Help--Problem w/ keeping flame after 1 hour's burning on propane

[Cake O' Maple]

I had my propane supplier hook up my 2 propane burners to my LP tank out back, so I don't have to keep schlepping 20# tanks to be refilled.

He had to replace the hook-up to the 105k BTU burner, don't really know if it was to fit what he could scrounge, or if it had to be to fit the adapter to use 2 burners from the one hose.

The replaced adapter has a leak in what he changed--will be calling him as tightening it didn't fix it.

So, I ran just the 210k burner to boil tonight, and without even opening it up all the way, the flames (2 jet-burners) were burning well. Just before it came to a boil, my neighbor decided there was too much heat being lost where the pans sit side-by-side, and blocked it w/ firebrick. No problem w/ me.

I don't know if it was before that, or after that, but at one point the sound died, and just before I could ask what was up, whoosh, the flame burned loudly again.

Neighbor left after it came to a boil, and the sound died again, came back, but not as loudly. Left it for another hour, (went inside, 'cause it was getting cold and I was hungry, and I can watch it thru a window) and it lost the boil. Turned the gas to the burner on all the way, removed the added firebrick, it got loud again and appeared to be a steady flame. Went back inside, and when I checked it 15-20 mins later, the flame was gone. It's not windy, and in a 3-sided shelter.

500 gallon LP tank was just filled in January, so it shouldn't be out of propane!!

I can't find my propane guy's cell #, and of course the office is closed on the weekend.

Any ideas on what happened?? I really want to boil tomorrow, as the work week will be busy, and I have about 60 more gallons of sap gathered, more in buckets.

5263

[Z/MAN]

Cake O' Maple, I believe you are running out of oxygen for your flame. You have to have air mixing with the propane before it gets to the burner. I think you have your bricks sealing off any input of air. Try removing a few of the bricks on the side where your hoses enter the burners. You will notice where the hose enters the burner that there is an opening around the hose. That is where the air needs to enter the burner.

[Cake O' Maple]

Thanks for the reply, Z/MAN. I thought I left enough space--am adding a closeup of one side to better see the gaps, and the other side w/ better lighting. [in pic w/ better light, the burner used is on the left of the long side, so the closer end.]

If you still think it's that, I'll take more bricks out tomorrow.

Oh, and thx for telling me it needs to draw at the bottom! I left spaces throughout the walls, on all sides.52665265

[Z/MAN]

Looking at the better pics you might have enough air intake. I have a large home made propane smoker that I had the same problem with. After five minutes or so the flame would go out. I would open the door and relight it and the same thing would happen. After opening the draft vent on the bottom of it the problem went away. I have played with it a few times and that is what makes the difference. When using my smoker the propane is turned down real low and I had that problem so you can imagine how much air you must need with that burner (burners) going full blast or near full. It doesn't look too hard to remove a couple of bricks. I would try that. Good luck.
Paul

[maple flats]

You have enough air inlet. I'd check to be sure the adjustable air gate on the units did not get knocked closed or vibrate closed. If that is not the issue, I'd suspect the regulator(s). I have a smaller bulk tank for my finisher, a canner, a 170,000 btu burner like a turkey frier to heat water, and a 500,000 btu weed burner torch to ligh the fire in the evaporator (it's fast). On a few occassions I have had regulators screw up and loose the good flame. My regulators all used to be mounted straight below a 3/4" black pipe feed and I think crud from in the pipe falls into the regulator. As I fix such problems I've been replumbing to make a drip leg and bring the regulator off the side of the drip leg. Problem solved. You might have a similar issue. If so, re-plumb and move the new regulator to a side position rather than directly under the feed line if they are not that way already. I was never able to fix a plugged regulator, couldn't tap and loosen crud so I had to get new.
Good luck,
Dave

[buckeye gold]

I'd bet Maple Flats has it nailed, I had problems with an inconsistent flame on my finisher and changing the regulator fixed it, be sure you get a good quality one. Othe than that it could be a plugged burner, take an air hose and blow them back from the burner to the air vent and vise versa. If not that it's a tank or line problem, I'd guess.

[Cake O' Maple]

Thanks for the advice, everybody!

I tried removing some bricks, first, this morning, and it seems to have done the trick. 4+ hours, and still roaring.

Mmmmmmmmmmm, smells good out there!

[Flat47]

I've had the regulator ice over on our bbq grill. All depends on the burner design. Some mix fuel/air at the regulator. When the cold and relative humidity are right, ice forms at the air inlet much like old cars/trucks/tractors with carbs ice up in the same conditions.