Burners 101

[Mikey98118]

On 3/19/2023 at 10:05 PM, Mikey98118 said:

like to use a needle valve at the burner, so that I can fine tune without turning away from the action

But, but, but, didn't I state over and over that I fine tune Mikey burners out in the open air, huh, didn't I ?!? Yup, and I stand by that. However, once the burner is mounted in the forge, and the interior surfaces are up to red heat, I like to use back pressure to fine tune the burner flame for that very last scintilla of power. Past red incandescence, there is to much internal light in the forge to see the flame well enough for this final tuning. Before red heat, internal conditions in the forge haven't change enough to significantly alter the burner flame. But, doesn't the burner do a very good job, without this final step? Yup; but proper geeks never quite short of EVERYTHING

[Frosty]

I just noticed your post Mike and I'm a little confused. "proper geeks never quite short of EVERYTHING," 

Does that mean geeks are greedy or not? EVRYTHING? even with all the junk I have it's a long way from EVERYTHING!

Frosty The Lucky.

 

[Mikey98118]

On 3/26/2023 at 7:52 PM, Mikey98118 said:

proper geeks never quite short of EVERYTHING

It should have read "proper geeks never stop short of EVERYTHING." My stumbling fingers, and stumbling mind create more typos all the time

Everything that can be squeezed out of a design.

[Frosty]

I took you to Mean never QUIT short of everything but it was such a juicy straight line I couldn't resist.

Thanks again Mike. 

Frosty The Lucky. 

[Mikey98118]

Never fear, Frosty. I can slow down, and clean up those typos. But the enemy at the back of my mind, will always slip in a straight line, hear and there, for your viewing pleasure. You might as well take advantage of the opportunities; as he has already done the damage

[Mikey98118]

That is to say, that your quips help break up the awkward silence

[Frosty]

Like I can pass on a chance to make a smart Alec remark. 

Frosty The Lucky.

[Mikey98118]

So Greg, are you ready to start planning on what size and type burners to mount in what size and type for your next forge?

[Mikey98118]

More on fuel economy

First class refractory and insulation choices are often considered too expensive to be used in larger forges; this is a mistake. Propylene fuel costs about one-third more than propane if used from refillable cylinders; it also gets about one-third hotter, which means that the burner can be cut back a lot, for the same heat level in your forge, or  smaller burners can be used. Either way, the exchange rate of internal atmospheres can be slowed; this reduces fuel consumption for work heated drastically, since most of the heat loss in forges and casting furnaces is through the exhaust port. Employing propylene calls for more expensive materials in the forge and in any flame retention nozzle, to withstand increased flame temperatures; thus, cheaper building materials costs you once again.

The other way to slow the exchange rate of combustion gases is to use several smaller burners in place of  fewer larger burners, since exhaust gases begin slowing as soon as it leaves the flame envelope. The smaller the flames the faster their speed slows down. And of course, multi-flame burner heads do the very best job of maximizing this advantage.

[Greg in Maryland]

Mike,

 I am thinking the “d” shaped forge we discussed earlier.  The burner is still up in the air.  What process would you recommend to decide on what type of burner to deploy?

[Mikey98118]

Either four very small burners positioned low in one side wall, and aimed upward and a little inward, so that their flames have a maximum of distance to burn completely, before impinging on the forge floor. Or a ribbon burner placed and aimed in the same position.

The ribbon burner would still beat out the four burners for slowing heat losses through the exhaust, but not by much. While certain of the individual burners can be shut down, and part of the forge partitioned off with a movable internal wall, to in effect, change forge size for small parts.

Just one more personal choice to make

[Frosty]

Isn't it funny how many folk ask questions thinking we'll tell them what to use and what we really do is give them more decisions to make?

Frosty The Lucky.

[Mikey98118]

Well, those questions have to be dealt with before anything worthwhile can even be started. It's the people who try to avoid these questions who usually end up creating very expensive door stops

[Frosty]

True but just try to imagine how many spectacular careers we've killed before they got started making expensive door stops! There's a market for anything out there.

Frosty The Lucky.

[Greg in Maryland]

I like the idea of a ribbon burner.  I have a pine ridge burner that I bought a long time ago and never built a forge for it.  Maybe now is the time?  It is a LPI 190 which is good for 1 cubic foot of area.

[Mikey98118]

I like the idea of using ribbon burners in "D" forges generally, and those particular ribbon burners, especially. However, since the size and shape of the plenum chamber is already set, you will probably need to adjust its position higher up the side wall. some people position their ribbon burners at top dead center; that is a mistake, Centered at two o'clock is a much better idea.

[Greg in Maryland]

Is the plan to use Kast-o-lite 30 for the flame face?

[Mikey98118]

That is always a good plan; with ribbon burners, it's an even better plan.

[Frosty]

Nice burners Greg, I wonder how much hassle it'd be to use NA instead of a blower. 

Frosty The Lucky.

[Greg in Maryland]

Frosty,

My lack of knowledge begs me to ask:  Will it put out the same heat/btu?

[Mikey98118]

If you are referring to fan-blown burners; they usually put out more Btu than a naturally aspirated burner. However, that doesn't necessarily mean that your equipment will reach higher temperatures. More commonly it means that your equipment will push excessive levels of heat right out the exhaust vent.

Understand that this is not an unavoidable condition. However, people who don't want to properly build and tune an atmospheric burner are unlikely to properly build and tune a fan-blown burner, either.

Both types of burner can be constructed and run skillfully--or not.

There is a company that makes commercial ribbon burners; their burners are fan-blown, and make perfect flames in their advertising photos.

Giberson has been making multi-flame ceramic burner heads for fan-blown burners for over half a century.

Either type will provide superb results, so we know it can be done.

[Mikey98118]

It gets a little harder to make perfect flames in naturally asiprated ribbon burners, but some guys on here are doing so.

Being naturally inclined to cheat, cheat, cheat, I would include a SMALL squirrel cage fan of the type used on computers at the burner's air entrance, so as to maintain better control of mixture pressure in a home-made ribbon burner's plenum chamber--not to provide more force to the flames.

[Greg in Maryland]

Copied this from the Pine Ridge  Burner website:

Does the burner require a blower?

Yes. Because the burner's plenum needs to be pressurized in order to have all the orifices burn evenly, you will need a blower. A venturi or "atmospheric" system using only high pressure gas will not work.

[Frosty]

Gun burners can typically be turned up higher than NA burners. All you have to do is adjust the propane to match the air. 

Just be aware the burner and forge are an integral unit, a machine. Turn the burner up enough and it starts blowing the flame through the forge (dragon's breath) where it doesn't do any good. If you look at some of the plans and as built and in use videos online you'll see forges that do indeed get steel to welding, even melting temps but they're blowing flame out both ends in a couple cases about 4'. That's FOUR FEET of propane burning outside of the forge! 

I didn't se your last post with the Pine Ridge quote. That is a Pine Ridge burner and is DESIGNED to require high static pressure. If you have a Pine Ridge burner block use a blower.

Those videos and plans are what caused me to develop the NA ribbon burner, the "official" designs were terribly unbalanced. The cause was a bit of mistaken intuitive logic which caused ONE problem that required crazy  high static pressure from the blower to overcome the mistake.

I don't argue for either basic type, gun or NA. What I encourage is buying or building a balanced system.

Take a look at the multiple outlet burners built by some of the guys on Iforge, they put mine to shame for encroaching on commercially made burners.

Frosty The Lucky.

[Mikey98118]

51 minutes ago, Frosty said:

don't argue for either basic type, gun or NA. What I encourage is buying or building a balanced system.

Yup!

I remember back in 1999, (when I first started looking into building a gas forge); there were lots of guys busy debating whether fan-blown or naturally aspirated burners were best. It all sounded like "my dog's better than yours" to me. Either kind of burner is exactly how good it is designed and built to be--for better or worse.