Refrigeration Type Air Dryer

I've got an inexpensive Harbor Freight refrigeration style air dryer. It has worked pretty well since I got it. The day before yesterday I had an airline blow out (rubber whip) and the compressor was running continuously until I unplugged the whip. The air dryer had shut down. Thermal switch tripped. I wound up with moisture throughout all my lines. I was in the shop office working on a design and I don't know how long the unit was shut down due to the trip.

I didn't run the shop yesterday as we were surrounded by thunder storms most of the day, and I can not afford to lose a machine due to a lightning strike, or lose a job due to a power loss.

This morning I've been in the process of trying to clear all the moist air out and run dry air in, but the dryer does not seem to be working. I've got a filter separator on both the input and the output of the dryer. The fan has kicked on and the compressor is running, but I still keep getting moisture in the down stream separator. The auto drain is working, and there is no more than a little moisture accumulating in the auto drain float bowl.

I'm at a loss unless its just no longer working. The only other thing I can think of is that the humidity has been really high for the last couple days. (High for Yuma anyway.) On-line weather says we are sitting around 46%. This is our "monsoon" season. The rest of the year we tend to run 8-15%. Maybe this cheap dryer just isn't up to handling that much humidity.

Ideas? Suggestions?

Run out and buy an Ingersol Rand air dryer is not an option for today. Maybe next time I get a big job.

Throw away desiccant filters on the individual machines might be ok, but they use continuous air on the spindle nose air seals. I suspect I'd be replacing them every day if not sooner.

*********************

A little more. I checked the input and output lines of the dryer's compressor. One is warm and one is cold. As I would expect. I do have a larger vertical rise from the output side separator. I am wondering if moisture is just still draining back down that riser. The last few times I've checked the separator there is has been almost zero moistures. Still not ready to run that air through any machines just yet.

Still contemplating a run to the store for some disposable desiccant dryers. Problem is the cheap ones are rated at 90PSI max and I distribute my shop air at 125. I have regulators on each machine, but those are set at about

15-20 PSI for the air seals. I don't really want to drop my shop air to 90PSI because I also run other equipment off of air. Impacts, air wrenchs, drills, sanders, grinders etc. Equipment that requires lower pressure gets its own regulator. I have two on the Hurco. One for the air brake, and one for the oiler. FYI: It was the whip to the Hurco that blew. LOL.

You are out of my hands on knowledge but the manual has a some troubleshooting tips:

Looking at that there appears to be a "strainer" at the input of the auto drain mechanism. Maybe it got plugged up?

You are out of my hands on knowledge but the manual has a some troubleshooting tips:

Looking at that there appears to be a "strainer" at the input of the auto drain mechanism. Maybe it got plugged up?

***************

I forgot about that. I disassembled it in place and did not pull the top part from the machine. Thanks. That could very well be an issue.

You are out of my hands on knowledge but the manual has a some troubleshooting tips:

Looking at that there appears to be a "strainer" at the input of the auto drain mechanism. Maybe it got plugged up?

***************

I forgot about that. I disassembled it in place and did not pull the top part from the machine. Thanks. That could very well be an issue.

***************

Ah! You got me thinking there was another filter screen in the throat on the top of the float drain assembly. There is not. There is just the one accessible from the inside of the assembly. I don't have to remove the assembly to service that one. Just unscrew the bowl, and then unscrew the retainer that holds it in place. I went ahead and cleaned it again anyway.

You are out of my hands on knowledge but the manual has a some troubleshooting tips:

Looking at that there appears to be a "strainer" at the input of the auto drain mechanism. Maybe it got plugged up?

***************

I forgot about that. I disassembled it in place and did not pull the top part from the machine. Thanks. That could very well be an issue.

***************

Ah! You got me thinking there was another filter screen in the throat on the top of the float drain assembly. There is not. There is just the one accessible from the inside of the assembly. I don't have to remove the assembly to service that one. Just unscrew the bowl, and then unscrew the retainer that holds it in place. I went ahead and cleaned it again anyway.

***************

After all this I think I am going to add a T in front of my shut off valve for one quick couple that is unfiltered and not shut off with the valve so I can have air to blow out a screen or fill a tire when I have the valve closed and the air dryer shut down. LOL.

Snort! Yep, always a pain to need the tool/machine your trying to fix to get it fixed.

I was always the odd man out at work but that was why I carried duplicates or very similar tools with me. Just in case the favorite failed or you wanted another opinion (test equipment) for some strange, hard to believe reading ;-)

So, you got it working again?

Snort! Yep, always a pain to need the tool/machine your trying to fix to get it fixed.

I was always the odd man out at work but that was why I carried duplicates or very similar tools with me. Just in case the favorite failed or you wanted another opinion (test equipment) for some strange, hard to believe reading ;-)

So, you got it working again?

******************

It seems to be working, but it was a sort of progressive thing. It just kept getting better. I think there was just so much moisture in the air lines to took a very very very very long time to wash it all out with air.

I'm still seriously considering secondary desiccant dryers at each machine.

Not directly related , but I bought a dehumidifier about a month ago. When I first started using it the humidity in the basement was about 60%. But after a week or so the humidity is down to about 40%. So it appears that it took several days to pull all the moisture out.

So maybe you got your air system wet and it is taking a while to dry it out .

Dan

Not directly related , but I bought a dehumidifier about a month ago. When I first started using it the humidity in the basement was about 60%. But after a week or so the humidity is down to about 40%. So it appears that it took several days to pull all the moisture out.

So maybe you got your air system wet and it is taking a while to dry it out.

Dan

**************

Yeah, I think you may be right. With the higher than average humidity I probably got it really wet.

Don't know how you were approaching this but I noticed that the HF unit was rated for "21.6 C.F.M." I would guess that means if you try to draw more than 21.6 C.F.M. it wouldn't be able to dry it sufficiently or keep up. I didn't see any mention of what they claim "dry air" to be either...

I just have an old Dayton 2hp 20gal portable unit. I drain it after almost every major use. Your worst humidity day would probably be similar to my least humid day here :)

check the freon lines to see if there is a cold line and ahot line.

i

The manual is online and says R134 refrigerant (so, it's a good thing you still have some cooling, I'm not sure that's currently available). As for the NECESSITY of a dryer, I'm not sure, but that air can't have (on average) any higher humidity than goes into the compressor, can it? A lot of air-sucking machines would JustNotCare.

This video details one possibility, and makes me think of using an ultrasonic cleaner...

Well, after doing nothing more really than my regular monthly service a week or so early I have dry air again. I ran the air dryer for about 8 hrs yesterday with zero moisture build up in any of the downstream separators. I used it simultaneously for two mills with air seal high speed spindles and assorted other air tools while putting the output shaft and wheel spindle back together on the front axle of my little 3320 tractor.

I guess the system was just really wet, and needed to be dried out slowly and tediously.

I think I am still going to add desiccant driers after the separators at the machines as a second line of defense.

Maybe just add one and see how it goes?