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.

 

[Bobby_M]

That's the rub with wok burners. There's no need for adjustability for their intended purpose.

 

[zachman]

Bobby, just received the 23-tip burner yesterday. I have one question if you don't mind. I already have a location to tap into the gas line. Would you share your connection method for your rubber hose that is connected to the brew rig? Are those connections quick disconnects? I have been racking my brain for the best way to make this connection. I am going to do about a 20' run with the hose.

I will also be building a CFC based on your tutorial. Maybe I can get both of these projects knocked out this weekend.

 

[Bobby_M]

Let me preface this with an extreme disclaimer. I'm not suggesting you should do what I did. In fact, you probably should NOT do it. Ok, good enough?

Realizing that this hose would only have gas in it for a few hours once a month, I was confident that if it did not leak, there would be no problem. It is essentially a garden hose. I used Goodyear utility hose from Lowes and terminated it on both ends with high quality Garden hose barbs. The reason I went that way is that the very pricy QD's that are meant for NG are highly restrictive. Again, I have a gas rated ball valve on the hard line prior to all this cludged hose work. It gets turned off (and the handle removed) after brew day.

Can we collectively think of enough reasons why my system is a bad idea and against code? How about the possibility of attaching my gas to the garden hose bib and flooding all my appliances like the three stooges?

 

[MoRoToRiUm]

Where's the boom!?!?

Say maybe 2 hour brew session... I'd probably justify your method as well; but I would have incorporated duct tape, somehow....

 

[Bobby_M]

Don't mistake DIY bravado for carelessness. Of course, after every explosion you'll hear a fellow say, "I didn't think it would happen". There are two substances that most people have an unrealistic fear of; gas and electricity. Yup, they can both kill you if you're not careful, but so can a steak knife. Gas kills by either asphyxiation due to oxygen displacement or by collecting in a closed area and then igniting. In my setup, the valve on the hardline is always closed unless I'm using it. Well, that, and it doesn't leak.

 

[BlindLemonLars]

The reason I went that way is that the very pricy QD's that are meant for NG are highly restrictive.

I'm thinking this is exactly why I've had less success than you with the multi-jet burners: supply restrictions. I'm coming off a 1/2" stub, through a ball valve, one of those pricey quick-disconnects and finally into a 3/8" hose. Why? Because the stub has to serve both my gas grill and brewing needs. Furthermore, my girlfriend sometimes fires up the grill, and I want hooking it up to be easy, safe and foolproof with no kludgey bits.

That being said, the "DIY bravado" you mentioned is acceptably safe in the hands of a cautious person who understands and respects the inherent danger, and proceeds accordingly. There is a lot of unnecessary hysteria about working with low-pressure natural gas...I'm inclined to think it's a lot safer than the high pressure propane rigs most brewers and holiday turkey chefs use.

How about the possibility of attaching my gas to the garden hose bib and flooding all my appliances like the three stooges?

Great visual!!

 

[DiveBrew]

Bobby do you know the difference in orifice size on the NG vs the propane version of the multi-jet? Just wondering if anybody has tried the propane version of this burner on NG to see if it limits the flow close to your jet blocking.

 

[Bobby_M]

They are very similar in size with the NG version having just slightly larger orifices. If you picked either one up you wouldn't know the difference. Side by side, yes. I suppose a propane unit would run cooler but the mix may not work right at all. It would be worth a shot.

 

[Jimmi_Jones]

I have a system in my garage (don't think I have any photos with me) running on natural gas. I put it on the wall that has the gas meter on the opposite side. I then replaced an elbow in the existing supply lines with a tee. From the now new opening in the tee I brought a .3/4" black iron line into the garage. I then split that and went to two .1/2" lines for each 23 jet natural gas burner. The HLT is operated by a PID and has a constant pilot light. The boil kettle is just lit with a match and adjusted with a ball valve. I mash in a cooler. The entire system is permanently mounted on the wall and gravity fed. (I even plumbed fresh water to a valve that fills my HLT) I have a hard time controlling boil overs with the ball valve for gas on the boil kettle and after reading this thread think I will try plugging some of the jet holes in the lower burner. I will try to get some photos up this weekend.

 

[Flomaster]

Jimmi I look forward to your photos.

welcome to HBT.

-=Jason=-