Water removal recommendations for Shoebox compressor?

[RobertMcC]

I almost forgot!  I need to put prices on what everything cost.  This is the scary part no one likes to mention.  The hidden costs.   

The upgraded Shoebox Max, the desiccant canister, 4 big sealed desiccant bags of silica gel and drierite, accessories, rebuild parts, one coiled hose and some small capacity Campbell Hausfeld filter group, that I didn't use, for $600 including shipping.

I got the membrane drier for $80.  The CAT compressor was $169.  All the filters, regulators and brackets were $452.  The brass fittings and yellow hoses were $83.  I didn't use all the brass fittings and I skipped the oil cooler so I didn't use it's associated fittings. 

The Alpha filter was $200.  The hpa fittings and moisture indicator were around $120. 

So the grand total is $1704 if my math is right. 

I could eliminate the first regulator, two filters following and the next regulator and save about $200 but may have to change the remaining micro filter cartridge more often.  I could have used my loud, old Craftsman 4.5 horsepower compressor and saved another $169.  If I find the canister filter isn't doing anything I can sell that off for about $50 and not need the last $100 particle filter.  I could probably sell the Campbell Hausfeld filters and hose for $30 - $40.

So the bare bones setup would have cost me around $549 less for a rough total of $1155.

That's around the cost of what a new F10 was selling for a couple months ago without shipping and it still needed water removal. 

A Carette compressor with the Alpha filter is $1699 plus shipping plus a surcharge if you use a credit card, so I have heard, from the exclusive U.S. seller. 

The Altaros is about $739 now.  It needs a huge compressor and water removal.

The $300 Yong Heng compressors are definitely cheaper but they need water removal as they have no water removal.  But they're not even in the running as they cannot top off a scba cylinder to 4500 psi without destroying themselves. 

I don't know anything about the Omega compressors. 

So I am hoping we can compare and contrast the current solutions in price and performance.  My setup is not fast but that was never a priority with me.  I solved that by getting two 30 minute scba tanks that cost me less than $200.  I can shoot off one while the other tops off. 

I was trying for a budget setup with efficient and cheap water removal.  The membrane drier will last for 10 years of continuous use as long as you keep it from getting contaminated with dust and oil.  It doesn't need to be regenerated and it doesn't need electricity.  And it only cost me $80.     But to be honest I did wait for a good deal on it on ebay the same way I got one filter and one regulator used to save money.

Compressing air is not cheap.  lol

Thanks,

Taso

WOW... I was going to ask how much it costs..

I'm at only 400 CAD for my shoebox, 25$ for my compressor, about 110$ in hoses, filters, descant, fittings. Knew I wasn't going to get 100% dry air. But its dryish.

[rnabholz]

Wow Taso, that did add up.

Here's mine.

Shoebox Max  $500
CAT 1hp 5gal compressor  $160
Gold filter  $90
13a Media, PVC and O rings  $20
Motor Guard M30 with 2 filters  $70
Low side hoses  $20
Low side fittings  $15

Total  $875

I could probably have saved $100 by going with a cheaper feed compressor, but the quiet operation of the Cat is a pleasure.

The low side M30 filter is very effective on moisture, oil and particles to one micron, and on the high side,  the Gold filter with the 13a molecular sieve hack is working very well too.

If you are filling guns, the Shoebox may seem slow, but as you mentioned, I have been able to pick up a couple of 44cf scba bottles, both with 2 or 3 years left on them for less than $100 total, so I always have air ready to go. I always shoot at a range, with no power to run a compressor, so a fill on site was never an option for me.

Offered as one more approach and data point for the discussion.

Thanks

Rod

[AlanMcD]

I think that is a great data point Rod. With all due respect to Taso's great set up, I have always maintained that we need to dry the air that we use whether it goes into a tank or directly into a gun.  That drying step can be either before or after the Shoebox, but needs to be done correctly with an appropriately sized dryer for the task.  We do not need to do it in both places - or in other words, if we dry the air adequately going into the Shoebox (aka remove the water vapor to a level that it won't condense when compressed), it won't pick up more water vapor as it goes through the system.

I think we can set up a good drying and filtering system going into the Shoebox for around $200 or a bit less.  Then the only other costs are the Shoebox itself and a shop compressor.  I already had my own shop compressor, and I will say that once you have one and get used to all the great things you can do with shop air you will always want to have one (even if you sell off the Shoebox and buy an all-in-one compressor).  I really don't consider it part of the costs, any more than I do the tools that I used to assemble my filter system, as I use it for so much else.

So in my view the real costs are $200 or so plus what you pay for the Shoebox.  When I bought mine it was over $700 for the Max, and now it is $500 for the Freedom 10.  So $700 plus some kind of oil free shop compressor will get you up and running.

[Taso1000]

Rod,

Yeah, I did geek out a bit.  lol  The two things that I think need to be tested better is the low pressure water removal and the high pressure pmv wringing out the water.

It had been suggested that the low side drying would not accomplish much.  But I think that was with the assumption that getting the dew point down to -4°F was not possible.  The membrane dryer accomplishes that.  Right now there is one used IDG1 membrane dryer for $57 on Ebay.  An AMH150C prefilter and AR20 regulator can be had for $135 new on Ebay.  That would be the minimum to protect the membrane drier and create the required backpressure for the purge air.  Any regulator would work so it doesn't have to be an AR20.

To test I could try running the CAT compressor directly to the Shoebox and see if there is water being collected in the outlet drip leg/trap, due to the pmv, the next time I have to top off a cylinder due to the pmv.  I also have the indicating disk before the Alpha so that would give me a reading of moisture too.

The Alpha/molecular sieve is not intended for bulk water removal as it has very little capacity.  It will remove some but not all of any remaining moisture.  I checked the cartridge in the Alpha after me my two top off's and the indicating strip is still blue.  The cartridge was used and open to atmosphere for about a year so It's got to be close to capacity.

I was looking for a replacement cartridge/guinea pig to use as a refillable cartridge.  Nuvair has a molecular sieve only cartridge for $32.  I was wrong about the stainless steel cartridge.  It's ~$201, not $100 like I thought.  I'm gonna try to use what I have.   

Thanks!

Taso

[rnabholz]

I think that is a great data point Rod. With all due respect to Taso's great set up, I have always maintained that we need to dry the air that we use whether it goes into a tank or directly into a gun.  That drying step can be either before or after the Shoebox, but needs to be done correctly with an appropriately sized dryer for the task.  We do not need to do it in both places - or in other words, if we dry the air adequately going into the Shoebox (aka remove the water vapor to a level that it won't condense when compressed), it won't pick up more water vapor as it goes through the system.

I think we can set up a good drying and filtering system going into the Shoebox for around $200 or a bit less.  Then the only other costs are the Shoebox itself and a shop compressor.  I already had my own shop compressor, and I will say that once you have one and get used to all the great things you can do with shop air you will always want to have one (even if you sell off the Shoebox and buy an all-in-one compressor).  I really don't consider it part of the costs, any more than I do the tools that I used to assemble my filter system, as I use it for so much else.

So in my view the real costs are $200 or so plus what you pay for the Shoebox.  When I bought mine it was over $700 for the Max, and now it is $500 for the Freedom 10.  So $700 plus some kind of oil free shop compressor will get you up and running.

[/quote]

Thanks Alan.

I took the approach of someone reading this today, trying to get the complete picture of the costs. 

You are absolutely correct on the usefulness of a shop air compressor.  You caused me to remember that anyone who would buy a Freedom 10 would ideally have a shop compressor that would provide a steady 125psi.  The one I have won't do that, but there are plenty out there that will, and probably at about the price I paid for the CAT if you can live with a bit more noise.

Your comment about attacking moisture on the low side is a good one - a lot cheaper to do it there as well.

I have seen results from the Gold Filter with molecular sieve, it has definitely collected moisture, but I do agree that it is a relatively small amount, and its capacity is very small, so it won't solve a moisture problem that was not addressed on the low side.  I recharged the media after about 12 hours run time, and Taso did the math that indicated it was at about half its capacity.  I took that to mean that the low side M30 filter was working pretty well.

At around $800 all set up, the Shoebox is still in the game.

[Taso1000]

I wholeheartedly recommend the Shoebox and would buy one again.  If something were to happen to my Shoebox I know parts are available.  Rebuild kits are $35.  I don't think you can kill a Shoebox.   

If my Shoebox were unrepairable I would buy another Max or an F8 or an F10 and figure out how to slow it down and make sure it can run safely at less than 125 psi. 

Taso

[rnabholz]

Rod,

Yeah, I did geek out a bit.  lol  The two things that I think need to be tested better is the low pressure water removal and the high pressure pmv wringing out the water.

It had been suggested that the low side drying would not accomplish much.  But I think that was with the assumption that getting the dew point down to -4°F was not possible.  The membrane dryer accomplishes that.  Right now there is one used IDG1 membrane dryer for $57 on Ebay.  An AMH150C prefilter and AR20 regulator can be had for $135 new on Ebay.  That would be the minimum to protect the membrane drier and create the required backpressure for the purge air.  Any regulator would work so it doesn't have to be an AR20.

To test I could try running the CAT compressor directly to the Shoebox and see if there is water being collected in the outlet drip leg/trap, due to the pmv, the next time I have to top off a cylinder due to the pmv.  I also have the indicating disk before the Alpha so that would give me a reading of moisture too.

The Alpha/molecular sieve is not intended for bulk water removal as it has very little capacity.  It will remove some but not all of any remaining moisture.  I checked the cartridge in the Alpha after me my two top off's and the indicating strip is still blue.  The cartridge was used and open to atmosphere for about a year so It's got to be close to capacity.

I was looking for a replacement cartridge/guinea pig to use as a refillable cartridge.  Nuvair has a molecular sieve only cartridge for $32.  I was wrong about the stainless steel cartridge.  It's ~$201, not $100 like I thought.  I'm gonna try to use what I have.   

Thanks!

Taso

Well, if a guy can't geek out on his hobbies, where can he?

If you are still inclined to experiment, I am sure I am not alone in my interest in reading about the results.

But don't forget to get out a shoot some of that air, the compressor stuff is fun, but not as much as shooting.

Thanks for sharing all your efforts.

Rod

[Taso1000]

Well, if a guy can't geek out on his hobbies, where can he?

If you are still inclined to experiment, I am sure I am not alone in my interest in reading about the results.

But don't forget to get out a shoot some of that air, the compressor stuff is fun, but not as much as shooting.

Thanks for sharing all your efforts.

Rod

Rod,

I agree on all counts!     I really should shoot more.  But I also love researching and testing.  I will find how to balance both some day.   

Thank you!

Taso

[RobertMcC]

I just finished my low pressure air filter/dryer system. Waiting on my high pressure filter. I got a hose that goes from the intake to higher up. Not installed,  And I run a dehumidifier in that room.

10 micron to 5 micron, than a desiccant filter, to another as a ref window. If I see that turning pink, than I know it time to dry out the bigger one I made. Which is just 12x2" pipe with some filter floss to keep in the silica gel litter I filled it with.

If I want shop air for a air blower. I just disconnect it from the bottom of the big desiccant filter.

[chwillbill68]

Well, I am filling my 45 min SCBA tank now. It was down to about 3600 psi. When I first started I had all kinds of leaks.  At this point I ended up removing everything on the pressure side except the single hose with the small Chinese filter. I did have a small ninja gauge after the filter and before the tank. But it popped off twice from it’s female side. It must be defective. Will see if ninga will take it and send me another. So I sat there and watched the the tank and of course the gauge on it showed 4500 and the shoebox ran for a while, but did shut off on its own. The air compressor would scare the &^^& out of me every time it kicked on.  Will need to mess with the fittings on my gold filter to get them to stop leaking. The small filter did catch stuff on it, but was clean on output side. Did not fill wet but want more filtering for future fills. I took a pic of the setup but it’s too big so I will see if I can shrink it and add it later.

Thanks Bill C!

[chwillbill68]

Ok here is a pic of my setup. The small black filter is to hook into the bottom of the gold filter. But I had some small leaks down there and will need to fix them.

[aceflier]

I ran a 100ft hose through conduit from my garage to my basement for my Altaros. I have 3 water traps. 1 at the compressor and 1 as it comes in the basement. The first one doesn't collect anything (to close). The second does quite a bit and the third just barely anything. Then there is a dessicant filter before it enters the Altaros. The Altaros has its own water trap and dessicant. I do have to stop every 2 hours and change the dessicant in the first one. I just got done filling a 4500 60min tank from 0psi and the beads in the Ataros did not change color one bit. So I'm assuming its doing a good enough job with this setup?

[chwillbill68]

I ran a 100ft hose through conduit from my garage to my basement for my Altaros. I have 3 water traps. 1 at the compressor and 1 as it comes in the basement. The first one doesn't collect anything (to close). The second does quite a bit and the third just barely anything. Then there is a dessicant filter before it enters the Altaros. The Altaros has its own water trap and dessicant. I do have to stop every 2 hours and change the dessicant in the first one. I just got done filling a 4500 60min tank from 0psi and the beads in the Ataros did not change color one bit. So I'm assuming its doing a good enough job with this setup?

That seams great!  How long do that set-up take you to fill a 60 min tank?

[Back_Roads]

You mentioned your ninja gauge was popping apart , I see you have some of the brass foster fittings, and they do not play well with the silver ones.

[chwillbill68]

You mentioned your ninja gauge was popping apart , I see you have some of the brass foster fittings, and they do not play well with the silver ones.

It was a silver foster fitting, so I assume steel.  But it's not a ninga it's an air venturi inline gauge.  I was just looking at it so I could write them and noticed I had the wrong company. LOL

[aceflier]

I ran a 100ft hose through conduit from my garage to my basement for my Altaros. I have 3 water traps. 1 at the compressor and 1 as it comes in the basement. The first one doesn't collect anything (to close). The second does quite a bit and the third just barely anything. Then there is a dessicant filter before it enters the Altaros. The Altaros has its own water trap and dessicant. I do have to stop every 2 hours and change the dessicant in the first one. I just got done filling a 4500 60min tank from 0psi and the beads in the Ataros did not change color one bit. So I'm assuming its doing a good enough job with this setup?

That seams great!  How long do that set-up take you to fill a 60 min tank?

Right around 7 hours from 0 to 4500. My compressor is around 6.4 cfm at 90psi. I turn it up to 120psi and use the altaros's adjuster for 60% on 40% off recommended settings. The shop compressor refills its 30gal tank at 90psi. It takes around 2 hours from 3000 to 4500 top offs.

[Taso1000]

Hi All,

My setup is evolving again because I have learned more facts about water removal.  I have decided to add another pressure maintaining valve with a 3000 psi setpoint before my Alpha filter to squeeze out more moisture before it reaches the molecular sieve.

Two other things I learned: one is that silica gel works best at higher humidity levels and ineffective at low humidity levels.  I'll attach a chart.  The second is that molecular sieve works best at 1590 psi and above.  So in my setup the desiccant canister doesn't offer any benefits placed after my membrane drier so I will be removing and the particle filter from my loop.

That would explain the silica gel not changing color after filling two 30 minute scba cylinders to 4500 psi.  I actually thought the silica gel looked bluer but figured it was my imagination!   

I will post pics of the new setup and hopefully have some water to show for my efforts.  It should be easier now that summer is coming. the next time I fill a cylinder.

Thank you!

Taso

[FuzzyGrub]

Do you have a graph for the molecular sieve compared to pressure?   I've contemplated a pmv a few times, but haven't convinced myself it is needed.   99% of the time, I'm refilling a tank, not starting from zero.  As soon as the valve is cracked open it goes to well above the 1590psi.   Very seldom would I take the tank down to lower than 2500psi, since all my pcps are 3k.  So, it would be just the unpressurized air that was in the microbore hose that would not see the full effect of the filtering.  Am I missing something?

[Taso1000]

Hi John,

I got the 1590 psi pressure from a link Guykuo provided in the first page of this thread:  https://www.gatewaytoairguns.org/GTA/index.php?topic=120428.msg1167974#msg1167974  I will see if I can find reference to the number when I get a chance later as I have to get to an appointment soon.  I wanted to give you a quick reply.

The pmv is pre treating the air and practically guaranteeing that there is no liquid water going further down the system.  My Shoebox starts at zero pressure and takes about 45 minutes to fill the Alpha and fill adapter to 4500 psi.  So all this startup air needs to be dried.  So does the following air.

If I understand you correctly, I think you are saying that the remaining pressure in your cylinder will flow backwards and pressurize the entire system once you open the cylinder valve.  Correct?

I don't think my first pmv would allow backflow through the Alpha filter.  I did mention you could probably mimic a pmv by pressurizing the system first before you opened the cylinder valve and as long as the equilibrium pressure doesn't fall below 1590 psi.  But you will also could potentially be moving liquid water back through the system too.  Liquid water produces a lot of heat when it contacts molecular sieve.  That could create an over pressure condition in the system when the compressed air is made to expand.  Like I said, I am just learning this stuff so I don't know if there is a flaw in these theories. 

The point being is that for $80 pmv and a pipe fitting water trap before the molecular sieve will extend its life versus not pre treating the air.  The pmv set at 3000 psi will bring the ambient pressure humidity to .5%.  That's from an article I have attached in my pmv thread here: https://www.gatewaytoairguns.org/GTA/index.php?topic=142737.msg1444769#msg1444769

Like I said, I'm trying ideas out to see if they benefit or don't. 

Thank you,

Taso

[FuzzyGrub]

Hi Taso,

Sorry I didn't respond quicker.  Did a 3 day weekend for spring fishing.     

I understand what you are trying to do with the second 3K pmv.  My comment is about the alpha filter with pmv.  or any filter followed by a pmv on the output of the SB.  When I was looking at the pmv, my goal was to keep the filter pressurized so didn't loose time at every fill.  That would work on a SB if the check-valve on HP cyl didn't leak down over time.  I was looking to put a shut-off on the input to the filter. 

If the media effectiveness is the only issue, and does not perform well/great under 1590psi, then back filling with the already filtered air in the tank, should minimize that concern.  The only air that didn't get filtered is what was in the output microbore hose.  That can also be further minimized by plugging the hose right after it is removed from the tank, so room air will not migrate into it. 

Anyway, it was my rational to not add even more plumbing and expense to my SB set-up.