vac pump

[3rdgen.maple]

Okay guys looking for next year but I have questions. I am a bucket guy so vac is all new to me. Im considering putting a new sugar bush on vac next year. A good cluster of trees that have never been tapped It is a young group of trees. So questions are running vac with treesaver spouts what is the smallest size tree you would tap? How many taps per size of trees? Pumps are expensive but in my line of work when I take a printing press in trade for new they get scrapped out if not worth updating it. Well they all have vac pumps on them. They are carbon vane pumps with oil drippers on them. Some guys run them all day and night so I really don't think overheating is an issue. Would they work? Also not sure how the vac pumps work in a sap extracting situation. Does sap get drawn into the pump or does the releaser keep it seperated so it does not enter the pump? Thanks and Im sure I will have more questions to follow.

[Russell Lampron]

How many CFM's are these vacuum pumps rated for? You will need a minimum of 1 CFM per hundred taps and overkill isn't a bad thing. You will need to put a regulator on it or there may be one that you can salvage from the printing press. It will overheat if you run it over 18" for any length of time. You will also need a releaser. Getting sap into a vacuum pump is a bad thing.

[Snow Hill Farm]

As far as tree size, I tap healthy 8" trees with the tree saver spouts and they seem to heal fine. +/-20" trees can have two taps and over 25" three taps. No tree should have more than three taps, regardless of the size.... This is much more conservative than it use to be and much better for the trees.

[3rdgen.maple]

thanks guys Not sure on cfms but I adjust the regulators on them to hold a 40 on the guage. They are pretty much the same size vac pumps I have seen on some sap lines but I never really payed much attention in the past whenever I seen one setup. So when you say 18" do you mean 18 psi? I figured you had to run a releaser but as I said I know nothing about setting up a vac. line. Hoping I can get this figured out I don't want to spend that kind of money on a pump setup for sap. It seems to me they are way way to high in price for what they are. I can by Gast pumps for presses for alot cheaper and willing to bet they are the same with minor accesories on them.

[PerryW]

Thanks for asking the question, as I'm considering Vacuum too.

When Russell say's 18" , he is referring to a vacuum of 18" inches of mercury (Hg) on a vacuum gauge.

Normal Air Pressure (0 % Vacuum) = 14.7 PSI (atmospheric Pressure) or 0 inches of Mercury on a vacuum gauge

a 61 % Vacuum = 5.8 PSI (atmospheric Pressure) or 18" Mercury on a vacuum gauge

A 100% Vacuum = 0.0 PSI (atmospheric Pressure) or about 30" of mercury on a vacuum gauge

Of course, gauges read the pressure difference between whatever you are measuring and atmospheric pressure; So I guess a pressure gauge would read -14.7 PSI (30") when measuring a perfect vacuum.


So correct me if I'm wrong, but.. It is impossible to exceed a vacuum of 30 inches.


EDIT 11:45 PM Found this after I posted it. Describes the difference between gauge pressure & atmoshperic pressure

Your indicator is a vacuum gauge, calibrated in inches of mercury. Technically, "vacuum" is not the perfect terminology to describe low air pressure, but it's a familiar word so we'll use it. Most people seem to think of vacuum as if it were "negative pressure".

Whoa, let's back up a tiny bit and find out why this is wrong. It may help to know that, scientifically, a perfect vacuum would be considered an "absolute pressure" of zero. Remember seeing storm weather on a barometer, which measures atmospheric pressure, typically reading between 29-31 inches? Yep, that's absolute air pressure. Indeed, the air we breathe all day long is under pressure. We can measure it in pounds per square inch (PSI, about 14.7) or about 30 inches of mercury or simply call it "1 atmosphere" of pressure. But no matter how we measure it, since we human beings are so familiar with breathing standard air pressure all day long (and not to mention we're a bit egocentric), we tend to think of it as "zero" pressure even when it really isn't. And this is how your dashboard gauge is calibrated: zero is standard atmospheric pressure. Given this point of reference, a perfect vacuum (absence of all air pressure) would therefore be equivalent to about -30 in/Hg of pressure. But nobody uses negative pressure readings; we think of "vacuum" instead, and we just refer to it as 30 inches of mercury.

from:

http://www.earlycuda.org/tech/vacuum1.htm

[3rdgen.maple]

AHHHH Perry Im not trying to launch a spaceshuttle around the moon. Just trying to consider a upgrade for next year. Was that all about me saying I adjust the regulators to hold at 40 cause if it was that 40 is pounds per square inch. These pumps I have on the printing equipment use the vac and the blow. The guages are on the blower lines coming out of the pump. Any more than 40 psi coming out of that line will blow the paper out of the room.
So next question is there a special guage to get the vac readings that reads the inches and do you guys test at the last tap and at the pump? Also this is probably a ford dodge chevy thing but who recomends what kind of tubing to run?

[brookledge]

I'm still not sure what your gauge is reading when you say 40
But if it is -40kPa then that is the equivilant to 12"Hg.
With vac systems for sap the more the vac the better. Most dairy pumps and other aircooled are good for 15-18"Hg before they begin to overheat.
Water or oil cooled pumps can maintain 23-26"Hg with out overheating.
The best thing you can do is to go to
http://www.gastmfg.com/rotaryvane.html
The key thing to specing a pump is making sure your CFM's are at the desired amount of "Hg and not open flow (0"Hg)
I have a gast pump that I have had for over 20 years on a choreboy milking unit and it has been great. The only thing I've had to do is replace the elec motor
Keith

[Russell Lampron]

3rdgen you would need to put a vacuum gauge on the inlet side of the vacuum pump to see how many inches it is pulling at 40 psi on the outlet. I bet it isn't very much if the manufacturer of the press isn't concerned about it. A vacuum pump can move a lot of air at a low load. Any vacuum pump is capable of pulling a lot of vacuum though and needs to be regulated to keep it cool. I have vacuum gauges at the pump and the releaser which is 900' away. I have built a tester with a gauge that I can use to test vacuum at the ends of the mainlines and at the tap.

[3rdgen.maple]

Thanks Russ for the info. I can get alot more than 40 psi on the outlet that is just how they are regulated. The are good size pumps and the vac is setup with what we call a toilet seat in my world. It is a valve that opens and closes as it picks up the paper and holds onto it till it makes the transfer. They are more than capable of doing this 15,000 times an hour but like you say it is not continous. I will get a vac guage and adjust accordingly. Plus I can alo put a reclaimer on it to reduce heat. I just gotta think being all enclosed in metal and running 7 days a week for 24 hours these pumps will hold up fine. Again thanks I am understanding more and more about vac. setups.

[Haynes Forest Products]

pulled taps Friday and shut it down for the year and I can now speak from experiance That if you have 110 volt 15 amp circuit and a 1 HP Gast dry vane pump with a tight system you can maintain 26 HGs out in the woods all day and night without a regulator using a Bernard doubble releaser. I also used a Masport with oil flood system and did NOT use a regulator and at low RPMs with a 9 HP gas engine on it I was pulling 25 HGs all day and night if it was 30 degrees out it never got hotter than 120 degrees in the pump.