Gravity powered releaser / extractor

[Shiftman]

I had an idea to build a releaser / extractor which uses gravity to pull sap out of the tubing vacuum. It would be quite simple, just a 1" line with over 30ft vertical drop to overcome the 28" vacuum. At the outlet end of the line would be a trap and a check value which would only open once the water pressure exceeded the vacuum pressure. This would be quite feasible in our forest, we have adequate fall. I suspect we could remove about 1400 of our current 2400 taps worth of sap and bypass our releaser. There are several advantages:

1. It would increase the efficiency of the vacuum as it no longer spend CFMs to extract sap and operate the releaser.
2. It creates a partial wet-dry tubing system by removing sap from out lines increasing air space in the lines.
3. Marginally increase vacuum as gravity will pull sap out of the tubing.

Has anyone seen this before? or anticipate any problems?

[BreezyHill]

It may be that I am not envisioning this the same way as you but if so then the vertical chamber will still be under vacuum since the pump is still pulling on the chamber. If you had more drop and sequential check valves to allow the sap to drop and enter a non evacuated chamber then I could see it working to some extent. The volume point of the dump needing to keep up with the flow of sap would be the issue that would concern me.

Having had a releaser not be able to keep up with the flow is a killer on production since the moisture trap floods and the system loses vac for a period of time.

So what is the issue with mechanical releaser or an electric releaser.

I use a dairy releaser jar with a electric pump. The volume it removes sap at it can keep up with around 15K taps at peak flow with its 75 gpm capacity. Cost was under $100. Then there was the new level switch, this past season that was $128. Found a better source of them now. $48 delivered.

[wiam]

Or if you have 30 feet of drop then use 3/16 and skip the pump

[GeneralStark]

Here is an older thread about the concept. Others have certainly tried it. The major issue in my mind would be with the vertical column of sap, and the sap in the mainline freezing.

http://mapletrader.com/community/showthread.php?609-Gravity-Releaser/page9&highlight=gravity+releaser

[Shiftman]

Thanks for the ideas. I'm not concerned with freezing or releaser undercapacity as this would be an addition to an already fully functional mechanical releaser system. I am putting in this line in anyways as it would be a wet line addition to open up space in my undersized mainlines. If it froze my mainlines would be able to take the slack until it thawed.

The "vertical" chamber would be just another mainline running down the side of a valley. This would make the vacuum chamber tall enough to only need one valve at the end.

I can't use 3/16 as my laterals are already in but that is a good idea.

Since i am running of a generator a electrical releaser is just another piece of equipment and pump that could fail. The less the mechanical releaser switches the less air gets sucked into the system. And i get all the benefits listed in my first post.