Air Compressor Dryer Questions

[Glen Blanchard]

Every so often I get some water from my compressed air line. So I have a few questions.



What options do I have in hooking up an in-line dryer for my compressor?
How easy are these to install?
How much do they cost?
Where can they be purchased?
How is it they remove the water?

[Todd Burch]

What type/size of compressor do you have now? What's your current filtration? How long is your line? What is your line configuration? (just a hose? Rigid lines that are installed to reduce moisture flow with drains?) What are you doing when you get water out the end of the line?

I'm asking these question to understand your current setup. Most of use would never need a dedicated drier, but depending on your compressor and other factors, and requirements for moisture free air, you might absolutely need a drier.

Todd

[Glen Blanchard]

Todd - The compressor is either a 20 or 25 gal. with maybe a 25' hose.

[Todd Burch]

What options do I have in hooking up an in-line dryer for my compressor?

Several. It can be as simple as an in-line filter as your (guessing here...) spray gun, or a wall or floor mounted dedicated drier plumbed into your piping system.

How easy are these to install?

Depends.

How much do they cost?

Depends. Large dedicated driers can cost thousands. In-line filters at the guns can cost dollars.

Where can they be purchased?

Depends.

How is it they remove the water?

Either through membranes, air circulation, all the way up through what could be considered a large dehumidification system, akin to a large house A/C system, with coils and cooling fins.

[Steve Jenkins]

I have an aftercooler that I bought from Grainger. Looks sort of like a car radiator with a fan behind it. Works great. Another option is to make a zigzag of copper tubing up the wall. All you are trying to do is cool the air so the moisture will condense out. If you want, come on by and see what mine looks like. I'm just about 10 miles east of McKinney.

[Todd Burch]

Todd - The compressor is either a 20 or 25 gal. with maybe a 25' hose.

A typical installation in this case would be a water and particulate filter mounted to the tank, and then plug your hose into that.

I say "typical", but certainly not recommended. The more you can cool your air after leaving the tank, the better moisture separation you can achieve. Cooler air holds less water than hot air.

When I had that size system, I bought a bunch of galvanized elbows and 4' straight sections and made a "radiator" looking, Z-shaped assembly that let the air go through before I hooked up my hose. That was enough cooling for spraying, but not enough for sandblasting. I mounted my filters on the output size of the piping.

[Randy Rose]

There are at least 2 types: "dessicant" and "coalescing" I have the latter and water collects in a clear bowl with a simple rubber bleed valve. Granger p/n 4ZK74 would probably be all you need. Easy "inline" install and $45.60. 4ZK76 adds a reg. gauge & bracket $ 59.85
China freight might be cheaper.

Do you drain your tank on a regular basis ?

[Glen Blanchard]

Randy - That looks easy enough. These are effective?


Granger p/n 4ZK74 would probably be all you need.

[Michael W. Clark]

The filter/regulator option is probably the best option for you. I have a filter/regulator plumbed in on my system and also have a drip leg configuration with ball valve before it.

You can cool the air after the compressor to condense the water out of it, but you also have to separate the water from the air, otherwise it continues to go downstream as droplets. This is where the filter/regulator helps. These type may be referred to as "coalescing" but most coalescing filters are used to separate the compressor oil from the airstream on larger systems before the air is used in dryers or other sensitive pnuematic equipment.

The air dryers that I have installed are either refrigerated or dessicant. The dryness of the air is usually measured by dewpoint temperature (temperature at which water will begin to fall out of the airstream). Refrigerated dryers can acheive a dewpoint around 35F and dessicants can go down to -40F. Dessicants are much more expensive and you loose about 10% of your CFM to regenerate the dessicant.

Aftercoolers are usually standard equipment on larger compressors. Air-cooled Aftercoolers would get the dewpoint temperature down to around ambient at best case. Water-cooled aftercoolers would get it a little lower depending on the water temperature going in. The efficiency of either of these depends on the effectiveness of the heat exchanger and cleanliness of the air and water.


Mike

[Randy Rose]

Randy - That looks easy enough. These are effective?

Certainly not high end, but works well enough that I`ve painted a few motorcycles with it.