New setup , not boiling in back pan.. Need help !!!

[smokeyamber]

I posted this in the Evaporator section, but since it's a homebuilt maybe here is better...
Yikes:o, My setup is a 2x5, 2 pans both flat and undivided , vertical wall for firebox ends under 24x24 syrup pan. Sloping under back pan started around 10inches up to around 4inches in back by exit. I have a blower coming in from the back of the firebox. Grates are down kinda low so I need to really pile on the wood to get flames hitting front pan.

Front pan always boils, back only boiled once ( with a full load and the blower off ).

Plan for tonight is to reduce the slope, go to 6inches up to 2inches, should I go even closer ? I have a 10ft 8" stack , opening in back is 29" wide so would the 2inches work ?

Other variable is I have no preheater, just a slow dribble from a pan in back...

Only have 2 more days to boil and then done... so any advice would help my sleep :o

[jmp]

Sounds like you may have too much draft. Can you put a few bricks in below the back of your sap pan to make the flue gasses slow down a bit before they go up the stack? I would fill the firebox as full as you can. Do you have AOF or AUF? CFM?

[kinalfarm]

The problem is the ramp. I would do what your talking about and raise the ramp and maybe even the grates. If your running a blower than make sure it's the right size maybe around 200 cfm. And also close up the arch as tight
As possible. Even the ash pan door if you have one. And also do what jmp said I stand up two full bricks as a baffle about 1/3 of the way uP the ramp seems to slow the draft down or divert it perfect.

[b116757]

Could try placing something one top the stack partially blocking the stack like a upper damper on wood stove or installing a regular butterfly damper in the stack

[smokeyamber]

Ok , all the advice was good, I raised the ramp, added a blocker at the outlet, raised the grate and added more insulation ( perlite ). It all helped !!! :lol: I did see a back pan boil much more ! I also ran the pans down to 1inch in the back and 1" 1/2 in front ( pans sit a bit different ). All the advice was awesome and I got my boil rate up closer to 10gph. I will be insulating the arch big time and also building better grates, more effective AUF and adding drop tubes to the rear pan for next year. If all that gets me to 15gph I will cheer ! Oh and I need way more wood than I thought. Planning on 2cords for next year...

[TessHayden06]

I've got a homemade 2x4 setup with one divided pan. I had a similar problem, the front pan boiled violently and the middle section of the pan boiled almost all the way back and the 2 sides of the divider did not boil. The problem was the middle divider was where the stack was and all the heat was going straight down the middle to go up the stack.

I added a wall to the back of the firebox where there is about an inch between the brick and the bottom of the pan and then put bricks all under the pan so there is only an 1" or so and then put one brick in front of the stack to create turbulence. I don't have a blower and I can boil a consistent 80% of the pan. I am running about 10-12 GPH and I had crap wood this year. Hoping to run more like 15GPH with dry pine next year.

[smokeyamber]

TessHayden... sounds like you found the sweet spot with your setup. If I don't do the rear drop tubes this next year i will mirror your setup. one inch seems close, but I think it would have worked on my setup. The blower never really made it roar like I wanted so my guess is it was already going as well as I could expect. Dry wood really is the key on that score so I will be splitting alot more this spring/summer for next season. Thanks for sharing what worked for you and hope you made lots of sweet !