Compressed Air After Collers

Come From:RISHENG Time:2018-10-18 Views:1928 Share:

What are after coolers and why are they required?

An after cooler is a mechanical heat exchanger designed to remove the heat-of-compression from a compressed air stream and to condition the air so it can be used in air-operated equipment.

Regardless of the type of compressor being used, the compressed air discharged from that air compressor is going to be hot. That temperature will vary according to the type of compressor being used.

High-temperature air is typically not usable in most air-operated equipment as it has a detrimental effect on the equipment lubrication and sealing materials. This hot air also contains large quantities of moisture vapor which, as it condenses, contributes to rust, scale build-up, washing out of lubricant and possible freezing issues.

Water exists in a vapor state in all atmospheric air (relative humidity) and as the air is drawn into a compressor and is pressurized, this moisture is concentrated in each cubic foot. Due to the high temperature of the air, the moisture remains in a vapor state (above the dew point temperature).

The "dewpoint" is the temperature at which this air becomes saturated at 100% of its capacity to hold water in a vapor state and, with any additional cooling, must give up free moisture as a liquid. A general rule is that for every 20 Deg. F. rise in temperature the air can hold twice the moisture load in a vapor state above the dewpoint.

As the compressed air cools this water vapor condenses into a liquid form and is removed from the air stream. As an example, if an after cooler is not used, a 200 cubic feet per minute (CFM) compressor operating at 100 psig can introduce as much as 45 gallons of water into the compressed air system each day.

This article comes from vmacair edit released

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