[TheForge] oxy-propane torch equipment

[Jerry Frost]

----- Original Message -----
From: "Andy Vida" <osan at netlabs.net>
To: "terry l. ridder" <terrylr at blauedonau.com>; "Sponsored by ABANA"
<theforge at mailman.qth.net>
Sent: Sunday, August 15, 2004 11:58 AM
Subject: Re: [TheForge] oxy-propane torch equipment


>
>
> "terry l. ridder" wrote:
> >
> > hello;
> >
> > as a follow-up to my previous reply i found my oxy-fuel comparison
> > chart:
> >
> >                Table : Fuel Gas Characteristics
> > Fuel Gas    Maximum Flame  Oxygen to fuel gas Heat distribution
> >             Temperature °C Ratio (vol)        kJ/m3
> >                                               Primary    Secondary
> > Acetylene   3,160          1:5                18,890     35,882
> > Propane     2,810          4.3:1              10,433     85,325
> > MAPP        2,927          3.3:1              15,445     56,431
> > Propylene   2,872          3.7:1              16,000     72,000
> > Hydrogen    2,834          0.42:1             -          -
> > Natural Gas 2,770          1.8:1              1,490      35,770
> >
> > as the above chart shows, oxygen use is going to increase 4.3 times when
> > using propane instead of acetylene.
>
> Uh, I think your math is off a bit. if the ratios are as you
> state, then you need 21.5 times the amount of oxygen.
> 4.3 * 5 = 21.5
> _______________________________________________


Sounds like a conversion tip on an acet torch.

Still, prop does have a higher oxy requirement than acet.

My All States oxy reg will put out 140psi before you're off the gage, it'll
put out more.

Looking at tables like this will give you an idea what theoretical
performance might be but can be very misleading.

For instance the chart gives us: 3160*c for Acet and 2810*c for prop.

Okay, what does it mean on the shop floor? It means zip. BTU/sec might mean
something but absolute temp? I think 2,810c is far enough above the melting
point of steel another 350c is irrelevant.

Not only is the All States rig more fuel efficient in spite of "using" 21.5
x the oxy (I'll get to why that number is so misleading next) It will flat
out beat oxy/acet speed wise in any head to head competition you want to
name EXCEPT torch welding. My OLD model torch won't weld worth spit. Heck
maybe one of the new models will weld.

Back when I still thought I could get the state to be a little more
efficient <sigh> I went head to head at the state heavy duty shop against
their oxy/acet rig. The brute force heating contest was: which would melt a
1" cube of mild steel fastest. The closest in size rosebud the shop has is
just about the size of a quarter and the #5 heater tip I have can be covered
with the end of my middle finger, larger than a dime, smaller than a nickle.
The All States #5 heater tip made a puddle of the 1" cube in just under 13
seconds, the larger oxy/acet rosebud took about 67 seconds.

The 21.5 x increase in oxy over acet might even be correct. (I still think
it's for a conversion tip) However while the acet rig was set at 15 psig and
30 psig for the above competition and the All States rig was reading 130
psig on the oxy reg, according to the chart (there's no gage on the prop
reg) it was drawing under 4oz. of propane. Ounces, not pounds.

4 oz.. vs 15 lbs. and over 4 x as fast with a smaller tip. I suppose I could
chart all that but what counts is this. The bottom line, shop floor numbers
are: an All States torch will cost you $0.02 for every $1.00 an oxy/acet
torch will cost you, cut per cut, heat per heat.

Don't take my word, call Lyle and get the demo.

Frosty
------------------------
If it ain't forged
it ain't real.
Wrought iron is.
The FrostWorks

Meadow Lakes, AK.