Ribbon Burners... Really that Efficient?

[MRB]

The hype today seems to be about the ribbon burner. People claim to have run these at 1/2 psi of propane for a small forge, and essential craftsman on YouTube says he runs his gigantic gas forge at 5 psi for regular forging. Compared to a Venturi burner, however, how relevant is this info?

I have a Venturi style burner made by someone named Steve Geisheimer, and it’s awesome! Very efficient, I run my Freon tank forge at around 3 psi for production forging. I’m looking at building a slightly larger forge, and am considering the ribbon burner if it will save me fuel and be more efficient at heating.

When comparing both styles, figure in the same exact forge, is 3 psi through the small orfice of a Venturi style burner the same consumption as 3 psi through 15 or so 5/16” holes in a ribbon burner? I feel like since the ribbon burner has more individual orfices, it has to burn more fuel at any given pressure then a Venturi would.

Any experiences or recommendations as which burner to use for my next forge?

 

[tinkertim]

Hi MRB,

The efficiency of the ribbon burner comes from having lots of small slow flames, rather than having one large fast flame.

The slow flames spend longer in the forge, completing their combustion, and transferring their heat to the forge lining, to be re-radiated to heat your steel.

The faster flame can be leaving your forge before it has completed its combustion, wasting it's energy as dragon's breath, outside your forge.

I've used both a single-port Normally Aspirated (NA) burner and a Normally Aspirated Ribbon Burner (NARB), using the same 3/4" AMAL propane injector and orifice, and I've found the NARB to give a more even heat to the entire inside of my forge. It doesn't have a hot-spot, which some might find useful for their kind of forging, but I've found I use a lower PSI and less gas for the same amount of heating cycles.

I'm only a part-time hobbyist smith, but I'm also a full-time engineer, and I appreciate efficiency. For the way I work, the NARB is more efficient for me. Other's mileage may vary, but I hope you find my observations of use.  Some of my NARB investigations & development can be found in other threads if you are interested.

Tink!

[Irondragon Forge ClayWorks]

Are they really that efficient.....yep. It's one reason most furnaces have multi-port burners.

[MRB]

Interesting. That’s another good point. I forgot there is the naturally aspirated (narb) ribbon burner, as well as the blown version (barb). I was referring to the blown version, but I wonder how the narb vs blown version compare to each other. My current forge is so efficient, I didn’t think I would be able to find something even more efficient. Before spending a few hundred on a blow assembly, I wanted to make sure I would see a notable difference

[Spronez]

I have to search for who did the math, but as far as fuel use is concerned- a ribbon burner and a na burner use virtually the same amount of fuel in a given amount of time.

It comes down to the size of the gas line orifice. In a na burner it is very small, in a ribbon burner it is relatively much larger. 

So while a ribbon runs with lower pressure, it is spewing out more gas at that lower pressure. A na typically runs at higher pressure but a much smaller stream of gas.

 

Regarding efficiency as it relates to full combustion and spread of even heat- ya typically a ribbon wins out based on its design. But a well built na and forge can do just as fine a job at full combustion. Given the different designs - aimed burn vs a spread - it is more difficult to get an even heat inside the forge chamber, with a na. (Then there's the whole swirl, forge interior shape, etc etc). 

Sometimes though a hotspot can be just what a blacksmith wants; to direct more heat at a certain place on their work. So efficiency is relative to the work I guess

[tinkertim]

Hi Spronez,

Your statement about ribbon burners having large orifices at low pressures is ONLY applicable to blown ribbon burners.

Normally Aspirated Ribbon Burners (NARBs) run a smaller orifice at higher pressures, as they need to induce air into the gas flow in exactly the same way as a single-port Normally Aspirated (NA) burner does.  I know this for a fact as I used exactly the same 3/4" AMAL propane injector and orifice for an NA and a NARB setup in the same forge with the same regulator, etc. The only difference was Single-Port Vs. Multi-Port.

This is why I can say that the NARB was more efficient (lower PSI and therefore less Gas used) for the same number of heating cycles to the same high-orange temperature.

These are the facts based on my observations with my near-identical setups. Others may have observed other behaviours with their setups, but I won't be going back to a single-port forge any time soon, as it costs me more money to run.

YMMV.

Tink!

[Brandon Ade]

OP, the claims that blown ribbon burners can run at low PSI are true.

I can run my 4.25"x8.25" ribbon as low as 1.5 PSI (with my 1/4" needle valve fully open) inside a forge chamber of ~1600 cuin. before flame out.
However, more typically I set my propane regulator to 5 PSI and use my 1/4" needle valve to dial in flame at higher air volumes.
I have not had a need to run above 5PSI as I still have to reduce gas volume with a needle valve. This gets to forging temp in 25 minutes from cold.

I have no comparison to the consumption of other designs, so I am only speaking to your first post questioning the low psi claims.

[Frosty]

They can run at low psi because there is no reason to develop a high speed gas jet to entrain combustion air so the gas orifices are typically large. The larger the opening the more will pass at lower psi or velocity.

Frosty The Lucky.

[Gradient]

Hi. I just joined this conversation and I have a question. 
Why not use a continuous narrow slot instead of individual ribbons? Width x length = area of circular input. Would this work equally as well as a ribbon burner?

Secondly, has anyone tried a dual or quad sided burner such that the flames hit the crucible on four sides instead of one?

I’m building a 55 gallon burner (top loaded) and am considering these ideas. 
Thanks,

Paul

[ThomasPowers]

Are you talking about a foundry and not a forge?   The swirl of a properly aimed single burner should heat the entire perimeter of a crucible, why settle for 4 sides?

[Frosty]

Paul: Please do some more reading, I don't understand what your asking, your terminology makes no sense at all.

We thrive on helping folk figure out how to do things and love good questions but they have to make sense.

Frosty The Lucky. 

[localsmith]

I don't personally believe that a ribbon burner is more efficient than any other burner design. 5PSI is a lot of gas when it's coming out of a 1/4" orifice. Each of the holes in a ribbon burner creates a high speed flame that ejects from each hole and ends up creating a wider hot spot. Based on what I've seen, a well tuned venturi burner is going to be significantly more efficient than a ribbon burner and it does not require electricity or blowers. Ribbon Burners are typically used in larger forges that are going to consume significant more gas regardless.

I've tested a few naturally aspirated ribbon burners and all that they end up doing is focusing the flames wherever the holes are facing. You don't get any vortex or good swirling action because the flames move out of the holes at a very high speed. It's similar to trying to create a swirling action inside of a cylinder using a hose with no head on it vs a hose with a shower head attached to it. Those small fast flames move quickly but lack momentum so they end up creating a very focused hot spot within a forge which is probably a reason why most ribbon burners are quite large (to create a larger hot spot within the forge). 

[Buzzkill]

My personal experience is different than yours.  I agree in the sense that it takes a certain amount of fuel combined with the right amount of air to produce a certain level of heat per unit of time.  However, I get plenty of swirl in my forge using a naturally aspirated ribbon burner.  I also get a far more even heat than I did with a single port burner.  There is no noticeable hot spot anywhere in the forge once up to temperature.  My forge is quite small - around 240 cubic inches.  It also seems to me that since the smaller flames lose momentum more quickly than a single larger flame, more of the heat stays in the forge a little bit longer which results in slightly better efficiency than I got with the same orifice/mixing tube setup as a single port burner.  Your mileage may vary.

BTW I've never heard of anyone running a forced air ribbon burner using 5 psi through a 1/4" gas supply orifice.  Usually people with that size gas supply opening report running around 1/2 psi.

[tinkertim]

I have to agree with Buzz.  I converted my single-port burner to a Naturally Aspirated Ribbon Burner (NARB), and used it in the same forge with the same jet size, etc. so comparing like with like.

I found I could maintain the same heat at a lower PSI, and with a much more even heat throughout the forge and less dragon's breath. The many smaller flames are aimed across the roof of my forge and swirl round onto the floor, making the whole of the inside an even hot temperature.  The burner is also much quieter in use and uses less gas.

With all the positives for me, I'll never go back to a single-port burner in a forge.  I will make a mini single-port for a hand-held burner though.

Localsmith, with your reference to a Ribbon burner with many high-speed flames, and mention of a large gas orifice, are you sure you are not referring to a Forced-Air Ribbon Burner?

Tink!

[Frosty]

Localsmith: Who's NARBs have you tested? NA(Naturally Aspirated), multiple orifice burners with high velocity flows won't stay lit, they blow the flame off the block. 

I'm running NARB one and two in approx 700 cu/in rectangular forge. I mounted them aiming straight down at the center of the floor because I LIKE a hotter zone. The strips directly under the burners only stay hot a short time and the entire liner reaches a uniform temperature. The flame flow pattern is surprisingly random, the only place I can make a heat shadow is directly under a piece of stock. If I raise the stock 1/4" off the floor the flame swirl patterns heat under the piece.

I don't know what experience you actually have but it certainly isn't with commercial multiple orifice burners, NA or gun, nor with a properly home built version of NARB. Iforge has many members who work with commercially made multiple orifice burners and have made versions themselves. Many other members who've made NARBs have changed them to suit themselves or use the NA inducers they have. 

The only people I've heard making your arguments have used gun multiple orifice burners with dangerous amounts of dragon's breath. Builds made with John Emerling's plans as seen in the ABANA magazines and reposted on other web sites such as Wayne Coe's. Looking at photos and videos of those ribbon burners in action and reading the plans, I have a printed copy in a ring binder, is what inspired me to make NARB. 

If you have evidence I would appreciate seeing it. What you're saying is contrary to even my experience even with the earliest prototypes with the wooden burner blocks. Please, I'm asking sincerely to provide me with the evidence, I made NARBs work but I'm far and away not an expert with multiple orifice burners.

Frosty The Lucky.

[localsmith]

On 5/5/2021 at 1:26 PM, Frosty said:

Localsmith: Who's NARBs have you tested? NA(Naturally Aspirated), multiple orifice burners with high velocity flows won't stay lit, they blow the flame off the block. 

I'm running NARB one and two in approx 700 cu/in rectangular forge. I mounted them aiming straight down at the center of the floor because I LIKE a hotter zone.

I've only tested my own. I've never used a commercial ribbon but I'm sure they would work much better than the ribbon burner that I made. The nature of the design of a ribbon burner is to push high velocity low pressure flames through each hole in the burner block (the small outlet holes in a ribbon burner produce high velocity flames with low pressure). The thing that I see with most ribbon burners is that each flame combines to form one large flame at the front of the burner block. To me, the main advantage of a ribbon burner is you get a much better heat spread. I don't see them as being any more efficient than a well turned NA burner. They seem ideal for heat treating and forging long stock.