air pressure: 16 bar
- Maximum water inlet temperature: 90°C
- Maximum water pressure: 10 bar
- Minimum ambient temperature: 1°C
Operating principle
In the heat exchanger, the compressed air flow passes through stainless steel pipes immersed in cold water, on the shell side. The cold water flow proceeds in countercurrent and is diverted by the diaphragms used to increase the heat exchange coefficient. The CWA range, with an appropriate exchanger sizing, has limited pressure drops on the compressed air side, and simultaneous excellent thermal performance. The cyclone separator, installed at the tube outlet, provides a swirling motion that separates the condensate from the compressed air, conveying it by gravity towards the drain.
