Understanding vacuum systems

[tonka]

Dose anyone know of a web site where a person can read about setting up for a vacuum system and to understand all aspects of a setup?

[bowhunter]

University of Vermont has a lot of good information on vacuum and other maple syrup info. Here's a link to an excellent power point presentation with much of the information you need.

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

[BreezyHill]

Tonka, If you really want to understand vacuum you want to get on line, Physics of vacuum theory and principles and vacuum dynamics.

Send me an email and I can forward some videos I took in my glass ladder in the sugarhouse that show some of these principles very well.

Also get Steve Childs or Cornell university book on mainline. It should have the calculation charts if not I can forward those also. This is a great resource as it shows the frictional affect of the tubing over distance on your vacuum transfer cfm ratings.

There are a few other tools that have expanded my understanding of vacuum 12151

This is a CFM tester for vacuum pumps. They are very hard to find in this analogy style anymore. Todays are simply wind speed instruments and you have to make a transition to the pipe size you are testing to the units inlet size or you do not get accurate readings. I use it after rebuilding pumps. You would be amazed at how small the orifices of the tester are for each of the graduations. This is used to graph the vacuum of a pumps performance. Awesome tool.

When you fully understand vacuum/ evacuation of a space, you will be amazed at what you can do with your tubing system, but you will become obsessed with finding and repairing leaks and pitching your mains just right.

My dad was also an industrial arts teacher and prior to that a surge milking equipment dealer so I got taught vacuum, pumps, and design soon as I started riding in the trucks with him to farms.

This is where I explain vacuum to kids, tours, and customers:12152

Yup, that is a pyrex dairy releaser. Nothing better to demonstrate vacuum transfer, ladders, leaks, injectors, vacuum dynamics than a clear system so you can see the affect instantly.

You are embarking on an eye opening journey, that will bring you to question a fair amount of what you have been taught by maple sales people. So don't question the science; just learn to think on your own and to apply what you learn. I will give you a couple of examples:

Many have heard of Booster Tanks... I stood and listen to a sales person tell a producer that "these tanks give you more vacuum to your lines" when in reality only a pump can increase vacuum. They should be called a balance tank as they are in the dairy industry and other industries that work on vacuum or vacuum operated equipment.
"The bigger the pump the more vacuum you will have"...the level of vacuum is dependent on the ability of the pump to remove air from a space. A pump with a scored or wavy housing will not pull as high of a reading of vacuum as a smooth or polished surface to compress the gas into prior to it being expelled. If the pump will only dead head 22" it will not do 24" on a tubing system, no matter how big a motor you put on it. LOL

Let me know if you get into a bind, I am pretty good at explaining vacuum.

Ben

[tonka]

Thanks both for the quick input!! After looking through the power point and reading, I understand the tighter the setup, the more efficient the system will be which is not the case in the one woods I tap in, the trees are spread out, right now I have 300 taps on about 2,000 feet of mainline but will be tapping a lot more in about 5 years (300-500 taps). I guess a few questions I have to start with is how long of a mainline can a person have before loosing vacuum? when will a person want to incorporate a booster? and how far can you have your pump away from your releaser? Keep in mind I am working with little slope, am able to make it work with gravity if everything is right on.

[unc23win]

The only way to answer your questions is to ask more. All can be answered by purchasing the New York State Vacuum Tubing Guide from Cornell I am sure Ben will agree. Here is the link http://maple.dnr.cornell.edu/pubs/index.htm

The answers start with these questions not necessarily in order for instance if you have a pump you need to not over work it or if you don't have one work backwards and determine the size you need to get.
1. Size of your pump
2. Desired length of run
3. Number of taps

Once you can answer some of these the guide has formulas to help you calculate the answers. You can get 100 answers on here fast truth is very few will be the same we all do it differently. The guide is a very good source. If slope is an issue and you are shopping for a releaser I would look into an electric releaser and have it pump the sap to your collection point.

[BreezyHill]

The point at which you start to lose vacuum on a 15 cfm pump is about 20 feet. From there out the farther you go the less you have due to frictional loses. After 2000' the 15 cfm is down to 5 cfm. For 800 total taps in the future on a tight system you need 8 cfm(1 cfm/ 100 taps), if you are not checking the system daily for leaks then 1 cfm per 50 taps to be safe. This will allow added cfms to over come leaks is the theory. Checking the system is as easy as checking vac gauges and turning some valves. You only need to walk the lines if there is an issue at the gauges.
IMO extra cfm for overcoming leaks is garbage. Lets say you have a 2000' mainline at 500' you have a main that Ys off with no leaks, but at 1000' another lateral main has a leak. The affect of this leak is affecting the following 1000' more than the first 1000' but all of the system is affected if the pump is unable to maintain vac to over come the leak. This is where your question of a balance tank comes in.

If you use a manifold rather than a Y connector to connect your lateral lines you have installed a balance tank. You can use 2" pvc to even 8" or larger PVC to make the manifold. The larger the manifold the more capacity to average out a leak to have less affect on the mainline.

This is also where the Wet Dry system has a massive benefit. From Physics of vacuum you learn that vacuum is moved thru the very center of a void. When your sap line is half full the center area of the line is restricted and no longer in a circle so vac transfer is limed. Thus the dry line becomes the main conductor of vacuum and still maintains its efficiency in conducting vacuum to the manifolds and the tubing system there after.

I learned that a manifold on its long side is better in several respects. The sap flow is more even into the conductor line and the air/gases are able to be removed from the top of the manifold easily with less chance of sap entering due to the use of gravity to aid in the separation. Just be sure to connect the two lines at the same end of the manifold to allow the gases to propel the sap toward its outlet; other wise you will get pooling and bridging of sap.

Last season I caught bridging in a sap line and videoed it. The sap would nearly fill the line to the top but the leaked air was making it over the last 3/16' of the top of the main, but in 2' the sap flow was the bottom 1/4" or less. Funny the things you learn from vandalism of a mainline.

[lpakiz]

Tonka,
Is there anyone you know that has a vacuum system? You can learn more in an hour by looking at the system than you could in a week studying it in a book. Nothing against reading a book, but it wil make more sense to a beginner by actually seeing it.
Where are you? I know a guy who has a system near Sandstone, north of the cities. Im pretty sure you could hook up with him on a weekend to check it out.
Also, if you might be spending any significant amount of money, dealers will sometimes wok your woods and give you hints if they think you will buy supplies from them.

[tonka]

Thanks everyone for the advise!! With a wet/dry setup, can there be more taps to a wet/dry system then a single main line? for example, 1" mainline vs a 1" mainline set up with a wet/dry system.

[Thompson's Tree Farm]

yes. definitely.

[tonka]

I assume then you can get away with running longer stretches of tubing on a wet/dry system then a single main with laterals?

[tonka]

My idea I have floating around in my head: I plan to have on my 5/16 lines a max of 5 taps and try and go no longer then 100' lateral long lines. The duel line will be 1" and no longer then 2,000', thinking more around that 1,500', will have 7 - 10 3/4" lines (ranging from 200 feet to a couple 1,000 foot lines that might need a booster installed if needed) coming off the duel lines (to start with, will add more over the years). From the high end of the woods to the low end with the pump and tank is almost a 40' drop in elevation (1.5% slope, not the most desirable). Off the top of my head I think I will be in the ball park of 300 taps, possibly 400 the first year. Might talk to a couple local farmers who sold their herd last summer about their milking pumps and probably buy a releaser that can handle 1,000 taps since I already have 300 taps on gravity line in the area the collection tank will be.

[BreezyHill]

I assume then you can get away with running longer stretches of tubing on a wet/dry system then a single main with laterals?

I have to disagree with this. The longer the line is of any size the more friction that is affecting vacuum transfer and fluid transfer.

Check out Steve Childs vacuum book. Looking at the data you will see the longer the line the lower the cfm rate is.

Small lines like 5/16 will have less volume but an indirectly proportionate amount of surface area that will generate friction. This is seen in Rx2xPi for surface measurement(perimeter) and R squared x Pi for volume.

Shorter tubing will still get the vac to the tap hole best on shorter runs.

I also did some measurements in my bush and found that shortening the 5/16 laterials by installing an additional 1" lateral line 50' from another main was less costly than extending the 5/16 lines to 100' and still only have 5 taps per line. The longer the mainline is and the number it collects will affect your costs but it is still far cheaper to run short 5/16 lats than to be only get 5 lines from every roll of 5/16 tubing to get 5 taps. Now if you go to 3 taps as some producers have it is even a bigger return spacing mains closer.

I do agree 100% with talking to the farmers..Great Idea, also ask them about there releasers.
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This is my releaser, water trap and manifold system from a couple dairy farms. This is an electric releaser that originally ran on 3 phase power but I changed to single phase power. This is a 2" releaser but the smaller 1.5" releasers will work just fine for the size you are talking. I like this model as it has two conections for a wet manifold and a separate for a dry manifold connection. My dry manifold is outside the building on the wall.

12200

The W/D shows its best results during peak flow on your vac gauges in the bush. On a single line you will inevitable get surges of sap that fill the diameter of the tubing. These are what case needle variations in sensitive gauges when checking lateral lines. These variations will be nearly eliminated in a wet/dry system with vac being transferred thru the dry line will the wet line is full of sap.

[tonka]

Since the lines will be too long to be efficient and considering the taps I think are in the woods, I will probably be better off running multiple single mainlines and keep it no more then 3 taps per 50' lateral lines. This woods dose not have electricity to it so I was looking at a mechanical releaser and would have to get a generator or replace the electric motor with a gas motor to run the pump.

[unc23win]

Since the lines will be too long to be efficient and considering the taps I think are in the woods, I will probably be better off running multiple single mainlines and keep it no more then 3 taps per 50' lateral lines. This woods dose not have electricity to it so I was looking at a mechanical releaser and would have to get a generator or replace the electric motor with a gas motor to run the pump.

It might be more of an issue that the lines are too long for efficient vacuum the way you have it designed. I use boosters/manifolds in a fan pattern where as one booster has multiple lines coming off from of it like a fan. You can network boosters together by connecting the wet and dry lines. Another method commonly used is the whip method where wet/dry sets run along a bush typically an edge sloping toward a collection point and the other lines tie in to them.

Here is a link of a thread where GeneralStark visited a professional installation near him. In the picture you can see both booster/manifolds and the whip method being used. http://mapletrader.com/community/showthread.php?24005-Insights-From-A-Pro-Tubing-Install&highlight=insights+large+install Thanks GeneralStark

It is a little hard to read the topography in your picture and the numbers, but one thing that stands out is that you want to try to avoid 90' connections instead of using Ts use Ys. Keep in mind that your lines could run one way to a booster and then the other direction to the collection point. Again hard to read the topography, but for instance what if your wet dry ran diagonal across the picture lower left to upper right then your other lines slant upper left to lower right to meet them. Nothing wrong with one set of long lines if they are big enough and centrally located to meet all the others.

Anyway you do it more mainlines = shorter 5/16" and shorter 5/16" with fewer taps on each will result in better vacuum transfer to the tap hole and that is what you want. Nothing wrong with setting it up on gravity first the same set up - the dry lines and boosters or whips will work then you could add them later.

Hope I didn't confuse you.

[tonka]

I do understand what you are saying Jared and really do appreciate your input!! Everyone's input!!! I love this page:) I tried to make the photo bigger so that it can be more clear to read the map but couldn't figure it out. Good advise on using Y's instead of 90's for running the lines into the duel line. After looking over the layout of the land, I think you might be on to something about running from the top right corner to the bottom left corner. I will be in the woods tomorrow cutting firewood so I will be looking at that option for running the main line. I am liking the whip idea looks a lot simpler then making the manifolds out of pvc that I seen on another thread on here.

[unc23win]

Both methods are designed to help you get the vacuum you need to the farthest tap hole and that's what you want. You might find that a combination of the two works well for you.

Don't forget that you can fan out quite a few lines from the releaser and you can add more holes if you need them both of mine have about 8-10 ports. That where it all starts.

Either way if you don't want to tube the whole thing or run out of time, so you could start at the collection point and work your way from there. Another thing to consider is using all the same size pipe say 1" over some 1" and some 3/4" even though in some cases it is not needed. Reason being it does not cost that much more and you simply buy all 1" fittings. For example if you use both 1" and 3/4" every time you join them you have to have a 1" to 3/4" reducer fitting and a 1" Y.

With vacuum the number one issue is leaks the best way to find them is to isolate them this is done by installing a gauge and then a valve after the gauge at every junction. If your not getting the vacuum reading you want at the releaser start turning off valves if you turn a valve off and the gauge goes up the corresponding line probably has a leak. Turn the valve back on and start following that line turn off the valve at the next junctions if the reading goes up follow that line if it doesn't change go onto the next one.