Stack size for steam hood

[Clinkis]

I just purchased a new pan set, a Lapierre 18”x60” junior evaporator pan set, with 18”x16” syrup pan and a 18”x44” flue pan. They are going on a homemade propane arch I just completed. I did a test boil with water this afternoon and it went well. Next step is to build a steam hood. My old steam hood only has a 10” stack which I’m sure is too small. What size of stack should I have for a steam hood covering an evaporator this size? Also does the height of the stack matter? Any advise is appreciated. Thx

[upsmapleman]

I would think it would be plenty big enough. Leader just built one for me for a 3x8 rear max flu pan and put a 12" pipe with damper.

[Super Sapper]

10 inch should be plenty big enough. I have a 2 x 6 drop flue and use the Smoky Lake Concentric Exhaust. The steam pipe is 12 inch but has the 8 inch stack inside of that and I have no problems.

[Clinkis]

My concern is with the previous 16x48 evaporator there was at times not enough draw to remove the steam with the 10” stack so I figured I may want larger. Does stack height effect this was well?

[tcross]

i would assume the stack height would affect how it draws out the steam. kind of like it does with evacuating the smoke on a chimney.

[Sugarmaker]

Just my 2 cents, and some questions. (And most folks ignore the old man!)
How were the steam hoods configured to/on the old pans? And what is your goal for the steam in your room? Do you want all the steam out? Dow you want some of the steam out? Placement of the hoods on or above the pans will dictate the steam exiting the evaporator. As example I have two stacks 10 inches each on a 3 x 10 boiling 120 gallons per hour. We only have a little bit of steam in the room. Hood placement/ position is everything. The steam stack/s needs to be heated to draw the steam. if hoods are too high off the pans cold air rushing in will reduce the draw providing you with a nice steamy environment. Congrats on the new rig!
Keep boiling!
Regards,
Chris

[Clinkis]

Here is a pic of how my old rig was setup. I’d say maybe 2/3 of the steam goes up the stack and the rest stays in the room. Also included a picture of my new rigF1495853-6E7F-4434-91D4-C26309E8E908.jpgAE813909-1E2C-4E87-A160-A64350EE098F.jpg

[heus]

My new 2x7 only has 6" stacks and they will be fine because they sit directly on both pans.

[Sugarmaker]

Clinkis,
Thanks for the pictures. Congrats that new rig looks nice! Upside down but nice! What you described is what I would expect in the first picture. Some folks love the steam, others want it out. So whats your goal?
I would agree with heus. His sugarhouse will be pretty much steam free. Jason, I saw your hoods in the shop yesterday! They look good on the evaporator. Should work very well!
Keep boiling!
Regards,
Chris

[maple flats]

a 10" stack on the 18x66 should be fine if the hood sets on the pan (s). If elevated you might want 12".