Moisture in air compressor, how to eliminate this?

[Nickathome]

Hey guys;

Need to know. Is there a moisture filter I can buy which will eliminate water problems within my air compressor? I have a filter that prevents dirt and moisture from getting into my air tools but, I have not yet been able to find a filter to prevent the compressor from getting moisture in it. On humid days I have drained my tank of water several times before storing it away. I know I can just drain the water out, but if I could eliminate it from gettin in altogether, that would be great.

[carter davidson]

Nick; I know of no way to do what you want to do except dehunidifying the air in the area the compressor is operating with a dedicated dehumidifyer. Filters don't work on the intake side, the moisture in the air is only condenced when the compressed air is allowed to expand which cools the air thus releasing the humidity as liquid water, a filter can not filter out moisture which is water in a gaseous state, which, as a gas, can not be filtered out, only liquids and solids can be removed from the air with filters, not gases such as moisture, the gaseous form of water. Maybe someone knows how to seperate various gases out of the surronding air but it will not be easy or cheap. Carter

[RickL]

Its probably easier and cheaper to replace the reciever tank then try to remove moisture from the intake side.

Maybe add a automatic drain on the tank to drain the water more often?

Thanks,
Rick

[powerwagontim]

I have a thing I bought secondhand and cant even tell you what it is called but it plumbed into the outlet line of the compresser and is basically like a little refrigerator or air conditioner. It removes the moisture from the air after it exits the compressor. All I know is it works, I used to have problems with spraying cabinets and now I dont. Naturally I still need to drain the moisture out of the big tank but the dryer is self draining. I will look at it later when I am in the shop and let you know the name of it. I bought it used for a couple of hundred bucks so they arent cheap. But then again either is re-doing a project due to moisture in your finish.
Tim

[RickL]

Sounds like an air dryer. Like you said not a cheap piece of equipment. I use 25' length of 2" pipe that then necks down to 3/4" to cool the air using the venturi effect. Works fine for my area.

Rick

[RickL]

Nick,

Where are you working that has the moisture problem? SE Pa does not get that humid unless it is summer time.

Rick

[JimmieD]

Hi guys,

Any industrial supply [worth its salt] can fix you up with an air dryer at a reasonable cost. Get the inline type that looks somewhat like an old glass fuel sediment bowl filter. These cause the moisture to fill the chamber, and then there's a petcock flush valve on the bottom to drain mositure whenever you want.

Arrow Corp makes an evaporative air drier for industrial air supplies, but the one I had was about $11,000.000 so you might want to pass on that one. They use refrigeration principals to remove moisture in a simple, and expensive, process. Your unit was a miniturized version.

There are automatic receiver tank drains available also, which can be set up to a timer control if you like. The Auto Drain is not that expensive and can be modified in many ways to suit your needs, plus they are simple enough to work for years. Basically it is a solenoid operated drain valve, and solenoid can be timered, so actually it's pretty easy to build yourself.


Check out a painter's air rig if you want to see other options for drying air.
JimmieD

[powerwagontim]

Hi Jimmie,

Way off topic here, I wanted to thank you for your advice on putting the little balls back in the power stering ball nut. It was simple once you steered me in the correct direction.

Thanks, Tim

[JimmieD]

Tim,

Glad that worked out for you!

JimmieD

[Nickathome]

I beg to differ on humidity only in the summertime. I used my aircompressor about two to three weeks ago with my new impact gun to rotate the tires on my wife's car. It was a very foggy morning with fairly warm temps. The humidity could be cut with a knife. Afterwards, I drained the tank and a bunch of brown water came out. Granted some of it might have been in there a while, but it was very humid that day.

[powerwagontim]

Unless you live in the desert, humidity to some degree is always present. The act of compressing air squeezes the water out. Even if you dont feel like it is a humid day you will still get water out of the tank drain.

[HWooldridge]

When air is compressed, it becomes very hot. If you can cool the air, it will drop the moisture (just like condensation on a glass of ice tea). I have read a few articles about doing this at home and the most efficient way is to separate the compressor from the tank, cool the air, then put it in the tank. That process is cumbersome for most people so some compromise is needed.

I have a big IR 7.5hp, two-stage compressor and the tank always retains some amount of water. I replaced the little drain petcock with a nipple and high-quality ball valve so I can reach down and drain the water without having to stick my hand under the tank and into the black widow webs. The compressor is in the barn and is piped to my shop with about 75 feet of black iron 1/2" pipe (I should have used 3/4" but I started with a much smaller unit and did not plan accordingly). The shop has a 40 gallon storage tank so I have 120 gallons of 175psi air. Everything is regulated to 100psi at the outlets and I can run almost any tool without straining the compressor.

Each leg that turns down has a drip leg with a ball valve to drain it. I never see moisture collecting in the remote storage tank located in the shop but I often drain a lot of water from each leg and the tank. Subsequently, I can use a sand blaster with no problems in very damp weather because the moisture drops out before it gets to the final use point.