Modified Oil Tank Evaporator with Float Valves

[TomorrowRiverMapler]

This year I modified my evaporator to take advantage of all the heat it produces by adding 2 more pans to it. It originally had just a 2x3 pan in the front and the back 2 feet was just part of the flue. I could not believe how hot that was last year so I decided to cut the top off and add a 2x2 pan to that. It boils just as good as the bottom pan. Next I added behind the oil tank an old semi saddle tank by cutting the top 1/3 off and added a 2x4 pan to that. Lastly I insulated all areas that did not have fire brick to keep the heat in. Evaporation rate is an easy 16 gph. With some minor tweaks like sap pre heating and constant fire stoking I think I could get close to 20. To automate things I added floats to each pan. I used Robert's float valves and modified flat bottom floats. I need to improve the float stability and adjustability as they are a pain to adjust and a little unstable in support but overall the improvements really worked well.13795137961379713798

[woodey24]

That is a sweet float valve. Where did you get the parts? The pan floats in the warmer and turns it on and off? We could really use one of those next year.

[Russell Lampron]

Nice looking evaporator set up you've got there. Can you make a box around the float pans to cut down on the turbulence? It looks like when you get a good boil going they are probably shutting the flow off instead of letting sap in. You would need to put some small holes in the bottom edges of the boxes to let sap in. I think it would help keep the floats from moving from side to side making them more stable.

[TomorrowRiverMapler]

Except for the float on the first warming tank which I used an old kitchen pan and was my prototype, I got everything else from Amazon. I was shocked on the selection of pipe fittings and prices they have. My local Menards wanted way more for the same fittings in brass and how can you beat stainless for less? The last two float pans are 1/6 steam table pans 4" deep. As Russell notes the problem with the last two floats was their instability rocking side to side. I have read previous comments about that and now I understand why traditional float boxes are off to the side versus in the boiling zone, but doing that would be a lot more work. I have toyed with a box to enclose the float or was also thinking of stainless rods along each side of the float welded to a u shaped bracket cantilevered over the float and clamped to the side of the pan. It's a little hard to describe but there would be a rod along each free side of the float as close as possible keeping it restrained from side to side movement. Any thoughts on that idea? I also plan to move the level adjustment to the top of the connecting point of the horizontal rod so it can be easier to adjust.

[Swagner]

Nice looking unit.I recently with a buddies help build one from an oil tank myself. We build it in levels using three hotel pans the front lowest one being my finishing pan.I have one question for you to make mine even better. What exactly did you use for the filler valves from one pan to the next ? How do they attach to the pans ? Compression or weld ? Cant wait for your response this is my off season mod.

[TomorrowRiverMapler]

Nice looking unit.I recently with a buddies help build one from an oil tank myself. We build it in levels using three hotel pans the front lowest one being my finishing pan.I have one question for you to make mine even better. What exactly did you use for the filler valves from one pan to the next ? How do they attach to the pans ? Compression or weld ? Cant wait for your response this is my off season mod.

Thanks I have 3/4 inch nipples welded in the corner of each pan and then have 3/4inch ball valves on that. Look up Robert float valve on Amazon and you'll find exactly what I bought. I was not going to do float valves this year but got a last minute surge of energy to build them just before my first cook. You'll have plenty of time to make them work well in the off season but make sure you test with boiling water for the last check. Good luck.