Air drier for compressed air

shell70634

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I've been looking at drying the air from my compressor. It's a 5hp single stage with 90 gal tank. I regulate the pressure to 165 psi at the tank and further regulate on different lines. I drain my tank regularly but still have to much moisture. I've been looking at used refrigerator units. Are they truly maintenance free? Will they dry the air enough for air tools and sandblasting? I don't do much painting but plan on a small desiccant drier to mount on any air source I may use for painting or wood finishing. Am I overlooking anything? I found used driers in the $500 price range but would sure like to spend less.
 
You won’t hear me say this often but harbor freight has a good one. My good friend has one which he uses everyday on a cnc plasma table. You cannot have air in the lines for a plasma table it works great. He still has to drain his tank on the compressor but maint. On the air dryer is keep the coil clean that’s about it. They work good
 
I use dual air filters Norgen F74 series (F74G and F74H) on my 5Hp compressor, the second filter is a coalescing filter which removes any residual oil/water from the first. I have several drops after my filters and I have yet to have any moisture in the traps, should be good enough for sandblasting and tools. Painters and for a plasma table people seem to use refrigerator driers and/or a descant filter, but I do not see the need nor expense for what you are doing. I would try a series of air filters first, on can always add the refrigeration unit later. They are pretty much maintenance free from the few people I know who use them.

My compressor does have an after cooler which also pulls a lot of the moisture out of the compressed air, the tank uses an auto drain which can drain quite a bit. Also depends on the outside humidity. Typically single stage compressors go to 135 PSI, you indicated yours goes to 165 PSI. The higher pressure (above 150 PSI) requires metal bowels on the filters, as opposed to the polycarbonate. There are a number of similar brands of air filters, I have use Norgen for years and they have always worked well.
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We have been pulling gallons of water out of our systems this week so far . The compressors are running full throttle , the dryers , seporators , heaters are keeping us busy here . We make filters so our air must be clean and moisture free , if not , we make scrap . Last summer we had a valve end up in the open position up in the mezzanine which was allowing un-treated air into our system . We were emptying 55 gallon barrels out of our seporators every night .
 
I just have 60 gal compressor with two Norgren FRLs. I don't use a lot of continous air but I never have a moisture issue. I have a 17 gal tank connected to one of the FRLs & it never gets moisture build up in it. I don't run a drier or dessicant. The Norgrens seem to do a good job at pulling the moisture out but again my compressor doesn't run often.

The elements in the Norgrens will turn pink when they start getting saturated with moisture. If I let them dry out they'll turn back to white. But I just have a second set of elements that I just swap in whenever I drain the bowls. I do it like 2 or 3 times a year. The tank I drain often, I just have a ball valve & a tube connected to the drain. Been running this setup for like 10 yrs now & still no rusty water comes out of the drain so I'm happy.


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I just run the air conditioner hard in my shop. Dry the air before the compressor ever sees it.
 
Do a Google search for "Franzinator". I've had one set up between my compressor and tank for a couple of years and have had no water accumulation in the tank.
 
Humidity in the outside air makes a ton of difference. When I lived in Pa, it was nothing to get a cup or more of water out of the tank every day. Here in the desert, I might get a drop or two a week. When I set up my compressor in Pa, I had the drain extended, then a 90 deg, and then a 3 foot 1&1/2" (what I had on hand), pipe, with the drain on the end. I wanted it with a big enough volume, so any moisture collected, would not rest in the tank itself. I think of it as a sacrificial moisture storage area. I tried the auto drain system that Harbor freight had, but it did not drain enough air to get all the moisture out.

Another thing you can do with a permente instalation, is reroute the air from the compressor and have it go through several feet of pipe, then back to the tank, with a moisture drop before it goes into the tank. Just remember to route the pipes, so that someone cannot accidentally touch them, as they may get hot. But you want them where the air can help cool them.
 
Just got back from a call . Water in the airline , turn-act rotary cylinder won't work . :grin: Love this time of year .
 
Will they dry the air enough for air tools and sandblasting?

Try an after-cooler first, then a dessicant system second, and finally an actual air dryer.

After-cooler and cheap electric auto drain works well enough for me in fairly humid Ohio to work for air tools, sandblaster, plasma table, and unimportant painting. Not good enough for proper paint and other high-purity requirements.

Buy a transmission cooler and mount it on the compressor where the compressor fan blows over it - or get a fan with the same voltage as the compressor and wire it to switch on with the compressor. Plumb it so the compressor outlet goes straight in to the cooler, and the cooler outlet goes in to a moisture trap/separator. Trap outlet runs back up to the tank inlet, and arrange it so the trap is below the tank inlet.

Pipe the trap discharge outside along with the auto tank drain so you aren't just dumping condensate on the floor to evaporate and get sucked back in the compressor air intake.

And make sure the cooler is rated at or above the pressure relief valve on the tank. If the cooler supplier/manufacturer doesn't publish the max pressure - don't buy it.
 
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