New score boast

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New score boast

Postby Doug Coulter » Thu Aug 18, 2011 4:49 pm

Well, and I have nothing to boast about, Bill's been at it again. He found a guy who refurbs oxy generators which purify it out of shop air. This one is good to 5l/m at about 5 psi. Shown here, it's running my little oxy-propane glass blowing torch wide open which takes about 1.5 l/m - it's loafing doing this. It might run an oxy-acetylene torch if it was a very small tip. Anyone who wants one of these (price seems pretty reasonable) and is willing to pick it up here or at HEAS should contact Bill Fain -- he's not making the drive to pick up more unless they're spoken for.
OxyPure.jpg
Refurbed oxygen generator. Score!

If I can find a regulator to fit a "normal" propane or mapp gas cylinder, it would fit into this unit and be a "forever" torch. I suspect the 20lb propane tank I have on it now would run it for about a millennium. I also bet this combo would work great off hydrogen, I'll try it. I've always wondered if the flame would really be invisible...since we have a little excess pure H2, this is my chance to find out. I already know that H2 from electrolysis carries enough junk in it to be very visible, but then that's not 6 9's pure.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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Re: New score boast

Postby Jerry » Thu Aug 18, 2011 11:48 pm

Those units are very popular with glass blowers. They will take several and put them in parallel. Saves a lot on O2

H2 does not burn completely invisible. You can still see a cone. But do watch out, there is a lot of UV coming off the flame.
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Re: New score boast

Postby Doug Coulter » Fri Aug 19, 2011 10:19 am

Right -- I hate it when I sunburn the whites of my eyes. I'd probably only burn H if I was doing quartz, and that's so doggone bright I use welding goggles for it anyway. I have the special sodium line blocking glasses for pyrex -- don't know if they block UV, but I don't burn H for mere pyrex when propane is plenty.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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Re: New score boast

Postby JonathanH13 » Sat Aug 20, 2011 4:33 am

Hmmm, I would love one of these! Getting it the UK is probably not worth the trouble though. Do we know what it weighs?
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Re: New score boast

Postby Bill Fain » Sat Aug 20, 2011 1:06 pm

Hi, It probably weighs 35 to 40 pounds. These are regulated in the US by the FDA. You can occasionally find these at thrift shops when an heir donates one. Don't know about the UK. Like Jerry says a lot of glassblowers use them for a cheap source of oxygen. I actually found out about these at HEAS from Sean Connery's Cousin, I kid you not. They use a specialized material that passes a molecule of about 5 Angstroms in size. So oxygen (and a minute quantity of other things) comes out one end and nitrogen and some other things come out the other. According to my understanding, they use two pumps (on one shaft) and two cylinders of the specialized materials. They are connected by directional valves and the whole thing is controlled by a logic board. One part of the cycle they push the incoming air through one cylinder and on the other they exhaust it; I guess while it is pushing air into the other cylinder; a little like a twin cylinder engine. I don't think the intake and exhaust cycles are the same length though. Carl Willis has also been using one of these for glassblowing as well. See also: http://en.wikipedia.org/wiki/Molecular_sieve -bill
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Re: New score boast

Postby Jerry » Sat Aug 20, 2011 5:27 pm

They do use a pump with a single shaft, but the outputs are connected together. I took a mostly scrapped one apart and still have the compressor.

The reason for two cartridges is one is being used while the other regenerates. They switch back and forth.

Wiki's little page about it:

http://en.wikipedia.org/wiki/Oxygen_concentrator
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Re: New score boast

Postby Doug Coulter » Sun Aug 21, 2011 2:50 pm

Bill's stronger than he realizes. Having just carried this dude up the stairs (pausing for rest between each two steps), I'd say double that weight before packing -- and it would need a crate as the plastic outers aren't all that robust. It's on wheels for a good reason. It's a mid output thing, it will loaf doing small stuff, and struggle doing anything big.
Here's a couple of pix with it hooked to a large glass blowing torch (just like the one Jerry recently scored -- ours wasn't labeled, so we used the info from Jerry to know how to hook it up, thanks!)
Without oxygen -- this shows the most propane you can use and still get to an oxidizing flame with the oxygen maxed out:
NoO.jpg
No oxygen, center burner only fed gas

And here it is with the output at the max 5 L/M or so. The camera didn't quite get the inner cone, but this is a noisy oxidizing flame with the middle cone about 3/4" long and about 1/8" diameter.
OxFlame.jpg
At full crank with just burner center fed

This is a much bigger and hotter flame than I used to make the glass/metal seal shown sitting on the brick with a tig rod as the conductor and very thick wall 1/2" pyrex tube. Just that center flame alone (and with the nice stable base) is going to be a happy plenty for the glass blowing I'm doing so far -- it will mostly be running between 1/2 and 1/4 this.

There's not enough output to quite run the bigger outer part of this burner off it, unless you just want a pretty small flame there. For grins, I tried a propane/air mix for the outer burner, but the orifices are too small for that, and the flame easily blows off before you get much of anything. It might be that a faster burning gas than propane would work with air there, but I've not tried that so far. Does MAPP burn faster than propane, or should I be looking at acetylene or hydrogen for that (in air)? Or perhaps I should just run this into the air blower intake and get "enriched air" for both...might work out great? I am using a sleep apnea air machine for my air, also found by Bill -- it's very smooth and very-very quiet.

Of course, just for fun, I also tried this on some small bench burners designed for gas and air -- it's a great way to make very loud popping noises - they really need air, not pure oxygen -- but a blend might work out.

This thing is loafing at 1.5 L/M on my homebrew point torch with the torch maxed out (someone should mass produce those, they're very nice). That torch uses a MIG tip, about .030" hole, as a gas torch tip - it just happens to have the perfect inside nozzle angle for this as well as for the original wire feeding use. It's just screwed into a hole in a steel block, with the gas and oxygen coming into the cavity just below it for mixing, with a couple needle valves for control. What's nice about that is that MIG tips define "dirt cheap" and are available in several sizes, all with the same threads - so rather than pay say McMaster's $175 for a mini torch -- you can make one pretty easily. Up till just now, that and a mapp gas regular bernz-0-matic propane torch are all I use for pyrex and anything lesser. For quartz, as soon as its bigger than about 1/4" tubing I have to go to the big oxy-acetylene guy, which is like going from "not enough" to "way overkill" even with a small tip and low gas/oxy feeds. Mark says they don't let him use acetylene as there are contamination issues, though I've not noticed that, so he does all his work with hydrogen. It's a little hotter, but fewer btus than acetylene.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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