Draining 4'x12' Evaporator

[VermontMapleMan]

I am upgrading evaporators to a 4'x12' evaporator. I'm wondering when i'm shutting down for the night and draining the pans to clean them about how many gallons of concentrated sap there would be in the evaporator if I boil it down until its almost to the top of the flues. I'm considering buying one of the two compartment rolling draw off containers for this to keep the front pan and back pan seperate but wondering how big it would need to be to fit it all...

Just curious if anyone running this size evaporator is doing this and can recommend one or knows about how many gallons they take off of there 4x12 after boiling.

[J. hutchins]

your back pan Will be 100 + gal and your front 15-20 gal. call the company that built it, i have a whole separate tank for the back pan and the front pan goes into my draw off container. I would not boil the pans low because it will create a monster surge the next time you fire up.

[wiam]

Need more info. Raised flue holds more than drop flue. How long is each pan. I have a 3 x 12 and finish a boil so the closest to the draw-off is way past. This way the whole front pan will be syrup. Then that does not have to go back in. It can go in the drum. The back pan ends up near the top of the flues. If you do this you want to put enough from the back pan to fill the front pan before adding more to back. My back pan is 3x8 drop and takes close to 100 gallons to bring to boiling level. I should add that I run oil so shutdown is quicker. But I used to run wood the same way.

[markcasper]

your back pan Will be 100 + gal and your front 15-20 gal. call the company that built it, i have a whole separate tank for the back pan and the front pan goes into my draw off container. I would not boil the pans low because it will create a monster surge the next time you fire up.

I don't know how much liquid you are figuring above the flues? But there is absolutely not 100+ gallons in a 4x8 flue pan if it just covers the flues as the commenter has asked. I currently have a 4x8 raised flue Leader pan and you can expect 50-60 gallons of contents if its barely to the top or the tops of flues are slightly dry. On my old drop flue King you could expect around 40 gallons if the liquid was just in the flues. The front pan around 10 - 15 gallons if its 4x4 and one inch or so. Keep in mind, this is not at regular boiling level, then there'd be 100 plus gallons in the flue pan. Most times upon starting the next day the level is up to an inch down in the flues and i've never had an issue of it hurting the flues, most of this occurs in evaporation when the arch is cooling.

On the contrary, if the pans are boiled low it makes start up a heck of alot easier and the syrup alot lighter in most cases, especially the first few draws. I'm baffled as to how you get a "monster surge" by having less sap in the pans at start up? Now I boil permeate in the flue pan at the end of a boil and that helps to push much of the sweet out of there. I have been boiling on the same rig for 20 years.

[motowbrowne]

I'm with Markcasper on this one, there's nothing I like seeing more the next morning when I come back to the shack than the tops of the flues just barely breaking the surface of the liquid. That means I nailed it on shutdown. I usually stop adding wood, pull my infeed line out of the float box for free flow, finish up my random activities, and shut the head tank valve. I hate having the flue pan 2" deep the next morning. Takes way way longer to achieve a boil. If that happens, I'm usually drain off some liquid into buckets and add it back once it's boiling.

My question for the OP is, why drain the flue pan? Generally speaking once the season is going, my flue pan stays full. There's exceptions, but I certainly don't empty it to clean it during the season. The front pan, absolutely, but that's not much volume.

[maple maniac65]

Some producers are draining the front and rear pans every day and doing a wash cycle to start the next day with completely clean fresh pans.

[markcasper]

Some producers are draining the front and rear pans every day and doing a wash cycle to start the next day with completely clean fresh pans.

I guess its the trendy stylish thing to do, but oh my gosh the time diddling around with this. It isn't no 5 minute job...and every day??

[wiam]

I guess its the trendy stylish thing to do, but oh my gosh the time diddling around with this. It isn't no 5 minute job...and every day??

I usually do it once mid season. Although I don't see much gain in it.

[wiam]

I will admit that when I ran a 2x6 with this many taps and 16-18% going in I probably should have cleaned back pan more often due to nitre.

[motowbrowne]

I guess its the trendy stylish thing to do, but oh my gosh the time diddling around with this. It isn't no 5 minute job...and every day??

I'm with Mark again. Sounds cute, but holy smokes what a lot of work. I guess if you've got money to throw at stainless stuff and can pump sap in and out quickly, go for it, but don't let anyone tell you it's a necessity.

[Super Sapper]

I would imagine that they are trying to make a lighter grade with cleaning every day.

[Thompson's Tree Farm]

I have a 4x12. We used to make 300 to 500 gallons per year on it boiling raw sap. We now make 10x that boiling 18% concentrate. I wish I could get the back pan cleaned on a daily basis. I do clean it a couple of times during season when things slow down a bit. Without the daily cleaning, lots of nitre builds up on the flue pan.

[Sugarmaker]

I would think you would need 100 gallon container ready to drain the evaporator. our 3 x 10 we get about 60 gallons when we drain it.
Regards,
Chris