My oil tank arch build

[crzypete]

I had an inquiry about how things were going on another thread and have decided to paste my response here as well. I'm really enjoying this thing!

I've been really pleased with it. Actual rate is a bit hard to determine as it really depends how hard I push it. I've gotten more aggressive in adding wood and it has definitely responded. I easily hit 10gph when I am stoking it hard.

I suspect a preheater for my sap will increase that rate- I'm debating the best way to build this for next year- thinking of a split pan so I can heat one side while I am filling from the other side, but this may be way overkill.

I'm also thinking that the ramp may benefit from being closer to the pan, I was planning on insulating that area, but haven't gotten to it- I'm planning on experimenting with some firebrick and sand to see if that makes a difference. I'm happy with how I built it though as it is pretty easy to move it up, but it's hard to move it down.

Things I did right- make the fire box deep enough to get a 16" piece of fire wood in straight. I find that I cross stack and having the ability to go straight in makes life easy.

I'm still not certain whether my blower should be closer to the fire or a bigger blower. It certainly makes the fire more intense, but I'm not experienced enough to tell what would make it even better.

The pan is 26" x 48" no dividers. After reading much about continuous flow, I am convinced that this is the method best for me. Continuous flow just seems overkill for my operation (36 taps this year, but enough maples to go up to 50 if I desire).

All in all I absolutely love it and its completely great for my operation. I am scheming on upgrades for the fun of further construction more than the need for higher efficiency.

Peter

[brass maple]

Crzypete
run a 2 inch metal pipe from the back to the front through the hole you cut. On the end of the pipe that goes to the front of the barrel make several short cuts on the end of the pipe and bend them over to plug the end of the pipe. Then on the top of the pipe drill 3/8 holes in three different lines down the length of the pipe only under where the fire will be. One line right down the top of the pipe one line at 11 oclock position and one line at the 1 o'clock position. On the other end of the pipe hook up the blower. It works well. Done this way you don't get a lot of ash blowing out of door when opened and you have the air aimed right where you want it. My blower is a leaf blower and it doesn't blow any thing out door with that much power, It will increase the heat in the wood chamber considerably. If you don't already have one fix a plate of metal that fits over the opening of the air Intake of your blower and put a screw in a spot that wont interfere with the fins of the blower so that you can open or close it to control how much air you are pushing through the grates.

[Austin351]

Crzpete- With exception to the fire door, your build looks exactly like the evaporator I built last season.


https://www.youtube.com/watch?v=Srfksbj39Hk

[crzypete]

Matt, Thanks for the piping idea. What are you using for pipe? I can't imagine listening to a leaf blower while boiling, ditto all the guys using shop vacs.

Austin, looks like a nice build. Love these oil tank evaporators!

Anyone have ideas towards a pre-heater? I am having grandiose ideas of a contoured stainless pan that sits on the top curved area of the tank and has a hole for the chimney to pass through. Why? because it sounds like a fun challenge to build and would look cool. Functional? Maybe? Stupid? Definitely!

Pete

[wobbletop]

I use a bathroom fan. Probably around $30 at home depot and not very loud. Add a speed controller for maximum adjustability.

[billschi]

This is the one I made last year.
https://youtu.be/oNUk0AQvoeU

[northwood]

Very similar to the one i have as well. I have one large flat pan (22 x 34) and one 12 x 22 finisher. Also have room at the back for 2 large stock pots for preheating. Last year I added a small quiet cage fan connected to the 2" hole under the front door. I went from 6-7 gph to easily boiling away 10-12 gph. The fan blows about the same amount as a hair dryer, but really keeps the fire hot. (and no buildup of coals) If I have to step away for a bit, I load up the unit with wood and sap, unplug the fan and it would simmer away with no worries. Mine is fire brick front end with a ramp to the stack. Short of buying a drop flue pan, not much more I can do to increase the gph.

[Sugarmaker]

Nice build! Probably what I should have started with!
You did the right thing on the big flat pan. getting gradient on a pan this size is not always easy.
Regards,
Chris

[Mendhammaple]

Hey Pete - this is my second year of sugaring and am looking to increase production by building an oil tank evaporator. Great pictures! I have a question for you. In the third picture of the inside there are holes drilled into the metal. What are those for? Do you have any hints or tips for making a successful evaporator?

Thanks!

[crzypete]

I think you're looking at the photo with the two large bungs that were originally part of the top of the oil tank. I eventually welded them shut. I really tried to use as much of the tank as possible.

My biggest tip would be to design the fire box around the size of your preferred wood length. You'll want to be able to get them straight in easily. the fire is so unbelievably hot there is not much time for messing around when you are loading it. If I didn't wear gloves when I was loading it, I would burn off my mid-digit hair.

I wish I had a bit more of a lip from the bottom of the door to the grate- it would hold the mountain of coals in a bit better.

Otherwise, I'm pretty pleased with the result. I'm planning some tinkering for next year, but this was the big hurdle. First and foremost is a pre-heater. I've been scheming on some fancy sheet metal ideas, but think I my be over-thinking it.

I'm also tempted to build a drop flue because it looks like a fun build project- I have been scheming on how to bend the flues with my press brake. But I suspect time and energy will get the best of this scheme.

My season total ended up being 10 gallons of syrup this year! A very nice improvement on last years 3 gallons. I pulled my buckets yesterday and called it a year.

Anyway, good luck with your build and ask any other questions you have, I'll try to help.

Pete