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.

"Bob La Londe" wrote in message news
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.

On Fri, 4 Aug 2017 10:50:21 -0700
"Bob La Londe" wrote:

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.

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

https://manuals.harborfreight.com/ma...0999/40211.pdf

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

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

"Leon Fisk" wrote in message news
On Fri, 4 Aug 2017 10:50:21 -0700
"Bob La Londe" wrote:

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.

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

https://manuals.harborfreight.com/ma...0999/40211.pdf

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.

"Bob La Londe" wrote in message news
"Leon Fisk" wrote in message news
On Fri, 4 Aug 2017 10:50:21 -0700
"Bob La Londe" wrote:

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.

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

https://manuals.harborfreight.com/ma...0999/40211.pdf

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.

"Bob La Londe" wrote in message news
"Bob La Londe" wrote in message news
"Leon Fisk" wrote in message news
On Fri, 4 Aug 2017 10:50:21 -0700
"Bob La Londe" wrote:

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.

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

https://manuals.harborfreight.com/ma...0999/40211.pdf

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.

On Fri, 4 Aug 2017 12:52:20 -0700
"Bob La Londe" wrote:

snip
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?

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

"Leon Fisk" wrote in message news
On Fri, 4 Aug 2017 12:52:20 -0700
"Bob La Londe" wrote:

snip
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?
******************

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.

On Friday, August 4, 2017 at 1:04:17 PM UTC-4, Bob La Londe wrote:



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

wrote in message
...

On Friday, August 4, 2017 at 1:04:17 PM UTC-4, Bob La Londe wrote:



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.

On Fri, 4 Aug 2017 13:11:24 -0700
"Bob La Londe" wrote:

snip
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.

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

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

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

i

On Friday, August 4, 2017 at 10:50:27 AM UTC-7, Bob La Londe wrote:
"Bob La Londe" wrote in message news
I've got an inexpensive Harbor Freight refrigeration style air dryer. ... Thermal switch
tripped. I wound up with moisture throughout all my lines.


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.

The manual is online https://manuals.harborfreight.com/manuals/40000-40999/40211.pdf
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 https://youtu.be/sa4DkE7OBUM details one possibility, and
makes me think of using an ultrasonic cleaner...

On Fri, 4 Aug 2017 10:04:11 -0700, "Bob La Londe"
wrote:


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.


Is the suction line to the dryer's compressor sweating? IF so then
the dryer is working.

My thinking is that it is overwhelmed by the amount of moisture that
was introduced into the system.

Does your compressor have an automatic moisture drain valve? If not
the period of continuous running probably collected an amount of
liquid water in the tank. That would cause air saturated with water
to flow from the compressor.

You need to check out the compressor and then let the dryer recover.
Unless there is a check valve in the dryer outlet, the dryer is slowly
trying to dry the downstream air system too.

The auto-drain you mentioned, is that on the compressor or dryer. If
not on the dryer, then how does the dryer dispose of moisture? That
would be worth looking into to see if it's working.

Do you have a downstream valve on the air line? If so then I'd shut
it and let the dryer dry out itself and the line leading up to the
valve. If no valve, then cap the line.

Once water quits coming out of the dryer, arrange for a small flow
into the outbound system. Barely crack the valve or unscrew the cap
to let a little air leak. Does the outbound moisture separate stay
dry? If so, then the dryer was overloaded. If not then the dryer
will require looking into.

Once I got the cover off the dryer, my first step would be to feel the
compressor's inlet and outlet lines. The inlet line should be cool.
If the dryer is simply overloaded, the outlet line will be very hot.

Next, check to make sure the condenser is clear and the fan is
properly running. The line coming out of the condenser should be
warm, just above room temperature. If it is hot then the unit is
probably low on refrigerant.

Where to go after this depends on what you observe. Does the unit
have refrigeration access ports? Do you have a set of gauges? I
doubt that a hermetically sealed unit is low in refrigerant but it
happens sometimes.

Tell me what you observe, especially temperatures around the system,
and we'll go from there.

John
John DeArmond
http://www.neon-john.com
http://www.tnduction.com
Tellico Plains, Occupied TN
See website for email address

On Sunday, August 6, 2017 at 12:02:25 PM UTC-4, Neon John wrote:
On Fri, 4 Aug 2017 10:04:11 -0700, "Bob La Londe"
wrote:


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.


Is the suction line to the dryer's compressor sweating? IF so then
the dryer is working.

My thinking is that it is overwhelmed by the amount of moisture that
was introduced into the system.

Does your compressor have an automatic moisture drain valve? If not
the period of continuous running probably collected an amount of
liquid water in the tank. That would cause air saturated with water
to flow from the compressor.

You need to check out the compressor and then let the dryer recover.
Unless there is a check valve in the dryer outlet, the dryer is slowly
trying to dry the downstream air system too.

The auto-drain you mentioned, is that on the compressor or dryer. If
not on the dryer, then how does the dryer dispose of moisture? That
would be worth looking into to see if it's working.

Do you have a downstream valve on the air line? If so then I'd shut
it and let the dryer dry out itself and the line leading up to the
valve. If no valve, then cap the line.

Once water quits coming out of the dryer, arrange for a small flow
into the outbound system. Barely crack the valve or unscrew the cap
to let a little air leak. Does the outbound moisture separate stay
dry? If so, then the dryer was overloaded. If not then the dryer
will require looking into.

Once I got the cover off the dryer, my first step would be to feel the
compressor's inlet and outlet lines. The inlet line should be cool.
If the dryer is simply overloaded, the outlet line will be very hot.

Next, check to make sure the condenser is clear and the fan is
properly running. The line coming out of the condenser should be
warm, just above room temperature. If it is hot then the unit is
probably low on refrigerant.

Where to go after this depends on what you observe. Does the unit
have refrigeration access ports? Do you have a set of gauges? I
doubt that a hermetically sealed unit is low in refrigerant but it
happens sometimes.

Tell me what you observe, especially temperatures around the system,
and we'll go from there.

John
John DeArmond
http://www.neon-john.com
http://www.tnduction.com
Tellico Plains, Occupied TN
See website for email address

All good advice, but very time-consuming. If it were me, I'd do it this way:

1) check that the refrigeration is working - suction line cold, discharge line hot. If gauges are available and there's a place to hook them up, go for it.

2) drain existing water out of compressor tank and dryer and whatever water traps there are.

3) hook up a "big enough" tank of nitrogen, argon or whatever is handy to the compressor tank. Set gas regulator for 100 psi or so.

4) purge the entire system. Open valves all over the place, perhaps one or a few at a time.

5) Done.

Of course, if the air lines don't all slope back to the compressor, there could be water trapped at the low spots. In that case, the same procedure would apply, but you need to purge more aggressively. I have done this to blow standing oil out of refrigeration systems.

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.

On Tue, 8 Aug 2017 11:44:11 -0700
"Bob La Londe" wrote:

snip
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?

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

On Tue, 8 Aug 2017 11:44:11 -0700, "Bob La Londe"
wrote:

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.

Bob,

Let me make a suggestion based on industrial experience.

In places where clean, dry air is imperative, say a nuclear plant for
instance, the air system is divided up into two parts, instrument air
and BOP (balance of plant air).

The BOP air is dried with a freezing type refrigeration system. One
cannot get the dew point below 32 deg with a conventional refrigerated
dryer. The reason is that below 32 deg, the water freezes to the
evaporator.

The freezing type system has two evaporator dryers and hardware to
switch the flow from one dryer to the other and to defrost the frozen
one. The moisture is allowed to freeze in the active dryer.

When it's time to defrost, usually controlled by a timer, the air flow
and refrigerant flow are switched to the other column while the hot
gas from the refrigeration compressor is used to thaw the first one.

Since most of the plant is located in unconditioned spaces, here in
the South, a dewpoint target of 0 deg F is used.

The instrument air is dried with an alternating column desiccant
system. It takes its air feed from the BOP output. This system has
two columns and instrumentation to detect when a column is saturated
(dew point rises). The air flow is switched to the other column while
the wet one is regenerated by a flow of hot air. The dewpoint target
is typically -40 deg F.

To put this in perspective, between 4 and 6 100 hp compressors are
running, depending on demand.

What I suggest you do is separate your air system into two parts. One
part for BOP comes straight out of the refrigeration system. For your
dry air system, feed is taken from refrigerant dryer and fed into a
desiccant dryer. Preferably a two column unit with a hand valve to
switch between columns.

Typically the column will be clear and the silica gel will be of the
indicator type - blue when dry, pink when wet. You'd have to do a
manual regeneration of the wet column. The usual method is to spread
out the beads in a ceramic bowl and put the assembly in a microwave
oven. As the water is driven off, the beads turn blue again. Dry
silica gel just barely absorbs microwaves so the system is
self-limiting.

Or you could spend a bit more on a self-rejuvenating system such as

https://www.mcmaster.com/#compressed...ryers/=18v6phg

The advantage of this architecture is that air for such things as air
tools and blow guns will be adequately dried by the refrigeration
system while the few SCFM of dry air will be really clean and really
dry.

John

John DeArmond
http://www.neon-john.com
http://www.tnduction.com
Tellico Plains, Occupied TN
See website for email address