sap in the drop flues??

[dirtnworm]

Newbie here. I have been looking at the drop flue pan designs and have what may be a stupid question. How do you get the sap out of the bottom of the flues when near the end of the batch since from my understanding that is below the level of the syrup pan. Thanks in advance.

[SmellsLikeSyrupNH]

i wonder the same thing

[Waynehere]

Usually you start adding water to your system which will push the remaining sap around to the syrup pan. Usually I only do this at the end of the season though on my last boil. Just like the differences in density between sap and syrup, the water will push the sap. Then you end up with just water in your flue pan. Works great.

[wiam]

Mine has a drain on the bottom that comes out through the side of the arch. I would not buy a drop flue that did not have a drain.

[jmayerl]

As wiam said most have drains but some manufactures make a hobby pan with no drain. This is to keep costs as low as possible. In that case something like a turkey Baster would be needed to suck out the sweet.

[Waynehere]

When I need to drain my pan, I take it down as low as possible with the pan outlets and then shop vac out the remaining. I only have a drop tube pan though. Flues would hold way more sap and a little pump would probably work better.

[WESTMAPLES]

a lot of the older higher end model drop flue pans ive seen had no drain at the bottom of the flues, and yes my near new leader wse pan set did`t have a drain when I got it. 2 hrs with my plasma cutter and tig, along with a section of 304 ss 1 in pipe. It turned out great, with spending anymore cash on the pan set that did. the drain is nice to have but I seldom use it. on another note a bucket top vac from home depot ($24), a section of food grade hose, and a fg bucket would speed things up on the cheaper side . good luck

[68bird]

I draw it down, and with a piece of 5/16 tubing I draw a vacuum with my mouth and drain each flue into a bucket.

[Big_Eddy]

Bck to the OPs original point.

A flue pan is not usually a batch pan. With a flue pan setup, the evaporator is typically filled at the beginning of the season and left full throughout the season, only emptied after the final boil. (or for extended cold / dry spells)
The flue pan is NOT emptied at the end of a batch.

A flue pan is used in conjunction with a flat bottomed "syrup" pan.

The flue pan does the bulk of the evaporating, with the flat bottomed pan being used for the final concentration to syrup or almost syrup density. At any given time, the flue pan has raw sap at the inlet, and ~50% sap at the outlet. The syrup pan has 50% sap at its inlet, and syrup at its outlet. Within the flue pan, the violent boiling mixes the sap at the bottom of the flues with the sap above the flues so the density is the same top to bottom.

As the other responders have pointed out - after the last boil of the season, the sap down in the flues can be removed by a drain, a siphon, a pump or a shop-vac. I close the valve between flue and syrup pans and siphon out the flues, pouring it into my syrup pan, then fill the flue pan with water while I finish off the syrup. The water gives me a head start on my cleaning and protects the flue pan while I finish off the last of the syrup.

[dirtnworm]

Thanks guys for all the quick responses. Very helpful.

[Ausable]

Big Eddy - Thanks for the explanation. I understood the purpose of the flues in the sap pan - more area exposed to heat. I also could picture how a raised flue sap pan could work in a continuous flow setup. But - never could figure out how a dropped flue sap pan worked in a continuous flow until You explained it. The light finally came on in the dark recess I call a brain. Again Thanks. ---Mike---