Fuel Oil Drum Evaporator

[C.Wilcox]

Thought I would post some photos of the progress on our fuel oil drum evaporator project. This project is very similar to, and is based heavily on, Gary R.'s project in this thread http://mapletrader.com/community/showthread.php?t=3621 and others who have shared info on this site (many thanks to everyone for sharing that information). Based on suggestions from Gary and others, we've decided to go with a bread and butter approach on this for the time being. Just a 2X4 flat pan that we may weld fins onto for the heck of it based on Jim Schumacher's experience in this thread http://mapletrader.com/community/showthread.php?t=6647. We are planning on putting in the right plumbing for a forced air system just in case our test boils don't give a satisfactory result, but are planning to use a natural draft for now. My dad is doing all the metal work on the project being that I can't weld to save my life. I am really good at getting welding rods stuck to steel though. :D So far he's got the top of the barrel cut off, a frame for the pan, and adjustable legs for leveling welded on. It's kind of hard to see in the photos, but we're trying to figure out the best angle for the ramp at the back of the firebox. At the moment it's tipped back so that the flames will have to run horizontally under the back 1 foot of the pan. The firebox will be approx. 24" deep and 27" wide so I'm thinking that with a good fire we shouldn't have too much trouble keeping that back foot boiling, but I could be wrong about that. Anybody have any ideas on whether this will work alright? Should we tip it all the way back so that it ends at the very back edge of the pan? At the moment we're planning on leaving 2.5 inches of space under the back foot of the pan where the flames will run horizontal so that we have a cross sectional area equal to the cross sectional area of the stack (8"). I was thinking that we could just add blanket, board, or more sand under the fire bricks as necessary if we needed to. Comments and suggestions are more than welcome if anyone out there has an opinion. Thanks!

[C.Wilcox]

Some additional photos.

[Gary R]

It looks like you have a great foundation to start with. I have only sugared for 2 years. I gleaned info off this site and tried what I thought would work. I hope you've learned from my mistakes:lol: There's some very experienced guys here. I've learned not to take shortcuts. It doesn't work.

Do you plan on addding air over the fire sometime? If so this is the time to plumb the duct work. I have completely torn down my arch 3 times in 2 years. It's dirty but it gives me something to do. It is much easier to decrease your flue space than to increase it. These guys keep coming up with great efficiency add ons. The latest being those fins.

Good luck and keep us posted.

[C.Wilcox]

Thanks Gary. My delay in starting this project was only partially due to my talent for procrastination. The other half of the delay was to see how your modifications turned out seeing as how we were starting with similar materials and working with similar numbers of taps. :) I am still tossing around the idea of over the fire air and haven't quite decided if I should bother or not. I suspect that by the time I really need it I will be ready to graduate up a step to a 2X6. I am very intrigued by the idea of fins on the bottom of the pan and will likely give that a try. I am going to have my dad put an air tight door on it so that we're ready for the blower should we decide to go that route. Again though, I'm not sure it will be necessary with a 2X4, but we'll see once we fire it up. I am really excited to see how it works.

[twobears1224]

hows this arch coming??

delbert

[rob1640]

I built a 2x4 oil tank evaporator last season with plans to put in forced air, but time did not allow me to install the forced air before we had to start boiling. I had installed the "ducting" - a 3" angle iron with holes drilled every inch on both sides, welded over the filler holes for the oil tank in the bottom of the arch. I added the blower about a week into the season and the evaporation rate doubled and the boil was not reduced after firing.

I would highly recommend installing your forced air you won't regret it!

[C.Wilcox]

Delbert,

Thanks for asking. Still working along on it. Things have been slow because the welder on the project, my dad, was busy finishing his homemade outdoor boiler so he'd have heat in the house. I just mentioned to him the other day that the arch would need to be done by February or we'd have to boil on the blocks in the backyard again. Having him finish the boiler first may actually work in my benefit though. It shared a lot of the same principles as an evaporator in regard to draft and forced air. I'll post more photos as soon as he starts making some more progress.

[C.Wilcox]

I built a 2x4 oil tank evaporator last season with plans to put in forced air, but time did not allow me to install the forced air before we had to start boiling. I had installed the "ducting" - a 3" angle iron with holes drilled every inch on both sides, welded over the filler holes for the oil tank in the bottom of the arch. I added the blower about a week into the season and the evaporation rate doubled and the boil was not reduced after firing.

I would highly recommend installing your forced air you won't regret it!


Rob,

If you don't mind my asking, what kind of evaporation rate did you get?

[rob1640]

Without the forced air I was getting about 8 GPH. I had to split all the wood very small and only load a little at a time or the boil would slow.

With the forced air evaporation went to 15-16 GPH. The need to split all the wood was eliminated and the boil was rapid at all times. We actually shut the air off every once in a while because we were amazed by the reduced boil that instantly followed the loss of forced air.

Rob

[C.Wilcox]

I've been using my drum evaporator and things are working pretty well, but I'm not sure I'm getting quite the boil that I should be seeing as how this is just a 2X4. It's fully insulated and bricked and yet I only get a rolling boil in the front half of the pan. The back boils, but it's pretty lazy. I was envisioning a whole lot more action happening back there. I'm wondering if I don't have quite enough spacing in my grates and am starving the fire. I attached a couple of photos of my set up for reference. The grates are made of heavy "C" channel steel turned so the open part of the "C" faces up. They're spaced approximately 1/8" apart so that air can slip between, but I was contemplating drilling some additional holes in the channels to allow more air in. Am I expecting too much out of a small firebox (24" X 24") or should this thing boil a little harder than it does?

[BryanEx]

C.Wilcox... in the back part of your evaporator what did you use to fill in under or otherwise support the brick? That's the area I need to redo on mine but not sure how to proceed without welding skills or using a 1/2 ton of brick.

[C.Wilcox]

BryanEX,

The brick is sitting on a layer of 1" insulation which is supported by a 1/8" metal plate that's tack welded to the sides of the drum. You could also accomplish the same thing by drilling and bolting angle to the sides of the drum and then bolting your plate to that. No welding required.

To be honest, while this thing works pretty good and was fun to build, I think if I did it all over I would go much simpler (assuming you're planning to use a flat pan). I would just cut an over-sized door in one end, add a stove pipe adaptor to the opposite end with a baffle in front of it to force the flames up against the bottom of the pan, add rails, and put a 2X5 pan on top. Instead of insulating and bricking the drum I'd dry stack concrete blocks on the sides and back to keep people from getting burned. Let the sides get as hot as they want. They'll last for quite a few seasons before burning out and by then you'll have found a replacement. No defined ramp and firebox in the drum. Just grates the entire length of the drum and if you used the original top of the drum as the bottom you'd have two built in holes through which to force air if you wanted or just allow natural draft. You'd be able to generate a great boil the entire length of the pan that way.

[BryanEx]

You could also accomplish the same thing by drilling and bolting angle to the sides of the drum and then bolting your plate to that. No welding required.
Good idea - thanks! Cutting, drilling, bolting I can do... it's just that pesky welding that gets me hung up on projects like this.

[matrob]

I agree with Rob1640. If you aren't pleased with your boil, add forced air draft. I have a 6" squirrel cage blower mounted to a 3"x3ft long iron pipe with holes torched in it similar to a gas burner. It is capped at the other end. This lays on top of my grate. When I turn on the blower, it turns the fire into a forge. Stand back when you open the door. My homeade arch is about 2X7 flat pans, and when I get going it cooks off up to 20 gallons an hour.