Home made pan boiling rate

[Grand Square Acres]

I have made 2 pans out of 20ga stainless trying to figure out about what the boiling rate would be. One pan 30in X 36in the other is 30in X 60in they both have 3 dividers and are flat bottom. Is there a formula on figuring out the boiling rate? I am hoping to get 75gal. plus per hr.

[SadSams]

I have made 2 pans out of 20ga stainless trying to figure out about what the boiling rate would be. One pan 30in X 36in the other is 30in X 60in they both have 3 dividers and are flat bottom. Is there a formula on figuring out the boiling rate? I am hoping to get 75gal. plus per hr.

I don't think you will get even close to 75gph. I'm thinking more like 20gpm max.

[Grade "A"]

I made a 2'x5' flat pan with dividers once and it boiled about 20gph.

[SeanD]

Yeah, sorry. Seventy-five gph is too ambitious for those pans. You have a little bigger than a 2x8. I have a 2x6 with flat pans and I average 19/20 gph. I think you'll get a very respectable boil rate - maybe something closer to 30, but to get up to 75, you'll need a flue pan. A blower will help you keep the back of that back pan in a constant boil, but you'll eat through wood pretty quickly.

Sean

[MISugarDaddy]

According to what I have read and my experience with a flat pan, the best boil rate for a flat pan is 2 gph per square foot. That agrees with 'Grade "A"'s response. Good luck with it.

[KenWP]

The boiling rate for flat pans up here is 1to 1.5 gal per square foot of pan at a hard boil.So you have to convert that rate to US gallons and it gives you a idea.That rate drops if you don't preheat you sap and fire hot enough.

[Grand Square Acres]

Thanks Guys it looks as if I will not be tapping all my trees this year. Not enough pan for boiling. Guess I will be only putting out about 150 taps. About a 3rd of what I could put out.

[whalems]

tap them all. Boil what you can and sell the extra sap. then you will have the extra money to start looking at something with a flue pan. Good luck, Mike

[Maple In The Woods]

I agree tap what you can and tweek the evaporator as you go, I have a homemade evaporator with a forced air blower with a 24" X 60" flat pan, no dividers and I preheat the sap and get 24 to 28 gph consistantly with all hardwood. Very important to keep the stack temperature fairly high not to loose boiling rate, I don't let mine get below 675 degrees right at the discharge of the evaporator.

[buck3m]

...Is there a formula on figuring out the boiling rate? I am hoping to get 75gal. plus per hr.

"In choosing the size of your flat pan to cook with, here is an easy calculation. You can generally boil off one gallon of sap an hour for every square foot of surface area on your pan. For Example: A 2 foot by 4 foot pan will cook off about 8 gallons of sap an hour (2 ft. x 4 ft. = 8 gal./hr.)"

In my experience that is in the ballpark for a starting point. On my 2 x 8 flat pan I could get close to about 25 gph, but that was really going through wood. 20 gph was more reasonable but even that was a hard boil.

[maple flats]

Try a test boil, clean water. After it hits full boil run it for 30 minutes maintaining the same depth in the pans. Double that number and you will be close. If you tweak it I think you might get 30-35 GPH if you have good hard wood. You must split it small, about wrist size and add wood about every 6-7 minutes. The wood must also be well seasoned, moisture in the wood will slow evaporation. You must give the fire lots of air too. On my 3x8 when I had no blower, the draft was open about 16 x 4", sometimes 5".

[treehugger]

I had a leader half pint which is basically 2x3 flat pan with dividers. At the most, feeding the fire non-stop, I got 8 gallons per hour. While using a preheater.