Home Built Air Dryer

[bhays]

I threw this together this week and it actually works great.

My compressor is housed in my shed, then the air lines runs partially underground and partially through the crawlspace of the house about 80 feet into the garage. Recently I moved my welding stuff and blast cabinet out to the shed.

I have always had a problem with water in my air due to the line running through the ground and cool crawlspace before it gets to the garage where I do most of the work. Last weekend I sanded on a project for about six hours and drained one and a half 2 liter bottles from the trap in the garage and had water slinging all over me all day. I decided it was time to do something about it. I looked at the $369 dryer from HF and figured it might work, but thought I would invest about $80 in trying something I saw online. It works awesome.. sanded eight hours straight yesterday and not a drop of water.

Here we go. My shed has roof vents to let out heat.

I scored an aluminum oil cooler from eBay (brand new but someone cut two of the brackets off, so got it for under $40)

I mounted the oil cooler up below the roof vent, made a shroud from cardboard so that it drew air only from outside, then used a blower from an old inflatable Santa Clause that had a hole in it.

So I plumbed a line using copper tubing from the pump on the compressor to the oil cooler (tried poly here and it couldn't take the heat.. looked like holding a lighter under a soda straw and blowing a bubble).. then poly out of the oil cooler to the moisture trap (3/4" pipe) and out of the trap back to the tank on the compressor.

The trap after the cooler catches almost 100% of the moisture before it ever makes it to the tank.. I am way impressed with how well this is working.

BTW, all the sanding is on my Vette project.. almost have it totally down to bare fiberglass and ready to start body mods now:

 

[ghnl]

Cool!
words words words

 

[rockwithjason]

so your air line comes straight from the compressor head to the cooler? the little blower motor cools the air enough to drop the condensate out? wow. simple and cool. how often do you have to drain the drip leg?

 

[bhays]

so your air line comes straight from the compressor head to the cooler?

Yep, so the air is cooled before it ever gets to the compressor's tank.

how often do you have to drain the drip leg?

After running the compressor all day yesterday, I would say it was half full. It's going to depend on the humidity in the air and ambient temp I would think.

 

[kbs2244]

That is good thinking.
Get the heat, and thus the moisture, out ASAP.
My only concern would be the PSI rating of the radiator.

 

[bhays]

That is good thinking.
Get the heat, and thus the moisture, out ASAP.
My only concern would be the PSI rating of the radiator.

I checked it out and most oil coolers are pressure tested to a minimum 200psi... most 500psi. Not sure why since engine oil pressure is usually way under 100psi, I believe.

 

[have2goski]

what size is the cooler? Are you pushing or pulling the air through the cooler? Looks like it would pull from the outside air.

Also, how did you assemble the trap? is it as striaght forward as it looks in the pcitures or is there something internal?

 

[bhays]

what size is the cooler? Are you pushing or pulling the air through the cooler? Looks like it would pull from the outside air.

Also, how did you assemble the trap? is it as striaght forward as it looks in the pcitures or is there something internal?

Yep, it pulls from outside air. The trap is just as simple as it looks, just a place for the cool air to expand a bit and drop moisture, then the air keeps moving upward letting any residual condensation roll downward back into the drain leg.

 

[pipehack]

Tell me about your user name please... Is your last name Hayes???

 

[bhays]

Yes. My name is Brett Hays.

 

[pipehack]

I thought you might be another Bill Hayes... Same last name . Different spellin.

 

[Lhorn]

Probably end up with a lot less corrosion in your compressor tank also. That's so simple and effective, it's amazing that this is the first time I've seen such a great low buck solution to a common problem.

 

[55dude]

that cooler looks like its for a hyd. system and they run higher psi.

 

[CenTex52Chevy]

do you end up with condensation in the copper line? and if so who do you prevent it from flowing back into your compressor

 

[BigE]

So the 1.5 - 2-liter bottles worth of water didn't come just from the 6 hours of sanding you did that first day? I'm just trying to resolve 6 hours of sanding making 3 liters of water versus sanding for 8 hours and not filling up that small trap pipe.

 

[bhays]

So the 1.5 - 2-liter bottles worth of water didn't come just from the 6 hours of sanding you did that first day? I'm just trying to resolve 6 hours of sanding making 3 liters of water versus sanding for 8 hours and not filling up that small trap pipe.

The compressor is located in a shed about 150' from my garage and the air line runs partially underground and partially through the crawlspace of the house to the garage. I was getting tons of condensation between the shed and the garage due to the relatively cooler temperature that line was running through on the way to the garage. The 3 liters was from the water trap in the garage.

With the air cooled before it hits the compressor tank, I am not getting that condensation. Make sense?

 

[bhays]

do you end up with condensation in the copper line? and if so who do you prevent it from flowing back into your compressor

That may be a valid concern that I have not addressed. Might make sense to install a drop leg with a trap between the pump and the cooler... thanks for bringing that to my attention.

 

[RBX]

great idea
Please give us some reports as time goes on. This is definitely a n idea i will incorporate in Man-tropolis.

Thanks for posting up this idea.

RBx

 

[lametec]

Inspired by this I made my own version:

A B&M model 70266 (11" x 8" x 1½") tranmission/engine oil cooler, an EBM Pabst model W2E250-HL06-01 230V AC fan (1160 cfm in open air) (wired in parallell with the motor so when the motor runs, the fan runs) and a Wilkerson model X01-04-M00 automatic drain.

I measured the intake temperature (on outside of the inlet of the cooler) to be over 310°F using an infra red thermometer. The outlet temperature measured the same way never went above 96°F. That's a drop of 214°F. Ambient temperature was about 86°F.

The clear hose going to the auto drain lets me see if the system is working (it is!).

 

[bhays]

Looks awesome. I need to get myself one of those auto drains.

 

[lametec]

Mine is a 1 qt capacity! Was the same price as a 5 oz so I figured might as well go bigger.

 

[tcianci]

I bought the HF auto drain, first one quit, they gave me another, that quit too. Buy a rea one!

 

[bmwpower]

What about mounting it on the outside of the pulley? Probably not a lot of CFM, eh?

I like this idea!

What's the drop in CFM though? That's what would concern me.

I'd run the drip line right to the bottom valve, but before the auto drain...at least on mine.

 

[Vicegrip]

The line from the compressor head out to anything needs to be downhill. Water can condense and flow back into the head. Air compressors have much higher compression ratios that car motors and even a small amount of water can cause hydraulic lock. This can bend a rod, knock the head or blow the reed or disk valves all over the place. At least add a large drip leg on the outlet to catch the drain back.

Even with (what looks just like a Mocal 16 row) oil cooler you will still have condensation in the storage tank. (if it is it can take the pressure just fine) Why not add a powered ball valve auto drain to the tank? You can plumb it in a way that causes the tank and drip leg to be blown down with each cycle. If it were my house I would replace the plastic line on the other side of the cooler as well. If the fan knocks out or your use gets ahead of the cooler you will overheat and blow that line out.

The inside of the tank will always be wet. An auto drain will remove the water but nothing can make the inside of the tank dry unless you use a large desiccant system on the intake side which for a well made tank is unnecessary. Stripping the water from the compressor before it has gone to the tank is much harder as the flow and temps tend to be higher and not optimal. cooling before storage water stripping or not helps cut down cycles. cooling between stages on multi stage compressors increases capacity quite a bit.

 

[lametec]

What about mounting it on the outside of the pulley? Probably not a lot of CFM, eh?

Thought about that, but yeah, very low cfm.

What's the drop in CFM though? That's what would concern me.

Don't know, but I'd say minimal. The cooler is not a restriction, I think. It probably flows better than the 1/2" copper pipe.

 

[lametec]

If it were my house I would replace the plastic line on the other side of the cooler as well. If the fan knocks out or your use gets ahead of the cooler you will overheat and blow that line out.

In my case I'm not sure I can use enough air to get ahead of the cooler. When pumping it up from 90psi to 145psi (where I did my temperature measurements), only the top 15% or so of the cooler got hot. After that the rest is very close to ambient temperature, and certainly nowhere near hot enough to soften the plastic.

 

[bhays]

I bought the HF auto drain, first one quit, they gave me another, that quit too. Buy a rea one!

ditto

 

[FLACOMAN]

I've used nitrogen cylinders for finish painting ; keeps things dry. Those might be a nice alternative

 

[LoneGunman]

Any reason an old 25,000 BTU window shaker with a bad compressor can't be used for this, specifically the evaporator/condensor and the fan? It'll take the pressure but I don't know if the copper tubing in the evaporator is too small of a diameter.

 

[Joe69]

that cooler looks like its for a hyd. system and they run higher psi.

Yes, but hyd. coolers are plumbed into the return side, which is little to no pressure. They also have a bypass valve to keep cold thick oil from over pressurizing them.

Joe

 

[90rev2sev]

Any reason an old 25,000 BTU window shaker with a bad compressor can't be used for this, specifically the evaporator/condensor and the fan? It'll take the pressure but I don't know if the copper tubing in the evaporator is too small of a diameter.

That sounds like a fine idea. I've got an 18000BTU unit with a blown compressor that I'm considering doing this with. Actually came to garage journal to investigate and see if I was the only one with that idea.

 

[bad_idea]

talk about resurrecting an old thread! i'm thinking flow rate would be an issue.

 

[54FordPanel]

Old thread, but best use of a blow up Santa pump ever.

 

[Garage5.9]

would this work on something smaller like a crapsmen 30 gal oilless ?

 

[JohnMcD348]

Just wondering about cooling the air before storage. Would doing thins increase the amount of air stored in the tank as compared to the heated pressurized air?

Just wonderin.

 

[Lippyp]

Won't the oil cooler just fill up with water though? I guess a decent intercooler from a car would work, you'd have to have the outlets at the bottom though and sloped to the outlet end so any water in there runs out to your water trap. An even cheaper fix that might work would be to pipe the air through a big coil of copper pipe sat in a tank of cold water.

 

[nate379]

I was worried on my setup, I have about 100ft of line underground from my shed to my garage. Even right now with no dryer and no drip legs other than right at the compressor I haven't gotten any water.

 

[lametec]

Just wondering about cooling the air before storage. Would doing thins increase the amount of air stored in the tank as compared to the heated pressurized air?

From a blog entry I made a couple years ago when I installed my "intercooler":

I measured the intake temperature (on outside of the inlet of the cooler) to be over 310°F using an infra red thermometer. The outlet temperature measured the same way never went above 96°F. That's a drop of 214°F. Ambient temperature was about 86°F.

Using Charles' law (V2/V1 = T2/T1), the increased volume based on my temperature measurements will be:

427.59°K / 308.70°K = 1.38.

Meaning there's a 38% increase in air molecules stored in the tank under best case/worst case scenarios.

Of course, it's a 60 gallon tank and it's going to contain 60 gallons of air no matter what. The "increased" storage capacity will be realized by the pressure in the tank not dropping considerably once the air cools down.

 

[JohnMcD348]

Cool. Thanks for that.