Since all atmospheric air
contains some water vapour and particulate matter, all compressed
air systems contain concentrated volumes of moisture and
contaminants. To remove moisture and contaminants from a compressed
air system, the following equipment should be considered:
Aftercoolers are a necessary
first step in compressed air treatment. They lower the compressed
air temperature to acceptable inlet conditions for air dryers, and
remove up to 70% of the entrained water vapour. Depending on site
conditions and utilities, aftercoolers are available in water-cooled
or air-cooled configurations. Where water and electric are not
available, air cooled aftercoolers with air driven motors are
available.
Air Dryers are used to lower
the dew point temperature of compressed air, further reducing the
amount of water vapour remaining in the process airflow. If applied
correctly, a compressed air dryer should eliminate the possibility
of liquid water forming in any downstream piping.
Refrigerated Air Dryers lower dew point by reducing the
actual air temperature to near freezing conditions, causing moisture
to condense from the air. Once the water is removed via centrifugal
action, the air is reheated to a usable temperature.
Desiccant Air Dryers use the chemical adsorption method of
drying and can achieve dewpoints as low as -365 F.
• Coalescing Filters collect and
extract liquid water and oil.
• Particulate Filters trap unwanted solid contaminants.
• Adsorbing Filters soften odors
and polish compressed air.
• Separators & Drains remove collected liquids and are used
in various locations throughout an air system.