55 gallon evaporator boil rates

[Rozzy]

No, currently I have 4" flat cinderblocks in the bottom just to fill the void and get my grates up to just under my door. I also dry stacked a brick wall about 14" in making my firebox 14" deep and 22" wide. The top of the wall is about 3" below my pan. I'm using dry hardwood split no bigger than 2" and a fire every 5-10 minutes depending on how close I can watch the boil. Also I use a hotel pan over the steam to preheat sap for when i need to add a larger quantity but my main feed is a constant drip of cold sap which doesn't seem to affect the boil at that rate.

[berkshires]

What's the inside look like? If it's just one big firebox like Dr Original's you could gain a lot of efficiency (read gph) by creating something to force the heat up under your pan. A lot of people do this with welded plate with bricks/fire-blanket over it. I did it with a cinder-block, firebrick, and fill material (a combination of fire blanket and vermiculite).

Gabe

[DrOriginal]

The fire brick does make a big difference. You can tell when it's cold out and you're boiling you can only stand in the front or back to get warm. But it makes it heavy, make sure you have it where you want it. Used and engine lift to move ours.
And the AUF wouldn't have to be too expensive. Mspina14's looks really nice. But I've seen people use bathroom exhaust fans and small hose to force some air in there. That's probably our 1st upgrade this summer is to get more air in there. I don't think we have a draft issue as much as we have a no air under our fire issue. We've had trouble getting a consistent boil due to our fire. Our barrels fills up with coals to the point it blocks our chimney. Throw some air under it and she should burn everything so hot that the coals are gone.

[wildwood]

I'm running a barrel rig, started with 3x steam pans (flared out barrel and used angle iron to make them sit down inside. Two lengthwise in front, one turned 90* behind them, stack out back of barrel). With firebricks and proper ramp it was no problem to hit 6-7gph once a good boil is going even when the rig was outside. This year I added a foot on the back of the barrel like you'd see on a "real" evaporator and stuck a 2x4 flat pan on it. With that and a real grate it hits 10-11gph easy with no preheater (but inside this year). Since everything is frozen I just added cheapskate AUF and hope to hit at least 12-13gph at full boil. Still haven't figured out what I want to do for a preheater.

How much sap are you running in the pans? The biggest efficiency gain on the 2x4 flat pan for me was getting comfortable running 3/4"-1" (sometimes less if I'm feeling saucy) of sap in it. Scary but man does it boil hard. Never dared run it that low in the steam pans

Good luck!

[DrOriginal]

AUF is night and day difference. Turn off AUF to feed wood... boil stops. Turn AUF back on... boil starts again.

OK, so we didn't wait till next year to add the air.20170325_095127.jpg
And what a difference. Burns so hot it burns thru all the coals. It's the most consistent boil we've had to date. And only cost us $28. Definitely worth it.

[SyncroScott]

At the end of this (my first) season, I was getting at least 3 gal an hour with my basic barrel arch. It was an improvement over the turkey fryer but not by as much as I had hoped, at least not in gph, but had other benefits though.

Now that I've gotten a solid beginner year under my belt, I've come to the conclusion that many of the cool labor-saving components of commercial operations also make a ton of sense for the hobby folks as well, or more so. Comm ops want the tubing and the ROs and the drop flues to be more efficient since time = money: I want them so I can enjoy boiling with the limited free time I have! I'm hoping I can increase my barrel arch considerably by getting a real 20x30 pan with baffles and then put 33 .75"x6" drop tubes in it, that would nearly double the surface area (4.17sq ft + 3.44sq ft) and get me close to 8 gph without breaking the bank too much. But its all theory at this point... LOL.

[STP92x]

My friend and I built our first barrel evaporator this year and are getting around 3-4gph. We have a fire brick and roxul lined barrel with 2 full size seam pans and run a hair dryer into a pipe under the fire. We think we might be able to get 1-2gph more if it were better insulated and we use some more fire bricks to direct the flames a bit more.