Black sooty smoke from jet gas burner

[HRNCBrewer]

I have a 23 jet natural gas burner for my brew kettle like in the attached image.
I also have a similar, but smaller (fewer jets) burner for the HLT.
The smaller burner works fine, but the 23 jet burner puts out lots of sooty black smoke.
I added a natural gas pressure regulator, but that made no difference.
I believe the problem is insufficient air to the jets so I am getting incomplete combustion (lots of CO!).
Can someone tell me how I can fix this so that I get more oxygen to the burner?

Thanks for any advice.

Tony B.

 

[PCABrewing]

Does it burn blue flame at very low setting?
That picture is too small to get a good look at the configuration, where does the air come in. Is that what the small hole at the base of each jet is for?

 

[day_trippr]

It is correct that super-rich gas mixture will result in incomplete combustion. Those jets are specific to the gas supply they're to be used with, so if they were meant for domestic NG but are being run on propane that would be a problem. The typical wok burner needs to be re-jetted to move from one gas supply type to the other...

 

[Broken Crow]

I have a 23 jet natural gas burner for my brew kettle like in the attached image.

I added a natural gas pressure regulator, but that made no difference.

The question in my mind is: Are you using natural gas?..'cause if you're trying to use it with propane, you'll need to drill out larger orifaces, but then there's no going back to natural gas without buying new jets as the ones in your pic have a fixed oriface on each jet.
If it's a complete natural gas system then look at adjusting the regulator;

 

[HRNCBrewer]

The question in my mind is: Are you using natural gas?..'cause if you're trying to use it with propane, you'll need to drill out larger orifaces, but then there's no going back to natural gas without buying new jets as the ones in your pic have a fixed oriface on each jet.
If it's a complete natural gas system then look at adjusting the regulator;
View attachment 883528

Thanks for the reply. Yes, I am using NG. The regulator is at the front of my brew rig and I have the 3 burners in series: mash tun, HLT and then the boil kettle. If I turn the pressure down at the regulator it may affect the first two burners which are currently working fine. I didn't know that one could adjust the pressure regulators. I'll have to look into that.
Maybe I can add a second regulator just before the problematic burner and adjust it there.
Thanks for the suggestion.

 

[Broken Crow]

Thanks for the reply. Yes, I am using NG. The regulator is at the front of my brew rig and I have the 3 burners in series: mash tun, HLT and then the boil kettle. If I turn the pressure down at the regulator it may affect the first two burners which are currently working fine. I didn't know that one could adjust the pressure regulators. I'll have to look into that.
Maybe I can add a second regulator just before the problematic burner and adjust it there.
Thanks for the suggestion.

That's a rather high-volume burner... your regulator may not be rated to supply that much gas. You might wish to get a couple more regulators and use one per burner.

EDIT: With apologies, I must retract: It just occurred to me to Duck "23 jet natural gas burner" https://duckduckgo.com/?t=ffab&q=23+jet+natural+gas+burner+&ia=web and many hits were from Amazon...reviewers complain of that dirty flame. To be blunt: That product sounds like the kind of crap that gives both China and Amazon a bed rep: I'd wager if you took a micrometer to the air-intake and the mixture outlet, you'd find they don't conform to the appropriate sizes for natural gas usage. I wish I could give you help.. In my life I've fabricated many burners and torch-heads for smelting, forging and heat treating (not to mention ad-hoc BBQing) for various gases and each has their own requirements re orifaces, but brain-injury has taken my science and math so I'm unable to suggest appropriate bore sizes or flow-rates. In the meantime: Welcome to HBT! Tell us more about yourself and what you're working with (if for no other reason than to keep this thread floating near the top where someone with the knowledge and a working brain might have a better suggestion).

 

[OakIslandBrewery]

Welcome to the gang!

I use a similar jet burner on my brew kettle also using natural gas, but no regulator. The burner is for natural gas, not propane. The stand I built it into has lots of holes to allow lots of air for good combustion, that's a must for that large of a burner.

I'm no expert, but running three burners sounds like too much load on the natural gas pressure coming into your house. I'm only guessing but that might be the reason? As Broken Crow suggested your regulator might be sized wrong. I don't use a regulator and it works fine for a single use kettle.

 

[schuchdan]

Propane has a different orifice than natural gas as propane has more energy density. You can drill out the propane one to the natural gas size, but not the other way. My previous job was industrial pressure washer repair. The hot water machines use a similar burner setup for gas heat. You can get a torch tip cleaner and make sure there's no burnt wort or other debris in the bottom gas inlet to each brass jet. Here's more from a website glacier tanks.

Cast iron jet burners, fueled by either propane or natural gas, are similar to turkey kettle burners and are typically only used in outdoor brewing as per most municipal codes. Jet burners can not be used in closed firebox and require substantial air intake to function properly. If allowed to be used indoors, a vent hood is usually required. Orifice sizes are #63 for propane, or #54 for natural gas, and burners come with 32, 44, or 88 tips, with each tip producing approximately 10,000 BTU.

 

[OakIslandBrewery]

I would stress a ventilation hood to the outdoors and makeup air is mandatory for any gas burner used indoors. A fire extinguisher and carbon monoxide sensor is mandatory too.

 

[ITV]

Natural gas is already at a lower pressure (than Propane) and does not require a regulator.

I have my Edlemetal burner converted to NG which I swapped out the orfice and had to readjust the air damper to get a nice blue flame.

 

[HRNCBrewer]

Welcome to the gang!

I use a similar jet burner on my brew kettle also using natural gas, but no regulator. The burner is for natural gas, not propane. The stand I built it into has lots of holes to allow lots of air for good combustion, that's a must for that large of a burner.

I'm no expert, but running three burners sounds like too much load on the natural gas pressure coming into your house. I'm only guessing but that might be the reason? As Broken Crow suggested your regulator might be sized wrong. I don't use a regulator and it works fine for a single use kettle.

Good thought, but I don't think so. Even when it is the only burner going it is still a problem.

 

[HRNCBrewer]

I would stress a ventilation hood to the outdoors and makeup air is mandatory for any gas burner used indoors. A fire extinguisher and carbon monoxide sensor is mandatory too.

I am well aware of the problem of the carbon monoxide, and I have no doubt that there is loads coming off the burner. I only brew outdoors so this is not a a major problem.

 

[HRNCBrewer]

Does it burn blue flame at very low setting?
That picture is too small to get a good look at the configuration, where does the air come in. Is that what the small hole at the base of each jet is for?

If the valve is turned way low, then there is less yellow flame and black smoke. I believe those holes at the base of each jet is for the air to come in.

 

[HRNCBrewer]

It is correct that super-rich gas mixture will result in incomplete combustion. Those jets are specific to the gas supply they're to be used with, so if they were meant for domestic NG but are being run on propane that would be a problem. The typical wok burner needs to be re-jetted to move from one gas supply type to the other...

It is supposed to be for NG and that is what I am using.

 

[OakIslandBrewery]

I am well aware of the problem of the carbon monoxide, and I have no doubt that there is loads coming off the burner. I only brew outdoors so this is not a a major problem.

That wasn't directed to you, more of a general statement for anyone reading your thread. I didn't mean it other than a safety tip for all

 

[OakIslandBrewery]

Good thought, but I don't think so. Even when it is the only burner going it is still a problem.

Maybe even that one burner isn't getting enough air. Each tip has holes that provide air individually but all of them together may need more. I don't know for sure just offering some ideas. On mine I had to open areas in the base to allow more air coming in .

 

[BrewZer]

Natural gas is already at a lower pressure (than Propane) and does not require a regulator.

I have my Edlemetal burner converted to NG which I swapped out the orfice and had to readjust the air damper to get a nice blue flame.

I don't see an air damper in his gas flow and that might be part of the problem. I'm not a gas guy, so I don't know if adding one before the problem burner would help... it might just turn the rig into a bomb

Good thought, but I don't think so. Even when it is the only burner going it is still a problem.

Have you checked the line between the supply and the bad burner for a kink or obstruction?

 

[Broken Crow]

I don't see an air damper in his gas flow and that might be part of the problem.

This style of burner doesn't use an air damper, each jet is it's own venturi. The holes in the side of the jet are where the air is drawn in, but it needs an adequate flow of gas to achieve a proper mixture;

As mentioned above, there probably simply isn't a high enough volume and pressure in the supply line.

 

[Bobby_M]

I have a lot of experience with these burners in the past. They are essentially wok burners which are either on or off and when they're on they are extremely high BTU. They are expecting a certain velocity of gas through the orifice on each of the burner tips so that they can draw in the appropriate amount of oxygen the one that you're having problems with is at the end of the line and is receiving the lowest pressure gas and therefore there's not enough of that Venturi action to pull in the right amount of oxygen. The other problem is that you have to ensure that the area where the burner is positioned has plenty of open air to allow for oxygen to arrive you can end up getting combustion byproducts like carbon monoxide creating a barrier or a pillow of no oxygen in that burner zone. I've tuned some of those burners in the past to be more at the appropriate heat output for the vessel that it's under is to remove every other tip and plug the casting so that you have say half as many tips with the same amount of gas and you'll tune the burner so that they're each running the right amount of fuel but you're getting half as much output. To be perfectly honest though these are not the right kind of burners for a brewing setup where you want to dial in a certain amount of heat you should be looking more at the 10-in castings that have the air damper on the gas input such as the blichman Hellfire type that way you can convert those to natural gas with a conversion setup or just drilling out the orifice a little bit bigger and you'll have a lot better control over the flame since you can adjust the air damper to match the velocity of the gas

 

[day_trippr]

It is supposed to be for NG and that is what I am using.

Then you should toss the regulator because those jets expect the full domestic NG gas pressure (typically 11" WC) to operate correctly.

Cheers!

 

[ITV]

They are expecting a certain velocity of gas through the orifice on each of the burner tips so that they can draw in the appropriate amount of oxygen the one that you're having problems with is at the end of the line and is receiving the lowest pressure gas and therefore there's not enough of that Venturi action to pull in the right amount of oxygen.

According to my plumber son, the gas line also has to be sized (diameter of the pipe) for the BTU's of the device(s) that it is feeding.

When he extended the gas line in my house for my NG burner, he extended the main trunk line close to the shut-off valve and reduced it down from there.

 

[whoaru99]

Aren't there specs with it that say the nominal gas pressure it needs?

Of course, with that comes necessity for the meter, piping, and regulator(s) to be capable of enough volume to maintain the correct working pressure at the burner. Matters what all runs on gas at your house, how much any other stuff uses, and how many/what things may be running simultaneously.

 

[Bobby_M]

I had those burners on my 3 vessel rig for about 5 years and they NEVER burned right consistently. They have to be spaced away from the bottom of your vessels by at least 8", more is better. They cannot be significantly shrouded with either a heat shield or wind shield because oxygen needs to enter and CO has to exit. As you're finding, the gas has to be distributed in a way that there isn't a big pressure drop to any one of them. That usually means bringing the gas in through a larger feed and choking it down a size at a manifold with equal length branches.

I had 23-tip units and I think I ended up plugging about 12 tips on each of them to get the burn right on a shared 1/2" feed.

Long story short. Use ANY other type of burner with dedicated air intake damper.

Better yet, go electric.

 

[OakIslandBrewery]

Nuclear, then you're prepared for the future. Power your entire house and maybe the neighbors.

 

[HRNCBrewer]

Maybe even that one burner isn't getting enough air. Each tip has holes that provide air individually but all of them together may need more. I don't know for sure just offering some ideas. On mine I had to open areas in the base to allow more air coming in .

Another good suggestion. I have the ring mounted on a flat plate. I think I will cut away most of the plate so that there is only enough to support the burner.

 

[HRNCBrewer]

I had those burners on my 3 vessel rig for about 5 years and they NEVER burned right consistently. They have to be spaced away from the bottom of your vessels by at least 8", more is better. They cannot be significantly shrouded with either a heat shield or wind shield because oxygen needs to enter and CO has to exit. As you're finding, the gas has to be distributed in a way that there isn't a big pressure drop to any one of them. That usually means bringing the gas in through a larger feed and choking it down a size at a manifold with equal length branches.

I had 23-tip units and I think I ended up plugging about 12 tips on each of them to get the burn right on a shared 1/2" feed.

Long story short. Use ANY other type of burner with dedicated air intake damper.

Better yet, go electric.

I think I have to get rid of some of the metal the ring is sitting on. I may end up changing the burner.
I upgraded my kitchen cooktop from NG to induction and I am really happy with the change, but I am not sure I am ready to go electric on the brewery.

 

[whoaru99]

Ya need to figure out the gas pressure required and see if you have that. The rest is sorta sprinkling in the wind until you establish the fundamental of proper gas supply.