Modifying set-up

[Jerome]

I was able to increase from a 2X3 to a 2X4 flat bottom pan and oil tank evaporator. http://www.mapletrader.com/community/attachment.php?attachmentid=84&stc=1&d=1194866011


What I would like to do is modify the inside of the fire box, right now it is the same size as the tank, what I was thinking was to block up about half to shorten the fie box. My questions are – what would be the best length of the firebox be under the pan? How much space from the bottom of the pan to the top of the blocking? Would it be worth it to have channels added to the back of the pan?
Thank for all your help.

[Sugarmaker]

Is that a flying tractor?????:)

[Jerome]

Yes that is my other life as a stunt tractor driver ;)
Wink
Here is what I have planed (see attached PDF)
Will this help???
thanks

[TapME]

I hope you can make the sap fly like your tractor out of your pan. Your plan looks good, are you planing to divide the front of the pan as well?

[maple flats]

Your space of 4" is too much, the space should be more like 1-1.5" until you get to the stack, then go to about 6 or 8". You want to force the heat up tight to the pans. The fire box is good but I might suggest going up about 10 or 12" straight and then a 45-60 degree ramp up to the narrows. When you put this in use vermiculite and then cover it with a layer of half brick or if too costly use a layer of refractory in powder form and mist it lightly with water. This will harden and keep the vermiculite from going up the stack with the draft. The vermiculite will insulate, weighs almost nothing and will not hold a ton of heat when you shut down. Good luck.
Dave

[RileySugarbush]

Regarding your firebox, I'd shorten it so that the length inside the firebricks is a few inches longer than your firewood. Mine is about 20" front to back. Your 27" would be fine as well, and make it easier to fier. I wish I'd made mine about 22"

If you raise the flue area, you want as much of the flue gases to touch the pan as possible, without cutting off the draft. Maybe about the same flue area as your stack. I'd set that bottom gap to between 1 and 1.5 inches, and flatten out your stack to widen it across the flue. Maybe even drop the fill a few inches for the full width across the arch to encourage flow along the full width of the flue.

[RileySugarbush]

Wow, Maple flats...

Same ideas at the same time! Except I really like the back of the firebox vertical to give the flue maximium length and to creat very turbulant flow. I think if you have plent of draft, you dont need the angle.

[maple flats]

I put a short angle section and I get a real good evap rate over the whole rig. My first rig was a drop flue and had a long taper upward, I shortened the taper length and went about 50 degrees upward. I never tried the full section straight up at the rear of the firebox so I don't know how well that would work, I just know mine works real well.

[Jerome]

thanks for all the help everyone. TapMe would dividing the front pan greatly improve efficiency?

[TapME]

It would give the almost syrup a little longer to travel(get pushed by the thinner sap being evaporated) to become syrup. My pan had three sections and it was better than the flat pan that we had the year before with no sections. It would not make a huge difference but some.