New frosty "T" burner! What causes flame outs?

[Adhamh]

Hi All,

I got a T style burner up and running. It seems to work well, although it might be too big for my paint can.

Anyway, I'm subject to "flame outs". Basically it seems like I'm losing the Venturi effect. When this happens it seems like the flames stops for an instance and then reignites, but it burns out the T ends and in the forge itself. It doesn't seem there's any pressure behind the flame.

This seems to happen more when material is not in the forge than when there is material....

I thought maybe I had my regulator set too low, but if I crank it up more ill have three feet of dragon's breath!

[Adhamh]

Some video and a pictures....

trim.7038C7AC-D3D3-423F-BCD7-C3882029911F.MOV

[Aden Cassidy]

I just got a gas forge and am having similar problems. Was fine yesterday but today kept on.... well you could call it chuffing, the flame would puff out then re-ignite. Think it may be the gas bottle is empty from what I could see with too much air in the mix with not enough gas is the reason I think.

[Chinobi]

i have observed this happening on brand new chili habaneros (twin burner model, that might not be the right name) when running both burners off a single 20lb tank.  not a problem with the forge at all, the things are incredible, but the twin burners were consuming too much propane causing the tank to freeze up and drop pressure.  so that could be a contributing factor in both instances.  empty bottle is easy to diagnose by lifting it, if you can see a frost line developing on the bottom it might be freezing up instead.

 

you might try elevating the intake end of the burner off the firebrick with a spacer so there is clear space for unimpeded airflow around the entire inlet as well.  that could restrict airflow and mess with your combustion.

 

thats about all im good for, sorry :)

[timgunn1962]

Chuffing is often (usually?) caused by too low a mixture speed. For a Venturi burner, this is effectively the same as too low a gas pressure.

 

The flame-front starts to move down the burner tube, through the gas/air mixture, faster than the mixture is moving the other way. Somewhere near the Venturi, it goes out because it has run out of mixed gas and air. There's a delay while fresh mixture makes its way along the burner tube to the chamber, where it ignites and the process repeats.

 

Turning up the gas pressure usually solves the problem. Obviously adjusting the regulator won't work if the low pressure is due to a frozen cylinder.

 

Once the mixture speed towards the chamber is higher than the flame speed, the flame will stay in the chamber

[Aden Cassidy]

Got a new gas bottle and for me problem solved. Had over an hour of forging my first piece of 1095, now to grab my anvil n stump from my local blacksmithing group so don't have to sit on the ground using a large piece of railway.

[Adhamh]

Interesting. There seems to be plenty of propane in the tank. My regulator tops out at 20 PSI, but I don't have a pressure gauge so I don't know where I've actually got it.

I'm pretty sure my tank isn't empty, but it is less than half full.

Ill try moving the intake around and cranking up the pressure just to see if that help. Although as much heat as this monster puts out I don't think I actually need more pressure.

Oh another data point. I used to have a 3/4 to 1" reducer on the end for my flare. The flame was actually burning inside the flare, and heating it up. I removed the flare and put the nozzle into the insulation so it would act as a nozzle. The end of the burner isn't getting red hot but now I have this chuffing problem.

[ThomasPowers]

Wind is another factor, as is alignement. I had to move my aspirated propane forge into shelter Saturday when the wind picked up.  Looked so good in the little building we used that the site owners suggested I leave it there....I'm trying to get them to build their own set up.... 

 

I looked at that video and noticed it didn't show anything about the regulator or gas bottle---sort of like asking why you car is having engine issues and only showing a picture of the body...

[Jack Evers]

I have a half dozen bottles around, Couple forges, BBQ, weed burner, camper, etc. I'm a codger so most of my stuff has the old style brass bottle connection that screws inside the valve housing on the bottle with a left hand thread and requires a wrench for a tight connection. .My camper has the newer plastic connection that goes over the bottle neck with a right hand thread and is designed for hand tight.. I have one bottle (I've marked it so I know which one it is) that will not give me pressure on my camper. It will pass enough gas (that sounds bad doesn't it) to sort of operate the gas range, but not enough to operate the water heater or furnace. It works fine on high draw items like my forges or weed burner that have the old style connection. If you have the newer style, you might want to consider a bottle exchange rather than a refill and see if its a valve problem.

[jcornell]

Oh another data point. I used to have a 3/4 to 1" reducer on the end for my flare. The flame was actually burning inside the flare, and heating it up. I removed the flare and put the nozzle into the insulation so it would act as a nozzle. The end of the burner isn't getting red hot but now I have this chuffing problem.

 

 

I suspect this may be your problem - if you don't like the reducer and don't feel like buying a flare, go to the big box store and pick up a 3/4" conduit connector (you'll find it in electrical, not plumbing).  It's probably got a shiny galvanized coating, so pickle that off with acid (add acid to water, not the other way around) screw it onto your burner tube and you're in business.  One of the functions of the flare is to keep the burning more or less in one place.

[Adhamh]

 

Oh another data point. I used to have a 3/4 to 1" reducer on the end for my flare. The flame was actually burning inside the flare, and heating it up. I removed the flare and put the nozzle into the insulation so it would act as a nozzle. The end of the burner isn't getting red hot but now I have this chuffing problem.

 

 

I suspect this may be your problem - if you don't like the reducer and don't feel like buying a flare, go to the big box store and pick up a 3/4" conduit connector (you'll find it in electrical, not plumbing).  It's probably got a shiny galvanized coating, so pickle that off with acid (add acid to water, not the other way around) screw it onto your burner tube and you're in business.  One of the functions of the flare is to keep the burning more or less in one place.

 

I read else where that people had done this intentionally and it worked well.

 

I don't mind the idea of a flare.  My flame is a little floppy right now, so it might even be useful.

 

The problem is that that flare was getting red hot, and I know that's not good.  Looking to solve that problem I took it off.  Maybe I should try a coupler instead of a reducer?

[Adhamh]

Wind is another factor, as is alignement. I had to move my aspirated propane forge into shelter Saturday when the wind picked up.  Looked so good in the little building we used that the site owners suggested I leave it there....I'm trying to get them to build their own set up.... 

 

I looked at that video and noticed it didn't show anything about the regulator or gas bottle---sort of like asking why you car is having engine issues and only showing a picture of the body...

 

 

Sorry about that.  The tank is tucked away in the back.  Actually things seem better today.  I don't know if its because I've been trying to run at higher pressure or because I'm using a newer tank.  The regulator is about 10 years old  Its a Chen Fong 9008 and came with a turkey fryer I used for brewing beer.  Based I what I looked up online it maxes out at 20 PSI.

[Frosty]

Wow, I don't turn my computer on for a couple days and a "T" burner tuning issue comes up.

 

What size jet are you using?

 

If you hit the local plumbing supply and ask for thread protectors they're likely to give them to you. They're screwed onto lengths of pipe to protect the threads in shipment but are not suited for coupling pipe in use so they usually get chucked i a box till someone hauls them to the dump or whatever.

 

A lot of things can cause chuffing but it's usually too low a propane velocity meaning you may be using too large a mig tip. I have my best results with a 0.035" mig contact tip on a 3/4" burner. You describe a fluttery flame which says to me a slow flame and also suggests too small a jet.

 

Back pressure can cause problems too and if the flame velocity is too low back pressure will have more effect.

 

Wind is a hassle naturally aspirated burners are subject to though commercial versions are much less sensitive. They're expensive though.

 

In future shoot your pics from the side of the forge so we can see the dragon's breath and another in the door before it gets, glare the picture out, hot so we can see the flame shape and characteristics.

 

Frosty The Lucky.

[Adhamh]

Wow, I don't turn my computer on for a couple days and a "T" burner tuning issue comes up.

 

What size jet are you using?

 

If you hit the local plumbing supply and ask for thread protectors they're likely to give them to you. They're screwed onto lengths of pipe to protect the threads in shipment but are not suited for coupling pipe in use so they usually get chucked i a box till someone hauls them to the dump or whatever.

 

A lot of things can cause chuffing but it's usually too low a propane velocity meaning you may be using too large a mig tip. I have my best results with a 0.035" mig contact tip on a 3/4" burner. You describe a fluttery flame which says to me a slow flame and also suggests too small a jet.

 

Back pressure can cause problems too and if the flame velocity is too low back pressure will have more effect.

 

Wind is a hassle naturally aspirated burners are subject to though commercial versions are much less sensitive. They're expensive though.

 

In future shoot your pics from the side of the forge so we can see the dragon's breath and another in the door before it gets, glare the picture out, hot so we can see the flame shape and characteristics.

 

Frosty The Lucky.

 

The pipe itself is 1".  One thing I like about not having a flare is that the burner won't ignite outside the forge.  Should I just forget about this and get a working flare?

 

I'm actually not using a mig tip.  I'm using a part from piece from my old turkey frier.  Here's what it looks like.

 

 

 

The actual opening where the propane comes out is about 1/8".

 

Before today it was screwed in as far as it would go.  Today I moved out as far I it could safely go.  I didn't have any chuffing at all, but I seemed to get more scale than I was getting before.

 

Picts in this new configuration:

 

 

 

 

Yes, I need to mount the burner better to improve safety.  

 

 

 

[Broomhead]

Could someone link me to Frosty's T burner topic? I've searched multiple times but haven't come with anything.

[WayneCoeArtistBlacksmith]

Today I Googled "Frosty's T burner and came up with this:  http://www.google.com/imgres?imgurl=http://anvilsandinkstudios.com/T_Jet_burner_concept.gif&imgrefurl=http://anvilsandinkstudios.com/burner.html&h=1572&w=1123&sz=28&tbnid=-v-oaGOxqeaZwM:&tbnh=90&tbnw=64&zoom=1&usg=__s5rzBFrtSb2_yE-8Qt9gA-H0sNo=&docid=SPbMU3tkH7DhcM&sa=X&ei=l1CLUomrN8qzkAfs64CIDw&ved=0CDUQ9QEwAQ

 

You can look at the concept drawings then click "Visit Page" then click "Frosty's Narrative".

 

I hope that some other responses come up so that we can have even more information on this.

[Broomhead]

Thank you Wayne. I was mistakenly searching this site for a thread or post.

[wpearson]

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[Dodge]

On the flare topic, if you mold a flare into your liner (if you use a blanket and rigidisizer type or castable or rammable refractory ) or carve into fire brick where the burner enters, you don't have to worry about the flare burning up. OTOH, as I understand it, (and I really don't understand the science behind it) you don't necessarily need a flare unless you are running the burner outside the forge. Many burners won't keep a flame outside the forge but work fine inside. In fact, I have found that the "T" burner really doesn't need an actual flare shape to run outside. Just a larger diameter tube on the end of the burner tube to change the pressure (and I think it mimics the back pressure that would be present inside the forge) so it will hold the flame.

E.G.

 

 

 

The short piece of pipe isn't even welded on. I wanted to be able to slide it back and forth to get the best flame.

[wpearson]

 

The problem is that that flare was getting red hot, and I know that's not good.  Looking to solve that problem I took it off.  Maybe I should try a coupler instead of a reducer?

flares get hot replace when burned out

wes

[Dodge]

Flares also gets burned up faster when they are too close to the inside of the forge. Hence the beauty of molded in flares. How close is the end of your flare to the inside of your forge Adhamh?

[Frosty]

Your flame looks pretty good if a little soft. A flare reduces pressure in the burner tube making induction stronger. This makes the burner less susceptible to breezes and back pressure.

 

I use the thread protectors instead of flares and they do all I need them to. I don't use forge burners outside a forge, I have air/oxy propane torches for that and those work SOOOOO much better.

 

Thanks for posting links to the concept drawings and narrative of my burner, I never can find the darned things. I probably should compose a more together set of drawings with parts list and a better description of construction and tuning. Now, where'd I put those round tuits?

 

I'll be more than happy to answer any questions.

 

Frosty The Lucky.

[Adhamh]

Your flame looks pretty good if a little soft. A flare reduces pressure in the burner tube making induction stronger. This makes the burner less susceptible to breezes and back pressure.
 
I use the thread protectors instead of flares and they do all I need them to. I don't use forge burners outside a forge, I have air/oxy propane torches for that and those work SOOOOO much better.
 
Thanks for posting links to the concept drawings and narrative of my burner, I never can find the darned things. I probably should compose a more together set of drawings with parts list and a better description of construction and tuning. Now, where'd I put those round tuits?
 
I'll be more than happy to answer any questions.
 
Frosty The Lucky.

How would I fix the soft flame?

Also, I'm seem to be getting a lot of scale build up. I'd also like to try some welding. How could I make the flame less oxidizing?

[Dodge]

Oxidizing flame means either too much air (oxygen) or not enough fuel also known as a lean mixture. Add more fuel or reduce air.to produce a carburizing flame. This will help reduce scale some, but gassers are notorious for producing scale and some is likely to form as soon as you remove from the forge and is exposed to the oxy in the air.

[Frosty]

Oxidizing flame means either too much air (oxygen) or not enough fuel also known as a lean mixture. Add more fuel or reduce air.to produce a carburizing flame. This will help reduce scale some, but gassers are notorious for producing scale and some is likely to form as soon as you remove from the forge and is exposed to the oxy in the air.

 

Nothing wrong with a soft flame if it's producing enough heat. In truth a soft flame is good for area heating.

 

Where is the scale forming? If it's inside the forge it's too lean, choke a it little or move the jet farther in. If you're getting a little orange dragon's breath coming out the door the mix is probably okay and may be turbulence drawing air in the door.

 

Hot steel WILL scale when exposed to air. You have to move fast when you draw your steel. You just can NOT stand there holding a piece of glowing steel and try to decide what to do. Think in the fire or better yet, do your thinking before it goes in the fire.

 

Frosty The Lucky.