23 jets on Burners - too many, how to scale down?

Howdy -

I brewed all grain for the first time on my new Brutus! It was a awesome although I had no idea it would take 6 hours! (up until 3:30am on Tuesday)

It took a very long time to get my kettle to a boil and I couldn't reach the ideal 'rigorous' boil.

Anyway, my burners have 23 jets and are rated at 192K BTUs. Unfortunately, I cannot have them on full blast (to get that really hot blue flame) as the flames are too big, wrap around my kettle, and are sure to drain my propane tank quickly. I believe having the yellow flames is less efficient than having blue flames as there was a lot of soot on the bottom of my kettle.

My question - I assume having 15 or so really hot (blue) flames would be better than 23 'yellow' flames. Is this correct? Should I plug up some of the jets to allow me to have my burner on 'full blast'?

Also - how long does it take to normally bring about 8 gals to a boil?

Thanks,

cmp

Here is a thread discussing your problem and a solution.

https://www.homebrewtalk.com/showthread.php?t=52154

You stated that your flames are wrapping around your kettle. Plugging up some of your jets with bolts won't solve your issue.

It sounds like your burner is too close to the bottom of your kettle. I know that a few of us (me included) have had to drop our burners another 1-2" to achive that perfect blue flame.

HarvInSTL said:

You stated that your flames are wrapping around your kettle. Plugging up some of your jets with bolts won't solve your issue.

It sounds like your burner is too close to the bottom of your kettle. I know that a few of us (me included) have had to drop our burners another 1-2" to achive that perfect blue flame.

Click to expand...

Yep, I had to go about 3 3/4" from kettle.

korndog said:

Yep, I had to go about 3 3/4" from kettle.

Click to expand...

Im about 2.5-3" and wondering if Im too close. But I took out all the jets where the flames would hit each other and it works ok. I just cant crank it all the way up or flames pour out the sides

I got flames out the side until I lowered mine to almost 4" from the bottom of the kettle.

I mispoke earlier. What I meant was that I had to drop mine a further 1-2" (to get to where I am now) because I started with the burner 2" from the bottom of the kettle.

I dont mind keeping the flames a bit lower to save on gas. These things will seriously suck down so propane with them turned all the way up. But then again I have to keep heat on it longer. Its a fine tuning toss up between the two.

This may be a stupid question, but is your burner set for propane or for natural gas? If it is adjusted for nat gas, and you use LP, you'll get mountains of soot and smudge, plus the monstrous yellow flames.

they are for propane.

pieper said:

Howdy -

I brewed all grain for the first time on my new Brutus! It was a awesome although I had no idea it would take 6 hours! (up until 3:30am on Tuesday)

It took a very long time to get my kettle to a boil and I couldn't reach the ideal 'rigorous' boil.

Anyway, my burners have 23 jets and are rated at 192K BTUs. Unfortunately, I cannot have them on full blast (to get that really hot blue flame) as the flames are too big, wrap around my kettle, and are sure to drain my propane tank quickly. I believe having the yellow flames is less efficient than having blue flames as there was a lot of soot on the bottom of my kettle.

My question - I assume having 15 or so really hot (blue) flames would be better than 23 'yellow' flames. Is this correct? Should I plug up some of the jets to allow me to have my burner on 'full blast'?

Also - how long does it take to normally bring about 8 gals to a boil?

Thanks,

cmp

Click to expand...

Yay!

Okay, my other favored hobby (blacksmithing) comes into effect here.

Blue flames, well defined, are signs of what is called a neutral flame. That means that the fuel/air mixture that is burning burns all the fuel, and also burns up enough oxygen. In blacksmithing this is ideal, as oxidation can be just as lethal to glowing metal as it is to brewed beer.

If you're getting a yellow flame, my guess is that your mixture is too rich. There is fuel left over after primary burn, and this fuel burns inappropriately in normal atmospheric environment, creating the lovely carbon scorching that you're seeing.

Move your pot up off the burner some, use some foil if you need to to create a heat shield (or look into 3000 degree insulated fire bricks to build a heat tube that can concentrate your heat, but be careful doing this, you can easily overheat your pot, 192k BTUs is a freaking lot).

Finally, a properly designed burner does not use a lot of propane. I can achieve temperatures, in a forge, of over 2000 degrees within 15 minutes, and maintain that off of a 20 pound propane tank for almost 8 hours.

If you want to work with some insulation, look into ceramic durablanket (1 inch thickness), which is rated to like 2700 degrees. Any stray heat from licking flames will be captured by the durablanket. It should run about 7-12 dollars a running foot. You can create all kinds of nifty insulation to speed up your heating and control your fire, as this is the same stuff (in a fiberglass-style blanket) that they use on the space shuttle.

I had flame issues until I got the air to propane mixture dialed in. Prior to that I had flames (and thus soot) halfway up my kettle.

now, no issues like that, and a wicked hot boil.

The thing with these burners is that the fuel/air mixture is not adjustable and therefore only operate in a very narrow flow band. If the full flame is too much, plugging the holes in the burner ring in strategic spots is the only real cure. However, I do agree that lowering the burner is the first place to start. If it is too close to a converted keg bottom, there's an area of low oxygen being created in the very location where the tips are trying to pull in oxygen for combustion. This actually suggests that this "in-tip-venturi" burner style (for lack of a better term) is not ideal for keg based vessels. Notice how on other burners the air intake is well away from the vessel. I've confirmed this because there are times I can't get a clean burn no matter what the gas valve is set to. A quick shot of air applied to the flame purges out the oxygen poor pocket and gets it burning healthy again.

I plan on experimenting with a metal collar that would encourage fresh air intake from well below the combustion area. FWIW, my burner tips are 5" from the very bottom of the kegs on my rig.

Bobby_M said:

The thing with these burners is that the fuel/air mixture is not adjustable and therefore only operate in a very narrow flow band. If the full flame is too much, plugging the holes in the burner ring in strategic spots is the only real cure. However, I do agree that lowering the burner is the first place to start. If it is too close to a converted keg bottom, there's an area of low oxygen being created in the very location where the tips are trying to pull in oxygen for combustion. This actually suggests that this "in-tip-venturi" burner style (for lack of a better term) is not ideal for keg based vessels. Notice how on other burners the air intake is well away from the vessel. I've confirmed this because there are times I can't get a clean burn no matter what the gas valve is set to. A quick shot of air applied to the flame purges out the oxygen poor pocket and gets it burning healthy again.

I plan on experimenting with a metal collar that would encourage fresh air intake from well below the combustion area. FWIW, my burner tips are 5" from the very bottom of the kegs on my rig.

Click to expand...

Interesting. That's a sign of piss-poor engineering. As a firebug, I'd never put the venturi holes in the burner tips themselves. You're getting all kinds of vortex issues with the oxygen, resulting in things like the aforementioned low o2 zone, plus your flame itself would have a harder time reaching neutral, as there is almost no room for the fuel to mix properly with the air. Finally, I'm a sucker for control, and a choke somewhere away from the burner (at least 6 inches away from the flares) would be ideal, as you could control gas/air mixture to keep a neutral flame at ounces of pressure per inch.

The cheap man's solution to your low O2 pocket is to get a small fan angled up into your burner and turn it on low. Forced air works fine, it's just a crappy solution.

I could probably build a mig-tip powered venturi burner for brewing (it costs about 20 bucks to build one for a forge) that would give a brewer unbelievable control over his flame. The only design challenge for me would be the burner head. You'd have an adjustable choke, and you'd probably use a 0-30psi regulator for fine-grain control over the pressure, and adjusting the two would allow you to maintain a neutral flame to the point where you could probably sustain whatever temperature you wanted. I'm almost positive that it'd be a hell of a lot more efficient than the ones you buy now.

I'll have to work on this some. It's an intriguing challenge.

TheFlatline said:

Interesting. That's a sign of piss-poor engineering. As a firebug, I'd never put the venturi holes in the burner tips themselves. You're getting all kinds of vortex issues with the oxygen, resulting in things like the aforementioned low o2 zone, plus your flame itself would have a harder time reaching neutral, as there is almost no room for the fuel to mix properly with the air. Finally, I'm a sucker for control, and a choke somewhere away from the burner (at least 6 inches away from the flares) would be ideal, as you could control gas/air mixture to keep a neutral flame at ounces of pressure per inch.

The cheap man's solution to your low O2 pocket is to get a small fan angled up into your burner and turn it on low. Forced air works fine, it's just a crappy solution.

I could probably build a mig-tip powered venturi burner for brewing (it costs about 20 bucks to build one for a forge) that would give a brewer unbelievable control over his flame. The only design challenge for me would be the burner head. You'd have an adjustable choke, and you'd probably use a 0-30psi regulator for fine-grain control over the pressure, and adjusting the two would allow you to maintain a neutral flame to the point where you could probably sustain whatever temperature you wanted. I'm almost positive that it'd be a hell of a lot more efficient than the ones you buy now.

I'll have to work on this some. It's an intriguing challenge.

Click to expand...

I will be following this thread. A better burner would definitely be something I am interested in.