Water removal recommendations for Shoebox compressor?

[Taso1000]

Thanks Mike.  I was confused on the "a" sizing.  Hopefully the 4a I bought will work well enough.  I knew 3a was smaller than a water molecule so 13a should trap almost everything?

I think you'll get better moisture absorption if you keep the sieve filter valve closed and let the system build up pressure.  The sieve media works better at higher pressure.

Thanks,

Taso

[Taso1000]

Mike,

I forgot to add.  There's a member on here, guykuo, that knows a whole lot about drying air.  Maybe if you search through his posts he may mention super high pressure filter optimization.

I'm trying to see what can be removed on the low pressure side.   

Taso

[Buldawg76]

Taso
Yea I do exactly that and do not open the fill valve on the tanks before the sieve is at 3000 psi or above and fill a gun from the tanks now but since I just got the on/off valve today I can just shut the valve to trap the pressure in the sieve to fill a gun if needed in between tank filling.

My thoughts were the same with respect to the sizing of the sieve medium and the 13X I got is roughly a 1/16" in diameter round balls that are beige and light blue colors mixed together. It is previously used medium that was professionally dried and packaged in foil packs of 3 LBs for resale so that's why it was a bit cheaper I guess. I have the remainder in two canning jars with the vacuum seal lids so it is air tight for future use.

I hope the 4A medium you got does work well enough at removing the water from the air on the low side but I am afraid you will still find some water vapor when bleeding off the high pressure with out any high side sieve in the line. I would be interested in knowing what you find after filling a few tanks.

I have seen the post by guykuo here as well but most of what he says goes right over my head as far as the dew points and humidity are concerned other than I do know that the lower the dew point and humidity the better. I just judge the best performance by the amount of water vapor I see at bleed off after running the shoebox for several hours filling tanks. So far the high side sieve has given the best results with no water vapor seen at bleed off.

Mike

[RAJOD]

Man, I would save the money from buying all that stuff and buy another air rifle. 

I have a very early Shoebox, zero upgrades. I live in the always humid southeast. I have a little water separator at the inlet of my Shoebox, and haven't seen a drop of water in it in 5 years of use. I think the air moves slow enough through my 6 foot hose that it condenses in the hose and runs back to the compressor.

And for the Shoebox outlet at 4500psi, I just open the bleed while it's running once an hour, or every half hour. There is always a puff of condensation that comes out.

That being said, I've never seen any moisture at the end of my 30" whip hose coming out of the Shoebox. So I never could justify the cost and hassle of adding anything else.

All of my PCP airtubes have been apart for reseals or work over the years, and I've never seen any corrosion in the tubes.

If I were you, before I spent all the extra money on filters, driers, and all that, I would just hook the thing up and see how much moisture you get from the end of the line. You may decide you don't need any of it....

Just my opinion, and what works for me. 

I like this reply.   I think people are getting a bit too anal on this water issue.   

[Taso1000]

Rajod,

My concern is mostly of water sitting in my carbon fiber bottle.  This is where water will accumulate.  Water in contact with metal will cause corrosion.  Yes, there is a chance that it will get trapped in my fill whip from the Shoebox and not make it into the bottle.  But since scba bottle valves have a built in tube to keep water out of the firefighters breathing equipment water is not easily removed.  It would be cool to remove the tube so that you can turn a bottle upside down, crack the valve open, and get rid of this water.  The scba bottle water trap will also keep water droplets out of your guns.  What will happen though is that your 4500 psi air still has water vapor in it. 

What I haven't found a hard answer on is at what percent humidity will corrosion start.  And I mean water vapor, not visual droplets.

Mr. Sterne's post on the Shoebox forum gave me a lot to think about:

http://forum.shoeboxcompressor.com/forum/showthread.php?268-How-does-the-air-from-a-Shoebox-compared-to-a-hand-pump-for-moisture-content

Taso

[Buldawg76]

Rajod,

My concern is mostly of water sitting in my carbon fiber bottle.  This is where water will accumulate.  Water in contact with metal will cause corrosion.  Yes, there is a chance that it will get trapped in my fill whip from the Shoebox and not make it into the bottle.  But since scba bottle valves have a built in tube to keep water out of the firefighters breathing equipment water is not easily removed.  It would be cool to remove the tube so that you can turn a bottle upside down, crack the valve open, and get rid of this water.  The scba bottle water trap will also keep water droplets out of your guns.  What will happen though is that your 4500 psi air still has water vapor in it. 

What I haven't found a hard answer on is at what percent humidity will corrosion start.  And I mean water vapor, not visual droplets.

Mr. Sterne's post on the Shoebox forum gave me a lot to think about:

http://forum.shoeboxcompressor.com/forum/showthread.php?268-How-does-the-air-from-a-Shoebox-compared-to-a-hand-pump-for-moisture-content

Taso

Taso
I use a setup similar to what ScottC has in the link you posted for the Shoebox forum. I have a first stage compressor that is a 5 gallon 1/2 HP that I have plumbed into a 33 gallon tank used as a storage tank for the moisture to condense out of the air before it gest to the shoebox. The only difference is my first stage compressor can only develop 125 PSI but I let it sit after filling the storage tank before starting the shoebox and there is a drier before the shoebox with some of the 13X sieve medium in it to catch any moisture that is pulled out of the 33 gallon tank. I am drawing the air out of the 33 gallon tank from the top of the tank so hopefully there is very minimal moisture in the air ( I have never seen the drier medium get discolored at all) . It takes about an hour of running of the shoebox before the compressor turns back on so I just follow the same method as Scoot does by letting the first stage air cool before turning the shoebox back on when filling the big tanks I have.

Then I have the molecular sieve after the shoebox to trap any moisture that is squeezed out of the air by the shoebox compressing it to 3K-4.5K.

So far it has worked well but my only complaint is the time it takes to fill my 66 CF SCBA and 80 CF SCUBA tanks, it fills my 90 CI buddy tank in about an hour and half depending on how close to 3K  it is at the start of filling.

I think the added drying/filtering you have on your low side will work very well so just watch for water vapor when bleeding the pressure off to determine if you need any drier setup on the high side.

Mike

[Taso1000]

Mike,

Thanks.  The SMC drier is supposed to get me to a -4 degree F dewpoint.  The molecular sieve should get down to -100 degree F dewpoint.  I don't know offhand what that works out to in % humidity but it's got to be in single digits.  I think that is good enough for our purpose.

The SMC drier will do the heavy lifting so that the molecular sieve doesn't need to be recharged very often.

Taso

[Taso1000]

I just remembered. -100 was for drierite. I'm not sure what the molecular sieve dewpoint is.  But I know it has more absorption capacity.

Taso

[Buldawg76]

I know that I had just the drier in the low side up until two weeks ago I would get some water vapor when bleeding the pressure off at the tanks and is why I put the sieve in the high side and since it was installed I have seen no vapor at all when bleeding.

I know some of it had to make in into my tanks so they will be inspected at regular intervals to determine if any corrosion is taking place.

Mike

[Taso1000]

Mike,

Now I understand.  I didn't catch it last night and the norco's make me a little dense.  Please accept my apologies.

Taso

[Buldawg76]

Taso
No apologies needed as I have been there with the pain and the pills to help function thru the pain. I hope you are mending well and get back to the groove soon.

Mike

[Taso1000]

Mike,

Thank you.  Monday I will see orthopedic doctor to go over scans and get a plan of action together.  Hopefully I can dodge the surgery bullet. 

I wen't back and read your post on the hpa filter you bought.  You did good in isolating the sieve from the aluminum shell.  Even though the capacity is smaller than the cylinder I have, yours should outperform my low pressure drier cylinder.  The sieve works much better at hpa pressures.

You should have got the filter with the Star Trek transparent aluminum option so you can tell when it's time to recharge the media.   

Taso

[BountyHunter1976]

You should have got the filter with the Star Trek transparent aluminum option so you can tell when it's time to recharge the media.   

Taso

You got an interesting idea there. I wonder how thick the plexiglass would have to be to make a small round container to hold a desiccant in line on the high side for maybe 3500psi??  lol
On the other hand I don't guess they have finished deciphering that formula for the transparent aluminum yet or we would be able to buy it at home depot.    

[Taso1000]

Allan,

Member Guykuo had posted a link earlier in this thread to a high side moisture detector.  It looked like an aluminum cylinder with a round sight window.  I'm sure that would be clear Plexiglas in there.  I've never seen one in person but it could have easily been an inch thick.

Taso

[Buldawg76]

Mike,

Thank you.  Monday I will see orthopedic doctor to go over scans and get a plan of action together.  Hopefully I can dodge the surgery bullet. 

I wen't back and read your post on the hpa filter you bought.  You did good in isolating the sieve from the aluminum shell.  Even though the capacity is smaller than the cylinder I have, yours should outperform my low pressure drier cylinder.  The sieve works much better at hpa pressures.

You should have got the filter with the Star Trek transparent aluminum option so you can tell when it's time to recharge the media.   

Taso

Taso
I hope it all goes well at the doc and you can avoid surgery so your down time will be much less.

I went back and found the link that guykuo posted since I missed it the first read. I may get one in time depending on how fast the medium becomes saturated and plan to check it after a few filling sessions just to get a feel on how fast it becomes saturated. It would be nice to have a visual indicator that can be seen without opening the sieve up but its not difficult to unthread one cap and pull the paper filter out of the plastic tube to see if the medium is changed colors.

Thanks for pointing that out since I missed it but have it booked marked now for easy reference to order down the road.

Mike

[Taso1000]

Hi All,

I apologize for no new updates to my project.  Still not walking since heel surgery.  In 5 1/2 weeks I should be able to put weight on it and learn how to walk again!   

I've never been laid up before and I will need physical therapy.  I don't know how long that will take to get me back to normal.

But I promise, once back this project will be completed and hopefully have some real numbers to see effectiveness.

Thank you,

Taso

[Buldawg76]

Hey Taso

Sorry to hear your healing is going slower than expected and it seems to be taking longer than you would like it to. I have been in the same boat and therapy is usually 6 to 8 weeks with two to three times a week. It is a slow process indeed. Bones are very slow to heal and more so for weight bearing ones such as your heel bone. 

No worries about the thread as we will be here when you can resume your posts.

Mike

[Taso1000]

Thank you Mike.  I was so close to actually filling a tank for the first time and I was anxious to see the results.  The biggest find was the membrane moisture filter.  I did pick up a second one for cheap, an IDG5 versus the first IDG1. 

I think I'm going to use the tubular one as I originally planned and probably put the IDG5 up for sale.

We'll see.  I may change my mind by then.   

I did find out that it is recommended to have a filter after the molecular sieve and media dust can get into Shoebox and create wear issues?  I think .1 micron was recommended.  I'll have to check my notes again and see what Ebay has used.

Thanks,

Taso

[Buldawg76]

Taso
I would wait on selling one of the filters till you see if what you have in the system works as planned. I most certainly would have a filter of some sorts before the shoebox to catch any sieve dust that may develop from use but hopefully it will be very minimal at best with none at all being excellent. I believe 1 micron would be very good for sure.

That's why I have my sieve particles between two paper type filters that came with mine so it traps any that may migrate into my tanks or guns since mine is on the high pressure side.

Mike

[Taso1000]

Hi All,

I haven't done anything with this project lately besides a lot of reading and thinking.  I am planning to add a Diablo filter vertically with a pressure maintaining valve on the output at the top.  I will also be installing a pipe fitting trap and bleed to trap any liquid water from the high pressure side of the Shoebox right at the output.  I think this will be good enough to keep any liquid water from going up the Diablo filter feed hose at the bottom.

I will install a tee on the output of my Shoebox where the current foster fitting is.  The fitting trap will obviously point down and the output to the Diablo filter will point straight up.  I will have to either raise the Shoebox or cut a hole through what my Shoebox will sit on for the trap to pass through.  I hope that makes sense.

I have been looking but I haven't seen if there is a cartridge to hold the desiccant in the Diablo filter.  It looks like it is the same outside diameter but longer than Joe B's Alpha filter.  I have no idea if the internal diameter is the same.  I guess I could make a couple cartridges to swap out and recharge in the oven without bringing down the Shoebox. 

I was also curious if ball valves could be used on the high pressure side to keep moisture out when idle?  I have a couple on the low pressure side.  Another question is is it safe to leave the the system with 4500 psi till the next time I need it or is it just better to bleed down when done and then repressurize the system when a tank needs to be filled up?  I can see the safety in relieving all the pressure when not in use but maybe some remaining pressure would be beneficial?

Also I was cleared yesterday to start physical therapy!  Tomorrow I have the appointment to get evaluated and see what the course of action and timeline to walking and driving will be.   

Thank you,

Taso