Flue pan, settleing question

[Breton heart]

How does sap keep from turning to syrup in the deep recesses of a flue pan? I understand you are constantly adding fresh to it, but if the denser sap (changing to syrup) and niter is heavier, won't it settle to the bottom and not get pushed through?

[WESTVIRGINIAMAPLER]

Way too much heat, the extreme heat and boil keeps the flue pan rolling and as the sap is at a rolling boil, it is slowing moving from the sap intake area into the flue pan thru both sides and to the outlet float box.

[Breton heart]

Ok, sounds good, but do problems ever occur even though you keep sufficient sap in the pan?

[Uncle Tucker]

I have only had foam as a problem. The nirer only seams to be a problem as it gets closer to syrup.

[brookledge]

Like Tucker and Brandon said you will not get any syrup in the flue pan. Even producers who have ROs and are running high concentate don't make syrup in the flues. As long as you have a syrup pan that is aproximately 1/2 the length of your syrup pan you will be fine. You wouldn't want to have a 8 foot flue pan with a 2 foot syrup pan on a 10 foot arch. but with a 6 foot flue pan and a 4 foot syrup pan there will not be any syrup in the flues and also no nitre build up
Keith

[ennismaple]

Agreed. We get gunky foam on the sides of our flue pan that has to be wiped off at the end of every day. There's a lot of violent mixing going on in the flues so everything gets pushed to the surface. There will be a bit of discoloration on the flues at the end of the season but either the commercially available acid or sap sitting in the pan for a month makes them shine.

[Jeff E]

I think it is possible to have poor sap movement in the channels of the pans if the sap is to deep in the pans, say 3 or 4 inches. It can continue to mix with incoming sap and not get pushed forward as effectively as it would with lower, 1.5 to 2 inch depth.

I had an occasion where I ran the sap about 3+ inches deep and it took forever for the syrup to get to the density to draw it off. I adjusted the float down and then I was drawing off constantly for a while as it seemed like everything in the pans was close to being syrup. The color gradient in the pans confirmed this, it was all carmalized.

Lessons learned.

I have a friend who is considering running a 4x14 and a 5x16 in series, with steamaway and RO'ed sap.
I am thinking he may make syrup in his flue pan! He will be drawing off syrup at a gusher pace. I hope I get a chance to see it all running this spring.

[maple flats]

I have a 6' flue pan and a 2' syrup pan. I have never made syrup in the flue pan. The rapid rolling boil keeps it uniformly mixed top to bottom at any point along the path of flow. You will not have a problem. I have heard of some making syrup in the center sections of the syrup pan but i have not experienced that either. I keep a steady constant draw once the temp reads right. I do tweak it as needed. I draw it just a little heavy and then thin it with almost syrup as needed thru the filter press and into the canner. This is the only time i draw from the syrup pan anything that is not a little heavy, except my final batch of the season.

[Breton heart]

Thank you! Now I think I understand. We recently had an opportunity to visit an equipment supplier and saw used syrup equipment. I saw that a drop flue pan has small holes at the end emptying into a pipe and a raised flue pan has a drain pipe also (I did not know that). Is that pipe used only as a drain or does the flow of liquid always follow that path?

[Haynes Forest Products]

with all the boiling and and steam bubbles flying all over the place the bottom tube really doesnt allow alot of sap movement thru the drain pipe. In the raised flue pans like mine I have to pull out the partisions to get it to drain quickly.