Converting oxycon for lampwork

[imagesinglass]

I just bought a brand new oxygen concentrator - apparently the person who bought it (the grandfather) did not live long enough to use it....
I tried using it today, but it breathes....which I suppose it's supposed to for patients.
Does anyone know how to turn the "breathing" off so I can use it with my Scorpion?
Thanks for any help.
Suzanne

[spixton]

have you used a concentrator before? Mine, which I use for lampworking, sound like they are breathing but it seems the output is steady. Might it just be the sound?

I'm also curious as I've become the owner of 2 concentrators that were used for medical reasons. Seems like the companies don't want them back...odd. I've yet to try them but if they work, I'll probably sell a couple (I now have 5 concentrators!....long story).

[glassymom]

Yup, mine makes the breathing sound too. Bought it locally from a person in the business of medical concentrators. I didn't do anything to it but hook it up.

[imagesinglass]

Hi Spixton,
Yes, I've used concentrators for years. I used to have a minor and ran it with one 5lpm. Then I bought the Scorpion and another 5lpm so I can do boro.
My plan is to hook the 2 5's together on the inner flame and use the 8lpm for the outer flame. The new oxycon is definitely putting out oxygen, but it breathes or surges like a patient would need.
Glassymom, I guess I should have been more specific...it not only makes the breathing sound it has a surge of oxygen that makes my flame hiss and get larger...then it stops hissing and goes back to where I want it...then it hisses and gets larger....
Medical oxygen companies don't want used oxycons because they can't guarantee they will sustain life and could be sued.
I'm hoping there's something simple I can do myself to stop this thing from breathing and just put out a steady stream of oxygen.

[Ed_Slawson]

The breathing sound is the concentrator switching between the two canisters (tanks) of zeolite, which separate out the nitrogen in one cycle, then pump out the remaining oxy into the holding tank in the other cycle.

[Alaska]

Using more than one machine may even out the "breathing" issue.

A Scorpion will not play well with one 5 LPM machine. The center fire will be OK but will come to life with two 5 LPM machines. Then add a third for the outer fire.

Use a Scorpion with three 5 LPM machines and NG at 5 PSI and it performs well. Also keep oxygen to the outer ring at all times. It helps cool the torch and form the flame. Plus there is then only one knob to turn on (fuel) when the outer is needed.

[kbinkster]

You could try adding a holding tank to act as a reservoir for your oxygen. This way, (1) you won't have the surges that come from the cycling of the machine, and (2) you have a reservoir to draw from for blasts of full flame. Once the oxygen is depleted from the reservoir, you'll go back to running straight off the machine's production and will have the flame fluctuation and limitation on size. A holding tank could hold you over until you get another machine.

Machines have internal holding tanks, but they're not large enough to act as reservoirs for our use. Some machines have smaller internal holding tanks than others. This may be why you notice a more pronounced breathing with some and not others.



The centerfire portion of the Scorpion (same as the Cricket) can run on 5 LPM for soft glass beads up to about an inch and some small boro. You can work larger, but it is slower. Adding more oxygen concentrators will allow you to get bigger flames.

Leaving the oxygen valve open on the torch and just adjusting the propane (like suggested in a previous post) limits the flame adjustments you can make, IMO. I don't recommend adjusting your torch that way.

Here is what I do (on a two-sieve machine):

I go in and open the oxygen valve on the torch all the way and make sure the propane valve is closed. I then turn on the concentrator and set the flow to its maximum rating (for a 5 LPM machine, that would be 5). You want to make sure that the middle of the ball is on the line at the height of the cycle. The ball should drop a little during the switchover when no oxygen is being produced.

I let the machine warm up for a few minutes. While I do that I turn on the propane tank and set the regulator. Once the machine is warmed up, I turn the oxygen valve on the torch off just long enough to turn on the propane and light the torch. I then adjust the flame with both the oxygen and propane valves on the torch.

Because I set the LPM on the machine when the oxygen valve was wide open as far as it could go, I've limited the output and won't run the machine over its recommended LPM regardless of the flame I use. I still keep an eye on the flow meter from time to time, though, to make sure that it doesn't drift up or down (temperature changes will cause the flow to increase or decrease). The flow from the machine will decrease when you run a small flame and increase (but not go over the point where you limited it) when you run a big flame.

As long as the ball is not resting on the bottom of the flow meter or reaching above the 5 LPM mark, you're good to go. If you shut off the flame, just shut it off and then re-open the oxygen valve to keep the machine from backpressuring and alarming/shutting off.

You don't have to keep the oxygen on on the outerfire, either. When you have oxygen to spare, it's nice to do that, as it can help ensure that you don't backpressure your machine and it can also enhance the centerfire. It is not necessary, as far as I know, to run the outerfire oxygen to cool the torch.

[Alaska]

Originally Posted by kbinkster

Leaving the oxygen valve open on the torch and just adjusting the propane (like suggested in a previous post) limits the flame adjustments you can make, IMO. I don't recommend adjusting your torch that way.

"Center fire enhancement. With the center fire running at a large flame size, turn on the outer fire oxygen only. This will stabilize and enhance the center fire flame for a larger neutral flame. This will also allow the addition of more fuel in the center fire flame for a larger cleaner center fire flame."

Originally Posted by kbinkster

I go in and open the oxygen valve on the torch all the way and make sure the propane valve is closed. I then turn on the concentrator and set the flow to its maximum rating (for a 5 LPM machine, that would be 5).

"Set the flow meter .5 – 1 LPM lower than the highest number on the flow meter unless the manufacturer recommends otherwise. This will usually provide the greatest purity of oxygen to the torch. Due to the differences in oxygen concentrators there may be some variations in the above recommendations depending on the concentrator, flow, purity and working pressure."

[kbinkster]

Originally Posted by Alaska

"Center fire enhancement. With the center fire running at a large flame size, turn on the outer fire oxygen only. This will stabilize and enhance the center fire flame for a larger neutral flame. This will also allow the addition of more fuel in the center fire flame for a larger cleaner center fire flame."

Yes, centerfire enhancement is nice, but when you are running on a 5 LPM concentrator, your centerfire needs everything you can give it without diverting any to the outerfire.

Regardless, my quote that you reference is in regards to this post:

Originally Posted by Alaska

Using more than one machine may even out the "breathing" issue.

A Scorpion will not play well with one 5 LPM machine. The center fire will be OK but will come to life with two 5 LPM machines. Then add a third for the outer fire.

Use a Scorpion with three 5 LPM machines and NG at 5 PSI and it performs well. Also keep oxygen to the outer ring at all times. It helps cool the torch and form the flame. Plus there is then only one knob to turn on (fuel) when the outer is needed.

There is no reason that you MUST keep the outer oxygen on at all times.
(1) You do not need to run the outerfire oxygen to cool the torch.
(2) You do not need to run the outerfire to form the flame on the innerfire. It does just fine on its own. The centerfire enhancement technique is neat, but it is an enhancement and is not necessary for the operation of the innerfire.
(3) Running the oxygen full on and only adjusting the propane limits the flames that you can dial in. It is not the best way to operate a torch.

Originally Posted by Alaska

"Set the flow meter .5 – 1 LPM lower than the highest number on the flow meter unless the manufacturer recommends otherwise. This will usually provide the greatest purity of oxygen to the torch. Due to the differences in oxygen concentrators there may be some variations in the above recommendations depending on the concentrator, flow, purity and working pressure."

I understand that that is on their website, but I happen to disagree with it. While running at a lower LPM will provide a higher concentration of oxygen, a 5 LPM machine in good working order will produce 90% purity at 5 LPM. That is how these machines are rated. There is a sharp drop off below 90% purity. At whatever point the machine hits 90%, that's where the machine is rated. A concentration of 90% also happens to be a good purity for lampworking. You can work sensitive colors and still get a good amount of heat from a 90% concentration. If you run into a particularly difficult situation where an extra 1-2% will make a difference, you can make the adjustment at the torch and run a smaller flame (because you will be drawing less flow with a smaller flame and will have a higher concentration).