Raised flue using tubes?

[Backyarder2014]

Has anyone tried making raised flues using individual pipes capped? It seems like an easy way to add a flue. Im just not sure how well the heat would get in them. I was thinking of using 2" round tubing maybe 3 or 4 staggered rows of them.

[RileySugarbush]

That probably wouldn't work very well. In a raised flue there is flow from front to back so you get some good heat up into the flue. At that, there is often a feature in the arch to force the flue gasses up into the slots.

With tubes, you wouldn't have that flow and the sap around them probably wouldn't boil well. Drop tubes on the other hand work great!

[Backyarder2014]

Thanks! What fo the archs usually have to deflect heat into flue channel?

[maple flats]

Tubes going up will be problematic. The only thing that will move heat into the tube is gravity, heat rises. This will not heat enough to boil the sap around it.

[madmapler]

Last year had a flat pan(24"x18"). I drilled 9 1" holes and fabbed 3 manifolds with 3 inlet pipes each (dropped through the bottom). It seemed to boil quite a bit better. I was thinking about your raised flue idea though and I think if you could bring the heat in from the bottom front and run the pipe the length of the pan and then discharge it out the back wall of the pan and into the stack it might work pretty good. Had I thought of the idea at the time I may have tried it myself. You might even choke the outlet down a little like from 2" to 1.5" to slow it down some. It would be a cool experiment and it sure wouldn't hurt. I'd like to hear about it if you do.

[wiam]

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Last year had a flat pan(24"x18"). I drilled 9 1" holes and fabbed 3 manifolds with 3 inlet pipes each (dropped through the bottom). It seemed to boil quite a bit better. I was thinking about your raised flue idea though and I think if you could bring the heat in from the bottom front and run the pipe the length of the pan and then discharge it out the back wall of the pan and into the stack it might work pretty good. Had I thought of the idea at the time I may have tried it myself. You might even choke the outlet down a little like from 2" to 1.5" to slow it down some. It would be a cool experiment and it sure wouldn't hurt. I'd like to hear about it if you do.
Thinking anything like this.

[madmapler]

I guess. Is that something you built? I should have known it was too good a concept not to have been tried already.

[wiam]

I guess. Is that something you built? I should have known it was too good a concept not to have been tried already.

Not me. It was made by W.F. Mason in Maine. Boils like crazy.

[RileySugarbush]

I guess. Is that something you built? I should have known it was too good a concept not to have been tried already.

It is also the basic theory behind most steam locomotives and many other boilers:

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