Taming the Wild Beast - Multi-Jet burner mod

[Bobby_M]

People sometimes buy natural gas burners that their source piping just cannot supply adequately. People like me that is. Then there is an issue with having way too much heat to be practical. The cheap 23-tip burners are claimed to put out anywhere from 80K to 140K BTU depending on the store you buy them from. I would have gone with 10-tip if they weren't twice the price and equally hard to find.

Anyway, enough chit chat, you can order a whole box of M8-1.0 pitch (Metric Fine Thread) bolts for about $10 from Mcmaster.com and plug up as many tips as you want. The burner will require less pressure/flow from the source and still maintain a good burn. I'm just guessing here, but if 23 tips (burning well) produce about 100,000 BTU, each tip does about 5,000.

So, I plugged 12 tips to leave 11 burning for about 55kBTU. This keeps 12 gallons at a ROLLING boil at half valve. For any tips that fired directly at each other, which contributed to a hot spot, I blocked off one. You can see how each flame kind of fires on its own. I hope this helps those of you who find them too hot (or burning crappy due to inadequate supply).

 

[sirsloop]

go figure... who says more is better???

 

[cheezydemon]

OK, fire, metal, beer....that definitely qualifies as cool!

 

[Soulive]

Glad to see you finally solved that...

 

[sirsloop]

throw in an internal combustion engine and we got ourselves a party! HAH!

 

[Bobby_M]

My one major gripe with these burners is the very narrow adjustability range due to the fixed air intake size. Once the flow is too low, the venturi affect is hindered and you get an orange flame. If the flow is too high, it pulls too much air and you get a gap between the tip and the flame making a lot of noise. Bottom line, these are mostly ON/OFF burners with a little bit of adjustment in heat. I'm guessing the adjustment is less than 10,000BTU.

 

[Soulive]

I'm surprised 55k BTU is sufficient for rolling double batches. I upgraded my regulator because I didn't think that would be enough...

 

[Bobby_M]

These ratings are all approximate ya know. For all I know, I'm getting 80K. Another thing is that I'm boiling in a wind-protected environment (garage) so more of my heat makes it to the wort.

 

[janzik]

I'm surprised 55k BTU is sufficient for rolling double batches. I upgraded my regulator because I didn't think that would be enough...

(Not to hijaak, but...)

(I do see Bobby say this is only his guess on what he's actually getting out of it).

I was wondering the same thing, though. Since I see a lot of people like the KAB5(185k or 210 with the upgraded regulator). My LHBS guy said that would be overkill and counterproductive (causing charring somewhere, keg or wort). The LHBS had the 55k Bayou in stock, so maybe he was just trying to sell me... any thoughts?

 

[HenryHill]

Might be 'Keggle-Half-Empty' guy....

 

[Bobby_M]

I think the top-down pic might be a little deceiving. Those little blue flames are actually 6" HIGH, which is also about the distance that I run the burner from keg bottom. Any closer and I can't stop a boilover even on the lowest possible setting.

The other consideration is that a propane flame of the same size would be something like 40% hotter.

The only real way to measure BTU is to time how long it take to raise a certain amount of water a certain number of degrees and then calcuate it out.

Even then, you're measuring effective BTU (how much is making it into the liquid inside the vessel) and not actual burner output.

 

[Boerderij_Kabouter]

I use a 55,000 BTU turkey fryer for my 10g boils. Easy as pie. Up to a boil in ~12min and great adjustability. I guess more BTU's would bring a faster boil but I would be worried about scorching.

 

[Bobby_M]

There's really only so much heat you can attempt to force into the bottom of a pot before you start wasting a lot around the sides too. What's a couple extra minutes in a 5 hour brewday? Go play with the kids for 5 minutes.

 

[sirsloop]

I wonder if you built a small metal apron around the side of the keggle. It would help trap a lot of the heat going up the sides and increase the keggle efficiency. You could use it to shield your sight glass and fittings too. Maybe put some small holes in it to help keep air moving through, but it would slow down the hot air, trapping it along the sides.

 

[Bobby_M]

With the reduced number of jets, I get VERY little heat out around the sides now. I can put my hand on the valve handle while it's rolling boil. I figure I'm getting the same amount of heat into the keg as before with close to half the gas use.

 

[sirsloop]

hmm... cool (HAR HAR HAR!)... I remember before it was like a wall or fire around the thing that you tamed with tin foil!

 

[HenryHill]

I remember 'Nad Guard.

 

[terrazza]

Bobby-m, what kind of high temperature thread sealant are you using? I've had trouble with teflon tape and getting the threads to catch on the cast iron. It seems like half of my jets are leaking. I was thinking about trying plain high temperature silicone sealant. thanks!

 

[Bobby_M]

It's just a brush-on type of pipe sealant I found at Lowes a while back. I like it better than tape.

 

[Desert_Sky]

Ok before I click buy......


M8 1mm thread

how long are the ones you got 20mm? and I see you did a fully threaded bolt. Any reason you just didnt seat them flush? too long?

 

[Bobby_M]

Yeah, just too darn long. I'd go with 10MM long ones if they had them and just crank them down.

96144A211
Metric Class 12.9 Socket Head Cap Screw M8 Thread, 20mm Length, 1mm Special Pitch, Alloy Stl
In stock at $9.41 per Pack
This product is sold in Packs of 50

Oh, like these would be great but it's a bit more money for half the bolts:

91180A525
Metric 8.8 Zinc-Pltd Steel Hex Head Cap Screw M8 Size, 10mm L, 1mm Special Pitch, Fully Threaded
In stock at $11.35 per Pack
This product is sold in Packs of 25

 

[Dycokac]

what are you using for a regulator for this thing? I want to build one (and do proper ventilation for my basement) but can't figure out a regulator and stuff...

I know I don't want to run any extra pipe from the NG entry to my house, but if i tap one of the lines already in the room I'm good to go.

links to regulators would be great, also what you use for flame adjustment.

 

[Bobby_M]

I'm running natural gas so there is really no regulator. I'm just throttling the flow with a ball valve right at the burner. You kind of have to go back to a main trunk at least though. You can't tap into a 1/2" line that is already 10+ feet off the main trunk, especially if it's supplying something that already needs that gas. A good analogy is trying to tap off of a dedicated air conditioner electrical circuit for running a heating element. Not enough current to supply both.

 

[Desert_Sky]

I'm stealing the hose and reg off my hurricane burner for mine. Look over at morebeer, they have a low pressure regulator.

 

[Dycokac]

I'm running natural gas so there is really no regulator. I'm just throttling the flow with a ball valve right at the burner. You kind of have to go back to a main trunk at least though. You can't tap into a 1/2" line that is already 10+ feet off the main trunk, especially if it's supplying something that already needs that gas. A good analogy is trying to tap off of a dedicated air conditioner electrical circuit for running a heating element. Not enough current to supply both.

Would it work if I tapped a line that wont be using the gas at the same time? like my gas dryer, or water heater (provided they are large enough diameter?

I figured it wouldn't be prudent to tap the line my furance is on

 

[Bobby_M]

Dryer sure, water heater and furnace bad. These are things that you would leave to their own thermostats to kick on. You'd have to put the water heater into "vacation" mode while you brewed.

 

[brewpal]

I ended up tapping into the line to the furnace in the garage. During a test run, the furnace kicked on and did not really affect the flame on the burner which was on high. Granted there is not as much heat output on my 32 jet NG burner compared to the 44 jet propane model I used prior, but the heat will be put to better use since it will not be curling out the side of the 55 gal drum as much. Maybe I got lucky with the supply flow at my house, but it works for me.

No regulator, just a ball valve to control the flame.

 

[Desert_Sky]

hey bobby thanks for all your help. Ill post some pics once everything starts to come together

 

[Bobby_M]

There are a few variables of course and I think the biggest are size of the supply and the length. My main supply is 1" and it goes 30 feet before getting a 1/2" tap to the water heater. I Teed off of this line for a total of 14 feet of 1/2" from the 1" trunk. Then I run another 25 feet of flex hose to the brew stand. Not good.

 

[WBC]

If any of you have the banjo type burner (propane) you know they have a really nice range of adjustment and a lot of heat too when you need it. That's the kind of performance you can get using natural gas and the right jetting. I have used hot water heater burners and older wall heater burners and you can get them for the asking at a heating and cooling store as they throw them out all the time.