Pan to Pan Siphon- any ideas that work ??

[Maplesapper]

I have two pans that are each flat bottom 2' x 4'.
I have these sitting end to end over a 9' arch. In the furture the back pan will be converted to a flue pan.
The back pan I would like to keep 8" of sap in as a preheater.
The front pan I would like to keep 1.5" of sap and will pull syrup from here and finish on the propane setup.

Has anyone ever devised a simple siphon system vs a float system that will help me keep these levels.
Too cold to walk to the shack but here is a sketch of the basic layout.
I think the key is I need the lower pan to draw from the big pan when the level drops.

[CampHamp]

See here (http://mapletrader.com/community/showthread.php?18050-Siphoning-between-pans&p=198282#post198282). There was another post somewhere on how to assemble them.

[happy thoughts]

Those siphons wouldn't work in this application. Maplesapper wants the levels to be unequal between pans. With a simple siphon the sap level between all pans would be equal ..... water finds it's own level. The only way I can see it working is if the lower pan was raised higher than the back pan so that the heights of the desired fill levels were equal and I'm not sure even that would work. I really don't see how this could be done with a simple siphon but I'm always amazed by what others come up with here.

[Maplesapper]

Thanks Happy-

My last thought was to put a simple ball valve, and a compression fitting with a 1/4" copper pipe on the drain in the pan that has the higher volume.
If I open the valve a little bit, the weight of the sap in the high pan will want to push the sap thru the copper pipe and empty it into the lower volume pan.
8 inches in my pan equals 40 gallons or almost 400 pounds. Hopefully enough to push a small amount of sap.
Will just have to tinker with the valve until the evaporation rate of the lower pan stabilizes.
Sound reasonable ?

[Ittiz]

Not sure if this set-up would work for you, but just elevate the front pan so that it's bottom is 6.5" above the bottom of the back pan. Then your siphon should function.

[happy thoughts]

That's what I was thinking too, but then your front pan is way above the fire and you're also siphoning uphill. Considering those u-shaped pan siphons lose suction because of boiling sap bubbles, I'm not sure how great that's going to work. A float system seems the simpler solution.

[happy thoughts]

Thanks Happy-

My last thought was to put a simple ball valve, and a compression fitting with a 1/4" copper pipe on the drain in the pan that has the higher volume.
If I open the valve a little bit, the weight of the sap in the high pan will want to push the sap thru the copper pipe and empty it into the lower volume pan.
8 inches in my pan equals 40 gallons or almost 400 pounds. Hopefully enough to push a small amount of sap.
Will just have to tinker with the valve until the evaporation rate of the lower pan stabilizes.
Sound reasonable ?

Give it a try I don't doubt your plan would work but maybe not as you intend. I still think water (sap) is going to seek it's own level, until the surface level of all pans is equal. I could definitlely be wrong, though. Physics was never my strong point :emb:

[Ittiz]

That's what I was thinking too, but then your front pan is way above the fire and you're also siphoning uphill. Considering those u-shaped pan siphons lose suction because of boiling sap bubbles, I'm not sure how great that's going to work. A float system seems the simpler solution.

If the sap levels are the same it will siphon to the pan that is evaporating the fastest. You only have to worry once you start running out and the levels in the 8" pan start to drop, you'll just have to dump it into the 1.5" pan. He mentioned the front pan will be on propane which should be elevateable. I played with siphons and sap before and have a little experience with it.

[happy thoughts]

Agreed, but if the if you raise the lower pan it will be way above the fire which presents it's own problem.

Post edit- Or maybe I'm just misunderstanding the set up. From what was described, the level difference would be on the 2 arch pans- Back 8", front 1.5". The diagram is unclear because it looks like the second pan is empty. Maple sapper, by front pan do you mean the finishing pan on propane?

[Maplesapper]

Hey Happy- sorry for the confusion.

Here is a pic of the arch.
One pan sits behind the other. Both pans are identical and have drain holes at the same height. That's my first challenge.
The pans closest to the stack holds the most liquid, After a few hours we decant off some liquid from the front or first pan and finish it on a separate propane burner in the garage.
A pure siphon will equalize levels in both the front and back pans- I don't want that.
I need a siphon that is triggered by a drop in the shallower front pan.
I don't have any room for a float box setup, nor any height difference between the two pans.....

8912

[happy thoughts]

If there's an answer, the creative guys on this forum will have one. You should also try your idea because you won't know if it will work until you do. I just can't picture any solution in my mind's eye. It's probably time for me to get some new mind's eyeglasses:)

Good luck. I hope you find something that works for you.

[CampHamp]

Those siphons wouldn't work in this application. Maplesapper wants the levels to be unequal between pans.

OK - I get it now. Thanks.

Why not run the back pan shallow and start boiling back there?

You might be able to get soft silicone tube to kink with a float (or a wood block) on your intake.

[Ittiz]

You can take a peek at the auto siphon I did (http://mapletrader.com/community/showthread.php?22432-Sap-Siphon). Though if you don't have room to have pans sitting at different height then it sounds like you won't have the room for a siphon tube either.

[Maplesapper]

Ittiz-
I was intrigued to read about your siphon.
The difference is your siphon is adding cold sap to a hot pan.
The cold sap bucket is sealed, if I read correctly, to control the pressure and airlock.

I'm trying to add hot sap from an open pan to another hot open pan.
The solution screams float box, but I don't know how to do that since my identical pans have one hole in each pan at equal heights

[Ittiz]

Ittiz-
I was intrigued to read about your siphon.
The difference is your siphon is adding cold sap to a hot pan.
The cold sap bucket is sealed, if I read correctly, to control the pressure and airlock.

I'm trying to add hot sap from an open pan to another hot open pan.
The solution screams float box, but I don't know how to do that since my identical pans have one hole in each pan at equal heights

True, but my bucket could be a barrel sitting over a fire.

The hole heights don't matter much with a siphon as long as they are both always below the level of the sap. You could always buy a plug for the holes. On the condenser for my vacuum still when I accidentally drilled a hole too close I just threaded it and put in an air tight threaded brass plug.

[maplerookie]

how big does the float box have to be...surely you can rig up a narrow float box . only a couple of inches wide. i