BAC-05 AFTERCOOLER

What is an aftercooler?
An aftercooler is a mechanical heat exchanger designed to remove the heat of compression from a compressed air stream and condition the air so it can be used in air-powered equipment.
A compressed air aftercooler has three primary functions: cool the air discharged from the air compressor via a heat exchanger.
Reduce the moisture content of the compressed air. Protect downstream equipment from excessive heat and moisture.

Why are aftercoolers needed?
Regardless of the type of compressor used, the compressed air leaving the air compressor is hot.
That temperature depends on the type of compressor used.
High-temperature air is generally not usable in air-powered equipment, as heat has an adverse effect on the lubrication and sealing materials of equipment.
Hot air also contains large amounts of water vapour which, when it condenses, contributes to rust, washing out of lubricant, and potential freezing problems.
Water exists in vapour form in all atmospheric air (relative humidity) and, since air is drawn into a compressor and pressurised, this moisture becomes concentrated in every cubic metre.
Because of the high air temperature, the moisture remains in vapour form (above the dew point temperature).
The dew point is the temperature at which this air becomes saturated at 100% of its capacity to hold water in a vapour state and, with any additional cooling, must release excess moisture as a liquid.
A general rule is that for every 6°C increase in temperature, air can hold twice the moisture load in a vapour state above the dew point.
As the compressed air cools, the water vapour condenses into a liquid form and is removed from the air stream.
For example, if no aftercooler is used, a compressor of 2000 litres/minute operating at 7 bar can introduce 2 to 5 litres of water into the compressed air system every day, depending on the relative humidity at the ambient temperature.
Our air-cooled aftercoolers have the capacity to cool the compressed air to 5 to 7°C above the cooling air’s ambient temperature.
As the compressed air cools, up to 75% of the water vapour present condenses into a liquid and can be removed from the system.
A moisture separator installed at the aftercooler outlet mechanically removes most liquid moisture and solids from the compressed air.
By using centrifugal force, moisture and solids collect at the bottom of the moisture separator.
An automatic drain is used to remove the moisture and solids.

Air-cooled aftercooler
Air-cooled aftercoolers use ambient air to cool the hot compressed air.
The compressed air enters the air-cooled aftercooler.
The compressed air passes through the aftercooler’s spiral tubing, while ambient air is forced across the cooler by a motor-driven fan.
The cooler ambient air removes heat from the compressed air.
As the compressed air cools, water forms. The moisture is drained off via the moisture separator and drain valve.