Panel Burner?

[Wrench53]

Hello all! I’m a plumber by day, and as such I install and replace a lot of in demand boilers. I took the fiber metal burner plate out of a 200k btu combination boiler and made this. This was the first iteration and test. Not sure how it will hold up in a forge or furnace, but hey, fire!

[George N. M.]

Welcome aboard from 7500' in SE Wyoming glad to have you.

IMO that blower would put out WAY more air than is needed in a home or shop forge.  And the filter end would just melt in a forge fire.

That said, the blower could be used in a forge if that was all you had if you used an air gate to dump most of what was being put out by the blower or had a rheostat on the motor turning the blower that thurned it at pretty low RPM to prevent blasting your fire apart.

"By hammer and hand all arts do stand."

[Frosty]

Welcome aboard Wrench, glad to have you. If you put your general location in the header you'll have a better chance of hooking up with members living within visiting distance.

Much as I hate downloading videos I watched yours hoping I'd get to see the panel burning. Do they always burn that rich? What do they look like burning neutral? Will the materials survive a 2,700f environment and probably getting jabbed and scraped on by steel?

What are the inner workings of them like, maybe have a link to drawings, parts list, manual you can share? 

I'm a propane burner guy and I'd love to know how a panel burner works and if it's maybe reasonably possible to home build them in a more reasonable size. What you have is probably at least 2x a practical size for a small scale forge.

Frosty The Lucky.

[Wrench53]

Hi George. I’m in Central New York. Yeah, that blower is horrible, but it’s what I had. It does have a rheostat but it’s cheap xx xxxx. I think it was the cheapest blower I could find.
Frosty, the burner came out of a Navien NCB 240 combination boiler. That was the first burn and I was messing with the gas and the blower. At standard household gas pressure they run around 97% efficiency and it’s just a small panel of blue flames. It’s designed to fire down through the heat exchanger. They’re reliable, if they’re serviced annually. https://s6e1619fceb451b6f.jimcontent.com/download/version/1512634722/module/11899834199/name/Navien Gas Boiler NCB-Service-Manual.pdf

Also, the metal mesh was cool to the touch 30 seconds after shut down.

Edited December 13, 2022 by Mod30
Language

[Buzzkill]

Hmm.  That looks a lot like the inner workings of the Richmond tankless water heater I installed last year.   Mine runs on LPG, so if it fails I'll definitely scavenge the burner assembly out of it.  Like the others here, I do have concerns/doubts about it holding up in a forge environment.  However, if it does hold up that gives us another potential source for burners without a lot of casting.  Thanks for bringing this up.

[Wrench53]

You’re welcome Buzzkill. I have 3 more of these old units that I’ve salvaged so I can sacrifice 1-2 to the forge gods in experimenting. I ran it for about 2 minutes and the fiber metal was cool to the touch 30 seconds after shutdown. I’m going to see if Navien has the temp rating for the fiber, the housing is aluminum.

[Buzzkill]

If the housing is aluminum then obviously it would have to be insulated from the forge chamber quite well to avoid becoming liquid.  Can the fiber mesh be reasonably removed from the housing without damaging it?

[Frosty]

Thanks for the manual and I'm not surprised it doesn't show how the burner itself works, it's a replacement part. LOTS about replacing it. page 136 is about the best pic and . . . . Thanks for the link, seriously. It's not the first time I've gotten what I asked for and been less than satisfied. I'm used to it. (we need a fatalistic shrug emoji!)

The blower for these units is palm sized. I'm wondering if a naturally aspirated version is doable without  exceeding the normal home shop equipment and expertise. From what I could see the thing is not much different than a multiple outlet burner. Hmmmm. Maybe when it gets warm I'll hit the local HVAC service company in search of a couple to take apart and see. 

Funny, we'd be talking about NA propane forge mantles instead of burners. Sounds like fun.

Frosty The Lucky.

 

[Wrench53]

Buzz, yes the fiber metal can be removed. It’s held to the manifold by 6 bolts. I’ll check to see if the frame can be separated easily and let you know. 
Frosty, the blowers that come with the unit are 24v and connect to the manifold in a pretty unique way. Connecting to that setup would challenging with the tools I have. I’ll take some more pics tonight and post them.

[Wrench53]

Here you go, guys. The small tube is from the gas valve. The blower sucks gas and fuel in. The oval with the rusty screws is the gas orifice, this one is for Natural Gas. Side note, that orifice is the only thing you have to change to convert it to LP. The screen frame is actually stainless and it looks sintered to the frame. Frosty, you can see the funky slotted collar that connects the blower and manifold. 

[Frosty]

Oooh, that's doable! I love a gun burner that introduces the fuel gas into the blower, especially if it's been designed that way. 

A little tweakage of the plenum's shape  to get everything farther from the forge chamber and some creative thinking to mount the fiber and outlet (diffuser?) plate and it might make a good forge burner. If nothing else I'll bet it'd make a nice heat treat oven.

Frosty The Lucky.