# Hmmmm. I wonder if this is a good idea???



## Rbeckett (Dec 17, 2013)

I just found a concentrator/ filler for filling oxygen tanks for a hundred bucks.  I wonder what else I would need to get good clean O2 that is suitable for welding from this rig.  It is a Divelbis (SPELLING?) machine and that's about all I know at this point.  Think it is worth a hundred bucks or should I low ball it to see how cheap I can get it to go. If it will fill Oxygen tanks It would pay for itself in about 4 or 5 fills, especially since I own my tanks anyway.  I think I am gonna give it a serious look anyway...

Bob


----------



## John Hasler (Dec 17, 2013)

Rbeckett said:


> I just found a concentrator/ filler for filling oxygen tanks for a hundred bucks.  I wonder what else I would need to get good clean O2 that is suitable for welding from this rig.  It is a Divelbis (SPELLING?) machine and that's about all I know at this point.  Think it is worth a hundred bucks or should I low ball it to see how cheap I can get it to go. If it will fill Oxygen tanks It would pay for itself in about 4 or 5 fills, especially since I own my tanks anyway.  I think I am gonna give it a serious look anyway...  Bob


 http://en.wikipedia.org/wiki/Oxygen_concentrator http://www.devilbisshealthcare.com/products/oxygen-therapy/stationary-oxygen             You won't do much welding at 5L/min and you need a suitable compressor (an air compressor won't do) to fill bottles.  I'd still buy it though, given the opportunity and the money.  Note that it produces (impure) nitrogen as well as oxygen.


----------



## Tony Wells (Dec 17, 2013)

Medical oxygen from one of those breathing generators is not as pure as what you get for welding. 

It is made by a process whereby the N is removed from atmospheric are, which contains ~78% N, so unless you
can remove much of the other gases, your Oxygen level tops out only after that is removed, which can be done 
fairly efficiently, but there are other gases, plus water vapor involved. Usual rating is around 93% concentration.


----------



## Rbeckett (Dec 17, 2013)

According to the fellow who is selling it for his dad it will fill a bottle to 3000 PSI, so it is not a medical concentrator like the one I am currently hooked to.  It is a high pressure compressor that compresses the gas to the point of liquefying it like our missile air on the missile system I worked on in the army.  I'm going to look at it and see what it actually will do in the next couple of days or so and I'll report back what I find out. If nothing else and it is a medical gas machine like I have I may go ahead and get it to hardwire in the shop so I will have one that can get dirty if necessary.  That would be OK too.  That way if I touch it with dirty hands I don't have to clean it all up to go somewhere like the Dr or clinic.


Bob


----------



## John Hasler (Dec 17, 2013)

Rbeckett said:


> According to the fellow who is selling it for his dad it will fill a bottle to 3000 PSI, so it is not a medical concentrator like the one I am currently hooked to.  It is a high pressure compressor that compresses the gas to the point of liquefying it like our missile air on the missile system I worked on in the army.


  In that case go over there right now and buy it.


----------



## xalky (Dec 17, 2013)

John Hasler said:


> In that case go over there right now and buy it.


Yeah...what he said.


----------



## GLCarlson (Dec 20, 2013)

For what it's worth, the original question is a really good one.

Remember that liquid oxygen is kinda exciting to have around. High pressure oxygen is dangerous two ways: pressure, and because it's very reactive. Liquid oxygen takes that to serious extremes.  There's also the issue of being sure your gas bottles are safe (hydrotested on schedule) and -depending on how this gadget works, not overfilled.

With all due regard to the competence, caution, maturity, and expertise of everyone here, this may be a good time to remember that there are tempting opportunities that on reflection are better avoided.


----------



## kevinpg (Dec 20, 2013)

Finally, an area where I have some experience!

first, the O[SUB]2 [/SUB]concentrator uses a nitrogen dessicant that traps the nitrogen under pressure. Oxygen and trace gasses are delivered through the cannula. and there is a continuous compress and exhaust of the N[SUB]2[/SUB]. they are not as effective at altitudes ( at least they were not when I was a therapist.)

as noted previously, the liter per minute output would be inadequate for most torches. also, as the demand increases, the purity generally decreases.  it can be a large or small difference.

the biggest problem is how you would then trap a sufficient volume and then compress that to be usable with a standard industrial O[SUB]2[/SUB] gauge?  I think it would be impractical.

now for the largest issue, how many hours on the meter? if over 50K, the dessicant canisters likely need replacement.  that would destroy the good buy.  I suspect this is the case as a crappy used one is worth 250 to any low rent nursing home.

my 2 cents
kevin
y

- - - Updated - - -



Rbeckett said:


> According to the fellow who is selling it for his dad it will fill a bottle to 3000 PSI, so it is not a medical concentrator like the one I am currently hooked to.  It is a high pressure compressor that compresses the gas to the point of liquefying it like our missile air on the missile system I worked on in the army.  I'm going to look at it and see what it actually will do in the next couple of days or so and I'll report back what I find out. If nothing else and it is a medical gas machine like I have I may go ahead and get it to hardwire in the shop so I will have one that can get dirty if necessary.  That would be OK too.  That way if I touch it with dirty hands I don't have to clean it all up to go somewhere like the Dr or clinic.
> 
> 
> Bob



I would love to see a photo of that! I have rarely seen a H cylinder filled beyond 2200psi, 3000 would potentially be exciting.  I know they are tested around that on recert. if you did not have a safe way protect yourself form the potential energy conversion, I would be nervous.  

If it is as the son says, it is a fractional distillation concentrator, but I bet it is a compressor for filling Large O[SUB]2 [/SUB]bottles from a liquid o[SUB]2[/SUB] source and expansion tank. very cool. take care to wear gloves and not even let oil from your hands get on the unit.


----------



## Rbeckett (Dec 20, 2013)

Havent been able to arrange a meeting to see the machine yet.  Still unable to really quantify what he is really selling.  Once I get a look at it I'll post back.  If it does really fill cyliders then it will work for me, otherwise I already have an O2 concentrator so the price will have to be way cheap for me to be interested in another.

Bob


----------



## aliva (Dec 21, 2013)

If your ever in Northern Ontario Canada my employer has a an O2 plant that produces around 5,000 tosn of liquid O2 per day, I'm sure I could sneak out a few pounds of liquid
.LOL


----------



## Terrywerm (Dec 21, 2013)

aliva said:


> If your ever in Northern Ontario Canada my employer has a an O2 plant that produces around 5,000 tosn of liquid O2 per day, I'm sure I could sneak out a few pounds of liquid
> .LOL



Ya, in your coffee thermos, right??  :rofl:


----------



## Pmedic828 (Dec 22, 2013)

Just for information - The Oxygen you breath in in the air is about 21%.  A concentrator used for a nasal cannula will generate around 44% Oxygen.  The only way to get 100% Oxygen is to purchase Medical Grade Oxygen.  This is considered a "Drug" and you have to be an EMT or Physician to obtain it.  I myself, work for a local Fire Department that fills their own Oxygen.  They purchase "M" or "G" size cylinders and refill the small bottles thru a cascade system.  If you have never filled a bottle such as a SCBA, remember that when pressurizing a cylinder, it gets mighty hot!  You have to cool the bottle in cold water, and have an explosion proof container to place it in while refilling.  
Hope this information helps -


----------



## GLCarlson (Dec 23, 2013)

Pmedic828 said:


> Just for information - The Oxygen you breath in in the air is about 21%.  A concentrator used for a nasal cannula will generate around 44% Oxygen.  The only way to get 100% Oxygen is to purchase Medical Grade Oxygen.  This is considered a "Drug" and you have to be an EMT or Physician to obtain it.  I myself, work for a local Fire Department that fills their own Oxygen.  They purchase "M" or "G" size cylinders and refill the small bottles thru a cascade system.  If you have never filled a bottle such as a SCBA, remember that when pressurizing a cylinder, it gets mighty hot!  You have to cool the bottle in cold water, and have an explosion proof container to place it in while refilling.
> Hope this information helps -



The only way to get 100% oxygen is to buy medical grade? Funny, my local gas supplier never asks about my medical qualifications when I buy a bottle of oxygen for my torch. We can dance all around purity and various grades, but there's really no difference between a bottle of industrial oxygen and a bottle of medical (USP or NF) oxygen except the paperwork. The contents are likely from the same bulk container of liquid oxygen, and will be >99% O2, with a trace of N2 as the primary contaminant.


----------



## psychodelicdan (Dec 27, 2013)

Used to work at a production plant that burnt a lot of steel parts. We got our liquid O2 tanks filled from a bulk truck. The driver told me a number of times that we his stop after filling the tank at the hospital down the road from us. He said "Yep,same stuff we just charge them more"


Master of unfinished projects


----------



## Rbeckett (Dec 27, 2013)

Never could get a response from the owner and the advert is gone, so I assume he sold it already.  Oh well, I tend to believe it was what I already have for that low of a price...

Bob


----------

