Base stack-how hot is too hot?

[Aa2tn]

Also, it may help to put a stack of fire bricks to block the center in the back of your fire box right where the flue pipe comes in. That might slow down the hot gasses making them go around the bricks to the sides and up the stack. Similar to a layer of brick across the bottom of the back section of the arch to push gasses up into the flues of a raised flue pan....

[BCPP]

Also, it may help to put a stack of fire bricks to block the center in the back of your fire box right where the flue pipe comes in. That might slow down the hot gasses making them go around the bricks to the sides and up the stack. Similar to a layer of brick across the bottom of the back section of the arch to push gasses up into the flues of a raised flue pan....

Our firebox rises up about half way down the evaporating pan until it is about 1/2" from the bottom of the pan so all the hot gases have to pass through the raised flues.
I keep draft as wide open as possible as I want the fire (and thus evaporation rate) to be as high as possible. I shut draft down only to keep pan from foaming over. Typically draft is open around 25- 50%

[Sugarmaker]

I would say that it is too hot! maybe firing to often? Pushing wood back to much? several things can be factors. type of material your burning?
Keep boiling!
Regards,
Chris

[Balrog006]

3-2-10 rule is your stack height to combustibles,as in when it comes up through your roof.

Maybe it’s because I haven’t had any coffee yet today but I’m still not understanding this formula/ratio as described. Can you give an example of some dimensions and how it applies? Thanks.

[n8hutch]

I believe its 3 feet above the ridge , or 2 feet above roof line and 10' latteraly to any combustibles. Thats if my memory serves me correctly. It was just kind of a general safe chimney rule.

[Balrog006]

I believe its 3 feet above the ridge , or 2 feet above roof line and 10' latteraly to any combustibles. Thats if my memory serves me correctly. It was just kind of a general safe chimney rule.

So it wouldn’t have any application on a stand alone evaporator outside of a sugar shack then? I just have a 55gal drum evap on a pallet.

[buckeye gold]

found this https://www.bing.com/search?FORM=U52...0+chimney+rule

It is widely known that masonry chimneys are required to meet the 3-2-10 rule. This rule means that they must extend 3 feet above the roof penetration on the shortest side, and the top of the chimney must be 2 feet higher than any portion of the building structure within 10 feet.

[Michael Greer]

So I'm not an engineer or anything, but I think a red stack is just wasted heat. Heating the liquid is what we're after here, and it seems to me that there should more heat transferred to the liquid before it gets to the stack. Maybe the pans should have been longer?? with more pan exposed to the fire. Another thought is that combustion that should be happening in the FIRE box is actually happening further along. Flames in the stack aren't doing any work for you.

[buckeye gold]

I checked my stack temp the other day and it was 460 degrees two feet up the stack.

[ecolbeck]

I checked my stack temp the other day and it was 460 degrees two feet up the stack.

It would be expected that your stack temp would be lower than the OPs because you have AOF, correct?

I have no blower and my stack temps are around 900 degrees.