My First Gas Forge - Couple Questions

[Spruce]

Hey All,

 

So this past week I wacked up a forge.  I used an air tank, and made Ron Reil burners.  I read quite a lot on different burner types, but at the local plumbing stores, I could only find the plumbing fittings for a Reil type burner, so that's what I went with.

 

 

It seems to be working awesome - my burner flares aren't flares at all, and it still seems to do well.  I used kaowool I was able to pick up at a local pottery place, and decided to just see if their refractory cement would work.  I forget what it's called, but unfortunately it doesn't - oh well, I will pull that inner layer of kaowool out and reline with ITC.

 

Since I had to order ITC and burner flares anyway, I decided to just order two more burners as well, from hightemptools.com.  So hopefully I should have to burners which work even better, and everything lined correctly as soon as that stuff gets in.  Which brings me to my first question: has anybody ordered from these guys on here?  It's been a week and a half, and still nothing shipped.  I am fine with a small business taking a while, but I would at least like to know what the status is.  Haven't heard anything from them yet, and am wondering if it'll ship any day, or in months from now???

 

Also, right now after my forge runs for 5 or 10 minutes and gets up to full heat, the burners start to 'flutter'.  Not too bad - it still seems to be hot as hell, but it's annoying and I know it's not efficient.  It's a lack of oxygen I believe, because if I blow into the bell, it stops fluttering and starts to roar smoothly again.  What should I do to fix this?  A bigger reducer?

 

One last thing - this puppy seems to spit a lot of heat out the doors - inside is a blue roaring flame, but I do get a pale white/yellow flame that licks it's way out the front door, and a helluva lot of heat coming out.  I'm a complete newb, and maybe this is normal, but it does seem a little excessive to me - to take stuff out of the forge I have to be quick and wear gloves - even leather welding gloves get hot in a hurry.  Seems to me like my burners aren't quite working right, and I'm getting a little more flame out the door than I should.  Thoughts?

 

I'm getting this all set up in my garage, which is not quite a double - kind of a 1 1/2 or 1 3/4 but in an L shape, with high ceilings.  Right now I'm working with the door open and the forge pointing out it - I would like to be able to work with the door closed or partly closed though, to keep noise down so I can work at night - does anybody else out there work in a space this small, and how is your ventilation coping?  Thanks in advance,

 

Spruce

 

 

[C.D. Mitchell]

The flame coming out of the mouth of the forge is normal, it's called dragon's breath, and it will take all the hair off your arm in a hurry.  In regards to your burners fluttering, it could be a combination of things.  Let me try to break down the key factors that make an atmospheric burner work, then you may be able to diagnose your problem:

 

1. Gas volume/velocity/pressure

2. air intake volume

3. mixing

4. combustion

 

Now don't treat this like it's out of a textbook...these are just very basic descriptions of what make an atmospheric burner work.  If #1 isn't correct, then #2 most likely won't be correct either, which means #3 won't work as it should, and #4 won't be successful. 

 

In an atmospheric burner, the propane regulator and orifice size are the two main things that control your gas flow.  If there's too much pressure and not enough volume, there won't be a proper mixture which will result in a less than desirable combustion as you have found.  This means the regulator needs to be turned down to slow velocity and pressure, or the orifice needs to be increased to allow more volume and decrease the velocity and pressure.  For a 3/4 inch burner, I've found an orifice of .030" to be the most effective.  I've run them with .023" and .035" but they do not run as well.

 

In regards to air, you must be able to take in enough air to get a proper mixture which will then result in a neutral and complete combustion.  If your air intake is too small, you will always be running rich with too much fuel in your mixture.  If your intake is too large, you will always be running lean, meaning too little fuel in your mixture.  Because of the venturi effect of an atmospheric burner, the intake of the air is directly proportional to the flow of the gas.  When the pressure of the gas flow increases, the volume of air it sucks in also increases.  However, the volume of air that the venturi can take in at one time is dependent on the size of your intake.  For example, no matter how how hard you try you can only pull in so much air through a straw.  The easiest way to tune the air intake of an atmospheric burner is to make the air intake larger than it needs to be, then find a way to restrict it to the point where you have the proper mixture.

 

When you have the gas flow correct and the air intake correct, the mixing takes care of itself as long as your burner tube is long enough.  For an EZ burner 8-9 inches works well.

 

If you go through factors #1, #2, and #3, #4 will be a success.  You will have a neutral flame, complete combustion of the air/fuel mixture, and lots of heat.  Again, there's a lot of physics that goes on with a burner like this, but hopefully this simplified it enough to make sense and allow you to diagnose and tune your burner.  Once you know what the key components of these burners are and how to adjust them, you will be able to figure out just about anything on your own.

[Spruce]

Thanks for the awesome reply Mitchell:)  I'll troubleshoot and see what I can come up with.  Overall I think it's pretty good, especially for slapping everything together and it working first try.  I think with a little tweaking I'll have it roaring in no time.  Thanks again,

 

Spruce

[C.D. Mitchell]

There's not doubt you built a nice forge, especially for the first go round.  Once you learn how to tune the burners it'll be smooth sailing.  Glad that explanation was helpful, it's just what I've learned from experience.