Anyone here build oxy propane torchesburners or other flame work equipment?

Anyone here build oxy propane torches-/burners or other flame work equipment?

Recently I saw a torch A guy made from plumbing parts and think he did good but the fellow glass blowers had a cow over his "Pipe bomb torch". Obviously its not difficult to slap a working unit together.




Now glass blowing torches are not cheap, for a $1,000 you can get a toy torch, not much better than this junk torch.

Im wanting to make something that will eat glass for breakfast. so here are my questions to the group.

Burner head and face... what is the very best material? Would be nice if its not hard as 304 stainless but if it would be the best then so be it. Its the business end of this bitch so it needs to be wicked bad ass. I still need to be able to drill ports in this matierial, I hope 303 stainless would work. Small hole drilling will be a factor.

Second If I make assemblies, slather on silver solder paste and throw it in a kiln. Is it A good idea to silver solder in a kiln? Im guessing it would be a very controlled way to silver solder.



I would like to build a prototype and 6 torches in the $3,000-$12,000 range. Torches of that caliber are available if you get on a long waiting list , well in 18 months I think I could make one hell of a set of torches.

This caliber of torch.
Quadzilla


Right now the market for upper end torches is lean and people will pay big money for a high caliber torch.

So any advice from the experts on the materials and possible machining of the toughest alloys involved?

I'm not looking for the cheap or easy way to do this and will certainly farm out any operations that are beyond my capability so they turn out right. I figure it would be easy to spend a few grand here and there so the wife does not give birth to a cow for spending big lump sums.

How do they work exactly, anyways ?
I am no glassblower but do have a certain interest in the subject since glass blowing and especially scientific glass blowing is probably the craft i admire the most amongst all crafts.......i have tried countless times to make simple gas dicharge tubes but getting a proper glass/metal seal without proper materials is pretty much impossible, then gave up, life is too short to fiddle with every craft and every trade just because i happen to like it.
I do have an evacuated sealed glass pipe though, which glows nicely in the presence of a tesla coil. In the RF range electrodes are rather superflous.

Anyways, my point being:

Naturally aspirated gas/air torches are usually venturi torches.
Acetylene/Oxy welding torches too, so the high pressure oxy can draw in low pressure acetylene, safety reasons.

Beyond that anything is possible. The metal casting and blacksmithing crowd sometimes just pipes propane into the outlet pipe of an electric blower and it works.

I once borrowed a simple, cheap glass blowers torch from school, it needed gas and low pressure air, no idea how the mixers worked, but i had some fun with it. But it was some form of internal mixing.

This torch you posted has all sorts of tiny ring shaped port inside port inside port coaxial structures. Is that just for show or are the gasses injected into each other outside the burner, without any premixing or venturi chamber ?

Edit: I googled some and found this diagram on the page of a french glass blower:
http://ceraverre.free.fr/chalumeau/dessin_chalumeau1.jpg
looks like all possible systems are in use: Internal venturi mixing, external mixing and torches capable of both...

Zonko, The fancy torch I posted has a patented triple mix with 2 ports of oxygen for each propane ports. They are the premiere company to get a high quality torch but the waiting list is pissing people off with a hell of a lot of money just sitting and waiting.

I will not even be trying to infringe on the triple mix design at all. I'm not going to copy anyone's anything. I may buy some off the shelve modular valves and use those.

I would be building a surface mix burner where the fuel is injected into a the center of a stream of oxygen. Its real basic just like all the other guys are doing. I just need the burner to have multiple rings of fire each ring with a set of valves. Small flame for small work and bigger flames for big work.

I have placed an order for a $1,200.00 torch and might get it at the end of summer because GTT is swamped with orders. Phantom

Having been a machinist so long its hard to throw money at something so simple and If I build one I may as well build 7. I'm wanting to have at least 80 jets of fire on it.3-4 separate rings and valves. feed it with 15psi of propane and about 60 psi of oxygen.

Iv been machining all my own graphite tools and make and compress my own oxygen.
Here is a small studio tour of the shop I have made in the last 9 months.

I am blowing glass outside for the summer, its 110F today but that dont scare me none.

oldbikerdude37 said:

Burner head and face... what is the very best material? Would be nice if its not hard as 304 stainless but if it would be the best then so be it. Its the business end of this bitch so it needs to be wicked bad ass. I still need to be able to drill ports in this matierial, I hope 303 stainless would work. Small hole drilling will be a factor.

Click to expand...

Industrial furnaces often use 309 SS for burner components. It has better high temperature oxidization resistance and strength than 303, 304, and 316. Since I'm not familiar with how these burners are used, I don't know if parts of them get hot enough for it to make a difference.

The torch you are describing is called "surface mix". These have a chamber in the front connected to one gas and one behind it with a small tube from each hole in the front back to another chamber for the other gas, usually propane or natural gas with oxygen coming out around the center tube.

A torch that mixes the fuels internally depends on the nozzle absorbing enough heat to keep the flame from burning back inside. Surface mix avoids this problem. Usually blast burners like the one illustrated have several sections so you can run just the center burners or outer rings for a flame covering a large area. I have some Bethlehem literature showing the construction. For material, you should have a good heat conductor and typically the burners have cooling fins. You can make your own. Silver brazing the tubes in place is fine. If the torch gets hot enough to melt silver solder, you are already in trouble.

Gas air torches are losers. To begin with, for every cubic inch of oxygen used to produce heat, you are blowing 4 cu in of cold nitrogen on the part. Secondly, natural gas and propane torches have a built in limitation because the flame propagation rate is not very high. If you turn it up too high, the gases are departing faster than the flame burns back and it blows itself out. Add all that nitrogen to make the airstream five times faster, and you don't have much.

We did a lot of silver brazing on locomotive contacts, at first with oxy acetylene, but the gases cost several hundred dollars a month. The work would support the expense, but that was money that wouldn't buy me a sandwich when I was broke. I got what is improperly referred to as an oxygen generator, actually an oxygen purifier, separating it from air, then we experimented with torches. We developed one for natural gas or propane that had almost no limit in flow rate. We considered marketing it, but the efficiency depended on turbulence, which means noise. If we ran it hard enough, it would develop Mach shock lines in front of the nozzle. We always wore Peltor earmuffs, but we would have no control over what others did and didn't want to get sued when it ruined someone's hearing.

Bill

P. S. I started writing this before posts #3 & #4, which is why it may seem a bit redundant.

I made a special vee shaped oxy acetylene torch for flame hardening purposes. I just drilled some tiny holes in a couple of blocks of brass and connected the handle from my cutting torch outfit.

It worked OK. It did not have any special features inside to mix the gasses.
I had to keep a spray of water on it because if it got too hot the flame would pop back inside the tip.

I was a bit concerned that it might blow up , but it never did!

Torches like that were the standard at one time. They were made in various radii, often with a bunch of tubes, each with its own nozzle. We used straight burners with multiple holes on each side of the heavy contact blocks. If they got too hot, they would flash back and burn internally. The worst problem was that they would collect carbon inside which would smolder and relight if we tried to relight them. We would get the carbon burning and shut off the gas, running pure oxygen through them until the carbon was burned out. Generally a pain to try to make production.

Bill

Maybe a bit off topic, but when in need for very hot flame for joining tungsten-rhenium thermocouple wire, I used a plasma arc welder in non-transferred arc configuration. It basically involves connecting the ground wire (normally connected to the work-piece) to the plasma nozzle. This produces a long, very hot flame of some 20,000 F and using only argon or/and helium.

adamm said:

Industrial furnaces often use 309 SS for burner components. It has better high temperature oxidization resistance and strength than 303, 304, and 316. Since I'm not familiar with how these burners are used, I don't know if parts of them get hot enough for it to make a difference.

Click to expand...

With good oxygen flow the torches do not get very hot, its using the small flame for detail that the end gets hot and ages.

309 ss sound great, is it decent to machine?

Im also was considering tungsten as a face material. Probably overkill but there may be a reason its not used more in building burners.

The problem is that anything as hot as a plasma devitrifies the glass. Oxy acetylene is too hot for soft glass or Pyrex. It is good for quartz, but all the glass blowers I know use natural gas or propane with oxygen. You can work soft glass with gas air, but Pyrex is difficult. One issue that is probably not that important for hand workers but is in industry is that natural gas varies in mix and heating value. A reed switch manufacturer I worked with gave up trying to keep adjusting for the variations and changed to propane.

Re sealing wires into glass, they used alloy 52 in soft glass and oxidized it before sealing. It seems counterintuitive, but glass is an oxide and it bonded well with another oxide. Eventually they went to laser sealing instead of torches. Then the parent company shipped the whole thing to Mexico.

Bill

Years ago I did work in a light bulb factory owned by Phillips. All the torches there were Oxy Hydrogen. IT was amazing how fast they heated and sealed a bulb. The flame was nearly invisible.

I've got a "toy" torch, a Knight Bullet Burner, and I've done some service work on it so I know the innards pretty well. It sounds like you want something more like a Knight Dragon Slayer or a King Fire ($4k?). IMO, it's probably not that hard to make a surface mix torch, just very tedious. You have to design an internal structure to keep the gas paths separate. I've always wondered if somebody could simplify the torch head by doing a pair of CNC made parts that nested together, one part being holes, the other plugs and routing, maybe for a big square face torch. Everything I've seen looks hand assembled and brazed.

I have to wonder about efficiency if a home made torch uses say 10% more fuel will you save any money over buying a more efficient one for $1500? I have to assume that the factory made, expensive, torches have some research behind them to improve efficiency.
That may be a leap of faith for such a low volume market and these designs are just copying each other on the theory that someone else must have studied what works best.
Bill D.

Oxy-propane cutting tips can be had for as little as $5 each (imports). Wonder if you could use a matrix of them?? Bigger tip in the center -- a ring of smaller ones around -- all individually valved to tailor the flame a bit??

Would probably suck compared to the $1200 torch; but you could buy a lot of tips and valves for a couple hundred $$.

This is an old work horse industry standard. A Carlisle cc. They are kind of gas hogs. They Sell for $1,400 and have the noisy ass pre-mix for a center fire.



The point of the concentric rings of burners separately control is to save fuel, also you can add a foot pedals to fire the out rings to do the big warm up for larger work.

Surface mix torches have a whole lot more complexity as far as tubes and porting but still not too bad.

I certainly will use off the shelf valves, I can get them for $25.

I chose to ask questions about this here vs a glass blowing site that is very limited in people skilled design and machining, listen to the blathering of some stoned bong maker telling me I need space aliens technology to make a simple torch.
They get all butt hurt when you make them look dumb. LOL

I was hoping for a good read, looks like PM won't disappoint, as usual
Though i gave up on glass blowing because Gas/Air sucks, as explained in detail by Bill, I may yet do some more work in that direction one day.
Going to make my own torch in that case. Gonna keep this thread in the back of my head.

oldbikerdude37 said:

I chose to ask questions about this here vs a glass blowing site that is very limited in people skilled design and machining, listen to the blathering of some stoned bong maker telling me I need space aliens technology to make a simple torch.
They get all butt hurt when you make them look dumb. LOL

Click to expand...

YEAH, that is universally true of all sorts of art and hobbyist tech related forums and subjects, isn't it? Had similar troubles myself when forum admins told me to go to hell for being realistic about electricity and the relative safety of working on electric stuff, given that mechanical hazards of all types kill like 50x as many people every year....not to mention the fact that many of those electrical deaths do not even happen on low voltage home/shop systems but really dangerous power distribution gear.
Equally funny is the reaction you get on other forums in response to some Joe Michaels grade technical read - that man should REALLY write a book - all you get is no responses or stupid ones. Gotta love PM...

IMHO i think theres a lot to be said for old school copper or brass nozzels, they suck the heat away from the tip, prewarming the gas flow and keeping the tip bellow oxidization temps, stainless of any grade may technically oxidize slower, but due to the real crap heat transfer the nozzel can get way hotter making the issue worse.

If you want the best, google Inox, its as tuff as buggery, but its used a lot in the combustion chambers of jet engines due to its heat resistance to oxidising environments + chemical resistance to damn near anything. PS if you think drilling 304 is hard dont bother!

If you want nice clean jet like flames, you need to factor in some turbulance reduction on the gas flows, ie real nicely made and internally reamed Jets with a realy sharp - square end (thats the key bit). May well be worth looking at the cnc options for that bit, as it sounds like your going to want a good 30+ of them for each torch. Bodies can be as simple or hard as you want to make them. Jet size needs to be matched between fuel and oxidiser in the correct proportions if you want efficiency.

Burn-back or popping in premix torch nozzles is controlled by two factors. One is, if the inner surfaces of the nozzle get to the autoignition temperature of the gas mix, the flame will, of course, ignite inside the nozzle. The other is flame propagation velocity. Again, every gas mix has a characteristic maximum flame propagation velocity,so the gas pressures and nozzle diameter have to be designed and operated so that the gas is travelling through the orifice faster than the flame can propagate back. Big OA tip throttled way back will pop because the gas flow is too slow, turn it up too high and the flame will detach and eventualkly blow out because the gas velocity is still too fast even after emerging from the orifice.

I'd be very interested to read more about the OP "making and compressing his own O2".

magneticanomaly said:

I'd be very interested to read more about the OP "making and compressing his own O2".

Click to expand...

Oxygen concentrators...very handy piece of gear.

My Grandpa had one, for his breathing difficulty, and i helped a friend who is a used equipment dealer load a bigger industrial unit that our local lab supply company sold for scrap price after downsizing and reducing the glass blowing workstations from something like 5 or 10 to 2.
Most lab machinery is automated these days and uses throwaway consumables, not as many custom glassware orders these days.

How do they work, well, kinda like an activated charcoal gasmask filter. You have a porous substance which has an internal surface the size of several football fields for every handful and the surface has tiny molecule sized imperfections or holes where foreign molecules fit.
That structure acts as a "molecular sieve". Molecules which fit the surfaces get stuck, and those which fit not, either due to size or chemical properties,pass through.

A gasmask passes air and stops toxins - a Zeolite sieve in an oxygen concentrator stops Nitrogen and passes oxygen and argon.

Obviously that sieve will saturate at some point so you have at least two filters and solenoid valves to switch the flow. One vessel is filtering while the other gets purged and nitrogen are vented.

Pressure swing adsorption systems work because zeolite adsorbs (adsorb, not absorb) nitrogen preferentially to oxygen. A cylinder of zeolite is pressurized with air to about 45 PSI, then vented to a receiver just like the one on a air compressor. The first gas released is oxygen rich, gradually transitioning to nitrogen as the pressure drops. After a time that is somewhat arbitrary, the valve to the receiver is closed and the remaining nitrogen and argon vented to the atmosphere. Using the first output gives purer oxygen but a low volume, so you have to strike a balance between purity and volume. The same system can be used to produce fairly pure nitrogen by capturing the last output. I have done work for a couple of local companies who make nitrogen concentrators. There seems to be a larger market for shielding gases than oxygen. The argon comes out somewhere along the way, but it works as well for oxidation prevention. A single zeolite cylinder will work, but most use two alternating to give a more constant supply. They also use some of the oxygen rich but too impure output to purge the other cylinder. Like so many things, the principle is simple but doing it really well is not. My unit gives about 95% oxygen. Running our torches in normal silver brazing cycles requires about 4 hp of compressor, a lot cheaper for the electricity than bottled oxygen and we never have to worry about running out in the middle of a job or keeping reserve bottles.

There are other systems, notably membrane ones where the air is sent through a long porous pipe that passes one gas through its walls. At the other end, one is in the center and the other is on the outside of the membrane.

Here is a torch I made to be used on a stand or as a flame pencil. It is about the largest size I would sell without some sort of legal protection against hearing loss lawsuits. It can be adjusted over a large range. Somewhat counterintuitively, it runs cooler at the higher flow rates. The oxygen cools the torch and the higher velocity flame departs before delivering much heat to the tip. I have had large torches of this design cooled by expansion of the oxygen condense moisture on the torch body while sending googleplex to the n BTUs to the great beyond.

Bill