Refrigerated air dryer question

[tinman13]

I have a Harbor Freight unit and it doesn't seem like there has been a lot of improvement in consumables. Is there any way other than blowing air onto glass or something to check if it is actually working?

Thanks, Steve

[WSS]

Originally Posted by tinman13 I have a Harbor Freight unit and it doesn't seem like there has been a lot of improvement in consumables. Is there any way other than blowing air onto glass or something to check if it is actually working? Thanks, Steve

Hey steve,

I have the same dryer. It helped alot and the results were immediate. I did install a "coalicing" (spelling?) filter right at the plasma inlet to keep out oil (the dryer does not stop oil) some time before but the dryer was the biggest improvement. One thing I do notice, in order for the dryer to drain, the pressure has to be relieved. I do this at least once a week and water just pours from the dryer. I have a ball valve at the outlet of the air comp that i swing closed and attach a blow gun to a free line to drop the pressure. The dryer is mounted over my head, so I have not seen were the water comes from but it does flow quite a bit. I also stopped coating the nozzle and electrode with anti-spatter internally, I can get away with this on oxy tips but the plasma parts don't like it. I will spray a light coat on the shield once in awhile.

What is happening to your consumables? does it seem like a problem with arcing between the nozzle/electrode? I recently had what appeared to be a problem hear, it caused the electrode to pit the center deeper and faster than usual and the nozzle went out of round. I changed the swirl ring (after lots of parts and blank staring) and it all cleared up. I went back to inspect the old swirl ring and could not see anything obvious, but problem solved. Wierd, but the cut would start to lean in one direction, not the same direction every time but consistent enough to see it right away. I suppose the swirl ring got out of round or something of that sort, causing the electrode to stick.

WSS

[tinman13]

Interesting.....
"in order for the dryer to drain, the pressure has to be relieved"
That must be why the manual talks about a bypass valve. I would have thought an automatic drain valve would drain.......... Well.. automatically!
I have had the most trouble with 40 amp nozzles, they don't seem to last very many pierces and then the hole seems like it erodes out on one side.
The electrodes will get a brown scale like coating on them quite soon....
I will see if I can get a good picture of one and post it.

Steve

[plain ol Bill]

Hmmmm - I have one of those also Steve and have never seen it drain out any water to date. Maybe I better find my manual and look at it. My consumables last a loooong time however (40A, finecuts). I changed out my nozzle a week or so ago because it had been on there a long time. After changing it I looked it over and will put it back in the next time I change. I looked at the old one with a big magnifier and couldn't find anything wrong with it.

[tinman13]

These have two pierces and 167" of cut on them. 100 amp. 1/2" a514 plate.
Kinda disappointing. Although the cut quality was still OK.
This discoloring on the electrode seems to be typical for me here.

The more I think about it nozzle and electrode life has gone down hill recently, Hopefully it is just a drain issue. (Great, one more thing to maintain!)

I took the valve off of the bottom and drained out around a 1/2 cup of water today, so I guess it doesn't "automatically" drain.


Steve

[WSS]

The pit on the electrode looks deep. Is that usual? That must be a TD machine? The electrodes on our HP do not work very well when they are that deep. The black seems normal, maybe not with as little use as you are getting.

WSS

[Dustin407]

These have two pierces and 167" of cut on them. 100 amp. 1/2" a514 plate. Kinda disappointing. Although the cut quality was still OK. This discoloring on the electrode seems to be typical for me here. The more I think about it nozzle and electrode life has gone down hill recently, Hopefully it is just a drain issue. (Great, one more thing to maintain!) I took the valve off of the bottom and drained out around a 1/2 cup of water today, so I guess it doesn't "automatically" drain. Steve

Hi Steve,

I thought about buying one of those refrigerated units from harbor freight, and I was very close to getting one. I talked with a number of people that were filter/refigerated water seperator engineers and they didnt recommend them on plasma machines. They said there is too many start and stops and some type of phenomenon that happens in the copper coils of the ref. unit that would not take all the water out of the line. So I asked him what he recommended and I bought 2 very nice oil/water seperators that work extremely well. I live in florida so the humidity here is extreme, even in the winter it is at 50 percent, so I put in alot of time researching this. After installing the seperators I seen a huge difference in cut quality and consumable life. As for your consumables I think they actually look pretty good. I wouldnt pay attention to color distortion but the size and shape of your tip hole. If this changes and gets bigger your cut quality will suffer dramatically. I usually take a wire brush and clean the spline electrode on my machine to make them last a little longer.

[tinman13]

In thinking more about it and the fact that I drained quite a bit of water out of the dryer it must have been building up in the dryer for a while.
I am paying more attention to consumables now that I drained it.... We shall see.

Dustin, what kind of separators are you using? I am not fond of the descant type, as they seem like a lot of upkeep.

As it is now the compressor is about 75 feet away with the first pipe run (PVC) straight up 14 feet, then a small water separator / filter to a motorguard paper filter, Then the refrigerated dryer, then the small Thermal Dynamics water filter.

I do have a air to air cooler to put in line someday......

Good God if that won't take out the water I don't know what will!

Does anyone know of a field test to tell if there is any moisture in the air system? It seems like a hard thing to test.


Thanks for the replies ,Steve

[jimcolt]

I have been using a refrigerated dryer in my home shop for years with plasma...it works very well, and is a better solution from a maintenance point of view as compared to other dry air solutions. I turn on the compressor, turn on the dryer, and every 6 months or so blow the dust out of the dryer. It has an auto drain, and is totally issue free......have had no water in my air system whatsovere since installing this unit.

Mine is not the Harbor Freight unit, it is an old Ingersoll Rand that I found on Craigslist for $75, however I have heard from over a dozen other plasma shops that the Harbor Freight refrigerated dryer works very well, and is reasonably priced at under $350.

Jim Colt Hypertherm

Originally Posted by Dustin407 Hi Steve, I thought about buying one of those refrigerated units from harbor freight, and I was very close to getting one. I talked with a number of people that were filter/refigerated water seperator engineers and they didnt recommend them on plasma machines. They said there is too many start and stops and some type of phenomenon that happens in the copper coils of the ref. unit that would not take all the water out of the line. So I asked him what he recommended and I bought 2 very nice oil/water seperators that work extremely well. I live in florida so the humidity here is extreme, even in the winter it is at 50 percent, so I put in alot of time researching this. After installing the seperators I seen a huge difference in cut quality and consumable life. As for your consumables I think they actually look pretty good. I wouldnt pay attention to color distortion but the size and shape of your tip hole. If this changes and gets bigger your cut quality will suffer dramatically. I usually take a wire brush and clean the spline electrode on my machine to make them last a little longer.

[Dustin407]

I am trying to find my receipt for the water/air/oil seperator to give you some technical information on them.... It is a Hansken made seperator, all S.S. body and membrane style that has to push the air through the very small micron holes for it to pass to the output line. The water molecules can not fit through the holes so they fall to the bottom of the retainer. Very simple design/method thats been around for along time.

Jim, $75 is very cheap... Thats a good find.. Ill buy it from you for $85....lol Sometimes im not in the shop for a few days and the main power switch is off... It takes a little while for those dryers to get to temperature before they start working properly, plus extra electricity cost. As for the seperators they are instant with no electric cost (psi from compressor). They probably have a little more maintenance to them though. Either way it is the same result.. How do you know you havent had any water in your system??? How Do you check this?? It is possible to have a small percentage of moisture going through the system unrecoginized I believe...

I always thought about buying those moisture color pads, putting them under the tip and turning the air on the plasma (with the torch off) to do a 2 minute blow through...?

[jimcolt]

It is rather easy to check for moisture in your air line....I use a piece of glass or a mirror that is slightly chilled (from a refrigerator), point an air hose at it for about 20 seconds and see if dew or droplets form.

A refrigerated dryer system needs a separator as well. Most of the commercial units have them built in. The refrigerated unit chills the air to its dew point, and as the air leaves the condensor coils it then enters a separator where the pressure drops and more efficiently separates the water droplets. The use of a refrigerated dryer and an auto drain on your compressor tank is very efficient. It is also important for your shop plumbing outlets to be up high, and to have drop legs that are down low with drains...either auto or manual.

A separator alone without an air cooling method helps, but is not as efficient. A Dessicant dryer, adequately sized for your air consumption in vert good at drying air, however it requires that the desicant powder be changed or dryed periodically. The refrigerated units for the most part do not require maintenance.

If you research (google) air systems for automotive or industrial paint spray applications...you will find good info on setting up a good system. If it is good enbough for paint, it is good enough for plasma. Humidity is the culprit, so if you live in an area with low humidity then it is less of an issue.

In NH where I live, humidity can be extreme in the summer months and very low in the winter months. In the winter I rearely turn on the power switch of my refigerated dryer, in the summer I always use it.

Watch Craigslist.....I have found a ton of listings for dryers. Every auto body shop has one, and when they go out of business or upgrade their equipment, you can often find them cheap! They are usually bundled with a compressor....so try to talk the owner into separating the dryer if you don't need the compressor!

Jim colt Hypertherm