Not too long ago, I was contacted by one of our customers regarding the Cabinet Cooler Systems and the quality of the compressed air used to power them.
The specific questions were:
- What happens if the compressed air gets dirty with oil or other particles if sufficient filtration is not available at the facility where Cabinet Cooler is being used?
- Where does the oil particle go, into the cabinet or out through the hot exhaust or both?
- If it goes into the Cabinet Cooler, should one expect a spray or will it simply form small droplets?
- Is there a way to filter the cold air outlet?
Dirty, oil laden air would exhaust throughout the Cabinet cooler (both hot and cold flows) as well as into the inside of the attached cabinet if the air were contaminated and there was not any filter located up-stream of the Cabinet Cooler System. This is precisely why we always recommend the use of filter/separator and oil coalescing filters to clean up the compressed air before it goes into the Cabinet Cooler. In fact, we include a five micron, auto-drain, filter/separator with all our stock systems. If oil is a known contaminant in a customer’s system, we will also recommend use of an oil coalescing type filter which we can provide as well. Without a coalescing filter, you can expect any oil in the compressed air supply to be atomized into a vapor which then has possibility of settling on components inside the cabinet.
Filtering the compressed air while it is still in its compressed state and before it goes into the Cabinet Cooler is the only way to make sure that the air is properly cleaned before processing through the Cabinet Cooler System. Filtering the air after it has gone through the Cabinet Cooler System is not possible. Many filtration systems rely on the high velocity of the compressed air for their filtering capability. If it is no longer in its compressed state (a condition that exists at the cold outlet of the Cabinet Cooler), then the right conditions for proper treatment do not exist. Also, by the time the air exits the Cabinet Cooler, your primary need for it is going to be for cooling anyway. Attempting to add filtration to the cold air output will interfere with the cooling function, which negates the purpose for having the Cabinet Cooler.
As compressed air and the systems that produce it become more widely understood, filtering, drying and removing oil from the compressed air stream are tasks that are done on the production side of things.
The best way to proceed is to have the necessary filtration on the compressed air supply, at the point of use, even if the facility has filtered, clean, dry air. It would still be good to employ it just in case any up-stream equipment that is normally used to clean up the air, went down for some reason. I call it the belt and suspenders method. The redundancy is worth the investment.
Neal Raker, International Sales Manager