Arch question for a set of 2x6 drop flue pans

[cpmaple]

I'm headed tomorrow afternoon to pick up a set of 2x6 drop flue pans only. I'm gonna make a quick are to boil this yr. but question how much space should be under flue? 1/2" comes to mind or is it 1"? 2x2 firebox how long should the ramp be? have not sugar in a few yrs an been missing it so last minute i'm jumping in have 94 taps out with max tap of 130 more than enough to have fun and give it away to people i know elderly that will enjoy it. thanks in advance i search for arch design for drop flue came up with zero.

[PaulRenaud]

I'd suggest planning your ramp so it reaches 1/3 of the way down your evaporator and go with 1" space beneath the drop flues.

[cpmaple]

thanks for the input

[Russell Lampron]

Build it with enough space under the flues to put your insulation material and filler in. If that's going to be ceramic blanket and firebrick add the thickness of that to the space that you need below the flues. I would only leave a 1/2" space but my arch is a raised flue and that's how much space I have and don't know what the industry standard is for a drop flue.

[PaulRenaud]

The space is different depending on your pan configuration - should be 1/2 inch for flat pan (raised flue) or 1 inch for dropped flue.

Attached is a design for a drop flue that incorporates convection chambers.

21215

[5iguy]

Hi Paul,

Would you happen to to have a drawing like that for a raised flue?

[maple flats]

That design for under the flues is new to me. I only had 1 drop flue, but under the flues, from the top of the ramp back to just short of the rear chamber under the base stack it was flat and 1/2" space,and maybe down to 1/4" space. On my 2 raised flue set ups I went with 1/4" space and flat. If someone has come up with a better design, clue me in please.

[5iguy]

Hi Dave,

I have a 20x68 raised flue from Thor. If I remember correctly your pans are from them as well. The bottoms of my flues are 1" higher than the bottom of the pan. Are yours the same? Next, should the insulation be higher than the arch rails to achieve the 1/4" space in the flat section?

Thanks,
John

[tcross]

my evaporator, from Thor, is very similar to the drawing of PaulRenaud's post, except it's a raised flue 30"x8. so where he has the two drops in the arch, mine raises up (like a ramp) to about 1/2" below the flues. it makes it very hard to brush out my flues this way, but i get a very good evaporation rate (bout 60 gph bare bones) and a violent boil all the way to the smoke stack! my insulation is flush with bottom of the top rail.

[Father & Son]

Hi Paul,

Would you happen to to have a drawing like that for a raised flue?

Here’s a link to CDL’s manual. Check page 8.

https://www.cdlusa.com/wp-content/uploads/2019/03/Evaporator-The-Traditionnal-User-Manual.pdf