Best location of refrigerated air drier in system?

[DC3]

In an effort to get the most dry air possible for my PM85, I decided to invest in a Harbor Freight refrigerated air drier. The cost was cheap enough to try. I have been running (dialing in) my new setup over the last month or so and could not get great cut quality. I suspected it was moisture/oil in the lines. I decided to redo my system the correct way. Utilizing my original undersized 3.5HP 60 gallon compressor, I designed and built a pre-cooler between the compressor and the tank, plumbed in a second 40 gallon receiver tank to further cool/store the air supply. I have a .05 micron filter/separator and then a very large one gallon capacity desiccant filter and a MotorGuard M60 filter right at the cutter. I have about a 30 foot run of 3/4 inch copper line (with drops of course) going from the compressor to the cutter.

My long winded question is this: What would be the best location for the refrigerated drier?
1. Right after the reciever tanks before the 30 foot run to the plasma cutter or
2. At the end of the 30 foot run and before the desiccant filter and the Motorguard filter?
3. Is it going to make a difference either way?

Thanks for the help.

[see&see]

You would want the air dryer to receive the coolest air possible after the receiver tank and the pre-cooler.. Then on to the .05 micron filter/separator and then the one gallon capacity desiccant filter and MotorGuard filter. Next into the cutter..

I run a fan cooled air to air condenser before the air goes into the refrigerated air dryer and the dryer doesn't have to work hard at all. Undersized compressors are OK if you have the excess storage as you described..

[DC3]

Thanks for the input see&see. I agree with you about having the coolest air at the cutter but my main reason I am asking is due to space constraints, it would be easier for me to plumb the drier in next to the compressor as opposed to under the table next to the cutter.

[_Ogre]

plumb the dryer next to the compressor
but have 40 feet of .75 copper line in between
the copper line can be on the wall, floor or ceiling
rubber line is the worst way to dissipate heat
you don't need the desiccant, save desiccant for paint spraying

and yes there is a difference on your scenarios
cool air into the dryer will bump up the efficiency

[DC3]

Thanks Ogre. Due to the shape of my garage and the location of the table, I have about a 30 foot run of 3/4" copper line between the last tank and the plasma unit. I think that should be sufficient if I keep it by the compressor. As far as the dessicant filter, I already built a 2" x 48" SCH40 pipe filter to use. Thanks to the guys on this board for giving me the idea and how to.

How much difference do you think I would see if I was to plumb the dryer right before the plasma cutter so the air would be at its coolest temp?

[DRB01]

I have a compressor that has been passing oil through the air lines and is compromising cut quality. Looking at oil separators but don't know which ones are actually good. Would love a recommendation.
Thanks,

[jimcolt]

The dryer should always be at least 20' away from the compressor....and with at least 20' of copper pipe between it and the compressor.....this allows a bit of air cooling before the dryer. The filter and auto drain go just after the refrigerated dryer.

Jim Colt Hypertherm

[gusagus]

I read different arguments on this, and the one I went with was closer so you have a bigger temperature difference before hitting the cooler. It appears to be working fine for me and when I get out of these rental houses, I'll listen to Jim and move it away. Last time I didn't listen to Jim I bought a TD, it hasn't been a bad machine but I should have listened.

[jimcolt]

If you go to compressed air manufacturers sites (I suggest Sharpe)....you will see where I get my suggestion from. Well,,,that and 38 + years of experience working for Hypertherm!

Jim Colt Hypertherm

[hsolve]

Good morning to all.
I have a rotary screw 3phase compressor, about 70cfm, It was ordered with the refrigerated dryer attached to the main body. The discharge from the compressor is plumbed to the receiver then through the dryer. The drier inlet line is fitted with a 5micron filter to stop 'crap' getting caught inside the cooling part of the refrigerated dryer. The refrigerated dryers are from what I have seen basically two stage. The incoming air is cooled by the refrigeration circuit then on it's way out is warmed by the hot air coming from the compressor. Please forgive me for the explanation which technically may not be correct but the schematics will explain. This cooling and subsequent warming reduces the relative humidity of the air out to the job or air users. My set up is as described, one thing to note that the dryer has an automatic drain, when the drain fills to the predetermined level, it lifts a float and opens the drain. Simple operation, the refrigerated dryer operates at 3Celcius due point. The air coming from the compressor when operating at full capacity is about 50 to 60 Celcius as the compressor is aftercooled, the air coming out from the dryer is about 16Celcius and quite dry. I also use the compressor to abrasive blast using smaller nozzels up to 1/4" and have not had any moisture in the system when the refrigerated dryer was operating.

[whiskeymike]

DC3, I have my HF dryer next to my 60 gallon and it works fine. You also have the pre cooler which should help. Additional line is helpful, but I would plumb it in unless your air feeding in is really hot. My feeding pipe is maybe 10 degrees hotter than room temp and the outlet is ice cold.(it collects a ton of condensation from the air in the shop it's so cold.) I have some issues with the condensation not draining out automatically, and once it froze up.

I would make sure you have a separator/drain before it goes in as its better to get the liquid out prior.