Two 5 LPM concentrators or one 8 LPM higher PSI?

Rhymnoceros · #1 2008-12-13, 3:47pm

So this may be a silly question, and it also may be an already discussed topic buried somewhere in the questions (but i havent been able to find this topic particularly)

Im going to be buying a N.M. Knight Bullet burner from www.zenglass.com (upgrading from the nortel midrange) and ive always been on tanked O2, now that im switching -- Im opting for a concentrator because im actually moving to the basement and there is no way im carrying a K tank up and down a flight of stairs every week and a half (yeesh!!)

There are alot of sales on concentrators going on right now and my question is which is better for the bullet burner: a 15 PSI 8LPM concentrator or TWO 7 PSI 5 LPM concentrators... I understand that with the first Id have more pressure to push less oxygen and with the second option the complete reverse, less pressure but more oxygen

I'll include the item descriptions:

M-15 15psi Oxygen Concentrator 8LPM
[M-15 B01] $700.00 $595.00

Click to enlarge
The Modified Oxygen Concentrator #15 is a 15 psi system that will save glass-artists a considerable amount of money by concentrating oxygen from the air into your torch. Instead of buying tanks of oxygen, simply plug the M-15 onto your torch, and it will EXTRACT OXYGEN STRAIGHT FROM THE AIR! Durable wheels provide excellent mobility. 3 year standard warranty.The M-15 has a Flow Setting = 1 - 15, Electrical requirements = 120V/60Hz 600 Watts

Oxygen Concentration = 92+- 4% @ 8 LPM

Weight = 60 lbs

Dimensions = 27in x 19 in x 13in

Operating pressure = 15 Psi

OR

x2: M-10 10psi Oxygen Concentrator 5LPM
[M-10 B01] $464.00 $395.00

Click to enlarge
The Modified Oxygen Concentrator #10 is a 10 psi system that will save glass-artists a considerable amount of money by concentrating oxygen from the air into your torch. Instead of buying tanks of oxygen, simply plug the M-10 onto your torch, and it will EXTRACT OXYGEN STRAIGHT FROM THE AIR! Durable wheels provide excellent mobility. 3 year standard warranty. The M-10 has a Flow Setting = 1 - 10, Electrical requirements = 120V/60Hz 600 Watts

Oxygen Concentration = 92+- 4% @ 5 LPM

Weight = 60 lbs

Dimensions = 27in x 19 in x 13in

Operating pressure = 10 Psi

Rhymnoceros · #2 2008-12-13, 4:12pm

I should add that i do about 70% soft glass (Focals and handles, sets but rarely ever bead sets) and 30% boro (1-1.5 inch dia. implosions, rarely ever do sculpturals)

kbinkster · #3 2008-12-13, 5:28pm

The Bullet relies more on volume (flow) than pressure. There are not a lot of restrictions in the torch. So, you would get more out of it with two 5 LPM units than one 8 LPM unit.

Trey Cornette · #4 2008-12-13, 5:45pm

OK. I will put in my 2 cents worth.
I have worked with this torch on on Tanked and concentrators. I ran it on 1 and 2 OU M-20's .
I ran the M-20s set on 9 lpm each and they have push just under 20psi on my psi gauge. With this set up I feel I was getting about 80% of the torch compared to running it on tanked 02. I did run the torch on just one M-20 and was not pleased with the flame.
If I were you I would save a little longer and go with 2 M-15s. I think the 2 M-10s would really limit the capabilities of this torch. Maybe run it at 50%.
I believe member Bclogan had a bullet burner for sale not long ago . PM her and see if she still has it. It could save you a few dollars that you could put towards the concentrators.
Also try putting a wanted add in the classifieds. There may be a Bullet out there at a good price!!

Good luck

Rhymnoceros · #5 2008-12-13, 5:47pm

thanks to both of you guys, any more information or insight from others?

ArtcoInc · #6 2008-12-13, 6:06pm

How much time do you spend using the outer flame?

The Bullet Burner comes configured as a 2 stud torch. With a couple of fittings, it can be easily converted to a 4 stud torch. Then, you can use a concentrator on the inner flame, and a bottle on the outer flame.

This doesn't eliminate the problem of hauling a tank up the stairs, but it should extend the time between tank exchanges.

Just another thought.

Malcolm

Rhymnoceros · #7 2008-12-14, 1:00am

i really like the idea of a concentrator inner fire and tanked outter fire, would one m-15 work well enough for the inner fire? and by well enough i mean something over 80% of it's capacity

kbinkster · #8 2008-12-14, 1:10am

My Bullet came as a 4-stud. I recommend getting the 4-stud version of any torch that has that option.

kbinkster · #9 2008-12-14, 1:13am

Quote:

Originally Posted by Rhymnoceros

i really like the idea of a concentrator inner fire and tanked outter fire, would one m-15 work well enough for the inner fire? and by well enough i mean something over 80% of it's capacity

I'm not sure if it would run it to 80%. The innerfire of the Bullet takes more oxygen than most other 7 jet torches. It's configured like the Mini CC, only I think it has a better flame, and the Mini CC needs 7 LPM just to make soft glass beads using the recommended 3/8" candle lengths.

Trey Cornette · #10 2008-12-14, 8:18am

Quote:

Originally Posted by Rhymnoceros

i really like the idea of a concentrator inner fire and tanked outter fire, would one m-15 work well enough for the inner fire? and by well enough i mean something over 80% of it's capacity

My guess would be that it would run the center fire very well. Probably more than %80.

Quote:

Originally Posted by kbinkster

My Bullet came as a 4-stud. I recommend getting the 4-stud version of any torch that has that option.

I would also recommend getting the 4 stud and make sure if you buy a new one that they do the conversion for you before shipping the torch. I may be wrong but I believe all the bullet burners come from the factory as a 2 stud and a kit is used to convert it.
If you buy a 2 stud used you can get the conversion kit from Ross at ABR Imagery for $30 or so.
I will say this torch is a bit temperamental on a foot pedal and would require some adjusting of the flame every time the outer fire was activated and deactivated. It was a bit frustrating. I believe this torch was designed to be a 2 stud and it just so happens that it was an easy conversion. Neither my Barracuda or Phantom are nearly as fussy.
Just my opinions. Take for what its worth.
Peace

kbinkster · #11 2008-12-14, 12:06pm

It looks like the one being offered by the supplier you mentioned is a two-stud version. I bought mine directly from NM Knight and got the four stud verision - they offer both.

http://secure.mediafusiontech.com/he...ubcategory=205

Quote:

The Little Dragon Bullet Burner offers separate valves for center fire operation and full operation, Minimum Gas pressure is 2psi and oxygen is 10psi, All Stainless Steel Shell and Tube construction

You can select either a single manifold ( one connection for Gas and one for Oxygen )or a Split Manifold which will enable you to bring 2 Oxygen and 2 Gas lines to the torch. This could be used with a gas saver for the outer 14 jets.

It's built as a four stud and adapted to be a two-stud. It would be easy to convert it back to a four stud, if you have the time, but then if something went wrong with the conversion and there's a leak, you're responsible. If it were me, I'd just get the four stud version.

Trey Cornette · #12 2008-12-14, 1:01pm

Thanks for the info Kim

kbinkster · #13 2008-12-14, 1:11pm

Quote:

Originally Posted by Trey Cornette

Thanks for the info Kim

You're welcome, Trey.

I wasn't trying to be contrary, or anything like that. I was just offering up my experience and opinion. For some people, buying a conversion kit and converting a two-stud to a four-stud is a good option - especially if they are mechanically inclined and have the time to do it. For other people, it can be more of a hassle/risk than it's worth. It's good to know that both options are available so a person can make a choice.