diagrams of how sap collection vacuum systems work?

[Dale Mahalko]

Are there any diagrams anywhere explaining what you're all doing with vacuum systems?

I'm just here because you people want to keep on using the "obsolete" Bender dairy milk vacuum breakers, though I don't really know what all you're trying to accomplish with it for sap collection.

If the intended use is only that:
* sap flows by gravity out of tree to a remote collection tank
* a vacuum line sucks sap from the remote tank to a storage tank by the boiler

Then that makes sense to me.

But if you're actually trying to suck sap directly out of the trees ... I don't see how that can work since there's no such thing as "pulling" a liquid. It's all push by atmospheric pressure. (Maybe ultra-high vacuum might lower the boiling point enough, to cause the sap to generate water vapor that pushes it through a high-vacuum line?)

[lastwoodsman]

I would encourage you to visit the University sites or Proctor and Cornell as there is a wealth of information not only on vacuum but the entire maple industry.
You are indeed lowering the atomospheric pressure in a vacuum system thereby drawing out the sap with a increase in production of over 200 to 300%. No other investment in agriculture will give a return on investment as quickly.

Woodsman

http://www.uvm.edu/~pmrc/vacsap.pdf

[DrTimPerkins]

Are there any diagrams anywhere explaining what you're all doing with vacuum systems?

I'm just here because you people want to keep on using the "obsolete" Bender dairy milk vacuum breakers, though I don't really know what all you're trying to accomplish with it for sap collection.

If the intended use is only that:
* sap flows by gravity out of tree to a remote collection tank
* a vacuum line sucks sap from the remote tank to a storage tank by the boiler

Then that makes sense to me.

But if you're actually trying to suck sap directly out of the trees ... I don't see how that can work since there's no such thing as "pulling" a liquid. It's all push by atmospheric pressure. (Maybe ultra-high vacuum might lower the boiling point enough, to cause the sap to generate water vapor that pushes it through a high-vacuum line?)

Yes, there are plenty of diagrams. Go to any maple equipment dealer and they can help explain it to you, or buy or borrow a copy of the North American Maple Producer's Manual.

Vacuum produces a lower pressure in the tubing system. The trees have a higher pressure (head). Therefore sap and gases from the tree (or from leaks) move from areas of high pressure (the tree) to areas of low pressure (the releaser). Because of the high pressure differential, sap comes out faster, and a larger volume of the sap in the tree is accessed (given a long enough flow period). Vacuum can double, or triple, your sap yield. So yes, technically you are correct....the higher pressure in the tree "pushes" the sap through the tubing line into the releaser.

Bender releasers will work, but aren't nearly as good as a releaser designed for maple use.

[500592]

When using vacuum you pull the sap through the lines and it dumps into the storage and yes vacuum increases sap production people have been using vacuum for years now.

[Maple Hobo]

With vaccume you will have flow on days that gravity systems will not. On days you get flow it will be stronger.

IMHO the system should FLOW under gravity, the vaccume exists over the flowing liquid in the lines and that gas helps chase the sap into the leteral lines from the trees.

I'm actualy thinking about adding a cross connect at the high end of the lateral lines and home running that back to the releasor... It will reduce the distance to the releasor and increase the end of line pressure, from what I can figure. I think the closed loop might even be better then a larger pipe?

My wet/dry lines run out and around to collect the lateral lines at thier 6% slope. It will be less then a quarter the distance if I run from the releasor straight up the hill and to the top end of the laterals.

The releasor should maintain the line pressure so it doesn't get drawn back into the tree or have to rebuild as much.