Drive Gas Haskell Question

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Desiccant isn't that bad. The good stuff is reusable after baking in an oven. My filter is fairly small, about the size of a soda can. I can fill all 6 of my 3L rebreather bottles before needing to recharge the pellets.
 
If you're using desiccant as your only moisture mitigation, you're doing it wrong. The indicating desiccant I use is $28 for a 5lb jug. My dryer holds more than 4lbs. None of it has never turned from orange to green, and I've never changed it. At my usage rate (couple times a month) it will last forever and it's a cheap way to provide extra booster protection.
 
If you're using desiccant as your only moisture mitigation, you're doing it wrong. The indicating desiccant I use is $28 for a 5lb jug. My dryer holds more than 4lbs. None of it has never turned from orange to green, and I've never changed it. At my usage rate (couple times a month) it will last forever and it's a cheap way to provide extra booster protection.
Are you running a refrigerated dryer?

I can cycle a lot of desiccant pellets through my toaster oven for a lot less than the dryer costs. Not saying a refrigerated dryer is wrong, I would love to have one, but have not seen the need yet.
 
No. I think an expensive refrigerated drier is overkill for home booster use. I have two air tanks, 2 small water separators, and pretty long lines. The second tank in the chain does a pretty good job collecting most water. If I found that my desiccant was getting damp quickly, I would just add another tank (100lb propane tank upside down would work) or maybe something like this upstream:

Img_1517.jpg
 
My boosters all run from low pressure high volume compressors. You will need a fair amount of drying, whether it be mechanical or refrigerated. Using desiccant to remove the volume of moisture you need to pull with be costly and annoying.
I have a 10hp 120 gallon compressor with another 90 gallons of auxiliary storage and a lot of mechanical cooling that feeds my boosters. It works well and it keep us, but it is a long stretch from hooking a $300 home depot compressor up to the booster.

You have more space than I do.

I'm wondering a 20 gallon tank will work as that's probably the biggest I can fit.
 
Most 20 gallon tanks are paired to a fairly small compressor. What is the 90PSI SCFM rating of what you are looking for?

My guess is the compressor will be undersized, running 100% duty cycle (which hose little ones typically are not rated for). Only being 20 gallons the flow will be so fast there won't be any cooling and thus blowing wet air out.
 
The one I've seen is 4cfm at 90 psi
 
The one I've seen is 4cfm at 90 psi
That is about ¼ the size I run, and mine will run over 50% duty cycle. Never timed it, but it sure feels like it is running more than it isn't.

Side note, the 12V compressor I have in my van is rated at 3 SCFM @90 PSI.
 
You have more space than I do.

I'm wondering a 20 gallon tank will work as that's probably the biggest I can fit.
The tanks are all in different buildings and plumbed underground below the frost line. That is my primary means of mechanical separation. Air flows from the compressor in the garage near my house into the large primary tank with an auto drain. From there it runs 4' underground 150' to my shed and feeds into a 30 gallon tank with an auto drain. From there, it flows back 4' underground for 200ish' to my basement where it hits another 30 gallon tank with an auto drain. From there it flows up to an inverted AL80 with no diptube and a the normal tank valve. I can occasionally open that valve and confirm no moisture has made it to that point. From the top of that, it feeds into a regulator filter combo and into the boosters.
By the time the air hits the boosters, it has been underground and in three different accumulator tanks. Regardless of duty cycle, my input drive air is around 60F. Cheaper than running a refrigerated drier and I conveniently have air plumbed in every building with only one compressor to maintain. It produces about 30 cfm at 150 psi and keeps up with any and all of my boosters.
 

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