Air Compressor Mods

[Markfothebeast]

I'm looking to share my experiences and also looking for advice on air compressor mods. I picked up this Husky C602H 60-Gallon 3.7hp 240v air compressor about 6 months ago. I was unable to use it until 2 weeks ago when we finally had power run to the garage. My first attempt at modding is to battle the moisture and heat this unit is generating.

The pump itself runs at 315 degrees fahrenheit at the air exit port on the cyl head after 12 minutes of operation. I need to run sandblasters that will tax the compressor beyond its duty cycle. I decided to build some type of aftercooler to relieve heat from the pump. I used some old 3/8" ID copper tubing I had laying around and ran it between the pump and tank with a water separator near the end. The line is approximately 14'. I just completed this last night and haven't had the time to monitor the temps. This 14' copper line still gets hot enough to burn skin. However, I noticed a large decrease in moisture levels. I'd like to get the temps down to levels where the line and pump cyl head don't burn skin.

My next plan is to use an old AC condensor I yanked from my 95' Trans Am. However, I'm a bit afraid that it may not handle the pressure when it is under stress from heat. Maybe someone out there can share advice that has used an automotive AC condensor?

I also have another interesting idea which I will share. I bought this large brick of recycled steel high temp insulation known as rock wool to replace oven insulation that mice had gotten in. At the time I was rebuilding an air cooled Briggs & Stratton V-Twin in a Cub Cadet Mower. I noticed that the engine ran at temps over 700 degrees fahrenheit at both exhaust ports on the cyl heads. I picked up a roll of foil tape and wrapped the rock wool around the exhaust piping. The exhaust port temps dropped to around 174 degrees from 700ish (photos). I'm thinking about using this same method on the air line exiting the air compressor cyl head but only for a short length. I'm not sure if this would have the same affect with a compressor pump.

 

[PSYKO_Inc]

Automotive AC systems can run at upwards of 350 psi on the high side, so it should be fine for your compressor. As for the insulation, I wouldn't. It will just keep the heat in the tank, rather than dissipating the heat into the outside air. You really want to get as much heat out of the compressed air as possible, just don't touch the hot parts. It's hard to see what's going on with your copper tubing, are you running 14' of tubing between the compressor head and the tank, or between the tank and the blasting cabinet? I would put the condenser between the pump and tank, but the wall of tubing should be after the tank to get moisture out of the lines before going to the blast cabinet. Start low and work your way up, with a ball valve teed off at the lowest point to drain water out. Put the water trap right before the cabinet for best results.

 

[Richard Cranium]

Your picture shows snow in it, I didn't see any insulation in your shop.
I am not understanding what you are trying to do, cool the air or remove the moisture?

 

[ClappedOutBport]

Your picture shows snow in it, I didn't see any insulation in your shop.
I am not understanding what you are trying to do, cool the air or remove the moisture?

Fixing one should fix the other. The hotter the input air into the compressor, the more moisture it will condense.

 

[Markfothebeast]

Your picture shows snow in it, I didn't see any insulation in your shop.
I am not understanding what you are trying to do, cool the air or remove the moisture?

That is actually the rock in the driveway but looks a bit like snow there. I am trying to both cool the air and remove the moisture. Cooling the air helps separate the moisture before it hits the water separator. At the same time I am also trying to lower the temperatures of the pump.

 

[Markfothebeast]

Automotive AC systems can run at upwards of 350 psi on the high side, so it should be fine for your compressor. As for the insulation, I wouldn't. It will just keep the heat in the tank, rather than dissipating the heat into the outside air. You really want to get as much heat out of the compressed air as possible, just don't touch the hot parts. It's hard to see what's going on with your copper tubing, are you running 14' of tubing between the compressor head and the tank, or between the tank and the blasting cabinet? I would put the condenser between the pump and tank, but the wall of tubing should be after the tank to get moisture out of the lines before going to the blast cabinet. Start low and work your way up, with a ball valve teed off at the lowest point to drain water out. Put the water trap right before the cabinet for best results.

The 14' of line is exiting the pump and has a separator near the end just before returning to the tank. My general idea was to use maybe a foot of insulation just at the exit port of the cylinder head line to keep the heat in the line and away from the pump. I'm not sure if that would work the same as it would on the exhaust of a gas engine. It wouldn't hurt to give it a try I suppose.

The 14' of 3/8" ID copper tubing only dropped the cylinder head port temps down 15 degrees. But the line is cool enough to touch just before it hits the tank. It also isn't cooling the air enough to trap moisture in the separator that is before the tank. I will be adding the AC condenser soon. I also have another water separator AFTER the tank. This separator is catching a lot of the moisture.

I am trying to do 3 things. Cool the air, remove the moisture, and keep the pump cool. This is because I have a couple sandblasters that make the pump run ALOT and I also use a HVLP spray gun and plasma cutter. The manual states that the duty cycle (max run time) should be kept at 30 minutes. As hot as the pump is getting (315 degrees), I don't feel comfortable running it for even 30 minutes. Oil breaks down when it approaches 240 degrees. However, the crankcase is probably much cooler inside than the cylinder head exit/exhaust port. I don't recall if I put in synthetic compressor oil but apparently synthetic is less prone to breaking down at high temps.

I intend to add more photos when I have a working mobile phone again.