55 gallon evaporator boil rates

[Rozzy]

This is my second year using a 55 gallon drum evaporator and I'm already planning for next year to improve evaporation rates. I'm curious what other folks with 55 gallon evaporators are getting for rates and what have been the best modifications. Basically, I'm not looking to drop the money on a hobby evaporator to make 3 gallons a year, so what can I do to my set up to get the best boil rate? What modifications are the best bang for the buck? I'm currently getting around 3GPH with a 24"x18" pan (flue on top of barrel) and no modifications, I would like to get to 10GPH or better. I was thinking of adding AUF and moving the flue to the rear of the barrel so that I could add a new 2'x3' pan. Also my current pan is 1/16" or 3/32" which seems to take way to long to get boiling so I would like to go with 20 or 22 gauge.

[Daveg]

Your set-up has 3 square feet (24X18) of surface area. Adding a 2X3 pan will probably double/triple your evaporation rate. Sounds like you have good draft with an adequate chimney. You could go with AUF and the additional pan and get close to 10 gph without having to change to 20 gauge.

[ACfarmerNH]

Your set-up has 3 square feet (24X18) of surface area. Adding a 2X3 pan will probably double/triple your evaporation rate. Sounds like you have good draft with an adequate chimney. You could go with AUF and the additional pan and get close to 10 gph without having to change to 20 gauge.

Given the dimensions of a standard 55-gallon drum (22.5 inches by 33.5 inches), I'd assume that not all of the 2x3 pan would be in contact with the flame and you wouldn't see a linear correlation between the old and the new without building the original drum outward.

[CaptT820]

I was getting 2.5gph to 3gph with a similar setup last year. You really cant get too much more out of it than that, just due to surface area and available heat. I built a block arch for relatively cheap money this year and I get right around 8gph when hitting on all cylinders. I figured that this was a good middle step from barrel to hobby evaporator and I could move up if I wanted to spend the money. 8gph with the block arch is good for the amount of sap we get, as we try to boil about 30 gallons per session. If we were trying to boil 50 gallons or more then we'd move up to the hobby evaporator. Its all about the time involved.

[mspina14]

I built and used the barrel stove below for one season:

stove 2.jpg pan 1.jpg

Had a custom made 24"x32" pan. I added AUF with piping attached to the bung hole and a small blower.

I'd estimate I was getting 3-4 GPH with the blower going. Can't get much more out of a rig this size.

As was said earlier, a rig like this just has a limited amount of surface area.

Mark

[berkshires]

One thing you could do to double the gph is add drop tubes to the pan(s).

Gabe

[DrOriginal]

We just bought a 55 gallon barrel unit this year as well. It kind of just came with the pan. It was such a good deal for the price that we took the unit, it was better then our cinder block setup. Ours has some sides built up on it that allow for a bigger pan:20161203_164153.jpg
We've had trouble getting good draft this year, might have to fix our chimney or go with a blower next year. But we did find this link from a guy named AndressMetal on pinterest, need to give credit:
https://s-media-cache-ak0.pinimg.com...e208dd294f.jpg

We might try to replicate this for our unit, would allow for an even bigger pan, maybe some drops or flues. And would also help with our draft. No idea how cheap it would be, but it's and idea.

[Rozzy]

Thank you all for your responses. I know I am asking a lot for a barrel stove set up, but when I look at a Half Pint or Mason 2x3 I see they throw out numbers between 4-9 gph. The half pint even goes to 10-15gph with the Smokey Lake Full Pint pan. So in my mind, other than the pan, what is $1000-$1200 going to get me with a hobby evaporator that I can't achieve with a barrel stove? My plan was to flair out the edges of the barrel to fit the 2x3 pan, much like DrOriginal's stove. Worst case would be that I don't extend the ends of the barrel and I'm left with a 2'x33" pan much like the half pint. As for drop flues and AUF, I'm curious how much difference they have made for others.

Here is my set up now.
Barrel stove.jpg

[wobbletop]

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

[CaptT820]

Is the inside of your barrel lined with fire brick? This will determine a great deal of how much you can evaporate.