Flue pan basics,,,seriously dont know ??

[TerryEspo]

I am sure some will laugh at me, but time I asked.

I batch boil, but know dividers, blowers and flues help, yadda yadda.

I do not know the layout.

Flue pan located above firebox at the front? or flue pan is at rear away from firebox?

If you have a flue pan, do you need to have a separate pan as well ?

Do flue pans have dividers?

Basically I am asking what the basic set-up is if you have a flue pan?

I picture it as the flue pan is at the rear, and you need a front pan, flat or divided and that is where you would draw off from, front pan. I am pretty sure I have read here that some pans are one piece with flues at the rear of the pan, so maybe two pans is not always needed.

Someone wanna give me the basics on a darn flue pan.

I should call this post Flue Pan 101.

Thanks.

Terry

[325abn]

Flue are sections of the pan that either raise from or drop from the rear pan. They increase the surface area of the pan that is exposed to the flame. Don't always need a seperate pan, my pan is a hybrid of sorts. so overall the pan is 2 x 4 with 18" being a flat syrup section with one divider while the back 30" is the flue section with one divider having 5 raised flues on either side.

[325abn]

Here is a shot of the pan from when I first bought it.

http://i2.photobucket.com/albums/y26/reagantrooper/Evaporator/8-06065.jpg

[TerryEspo]

Oh My,,That is a pretty pan.

So, the front flat pan area is over the firebox area then?

I see two taps,one on each side,,, why two ?

Nice pic.

Terry

[325abn]

Yep the front is over the fire. The valves you see on each side are one each a draw off valve and a valve to let the concentrate move from the flue section to the syrup section. These valves are controlled be me. There is a set of valves on each side so that if I choose I can reverse the flow to help controll niter build up.

So the raw sap will enter the pan at the "top" of the flue section. So in this pic, the middle bottom of the pic where you see the valve. As it concentrates it flows though the pan to the other side where I will open the valve and let it flow into the syrup section. As it concentrates further if flows though the divider to the other side. When it reaches the correct temp I will open the draw off valve and the flue section to syrup section valve thus drawing off syrup and moving more concentrate into the syrup section to replace the liquid I am drawing off.

Make since?

[boondocker]

Here is another view of a raised flue pan with two seporate front pans.7100

[Adk sugar bush]

Hi - I've been reading this with interest. I resurrected my Dad's old Grimm Lighting evaporator that looks very similiar to this picture - Except sap would enter at top right, sugar pan is separated (and lower) and I have 2 draw offs (top and bottom) from sugar pan - I've been running sweetened sap into sugar at bottom left, then pulling (close) to syrup at where your top left valve is.

Can you tell me if this is the correct sequence? Also, what temp should I be drawing into the sugar pan? I finish on a propane stove, but always seem to think that I need to get closer to syrup in the pan. Thanks for any help.

[edscout78]

7186
3X6 flue pan and 3X3 syrup pan w 4 compartments
syrup pan over fire box

[Big_Eddy]

Here's the picture from my Sugar Shack Wall
Shows the flow, and also how the concentration changes from section to section

[Adk sugar bush]

Neat graphic. Thanks. Can I just ask one more question. At what brix/temp do you go from flue pan to sugar pan?

[Big_Eddy]

Really going to vary from evaporator to evaporator. With an open valve between pans, gravity does the work for you. As water evaporates from the front, it is replenished from behind with less concentrated sap. When you draw off, it is replenished from behind.

The concentration at the transition is going to be dependent on the evaporation rates in the flue pan versus the syrup pan. The size of each pan / number of dividers / number of flues as well as the design of the arch will all affect evaporation rates in the each section.

[Adk sugar bush]

Thanks for the input. Sounds like I have to figure it out for this evaporator. My valve to sugar pan is at the bottom, so can't leave open. Right now I have to manually open valve to add to sugar pan, but have a float to figure out and install - that may make the process easier. This is my 3rd year, and really haven't had a good run. The first year I was setting up and had issues, last year was really slow, so will see how it goes this year.