One of the real benefits of a multiple orifice "ribbon" burner is the low flame velocity. The flow is still strong enough to use for circulating the heat in the forge and makes serious mistakes in orientation even worse. 

The way you have the burner oriented in your sketch above is one of those real mistakes, the flame is aimed into a corner which will increase back pressure against the burner orifices and inhibit burner performance clear back to the injector. 

Orienting the burner upwards invites debris falling into and blocking orifices, reducing the number of flames and increasing back pressure both B A D things.

Orienting a ribbon like you show above will work fine if you place it so the flames impinge on the floor on the close side so the flow has a clear path to and then up the far side. Lowering the floor so the cylindrical wall meets at a more obtuse angle will help as well.

Ribbon burners actually work pretty well aimed straight down at the center of the floor. The flow will create turbulence rather than a circular flow in the forge but the low velocity still means the flame will remain inside the forge longer. If you can keep the flame velocity reasonable.

Frosty The Lucky.

On 12/15/2025 at 1:56 PM, tinkertim said:

I used a 3/4" AMAL injector with about 9" of malleable iron pipe

So, this ended up on the back burner (excuse the pun) as a little jiggery pokery got 1 of my burners usable again. It also took a while for recommenting a thread with Frosty to stop feeling weird (not entirely there yet). Well, it stopped being usable yesterday (no idea whats actually changed) so I've just ordered myself a 3/4" AMAL injector. Is 3/4" the size of the pipe nipple? cause that feels awfully skinny.

On 12/14/2025 at 3:47 AM, Drunken Dwarf Iron said:

Also, would forcing the gas and air into the forge at a constant pressure rather than relying on air being drawn in by the gas flow also fix the issue of the forge going out and puttering?

The original (commercial) ribbon burners use fans for positive air pressure. For several years now people on this site have been building successful naturally aspirated ribbon burners, while a few have gone the forced air rout...less successfully. I do not find that surprising. I think their problem is way too much air pressure input, which they then find difficulty in controlling. The likely solution is to use way weaker fans; computer fans are what I would recommend, because the difference between naturally aspirated and computer fan blown is just a whisper more air--and that is all that is desirable. 

Good Morning DD,

I have 2- 3/4 Amal Burners/Injectors, not in the same Forge. They are simple, very little adjustment needed, 3/4 pipe is inside dimension. I have one on a Forge that some people show no respect for someone else's Equipment. They do not Monkey with it, it keeps on Tickin'. I bought 2, expecting I would need a spare, it still is brand new.

You will like it!! Naturally Aspirated.

Neil