Knowledge Points of Compressor Aftertreatment Equipment

When undertaking project sales, we usually provide customers with a complete compressed air system solution. Apart from air compressors, aftertreatment equipment is also indispensable. 

It is generally divided into three functions: moisture removal, filtration and air storage, namely drying compressed air, purifying compressed air and storing compressed air.

Dry Air: Refrigerated Air Dryer
We will ask customers about their required pressure dew point. The dryer model is selected according to the temperature provided by customers.
Refrigerated air dryers are chosen for pressure dew points above 10°C, while adsorption dryers are adopted for -20°C, -40°C and -70°C.
What is Pressure Dew Point?

Air contains a certain level of humidity. After being compressed, the density of water vapor rises and temperature increases. When compressed air is cooled, 

its relative humidity goes up. If the temperature keeps dropping until the relative humidity reaches 100%, water droplets separate out from compressed air. 

This temperature is defined as the pressure dew point of compressed air.

The refrigerated air dryer works based on physical principles. It uses refrigerant to conduct heat exchange with compressed air and remove heat from the air. 

Moisture precipitates out once the humidity inside compressed air reaches saturation, so the compressed air gets dried.

Some premium brands add an extra heat exchange (reheating) process for dewatered compressed air to prevent condensation caused by low temperature inside pipelines at the dryer outlet.
Clean Air: Filters
Besides the pressure dew point, we need to confirm the required air filtration precision from customers, which is exactly where filters function.
Filters available on the market are generally categorized into four types by filtration precision:
Water Separator: Removes water droplets and impurities larger than 5 μm
Coalescing Pre-filter: Removes 1 μm impurities and oil aerosols
Coalescing Fine Filter: Removes 0.01 μm impurities, oil and oil mist
Activated Carbon Filter: Removes oil and odors, with filtration precision of 0.003 wtppm
Important reminder: When selecting dryers and filters, their rated air processing capacity must be greater than the customer’s actual air consumption!
Air Storage: Air Receiver Tank
Air receiver tanks are used for pressure stabilization and compressed air storage. Model selection is determined by working pressure and volume (cubic meter).