Steam Hood Stacks - Connecting syrup and flue pan stacks

[bryankloos]

Hello All,

I posted in the evap section but no traction, so figured I'd post over here...

I have a new evap that I am starting to set up, and I have questions.

I have 2 hoods, one on the raised flue pan and another on the finishing pan. They each have an 8" vent hole.
My question is how and where to connect the two before going through the roof with a single penetration.
For ease of install and space I'd like to go straight up about 4 feet into the loft with both pipes (2 holes through the ceiling), run the front (finisher) to a 90 and connect to the flue with a tee.
This would allow a straight run up and out for the flue pan, which I suspect will produce more steam.

Another idea would be to run a 45 from the front hood to a 45 wye meeting the straight run up from the flue pan. This would eliminate a horizontal run and keep things moving up versus sideways.

What do you guys do, and what works?

Thanks

Bryan

[maple flats]

My most recent evaporator was a 3x8 raised flue. It had a hood over all, flue pan and syrup pan. Each had a 15" stack. I had a Y made to bring the syrup pan stack into the flue pan stack, it worked very well. The flue pan hood was 1 piece and the syrup pan hood another piece, but they were joined together straight across the top. On those pans I designed both, especially as to the height of each. The flue pan was 20" tall and the syrup pan was 14" tall. The hood over the flue pan was another 18" tall, while the syrup pan hood was only 10" tall, thus when they were connected across the top, and sat down on the flue pan I had about 14" open above the syrup pan, it worked very well. All of the steam from the flue pan and about 95% from the syrup pan went up the stack. I did have a slight bit of steam from the syrup pan that went up in front of the syrup pan portion of the hood. It was never a problem, it went up and out the cupola.

[bryankloos]

Super info!

This is exactly what I was looking for and what I was planning.

My hoods are separate as well but connect together. The flue pan hood sits on the pan directly and the syrup pan has maybe a 12" gap between the pan and the hood. The tops of both pans are flush with each other. Seems like a very similar setup.

I was hoping to limit the holes in the roof (no cupola) to 1, hence the want to connect with a wye.

I'll give it a go and see how it works. Hoping to be able to evacuate all the steam with natural draft and no blowers.

Time will tell, but at least my plans have been validated.

Thanks!

[maple flats]

You may want a cupola too, not only to make it look like a sugarhouse, but also to get some of the excess heat out, and if some of the steam fails to enter the hood (like mine did) you don't want steam building up in the air . If steam starts to fill the space, it can even fill from top to bottom and like a heavy fog, it can fill the space. I have seen that in a sugarhouse before, then you need to address it while you want to be boiling.

[bryankloos]

Understood. If this season doesn't go as planned a cupola will be in the cards next year. I'm simply not going to have time to build up a new roof structure this season...

I have gable vents to handle the heat, and can add vent fans to both gable vents if things don't draft like I hope.
I was also toying with the idea of adding an inline blower in the steam stack to force the draft, though I'd imagine that may not be a viable and long term solution (electricity and condensate).
I'm very curious to see how this system works... Lots of work to do before I can test.
I appreciate the info and suggestions.