1/2 pint is a flame thrower!

[johnallin]

Thanks to all of your help, I got the half pint all set up and running, boiled about 70-80 gallons this weekend and tonight and made some nice light colored syrup.

Big question, after sunset I noticed that the stack was throwing a huge red flame? for about 8-12" out of the top. More like a red pointed glow right out of the stack top. I've got lots of good hardwood but is this normal or should I tone it down a bit?

Thanks john allin

[skinny78]

John,

If the flue pipe is red hot six or eight inches from the stove you are probably wasting fuel. I have a blower on mine and I cut it back when the flue pipe get red hot that far up.

[Brent]

I had the same last year. After dark I could see that the whole stack was glowing dull cherry red.

I slowed the fan a bit, used less fuel and made no detectable change in the boil rate.

[Dennis H.]

For what I understand is that you are not burning up all the gasses prior to it going out your flue. I believe what is actually heating the pan is not the wood burning but the gasses that are burning from the wood being converted to gasses. Something I think is called gassification??
It is something like there is not enough oxygen for the gas to finish burning in the firebox and once it hits the air above the flue the gasses are so hot it instantly ignites it self and burns.
So yes it is wasted energy that you could use to boil the sap.

I could be wrong on this, but hey, I did stay at a Holiday Inn Express last night!

[johnallin]

The stack did not appear to be glowing, but the top of the stack looked like the exhaust from jet engine. I do not have a blower, but do burn with the lower door open. Seems like an awful lot of wasted heat, wish I could "tap' into that!

john allin

[WESTVIRGINIAMAPLER]

You can try adjusting the damper door closed a little more or even play with a damper in the stack. Just try it different ways and see what works the best. Are you concerned about saving wood or making it boil as fast as possible. This way, it may be boiling faster but using more wood.

[MaineMapleDave]

My Experience after using a 1/2 pint since '97:
It's very easy to develop a HUGE boil under the pan, but so much of that heat is lost by going straight out the stack without really influencing the pans.

I have noticed a HUGE difference by adding a simple damper in one of the lengths of stack after the pan and forcing the combustion of wood and gasses to happen within the firebox, increasing the boiling rate a lot.

[Brent]

to give an even more graphic idea of the possible heat waste in a Half Pint, I have noticed that the 2 x 6 and 2 x 8 evaporators have virtually identical size fire boxes. So mostly the longer pans and flues give the increased boil capacity.