Diesel Ribbon Burner

After reading the many great threads here, I am officially acknowledging that there may be a better/more efficient method to reach iron melting temps. I thought I was doing great on propane, but thanks to many of you, it looks like it's time to move up a notch... starting with diesel.

The problem I face is that I just built a really cool 27 port ribbon burner. Well, cool as far I'm concerned. And I'm simply not prepared to hurt her feelings by putting her in storage.

With that said, I've been wondering if there's any way to use diesel with a ribbon burner? I can't find any threads on the topic, and hoping someone will help me find a way to make this work.

I'm using a high pressure blower and 2" pipe in a slightly oversized furnace. Is there any chance of success if I introduce the diesel at the back of the burner, and switch from propane once everything gets good and hot?

 

Thanks. I was afraid this would be the consensus.
A ribbonb wasn't my first choice for a furnace, but I placed one of the ribbon burners from my forge into my furnace for testing, and found that I could bring it to steel melting temps in about 30 minutes burning propane. This was much, much quicker than my previous burner. With such success, I figured this was the way to move forward... but now I'm not reaching the same temperatures with my new and improved larger burner. So much for bigger and better.

I'll look into building a specific diesel/oil burner for the next phase, which will also require some mods to my new furnace. In the meantime, do you think I have any chance of success dripping diesel into the tube right before the ribbon burner?

 

After further research, I think I'm ready to attempt dripping the fuel into the ribbon burner. I have nothing to lose since I need to rework things anyway, and I'll learn something from it either way. In fact, it seems like the split airflow could possibly even improve combustion.

One question that pops up after studying oil burners is whether the soot will build up and begin to clog the burner holes or plenum. Any thoughts on this?

 

A diesel ribbon burner would be super neat. I personally wouldn’t drip it into the ribbon burner though. I would do a dual manifold. But it would just be so much work. I personally would not want the flame in any of the metal.

I came across a few problems building my little micro burners. The airspeed is so fast through such a small twisting chamber my diesel doesn’t seem to want to stay lit. My flame won’t start until it hits something hot. During my tests I didn’t start getting flame until 2-4 inches after the end of the torch.

I guess if I was to build a ribbon diesel burner, I would build it on the very same premise as my micro burners (Actually right now, I would not probably change a thing).

If you can mist the Diesel 2 inches away from the end of the burner. You got most of the Battle beat!

Where I ran into problems, when I switched from diesel to WVO I didn’t have the pressure or the droplet size fine enough. Viscosity was playing a game with me.

 

The only reason I would attempt a ribbon burner in a furnace is so I can burn readily available natural gas in it. No real reason to run liquid fuel through a ribbon burner, it's just not what it's designed for. Hell, I wouldn't even bother pushing propane through a ribbon burner. There is much easier ways to burn that stuff.

 

Natural gas ribbon burner huge thumbs up. But you would need about a 1“ Feed-line less than 30 feet from your meter.

I have a half inch line feeding my shop that is almost 40 feet (with my calculated 90° elbow’s). Maximum BTU I can tap off that line is 52, 000 BTU. It is connected to a 30,000 BTU overhead radiant heater. Maybe I’m guessing but, 52,000 BTU might get 5 pounds of aluminum melted (in an hour)???

 

There is more to natural gas and LP then people want to consider. Every 90° corner adds about 6-7 inches of drag, Or pipe length. Total length is a killer in LP or NG systems.

Here is an example, you have A 10 foot run of straight pipe “additive”(from main pipe non-disturbed) and you have 20=>90° Elbows. Each elbow is worth about half a foot. Your 10 foot line with 20 elbows now equals 20 feet. This is a huge reduction in BTU! Go back to the chart.

There is more to the chart than I specified. There is also a whole calculation of all demand appliances which could redirect (or choke) if the system hasn’t been properly designed or sized.

Some DYI’ers I think they have 106,000 BTU coming from a half inch NG pipe. They are dreaming!

How did I lose almost 50,000 BTU for my 40 foot 1/2 line??? A few too many elbows maybe?

More drag is applicable for a bigger 90° elbow’s. A 6 inch elbow is worth 6 feet in drag calculation length ballpark.

This is called A static load calculation.

 

You havent seen my forge have you? 1/2" feed pipe on piddly 7" wc ng. I can reach forging temps with ease.

 

Okay, I get it now. I was just hopeful there was a way to burn diesel through my ribbon burner. I designed my furnace specifically for this burner, so I need to rethink how to introduce a wo burner into it. I'm traveling at the moment and unable to take a detailed picture, but here is what I have on my phone:





The internal diameter is 9 inches, with about 15 vertical inches. 2" ceramic wool with 1/2" of mizzou hardface. I have a 2" pipe running into the ribbon burner, and have connections 18" back for both lp and ng. However, I have way too much airflow, and can only open the air valve about 15% to get a full burn.

I'm now thinking about drilling a new hole 180 degrees from the ribbon burner for the wo burner. I'll tee off my original air stream and reduce it to 1", and thread a 3/8" OD tube through it for the fuel supply. Do you think this will be sufficient?

 

Interesting idea. To clarify, would providing a separate diesel mist directly ahead (or after) the ribbon burner in the furnace offer a sufficient fuel/air mixture for the burn? This would allow the use of the existing air and propane streams, and the propane could be shut off once the diesel mist begins.

 

If I was in your situation, I would probably just add a drip pipe just in front of your ribbon burner. You might even be able to add a little blowing air into it to get the drips moving. The rest of the air can come from your ribbon burner. But that ribbon burner will slowly start melting in time. If you add a little brick baffle to deflect some of the direct flame you might have some more longevity.

 

Got it. Thanks.

Would it be better to locate the drip pipe above the burner, or somewhere lower for more burn time?

Before you replied I was thinking of running an oil pipe through the air pipe->through the plenum->and through one of the center burner holes in an attempt to more closely replicate the moya burner. This would certainly require more effort than your suggestion, do you think one method would produce better results than the other?

 

Boring a hole through your refractory without cracking up your furnace might be tough. I actually like the last idea you had about introducing the oil through the plenum and one of the burner holes. Seeing the amount of air you have available coming out of your ribbon burner you could preheat with propane and then switch over to oil. I don't think I've ever seen one designed that way but that seems like a reasonable modification to what you have without having to break out the chisel. Is your ribbon burner made of metal or refractory? If it's mizzou I don't think it will deteriorate.

Pete

 

Your burner seems to work really well. And it looks like your furnace is constructed around it. Maybe some others might have some ideas. My idea is to get the oil blowing around that yellow strip (I drew), once your refractory is glowing red.

 

Your chart does not work for higher pressure applications, Matt. My natural gas company says they can give me up to 30 psi, if they ever get around to hooking me up.

But if you can't get to high NG pressure put in 2" or 3" pipe and suddenly you have no pressure drop.

Lots of folks use 30 psi propane, I use a 15 psi regulator cranked to 15 psi and get plenty of propane.

 

30 minutes is pretty quick. Maybe you should revisit your propane ribbon burner design and make it work.

I think you could mist diesel into your ribbon burner supply line so long as you keep the flame in the furnace not back in the burner. The fuel and air will help keep the burner cool enough to survive. Start it on propane and once the burner and furnace is hot start adding diesel. Like you said you don't have much to lose just by adding diesel and see how it does. Waste oil would be a different story, you would accumulate tar/contaminants in the hot burner body.