buck3m
03-27-2009, 10:51 AM
This is my first year with this divided flat pan and it's working well. I enjoy being able to draw syrup right from the evaporator rather than doing it it batches.
I calculated it's evaporating about 18 gallons an hour. That's actual boiling time not counting warm-up and cool-down, but it DOES include the evaporation during those times.
I fire every ten minutes with good dry hardwood. Most of it is split (say 3" average) with a some chunks of unsplit smaller stuff, almost all of it ironwood (hop-hornbeam.) The whole pan is usually boiling except for parts of the first section where the sap is trickling in. I have no preheater other than the 1/2" copper tubing leading from the sap feed tank to the sap valve near the draw-off valve, and back to the other end of the tank (condensation is diverted to the side.)
I see some very impressive evaporation rates quoted for flat pans, much higher than what I'm getting, but here's what Anderson's Maple has to say:
"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.). Using the above calculations you can then determine that this size pan will be good for up to 80 taps."
Seems like I'm in the ballpark based on that quote. Out in the woods I don't see forced air as an option, and it looks like a more efficient preheating system will only gain me about 10% more per hour or so.
Have I reached the point of diminishing returns and should I be happy with that rate, or can I do a lot better with a hotter boil, say by splitting the wood much finer?
I calculated it's evaporating about 18 gallons an hour. That's actual boiling time not counting warm-up and cool-down, but it DOES include the evaporation during those times.
I fire every ten minutes with good dry hardwood. Most of it is split (say 3" average) with a some chunks of unsplit smaller stuff, almost all of it ironwood (hop-hornbeam.) The whole pan is usually boiling except for parts of the first section where the sap is trickling in. I have no preheater other than the 1/2" copper tubing leading from the sap feed tank to the sap valve near the draw-off valve, and back to the other end of the tank (condensation is diverted to the side.)
I see some very impressive evaporation rates quoted for flat pans, much higher than what I'm getting, but here's what Anderson's Maple has to say:
"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.). Using the above calculations you can then determine that this size pan will be good for up to 80 taps."
Seems like I'm in the ballpark based on that quote. Out in the woods I don't see forced air as an option, and it looks like a more efficient preheating system will only gain me about 10% more per hour or so.
Have I reached the point of diminishing returns and should I be happy with that rate, or can I do a lot better with a hotter boil, say by splitting the wood much finer?