rolling boil on 2bbl direct fire

[imperialipa]

Did our water test this weekend and the boil was pretty feeble. Only boiled off 2 gallons in an hour.

It took 1hour to heat 75 gallons of water 36 degrees.

We have a 32 port ng burner on a 3/4 in gas line.

There is a small 3 inch skirt around the kettle. But we seem to be losing a lot of heat out and up the sides of the kettle.

Any suggestions on making this more efficent?

Will wort boil more vigioursly than water or can I expect to see a pretty flat boil with the wort?

[Brandjes]

My 2bbl system arrives in September. I'm going with 2 NG burners for 220k BTu. Your burner is probably 160k and might be a bit under powered. I'm using a 160k burner for my HLT with HERMS coil.
The smaller footprint of the 110k burner also allows me to position the burners to sides of the the bottom outlet on the kettle.
Just my 2 cents for what it's worth

Good luck,
Eric
Cole Street Brewery

[imperialipa]

My 2bbl system arrives in September. I'm going with 2 NG burners for 220k BTu. Your burner is probably 160k and might be a bit under powered. I'm using a 160k burner for my HLT with HERMS coil.
The smaller footprint of the 110k burner also allows me to position the burners to sides of the the bottom outlet on the kettle.
Just my 2 cents for what it's worth

Good luck,
Eric
Cole Street Brewery

Thanks Eric!

The burner we have is a 320k BTU burner.

http://www.glaciertanks.com/Jet_Burners-Jet_Burners_Cast_Iron_320_000_BTU_32_Tip_Nat._Gas.html

It puts out a god awful amount of heat. Its just that the head seems to be dissipating too fast up the sides.

I have seen designs where people wrap the whole bottom in a metal shield to keep the heat in there longer. Not sure if this will solve my problem or not. But we will give it a shot.

If anyone else with a direct fired NG burner has any tips I would love some feedback.

[almalkin]

We have a kettle and burner that are roughly that size, and definitely don't have issues getting an extremely vigorous boil. In fact we never run our burner at full throttle, and have to dial it back once we reach boiling. Our kettle is a 2 bbl Stout, which doesn't have a skirt but sits on a custom steel frame. Here are a few possibilities, from my experience.

1. Your flame is too close to the bottom of the kettle. The tips of our burner are about 6.5" inches from the bottom of the kettle.
2. Not enough airflow from around the bottom. If you have the burner somewhat enclosed, or too close to the floor, the flame may not be burning as efficiently as it could.
3. Your gas supply is insufficient. You mentioned a 3/4" gas pipe, but that might not be enough depending on how far you are from supply. We ran a 2" pipe from the gas meter to our brew stand, which is about 40' from the meter, and then reduced to a 3/4" pipe at the stand.

Those are my thoughts. If you posted a picture of the setup it might help with some more feedback.

-Steve

[populuxebrewing]

There is a small 3 inch skirt around the kettle. But we seem to be losing a lot of heat out and up the sides of the kettle.

We have a 1.5bbl Stout Tank kettle which we heat with a Blichmann burner on a propane tank. We started out using a 44 tip jet LP burner from Glacier like the one linked to, but found that we were losing so much heat out along the sides of the kettle that it wasn't worth using. Basically we were burning half our gas just heating the room, not the kettle.

If you're losing a lot of heat off the sides, I'd say look to improving the firebox/skirting to help direct the heat more appropriately. At 2bbl I can't recommend the Blichmann burner since while it's efficient, it's under powered for our needs. We do get a good rolling boil with it, but getting 63 gallons to boil from 180 usually takes about an hour.

Good luck,
Peter
Populuxe Brewing
Seattle, WA

[callmetim]

You don't have to wait until your kettle is full to start the burners. start your burners on low as soon as you have a couple gallons in your kettle and monitor the temp of the wort. this will at least help your lag between sparge end and boil start.

[JNelson]

Just did boil tests over the past two days on a 7.5bbl kettle using a 440kbtu burner. I originally enclosed the burner completely inside a masonry firebox with a B-vent through the roof; this test gave us a 9bbl water boil from 160 degrees in 5 hours as most of the heat went up the exhaust and did not get into the kettle. The second test we raised up the kettle 2.5" on spaced bricks so that the heat will flow up the sides of the kettle and we got to boil in 2:30. My original design had a masonry enclosure going to the top of the kettle with the B-vent at the top, letting the heat have a much longer contact time with the kettle. Due to time and money constraints I went with only a firebox under the kettle, and realize now that I will eventually go all the way up the sides.

If you do the math the 2:30 is still horribly inefficient. For 9bbl, the amount of heat required to go from 160 to 212 is 120kbtu. If the burner really is producing 440kbtu I am only transferring 8% in 2:30.

Hope this helps everyone. Jerry

[Brandjes]

Just thought I'd post an update.
2bbl Stout Kettle with flat lid and condensate stack. 2 - 23 tip (100k btu) NG burners.
Start heating with 30 gallons in the kettle. By the time it's full (80 gal) it takes 15 minutes to boil.
Boil off is 4 gallons per hour with the lid open.