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Comp. Air Freeze up

Comp. Air Freeze up

Comp. Air Freeze up

(OP)
I am an electrical guy, so please bear with me. I work in a steel foundry in Pittsburgh, PA. It's freezing cold right now. The ambient temperature is getting down into the teens, even inside of the mill. The last 2 days we have had some downtime due to solenoids freezing up, both in the same area. When I pulled the valves, there was frost on the spools, probably from when the air expanded. Upstream of the valves I have a water separator, and separate oiler. I noticed that the separator was full of liquid water. I manually opened the drain and ran it out. The oiler had some oil in it. This 1/2" air line is in the low point of a main run, which is naturally why water is settling here. We have a refrigerated air dryer for our compressor system, which I know looses effectivness at these temperatures. We bought a new desecant dryer, but won't have it running for a while. My question is, are there any devices other than what we are using to place in line with the piping to eliminate water? And how effective are water separators in relation to our ambient temp. and dewpoint? And one more question, the water separator looks to be the auto draining type with a float. It seemed to be full, and I was wondering why it didn't drain automatically. There is a push lock fitting on the bottom for a drain hose. Do we have to have a hose pushed in for it to work?

RE: Comp. Air Freeze up

The push lock fitting may also be a check valve.  You would need a mating fitting connected to open the check valve.

The refrigerated air dryer needs to be doing a better job of reducing the dew point of the compressed air.  The dryer is supposed to remove heat from the compressed air causing more water to condense to be removed by the separator.  The separator needs to also be doing its job collecting and discharging the water.

Has the air reservoir been drained of water?  If it is holding water, the water will go back into the compressed air and out into your system.

Ted

RE: Comp. Air Freeze up

why would you run wet air to instruments in a climate that can be under 40F?  Install an air drier, problem solved

RE: Comp. Air Freeze up

If not using an oil free air compressor then oil in the system can kill the air dryer too.

RE: Comp. Air Freeze up

Get the air cleaned up at the compressor to the required quality level. At your point of use, install the proper filter, regulator and lubricator sets. Also, make sure they are maintained correctly and properly (perhaps the biggest problem). Auto-drains are notorius for failing. Not too mention, keeping the filters cleaned or replaced.  Also, hunt down and eradicate all air leaks.

Good luck! Plant Air systems as a Utility is most often the most overlooked and abused system in the Plant. I repaired and upgraded one system that saved the owner approx. a million dollars a year.    

RE: Comp. Air Freeze up

Install drop legs just prior to the valves.  At the bottom of the drop leg put a petcock to drain off fluids occasionally.

RE: Comp. Air Freeze up

(OP)
Thankyou all! Happy Holidays

RE: Comp. Air Freeze up

Auto and manual drains do not work if they freeze. The drier itself may not work correctly if it is below freezing. The compressor room and drier must be kept above freezing, and the dew point of the air leaving the drier must be less than ambient. If drains are filling with water then the air is not dry. Drier efficiency strongly depends on air flow rate. If you have large swings in air flow, you may have wet air coming out of the dryer.  

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