Cheap/easy compressor aftercooler?

[mct75]

I have a 5 gallon craftsman air compressor that I found on the side of the road. It is a portable unit with a carry handle and rubber feet.

Where I live it's super humid, as in my blow gun blows visible mist. I want to filter some of this water before it gets into the tank, but apparently the little can style coalescing filters only work when the air has been chilled.

Are there any plans/suggestions for an easy way to cool+filter the air after it leaves the compressor, and before it enters the tank? I was thinking a length of copper pipe that runs back and forth, a spiral wound tube, or maybe an automotive engine oil cooler. My problem is that I don't have a lot of space (on the compressor) and I don't want to spend a lot of money. I think a smaller oil cooler and a 120v fan powered from the pressure switch will work well, but I don't see a lot of people using those.

 

[Ridjobradi]

Search after cooler on YouTube and you will see a few options for using automobile condenser coils. You can also buy automotive transmission coolers with 1/2" ports.

If you mainly use it in your garage, you can plumb vertical runs of pipe with drip legs to give the air surface area time too cool.

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[[memphis]]

Could also plumb in a copper base board heater. Something that small is going to cycle a lot = more heat

 

[mct75]

Finned tubing might work well. I'd like to rig up an AC condenser, but that would ruin the portability of it.

Would something like the transfer pipe of a two stage compressor make sense on a little unit like mine? Currently the hose going from the compressor to the tank is about 4 inches so anything will be better than that.

 

[jlipsky14]

I have done a 50ft hose coiled in a 5 gallon bucket of ice water with a filter after about 5 feet higher when I needed to do it once and it worked flawlessly. I took some water bottels and froze them so I could keep refreezing and reusing them.
Could do the same thing with some coiled copper pipe to be more permanent.

 

[Ridjobradi]

There are smaller versions of this also.
https://m.summitracing.com/parts/de...BJmClqFF5NBoCXbfw_wcB&ibanner=MobileSwitchYes

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[pop pop]

You are fighting physics. If the ambient is 70* and you cool the compressed air to near 70* (next to impossible) you have saturated air, compressed even if you drain off the liquid condensed water. When you release the compressed air (blow gun) you have a refrigeration effect and will condense more moisture as the saturated air temperature drops.

 

[mct75]

I have done a 50ft hose coiled in a 5 gallon bucket of ice water with a filter after about 5 feet higher when I needed to do it once and it worked flawlessly. I took some water bottels and froze them so I could keep refreezing and reusing them.
Could do the same thing with some coiled copper pipe to be more permanent.

Something like that would be nice, but there's no way I could fit it on a 5 gallon compressor.

There are smaller versions of this also.
https://m.summitracing.com/parts/de...BJmClqFF5NBoCXbfw_wcB&ibanner=MobileSwitchYes

Sent from my SM-T330NU using Tapatalk

I've been eyeing this. Their website states they are tested to 300 PSI. Not sure how I'd get NPT fittings on it though. https://www.amazon.com/dp/B000C39C86/

You are fighting physics. If the ambient is 70* and you cool the compressed air to near 70* (next to impossible) you have saturated air, compressed even if you drain off the liquid condensed water. When you release the compressed air (blow gun) you have a refrigeration effect and will condense more moisture as the saturated air temperature drops.

So trying to remove moisture from the air is a lost cause? I also want to keep some heat and moisture out of the tank.

 

[mct75]

Alright, I'm leaning towards the transmission cooler, something like the below:

Along with a 120v 120mm fan that is powered from the compressor pressure switch.

What I can't decide on is if I should get a standalone filter or just let the water go into the tank and drain the tank. I'm worried that the still very warm air will damage a plastic filter bowl.

 

[theoldwizard1]

With a cooler, you still need something to trap the moisture.

 

[shoot summ]

I made the one in the pic, goes to a drop leg with a drain valve, lots of water comes out of it...

 

[mct75]

Cool! I have been trying to decide to either collect it in the tank and drain it, or use an additional coalescing filter. Space is at a premium as I want to be able to carry this unit around if I have to.

 

[buening]

This thread may help: http://www.garagejournal.com/forum/showthread.php?p=5944844#post5944844

 

[pop pop]

So trying to remove moisture from the air is a lost cause? I also want to keep some heat and moisture out of the tank.

No, that's not what I addressed. Cooling the compressed air will condense water and it can be removed, just not all of it. To get "dry" air, you have to reduce the dew point of the compressed air below ambient. That means you need refrigeration to be successful. A simple heat exchanger will remove some water, but you will on occasion find that same vapor at your blow gun.

You could also use dessicant, but it's messy and bulky. You just have to reduce the dew point lower than ambient temp will do.

 

[mct75]

This thread may help: http://www.garagejournal.com/forum/showthread.php?p=5944844#post5944844

I've read that one many times. A lot of the posts deal with larger compressors though, I think my application will be the only one with a handle!

No, that's not what I addressed. Cooling the compressed air will condense water and it can be removed, just not all of it. To get "dry" air, you have to reduce the dew point of the compressed air below ambient. That means you need refrigeration to be successful. A simple heat exchanger will remove some water, but you will on occasion find that same vapor at your blow gun.

You could also use dessicant, but it's messy and bulky. You just have to reduce the dew point lower than ambient temp will do.

True, I should not have been so curt. I was thinking about a peltier element, but that is probably more trouble than it is worth. I just want to knock out some of the water and heat. I think an aftercooler will get me most of the way there.