Well I do need a filter

[FuzzyGrub]

Bob,

I just use male/female compressor hose fittings.  When not in use, just wrap the input to the output.  I do that for the longer coiled hose with inlines, and the larger filters that are about 2' away from 1st stage compressor.   Just a thought.

[Taso1000]

My filter is a lot smaller than Alan's.... but way bigger than the two small inline filters I have now.... The flow rate is, like on Alan's, MANY times greater than what goes through a ShoeBox.... I am thinking I should install valves on both sides to isolate it from the air when not in use to prolong the life of the beads....

Bob

Or you can use a dead head.  I have a couple from hpa pumps.

Taso

[rsterne]

Output back to input with a rubber hose might work, I will keep that in mind when I do the installation, instead of using hard pipe.... If not, I had already thought of a deadhead on the input to my holding tank, where I usually hook up the compressor hose.... If I turn the crank on the shoebox vertical it shuts off the flow there.... just have to remember to do it after use.... Dessicant filter is supposed to arrive tomorrow....

Bob

[AlanMcD]

Bob,

I used a 1/4 turn ball valve on the input, and I rotate the Shoebox pistons to full compression on the output side for a shut off.  It is easy to remember to do that - I always vent the high pressure air out the hose with the Shoebox vent (never the tank fill line vent), and then rotate the crank to shut off the air flow that I continue to hear venting.  Then I close the vent and disconnect the tank hose.

Here is a picture of mine.  Since I have the Shoebox Max I regulate the pressure into the unit at 100 psi, and I also have a 0.1 micron filter in line after the desiccant filter to trap and silica dust.  You will notice that I also have a quick disconnect on a flex line into the Shoebox.  I did this so that I could easily use my dryer for other purposes besides the Shoebox, like for spray painting or anything, but I am yet to do so.  It stays with the unit on it's stand all the time.

[Doug Wall]

Taso-
The calculator that you linked in an early post, is for atmospheric pressure only. High pressure air is MUCH more corrosive, both to steel, and aluminum.

"Another point I'd like to add is that breathing air is required to have some humidity as to not dry out diver's air passages.  So I don't agree that the breathing standard humidity level is correct for air rifles or air cylinders.

SCUBA divers don't need moisture in the air. Breathing air is specified to be very dry, whether it's SCUBA, or SCBA.
https://airanalysis.com/Moisture_In_SCUBA___SCBA.html

[Taso1000]

Doug,

Thank you for the clarification on the humidity level on breathing air.  I misunderstood and thought there needed to be more humidity in the air for not drying out divers. 

You are correct on the first dew point calculator, that is only for atmosheric pressure.  But I mention it's the first and only one that has included a corrosion level.  I later link to another calculator that does take pressure into account but I'm not sure how to use it.

I just found this calculator: http://www.michell.com/us/calculator/ but I don't know what figures to enter for pressure. 

I agree that high pressure air is more corrosive than atmospheric.  What level of moisture does that final hpa need to be under to not promote corrosion?  I know that it has been discussed to remove all liquid water from 4500 psi.  So I posed the question do we still need to be concerned?  I think we do.  The air may still be at 100% relative humidity and may still cause corrosion.  Or not.  I don't know for sure.

Thank you,

Taso

[Taso1000]

So I was drinking my coffee and thinking lol.  So is it this last bit of water vapor at 4500 psi that the molecular sieve is supposed to target?

I do geek out with all of this and is possible I go a little overboard sometimes.  So I was hoping we could come to an effective frugal setup that will do what is required. 

I had included ideas from reading in my Shoebox drying thread but as I learned more about drying air the plan of attack has changed.   

Thanks,

Taso

[rsterne]

I got my new filter yesterday, and installed it today, with a ball valve on the inlet like Alan did, so by closing that and putting the ShoeBox on full compression the dessicant is isolated from the air in my shop.... The filter is smaller than I thought, I guess the dimensions (3' x 3" x 8") were for the box, the filter is only about 6" tall.... The bowl is only about 2" x 4", but still holds probably 10 times as many beads as the small inline filters, and it came with two (sealed) bags of dessicant (a fill and a spare).... Anyways, I'm sure it will last way more than 1 fill, which would turn the first inline filter I had pink and the second one about halfway, which didn't give me much confidence.... We'll see how long the new setup lasts between reconditioning the beads....

Bob

[rsterne]

I used my new dessicant filter for the first time today.... a 4 hour top-up of my 88CF SCBA tank.... The silica beads are all still bright blue, with no hint of pink anywhere.... I am DELIGHTED !!!

Bob

[chwillbill68]

I used my new dessicant filter for the first time today.... a 4 hour top-up of my 88CF SCBA tank.... The silica beads are all still bright blue, with no hint of pink anywhere.... I am DELIGHTED !!!

Bob

Cool I have mine set up but have not filled my tanks yet, still need to shoot some more to get them down to where I need to fill them.

[HuskyDude]

I got my new filter yesterday, and installed it today
Bob

Don't we get to see a picture? 

[rsterne]

Here you go....



The new filter has been used for two top-ups from <3000 to 4500 of an 88 CF SCBA tank.... and as you can see the beads are still bright blue.... The ShoeBox is a Freedom 8, mounted on the white plywood base, along with a 2 gallon air tank from a dead compressor.... The 125 psi regulated air from my 6 gallon Shop pancake comes in through a 25' coil hose (red) to allow it to cool, and then through an oil/water trap (which never has anything collect in it) into the blue 2 gallon tank.... From there it goes through an isolator valve (shown closed) to the new Silica Gel dehydrator, and from there via a flex hose to the inlet of the ShoeBox.... The vertical piece of 2x2 is screwed to the corner of the white plywood and supports the output end of the filter to prevent vibration and/or damage from bumping it.... To isolate the beads between uses, I shut off the valve on the inlet side of the dehydrator, and turn the output crank of the ShoeBox to full compression (as shown).... Alternately, I can remove the flex hose from the ShoeBox inlet and wrap it around to the QD fitting on the oil trap.... I think isolating the beads from the air in my shop greatly increases the time that will be needed between reconditioning the Silica Gel.... I will do that by baking for 30 min. in a toaster over an 250*F.... I am keeping track of how many hours I can run the ShoeBox before having to do that.... With my previous setup (2 small inline dryers) I had to bake the beads before every use....

Bob

[Nvreloader]

Bob
Thank you for the photo's/info along with the others that posted photo's on their dryer/filter set up's,
I can now see what everything is and get an Idea on how to follow in your/everyones foot steps etc.

Would a larger Wilkerson filter be or provide better protection?
There is 2 different sizes.
I have found some Wilkerson's that are 12-13" tall, kinda expensive thou.

Thank you
Don

[rsterne]

It doesn't matter how big the filter is, provided you can get a few fills before it starts to turn pink, IMO.... The filter I now have has many times the CFM capacity that the ShoeBox uses (my Freedom 8 is about 8-9 CF/hr., so about 0.15 CFM), so a filter with a 15 CFM flow rate is 100 times what you need.... The bigger the filter, the longer the air takes to move through it, but past a given time, I really doubt that makes it any drier.... The size filter I have probably takes about a minute for the air to move through it.... I have no idea (yet) how many fills I can get before I see any pink....

I previously had two small inline filters that held only about a tablespoon of beads each.... and the first one would be pink, and part of the second one (how much depended on the humidity at the time) during a refill of my 88 CF SCBA tank from 2800-4500 psi (which takes about 4 hrs.).... I had to bake the beads before each time I used the ShoeBox.... I have two of those fills on the new filter, and no sign of any beads changing colour yet....

Bob

[HuskyDude]

Thx Bob for the pic. Looking Good !

You say that after 4 hrs of running the beads never showed any signs of color change...is that a good thing? At what point do you think they will start turning. After 4 hrs a slight color change would be a good thing. No ?? Does that filter flow bottom up?
I see all filtering is done on the low side...Do you have filtering down stream of the ShoeBox?
Geez..Sorry for all the question...Trying to piece things together myself.

[rsterne]

Actually about 8 hours, and while the beads may be a slightly lighter blue, there is definitely no pink.... AlanMcD has a much larger filter (1.75 lbs. of beads) and after 145 hrs. his beads were a lighter blue than after he baked them.... I have no filtering downstream of the ShoeBox, the volume of the filter would take a lot of air to fill at 4500 psi, plus the filter has to be built for that, of course.... I believe the flow is bottom up, I'll check when I eventually pull it apart.... The flow direction on the inlet and outlet is marked on the housing with triangles cast right in....

Alan has a link to his filter on the previous page, and if I read it correctly, it can remove the water from 4,400 CF of air.... about 50 complete 88CF fills or 150 top-ups.... Mine is much smaller, but huge compared to the two inlines I had before....

Bob