What is your stack temp?

[Sugarmaker]

I have a old wood stove temp indicator (its about 4 inches in dia ) it is screwed in place on the exterior of the base stack (no probe) about 5 feet above the arch.
The old pans were very inefficient ran about 600-700 deg F. The new pans: drop flue, 9 inch deep (14) pull that same indicator down to 400 deg F and it stayed withing 20 degrees all season. At first I was concerned, but it boils around 130 GPH so its getting most of the good out of the fire before it exits the arch.
Regards,
Chris

[ennismaple]

I eyeballed the calibration of our stack thermometer so the accuracy is probably ±20 F but our evaporator hums along at about 750 F stack temp. Less than that and the boil isn't rapid enough for me. More than that and we're throwing smoke out the stack and reloading wood too frequently.

[Waynehere]

We started out running the AUF at half throttle and the stack was running 6-700, but our boil rate was about 40 gph. We were firing about every 15 mins. So we went full throttle and got our gph up to 50-55 with stack temp running 900-1000. We are now firing every 10 mins, but the increase was worth it to us. Maybe when we get an RO we can throttle that back to be more efficient.

[wmick]

WOW - I'm surprised by the high stack temperatures reported... I have no experience yet, but read in a Leader instruction manual to keep the stack around 150F..

With these kinds of heat in the stack, Id think you could almost add another 8'or10' of Pans...

[ennismaple]

I have no experience yet, but read in a Leader instruction manual to keep the stack around 150F..

Something's not right - there's no way our pans would do anything more than simmer if the stack temp was 150 F. At 1900 F at the back of the syrup pan there's no way you can get that much heat out of the combustion gas in a 10 foot contact length. Maybe if you're running a piggyback pan system and routing all the gases through tubes in a secondary pan before the stack but not with a forced air arch.

Lapierre's published numbers from actual testing of their Force 5 is:

http://www.equipementsderabliere.ela...36/files/1.pdf

[wmick]

Something's not right - there's no way our pans would do anything more than simmer if the stack temp was 150 F.

Kinda wondered about that..... Must be a typo-- (1500F probably)... below is copied from the instructions for a "Revolution Pan Set"

3. When using a wood fired arch
a. Keep stack temperature in range of 150F
b. Maintain arch ½ to ⅔ full
c. Fire consistently with small amounts of wood to maintain level
d. Use timer to stay on schedule with firings
e. Adjust firing intervals as needed to maintain an even boil

[Ranger_Andy]

I built a new arch last year for our 3x12 and added the Auber digital & probe...We found that we run max temp at 1350 and when the temp drops to 1185 we fire, so we have the Auber alarms set up and fire according to the stack temp...We are running both AUF and AOF with multiple entry points for the AOF much like the store bought arches...Same pans, but different arch...with the old traditional arch with back ramp and small fire box, the stack temps were around 800 - 900 and we got about 1.0 - 1.25 gpm sap flow into the pans...In 2016 we were running 2.25 - 2.5 gpm sap flow in and burned about 30% less wood even though the fire box was twice as large as our older arch.

[Sugarmaker]

Andy,
Impressive numbers on improving your boil rate using stack temp monitoring!
Regards,
Chris

[Brad W Wi]

Wood fired, temp probe at eye level reading 1000F degrees . Feeding wood in 7-10 minutes. 45+ gals/hr. Mostly hard and red maple with some ash in there also.

[Brian Ryther]

I believe there intention is to keep the temp range within 150F. For example we run our stack temp 850F - 1000F.

Kinda wondered about that..... Must be a typo-- (1500F probably)... below is copied from the instructions for a "Revolution Pan Set"

3. When using a wood fired arch
a. Keep stack temperature in range of 150F
b. Maintain arch ½ to ⅔ full
c. Fire consistently with small amounts of wood to maintain level
d. Use timer to stay on schedule with firings
e. Adjust firing intervals as needed to maintain an even boil