propane burner question

I have built a burner using all info gained from Ron Reil's fantastic web site, but I have a problem getting the damn thing to run . Sure it
will ignite and burn but the flame is all over place,nothing like what I seen as examples of a good flame with a nice well defined inner cone,... plus the ignition point is only about 50-70 mm (2-3in) from the jet in the burner tube . Is this right??? My burner specs are :- 1.25" burner tube X 12" , 2" bell reducer , jet sizes from 1mm to 1.5mm.
Any ideas or help would be gratefully welcome .....
Greg in OZ
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Which burner are you building? This is the one I have found quite satisfactory: http://www.reil1.net/design1.shtml#Reil I'd like to try out the other designs, but they never seem to come high enough on the priority list.
Assuming the above is the burner you are using.... I use this burner as drawn, with some mods to how the jet is supported. 1mm sounds about right; I use a #58 drill. The flame should be as pictured various places--starting at the end of the burner flare, nowhere near the jet. If you are using this burner, your burner tube sounds pretty big.
If the pipe sizing isn't your problem, it might be jet alignment or burner flare position. Jet alignment can be checked by hooking up the jet to water under some pressure. It should squirt a nice jet of water straight down the tube. I start with my burner flare halfway onto the tube--in other words, for a 3" flare, 1.5" is overlapping the tube. I adjust back and forth to find the extremes of operation and pick the middle.
Write back with some more details and we'll (the group) figure this out.
Steve Smith
hotshod wrote:

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Hi Steve, The burner design is one of Rupert Wenigs The address below is a drawing of the burner. ( sorry it's not a link )
http://www.frugalmachinist.com/mburner.jpg
It is almost an exact copy in every repect , except for the unknown distance of the jet tip to the 1.25" burner tube..... Mine is set up at 13mm ( .5")
I'm using water pipe and it has a bit of a weld seam inside it. I haven't worried about a choke at this stage.... but it seems wrong that the ignition is happening only 2 inches from the jet, thus having the flame for 10 inches of the tube before hitting the air. I need to go and buy some more jet holder blocks and experiment with them rather than using the mig tip as a jet. I have an adjustable gas regulator , but without a gauge.
Any ideas...... Greg
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my first guess ( being still in the process of building a burner rather than using it...) is that because it is designed for a furnace, it may not burn well in free air. The flare on the end of the reil style burners is to slow down the flow rate to convince the flame to hang around the end of the tube. Try either fabricating a flare ( 1:12 seems to be the recommended taper), or put it into your forge. I saw this effect exactly on a 'mini-mongo' style burner, from memory the flare fixed it.
An alternative flame holder ( cant remember the link sorry) was a set of concentric tubes ( rings really) spaced with short bars, at the end of the burner tube.
regards, russ from Oz (melbourne actually)

middle.
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If I understand what I _think_ I understand, you are (here) describing ways to to keep the flame from blowing off the front of the burner, and the OP has the flame going well down inside the burner tube (the opposite problem). But I may understand wrongly. I'm also in the state of having read more than I've done with these, but I hope to build something within a year or so.

Wire mesh is used on some lab burners. That would tend to keep the flame front from coming back inside the tube , but is probably not the "right" way to do it, since most burners of similar designs don't need it.
--
Cats, Coffee, Chocolate...vices to live by

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i know it seems strange.....but i did some experiments with my brother, and while memory is hazy, i think one of the 'failures' had the burn inside the tube, the flare fixed it.
if the op tries it, i'd love to know...
russ from Oz
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Thank you all for such genuine concern and response to my problem !!!!!
My question to Bob is.... What is the size of your burner tube/ bellmouth reducer/ and is it important as to EXACTLY where the jet tip/ fuel hole lies within the bellmouth. Also a #52 fuel hole is quite large compared to other web designs that I've seen, that would make it about 1.5mm. Did you come to this drilling hole by experiment with smaller holes to start with.
( My burner at this stage of building is 2" bellmouth... 1 1/4" burner tube X 12" long...) Next comes a flare if it wont run in the forge....It has been suggested to me maybe to try making a 3/4" burner first up. I'm tempted to do another burner using Rupert Wenig's design of the "MiniMongo" ie. 1 1/4" tube with fuel pipe entering at the rear , and air holes drilled into the burner tube ???? maybe, who knows ???
To all you guys out there who have taken the time to respond to this posting Many Thanks... I'll keep you posted, obviously I still need help. Greg in OZ
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Sorry for the late reply. I have been out of town.
The #52 came from trial and error. I started with #60 and kept changing until I liked the way it worked. I have discussed this burner with Rupert Wenig and even have this burner design on my web site (with his name and permission of course).
I made mine EXACTLY like the drawing. The tube is 1-1/4" X 12" I assembled it so that the center tap of the tee is as close as possible to dead center. Then I drilled the #52 in the cap from the inside so I could get it centered. File it to remove burrs. I need a lot of gas for my forge. Welding requires a LOT of heat and the #52 gets the job done for me. It may be different for you depending on your altitude and other environmental issues (I am near Dallas, TX). I recommend you start with a #60 and see how it works, then start drilling it out until it seems right.
As for flairs, don't have one. Don't have any rings welded into the end as flame keepers either, just a straight pipe.
If you need more help or just want to talk about it, go to my web page www DOT warnerknives DOT com and get my number from the contact page. Since you converted my #52 to a metric measurement, I will assume you are not in the USA so e-mail and this group may be the better alternative for you. Whatever you want.
Take care,
Bob
On 30 Jun 2003 16:17:42 -0700, snipped-for-privacy@optusnet.com.au (hotshod) wrote:

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Greg,
You may want to look at www.ckdforums.com as another information resource. The site is a forum for knifemakers but there is a lot of discussion on forges there. Just use the search button at the top right and search for "forge" and you will get quite a bit of info.
Feel free to give me an e-mail anytime.
Bob
On 8 Jul 2003 16:05:23 -0700, snipped-for-privacy@optusnet.com.au (hotshod) wrote:

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Thanks Bob, I'll tell you where I'm up to now ......
I have made 3 changes.... First i Had to start using a choke , and make adjustments on the run..... next I added a 1.2 mm mig tip(slightly bigger than a #56 drill hole). That put the initial fuel delivery further down the burner tube tube and then I added a flair , cut from a soup can. Hey presto flame jump down to the end of the burner tube , the loud, high pitched noise changed to a deep roar , and I had a flame about 2 foot long and a well defined inner cone...... That's with it sitting in the bench vice.
Next step stick it in the forge ( made from 20lb LPG bottle ).Not quite perfect .... it runs in half-second, mini popping explosions...( flame-nothing-flame-nothing-flame-nothing-flame- then goes out...... all without any degree of control Obviously more fine tuning required....
Due to surplus materials I'm also experimenting with the other of Rupert's design.... ie. with the fuel entering from the blanked off rear, and a series of air holes drilled into the burner tube.....( should have that assembled tomorrow)
I have been to your website , and I must say it was in part responsible for me choosing that design.
Cheers Greg (hotshod) Sydney ,Australia.....

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Greg, That flame-nothing-flame-nothing is what I call "Huffing" and can usually be corrected by increasing the gas pressure a little. Then after the forge gets hot, you can usually turn it back down.
Keep us posted.
Bob
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HI RUSS,
Sorry for the delay in replying to your posting. The burner is coming on fine now and it has been a learning experience tuning the damn thing.
First I was trying to make it run sitting in a bench vice . I made 3 changes, 1. added a longer Tweco mig tip 1.2mm .....2. added a choke......3. added a flare end..... after this the burner would run in the vice.
**** These burners work better in the forge than out.
Then I moved it into the forge ( coverted 9kg LPG bottle )..... discarded the flare and was very pleased with the result . This setup still has to tested as to just how HOT it can go, but after about an hour of general use it's working well......the only draw back seems to be if I want to slow it right down to near zero flame or idle , but this may be rectified with more use and fine tuning....
Cheers Greg (hotshod ) in Sydney, OZ
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wrote:

Hi Lawrence,
Your right , the burner started to behave itself after I put it in the forge, I also added a choke ,and a larger mig tip (1.2mm) thats approx #56-55 drill size
The setup is operating quite well, I'm having trouble getting it to run at a very low idle, but I'm real happy with the overall performance.
Greg in Sydney,...OZ
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Speaking of burners/flares, Reil design, etc - how do the straigh-pipe, naturally aspirated ones compare to those which have an angle (around 45deg I believe) in them (also naturally aspirated)? These are the type which appear to be used on NC Forge forges, as well as a couple of other commercial ones. I have read a lot (on the web) about the straight ones, but very little on the bent ones so I was wondering about any pros/cons. Efficency? Heat? Air/fuel mix?
I assume that the angle is to induce mixing, and it probably also slows down the gas also. These also seem to have a smaller intake bell. What about the jet orifice size? Anyone have any insight/experience with such a burner? They look pretty simple to build, and a bit more compact then the 8" long w/ a large bell on them, so I might consider those as my current burners seem to be eroding away.
Thanks,
don
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don schad wrote:

Don, I don't know about bends, but I have seen a couple of forges built that way.
It sounds like your burner end is eroding. Are you using stainless flares? They last a lot longer than plain steel or cast iron pipe.
Steve Smith
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You are correct about the bend causing increased mixing. It also causes increased friction, and therefore less gas through the burner, and less BTU output, hence the smaller intake bell. The more output you get from a burner the bigger the intake bell needs to be, given a specific design. There is a price for putting in a bend, but on the positive side is the compactness. I have always wanted the most heat I could get out of a burner, not the least, so I have never put any bent tube burners on my web site. If you explore the commercial forges out there you will discover that some of them can't forge-weld, they just don't have the BTUs or temperatures necessary to get the job done. I can't see those bent burners as much of an advantage when you consider what you lose by using them. That is the same reason I don't have flame-holder designs on my site. They work too, but why have a 3/4" burner tube and not get all the output it's capable of delivering. The higher the temperature in your forge chamber the better for your work, so I suggest designing for the most useful tool, not the most compact one, unless you are hauling it around and need the convenience of portability.
Ron
--


Golden Age Forge
http://www.reil1.net/gallery.shtml
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Hi Ron Sorry to but in on your response here, but I thought i might ask you and all the others out there about burner design........ OH by the way my initial posting here has almost been resolved. The only problem my burner is experiencing now is how can I run it at idle, ie. I have taken my piece of iron work to the anvil, or vice or where ever, I find it near impossible to slow the burner down to next to nothing. ..!!! Am I expecting to much...?????? So far my solution has been to work on 3+ pieces at once..... Otherwise it's working well. Any ideas...????
The other situation I have is that after building one burner I tried to do another (left over spare parts). This was Ruperts other design , the mini-mongo, ie. with the fuel entering via the back of the blanked off burner tube , and air entering via holes drilled in the burner tube...... I'm using the same specs as Rupert , ie 1.25" tube..... The burner runs pretty good for about 3-5 minutes but after that is becomes very difficult, roars, flame goes back up the tube ,and it needs a lot more fuel to run ....My observation is that this all happens after the heat has built up with in the forge body, also this burner has a choke , and this choke is far more sensitive than the other design of Ruperts burners. This burner ..... mini-mongo , would appear not to get as hot as the conventional mongo built around a 1.25" burner tube and a 2" bell.
Any comments would be welcome.
Greg in OZ
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First, if you read the information in the Mongo section of my site, http://www.reil1.net/design1.shtml#Mongo I strongly suggest not using a Mongo design unless you change it over to a slotted intake design. The drilled hole Mongo just doesn't allow enough intake air. The Mongo burners are inferior to the "improved" Side-arm, or slotted designs, such as the Rex burners. A "Reil or EZ" burner fitted with a large intake bell and TWECO tip will also far out perform the Mongo. I do think the Mongo has some use, mostly for history reasons, so I have left it on my page. But the text of the document explains what I have just stated.
You have not given me enough information to really make a guess at why you can't get the burner down to an idle. When all is built correctly you should be able to get it down to zero gage or close to zero, perhaps only an ounce or two of pressure...will not even budge the gage. Do you have a good flared nozzle on it that you tuned in open air, is your choke setting too far open, generally not a problem with a Mongo? Do you have a back-pressure problem?
As to your strange behavior problem with the second burner, why not send me an image of the burner, taken at an angle from the intake end so I can see the details of your jet and intake structure, as well and the flared nozzle. Make it 30-60 K in size, no bigger please, and send it to me. A picture of your forge might be a good idea too. Is the burner nozzle set back into the Kaowool an inch or so in your forge? If it is sticking into the forge, or too close to the interior surface of the forge, it will overheat, and that may be a problem.
It is pretty difficult to try to diagnose a burner problem with such a sketchy outline of what you have built. All the details are needed, and a picture can often be the best way to check it quickly.
Don't forget to look at the following documents too. There is a lot of information contained in the three documents that can often solve problems.
Troubleshooting Burners and Forges; http://www.reil1.net/troubleshooting.shtml
EZ-Burner Document; http://www.reil1.net/ezburner.shtml
FAQ; http://www.reil1.net/burnerdoc.shtml
Yours,
Ron
Golden Age Forge http://www.reil1.net/gallery.shtml E-Mail: snipped-for-privacy@reil1.net Boise, Idaho

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"RONALD S. REIL

Hi to Ron and all the others that view this group......
I have done all the things that you suggested ...... ie slotted the air intakes and opened up the exhausting ports on the forge . BUT still I can't get the burner to run at idle or low pressure,....... I'm wondering if this is due to the distance from the burner outlet to forge floor ( this forge is made from 20lb propane bottle), and this distance is 7 inches (18cm ) and it is sitting 2cm or 3/4" inside the Kaowool.... thus kaowool to the forge floor is 16cm or 6.25 ".....
When I try to get the burner to run slow or idle it makes a high vibration noise (like blowing air out of your closed lips) then the flame runs back up the burner tube to the fuel tip. Burner Specs are .... 1.25" tube, 12" long , 1.2 tweeco mig tip , with fully adjustable choke....No Flared end
At this stage can I add something to the burner make the flame stay at the end of the burner ..... ( I guess if I do that I'll have to open up the mounting point on the forge )???
I must say the burner is very good when running and will heat bar stock up very quickly.
Any help will be appreciated
Greg in OZ
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