Continues flow pan?

[Kacey small scale maple]

Hi all I have a 2x6 continues flow pan and I have boiled on it 2 times and am a little confused on how it works. I have a 50 gal feed tank and a float going into the back pan (open flue) and from there it goes to the 3 section divided syrup pan from a free flowing copper pipe crossover on the outside of the pan going from flue to syrup pan with a temp gauge and a drawoff valve in the 3rd section syrup pan. I've never had a continues flow pan so I don't really know the ropes. If sombody could give me the lowdown if it that would be great. Thanks a million,
Kacey9269

[Sugarmaker]

Well there are a bunch of answers. Do you have a more specific question? Sap flows into the flue pan, starts boiling and flows into the finishing pan where the gradient moves the syrup towards the draw off valve.
Regards,
Chris

[Kacey small scale maple]

Well, I've had trouble figuring out how to draw offand when,also what level to keep the pans. And what if the middle divider in the syrup pan boils first does that make the gradient mess up.and also how much sap do I need to boil? Thanks, kacey

[Sugarmaker]

Kacey,
Draw off when the syrup temp is 7.1 degrees above wher water boils that day.
stop drawing off when the temp drops a few tenths of a degree below.
Keep sap in the pans to a depth of 1.5 to 2 inches when there is heat below the pans.
watch the middle divider but if you have 1.5 inches of sap you probably wont make syrup there.
You need enough to fill the evaporator and have enough to boil for maybe a hour or so, then enough to shut down and cool off.
Hope that helps.
Regards.
Chris

[eustis22]

Hi, Kacey...my first year with a continuous flow, too so I feel your pain. Here's what I am doing....I boil with 2 inches of sap in my pan and keep a close eye when the boil starts, then I trickle sap from my preheater just enough to maintain the two inches. Now, I have had a couple different answers to my "how much to sweeten" question. One was 100 gallons, one was 150. This is a 2X3 and you have a 2X6 so try to search the site for "calculator" or track down a poster "Big Eddy" who gives good Response. Once you've boiled enough to "sweeten" then you can just do regular draws based on your sugar % (44:1 at 2%...I think). Since I'm still getting used to this I plan to draw off at 217 degrees or thereabouts and finish it on the stove. That way I don't risk scorching my pan. When I get a few boils under my belt and get comfortable with it I will reduce my sap depth gradually to inch in order to get the fastest boil. This may be a season or two :). Hope this helps....I'm just passing on what people here have passed on to me. Good luck.

[psparr]

Theres a lot to concider on a continuous flow. Best to read, read, read.

1. Keeping the fire steady to keep gradient.
2. Adding defoamer on a consistent basis to keep gradient.
3. It will boil a little harder in the middle channels, but if its barely boiling on the outsides, theres a problem somewhere.
4. On a small rig like a 2x6 (same as me) if you draw too much at a time, or too fast it will mess up gradient.

The way I do it, take it for what it's worth. Run it till i'm at temp at the draw off, check density, and note the temp in the pan.
Then I crack the draw off valve so I have a trickle flowing out. I keep my eye on the temp and try to adjust the flow to maintain the temp. If it starts to go down, I slow the flow, and vice versa. Sometimes I have to close the valve and let it sweeten up some more till its ready to draw again.

I'm uploading a video to youtube right now of me drawing off. Once it's done I'll post a link.

[eustis22]

>Adding defoamer on a consistent basis to keep gradient.

I skim...but how does it keep gradient?

>It will boil a little harder in the middle channels, but if its barely boiling on the outsides, theres a problem somewhere.

my sap channel doesn't boil much but what problem could it be?

[psparr]

you add defoamer it should go in the sap or flue pan. And at every firing. It keeps the foam down generally. When the foam drops suddenly, it pulls the syrup toward the drop in foam. Which can mess up gradient.
One other thing to concider, once your near syrup in the last channel, it's really gonna foam up without defoamer. That could push sap out of the channel, and potentially scorch from lack of liquid.

You say sap channel meaning the first channel in the front pan?
how does the back pan boil? Could be too much room under the back pan allowing heat to race back to the stack without hitting the front pan enough.

[psparr]

Heres my video. Watch "Maple syrup continuous draw" on YouTube
Maple syrup continuous draw: http://youtu.be/KALDSv8QPvc

[superiorsyrup]

Good info. I know you posted in my thread as well. I have many of the same questions. Thanks. Things are getting clear as syrup

[Kacey small scale maple]

Thanks guys, kacey

[eustis22]

ok, my pan is a 2X3 longitudinally divided with baffle holes in each divider. I've figured that my arch is letting too much heat go out the stack vs against the pans so I will install a firewall this weekend before my boil sunday and replace the sand/brick ramp I have. I'll let you know if this helps with my boil, which is mainly in the center channel but some in what I am calling the syrup channel.

Another question: due to time constraints, I'm still in the middle of sweetening the pan...I would like to rotate the pan between boils.....right now the shutdown process left me with an inch of concentrate (from 60 gallons) in the pan. Will draining the pan to make it easier to rotate and then pouring the concentrate back in after the rotation affect the gradient? I will be adding another inch of sap to the pans before starting another boil.

[psparr]

ok, my pan is a 2X3 longitudinally divided with baffle holes in each divider. I've figured that my arch is letting too much heat go out the stack vs against the pans so I will install a firewall this weekend before my boil sunday and replace the sand/brick ramp I have. I'll let you know if this helps with my boil, which is mainly in the center channel but some in what I am calling the syrup channel.

Another question: due to time constraints, I'm still in the middle of sweetening the pan...I would like to rotate the pan between boils.....right now the shutdown process left me with an inch of concentrate (from 60 gallons) in the pan. Will draining the pan to make it easier to rotate and then pouring the concentrate back in after the rotation affect the gradient? I will be adding another inch of sap to the pans before starting another boil.
You should have the same square inches under your pan as the square inches of your stack. Like a 6" stack you would want about 1-1/2" under the pan.

Your boil problem might be the depth of the sap. Try to run as shallow as you can. But you really have to watch though. I run between 3/4-1"

You shouldnt need to rotate the pan. The bigger guys do it, but their boiling way more an hour than we are.

[psparr]

One other thing, to keep the gradient when you shut down. Take about 2 cups of sap from each channel. After you fire up again, as soon as everything is boiling again, add the sap back in the same channels you took them out of.

You dont have to do it though. If yoy dont you'll just have a bigger draw when it is ready

[eustis22]

how many inches for an 8 inch stack?

[psparr]

how many inches for an 8 inch stack?

I believe it's around 1-1/2 - 2

[eustis22]

ok, final question, I promise :)

my stack hole is a six inch hole cut in the back of my stove, not the top. The bottom of the hole is prolly a 8 inches down the wall. Do you recc TWO (2) firewalls, one at the end of the firebox and one just in front of the stack hole, and the gap filled to within the two inches or should the top of the firewall be level with the bottom of the stack hole?

[psparr]

How far from your back pan is the hole? Right near the pan, or does it go back a ways yet? Not an ideal situation to force the heat back down to reach the stack. Maybe a v shaped firewall to force the heat towards the sides of the arch. Sounds like the heat is taking the path of least resistance right down the middle and out the stack.

[eustis22]

stove's 2 X 3, pan's 2 X 3. the hole is directly underneath the back of the pan

[psparr]

Thats probably whats happening then. If it were me, id try the baffle idea first.

If you have a welder and the tools to do it, you could make an opening 2" x the whole width of the arch, and transition that to your 8" stack.

Just my 2 cents.

[eustis22]

allrighty then

[eustis22]

I know I said I wouldn't ask another but I found this pic on the Intertoobs that looks like I what I want to do:

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I think thats vermaculite he's using as a filler. The stack looks exactly like mine and my question is this...how much can I obstruct that hole before it negatively affects my draw?

[psparr]

Yup! Should help keep the heat under the pans.

[eustis22]

I may have to insulate my door, which was glowing cherry red last night...but I got thru 25-30 gallons in about 3 hours, which works out to about 8/9 gph....how much better can I expect under optimal conditions. I worry that I;ll burn the pan on shutdown..I waited as long as I could last night and still slow boiled almost 2 inches off.

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