PDA

View Full Version : Friction Loss over 600ft



Maplewalnut
11-17-2014, 01:16 PM
Alright guys..need some help. Putting old gravity bush on vacuum, on the cheap. I have a sp-11 not being used and about 3000ft of 1 inch black pipe. Pump will be about 600ft away from releaser because that is where electricty is. Only about 300 taps with 400 max if I get to it. Plan is to run 1 inch from pump to releaser, how many cfm can I expect to have left?

Thanks
Mike

unc23win
11-17-2014, 01:30 PM
1" can do 4cfm up to 1000 feet. I would try it and add another line later. Your releaser would act as a reservoir like a booster so you should be able to maintain the same level of vacuum always. SP-11s are good pumps I have 500 on mine 450' to one booster I run 1" dry over 1" wet.

GeneralStark
11-17-2014, 02:15 PM
What is the cfm rating of the pump at your desired vac. level? It looks like you would lose 7cfm through 600' of 1" pipe. If you have 10 cfm at the pump you will have 3 cfm left. You could use 2 lengths of pipe for more cfm at the releaser.

BreezyHill
11-18-2014, 10:51 AM
Mike,
Not sure what charts people are all looking at??? The charts that I have from Steve at Cornell how made the charts from his research:
for an SP -11 on higher rpm setting you will be looking at getting just under 8 cfm; provided the pump is at or near original vacuum production.
The frictional loss on this size unit will be less than the smallest on the chart that is listed (15 cfm). The larger the pumps cfm the more the loss is over distances under the first 200 feet. After 800 feet a pump of 15 cfm and a 100 cfm are only able to supply the same amount of cfm due to frictional losses. This does not mean that the loss of each pump is the same over the same distance it only means that the amount supplied at the end of the distance is the same.

In your area there had been some rolls of the MCI fiber optics line laying around. This is a 2" think walled tubing that could be used to provide the max vacuum of your pump to the releaser at 600'. I would not use it as sap conductor but fine for vac from pump to releaser.

If your pump is mounted on the 14741 tank it will aid you in your cfm supply by having a balance effect on your releaser.

A releaser is actually a cfm eater. Every time they dump they go to 0" of vac and the entire chamber needs to be brought back to vacuum level of the system or you will have surges and back flow in the tubing system. You can often find a used dairy balance tank to install next to the releaser. Most releasers are the same size as the old milking pail so a dairy balance tank is a near perfect fit.

Booster tanks are an oxymoron. Only a pump can boost vacuum.

To supply enough cfm to the releaser should be no issue for 400 thru the 1" line unless you have a terrifically over sized releaser.

You will be close to max sizing with the sp -11 at 600 feet from the pump with 300 taps, depending on how long the mains are after the releaser. If using all 3000' then you will be struggling at the end to support your tap count.

Understanding the way the charts are set up is very important for correct calculations.

Good Luck!

unc23win
11-18-2014, 11:08 AM
Breezy what is the CFM of an SP-11? I have heard 5 and 9 which is correct?

BreezyHill
11-18-2014, 06:50 PM
Factory numbers for the 440 rpm setup is 9 cfm and the 475 setup is 10 cfm...these are at dairy ratings of vac. So if one is looking for higher vac then it will be much less than these numbers.

brookledge
11-18-2014, 08:21 PM
Just to add my opinon to what Breezyhill said about booster tanks. I agree that only a pump can increase your vacuum level over all, but where a booster tank or as call them manofolds do there thing is when you are using a wet/ dry line and the booster removes the air and gasses from the wet line, it will increase the vacuum to the taps.
Keith

DrTimPerkins
11-19-2014, 08:42 AM
... but where a booster tank or as call them manofolds do there thing is when you are using a wet/ dry line and the booster removes the air and gasses from the wet line, it will increase the vacuum to the taps.

A small clarification to the terminology. A booster tank is typically a small-medium sized tank (usually) made of PVC that is placed in a line to serve as a connection/distribution point for several mainlines or for connecting a mainline into a wet-dry line system. The purpose of a booster tank is generally to connect several different mainlines together (perhaps as a manifold), and also serves as a reservoir to smooth out surges in sap and air flow. A manifold generally means any type of device used to connect a mainline to a wet-dry line system, and can include a booster tank, a PVC or stainless-steel pipe type device, or a "whip" type manifold. The purpose of a manifold is to separate sap and gases so that the sap goes into the wet line and the air goes into the dry line, and to also serve as a secondary liquid conduit if the wet line freezes up. So a manifold could be a booster tank, or could be some other style. A booster tank could similarly be used as a manifold, but isn't always.

Maplewalnut
12-22-2014, 05:07 PM
Ok guys I need to revisit this. The distance is more like 800 feet instead of 600. To refresh everyone, sp-11 will be at electrical source about 800 ft from Releaser. I have 1 inch pipe to use. Only about 300-400 taps. Looking to do this on the cheap this year. Do I still have enough pump? Should try and absorb a couple hundred feet with extension chords from power source to pump closer to releaser? Other ideas

Thanks
Mike

Thompson's Tree Farm
12-22-2014, 05:46 PM
How much pipe do you have? If you don't have larger pipe, you could run 2 sections of one inch to lower your friction loss. It would be best to use inch and a quarter or inch and a half.

GeneralStark
12-22-2014, 06:44 PM
Once again, without the cfm capacity of the pump you are using at the desired vac. level, it is tough to say for sure. If we use Breezy's #s from earlier in the thread, you might have 9-10 cfm at 15". At 20" you may have 5 cfm, and above that is hard to say. This was calculated using a 10% per inch of vacuum capacity loss. If someone has a pump curve for this pump it would be helpful. Anyway...

My line loss charts don't show values below 15 cfm, in which case at 800' you lose 7 cfm. AT 800 ft. the line loss becomes pretty equivalent regardless of the cfm rating of the pump so if you have 10 cfm to work with you are probably losing 7-8 cfm, but maybe a bit less, which leaves you 2-3 at the releaser. If you have less pump cfm to work with, then it gets really questionable if you will have much to work with at the releaser.

I think running two lengths of 1" pipe, if that is all you have, is your best bet, because one 800' length of 1" pipe won't cut it.

OGDENS SUGAR BUSH
12-22-2014, 06:58 PM
sp11 is only good for 5 cfms, not sure but im guessing thats at 15hgs

unc23win
12-22-2014, 07:09 PM
As others said if you can run a larger pipe or multiple pipes that's easiest solution. I would lean towards multiple pipes if you have it or can come up with the $. I would leave the pump where it is. I wouldn't take a chance of not getting enough power to the pump.

My SP-11 runs about 600 taps @ 22" I run 1" over 1" to a my booster/manifolds one of which is about 450-500' away. From there my longest line is another 800' all gauges read the same releaser, booster/manifold, and end of line.

Maplewalnut
12-22-2014, 07:44 PM
I have plenty of 1 inch pipe...maybe 3500 feet. So to run multiple lines I assume I would just T off two lines from pump an T it back together at the releaser.

Doug- thanks, I know 1 1/2 would be best but I want to try and use what I have...since I am not convinced this bush we pay off in long run. I figure I will unspool long runs of 1 inch that I could use elsewhere if it falls through.

At the end of the day I'll be happy with a system of 18-20 inches this year.

markcasper
12-23-2014, 12:02 AM
Factory numbers for the 440 rpm setup is 9 cfm and the 475 setup is 10 cfm...these are at dairy ratings of vac. So if one is looking for higher vac then it will be much less than these numbers. The actual rating at 15" is 5.5cfm. Don't know where 9 and 10 is coming from, but is rated at 11cfm New Zealond style, but that is not the english version which is right from a former Surge dealer.

I run 650' of 10 gauge cord @ 220 to one of mine going on 10 years now.
An 1 1/2" air line would be the best, but I guess by running multiple 1" (enough to make up friction loss) would be ok.

BreezyHill
12-23-2014, 12:26 AM
My line loss charts don't show values below 15 cfm, in which case at 800' you lose 7 cfm. AT 800 ft. the line loss becomes pretty equivalent regardless of the cfm rating of the pump so if you have 10 cfm to work with you are probably losing 7-8 cfm, but maybe a bit less, which leaves you 2-3 at the releaser. If you have less pump cfm to work with, then it gets really questionable if you will have much to work with at the releaser.

.

Don't confuse water flow rates and cfm.
The smaller pump will not be able to have as high of a start on the cfm but if you study the charts you will see that the larger the pump you can only move upto a certain amount of air. If you were to use what you are saying then the 100 cfm pump lost 92% of its capacity at 800 feet; while the 15 cfm pump only lost 46%. The chart is showing that the pipe will only allow so much air to pass at the point no matter how large the pump.

The smaller pump will lose less of its cfm as a percentage as did the 15 compared to the 100.

To connect two lines you would want to use a tee or build a manifold out of pvc. by feeding the tee with a 2" pvc or even better a 3" you will have a better transfer rate. One must remember that every elbow and connector will negatively affect CFM transfer rates.

That pump in good shape will pull 24". So you should have no issue getting that at the releaser on a single length of 1".

I have a bb 2 coming in and will hook it up to 1000' roll of tubing and put the cfm tester to the unit and see what the readings are in the next few days.

GeneralStark
12-23-2014, 11:54 AM
So if you have 5.5 cfm at 15", you will have about half that at 20" as there is approx. a 10% loss for every inch. Whether you are running at 15" or 20" with a 800' 1" air line between pump and releaser, you're not going to have many cfm available to even run your releaser let alone get effective vac. out to your taps. Running two or even three lengths of 1" is once again your best bet to get you through this season.

unc23win
12-23-2014, 12:02 PM
Isn't it true that the max CFMs for 1" up to a 1000' is 4CFMs period regardless of pump size.

GeneralStark
12-23-2014, 12:22 PM
Isn't it true that the max CFMs for 1" up to a 1000' is 4CFMs period regardless of pump size.

That's a good rule for sizing lateral mainlines with laterals, but for a dedicated air line between a pump and releaser, the size of the pump is a major factor. But, once you get to a certain pipe length, the size of the pump doesn't matter any more as the friction can no longer be overcome by more cfms. For 1" pipe that is right about 800'.

10188

unc23win
12-23-2014, 12:44 PM
That's a good rule for sizing lateral mainlines with laterals, but for a dedicated air line between a pump and releaser, the size of the pump is a major factor. But, once you get to a certain pipe length, the size of the pump doesn't matter any more as the friction can no longer be overcome by more cfms. For 1" pipe that is right about 800'.

Ok I got it now I forgot that in this case the releaser was going to be that far away from the pump.

BreezyHill
12-23-2014, 05:45 PM
Isn't it true that the max CFMs for 1" up to a 1000' is 4CFMs period regardless of pump size.

I am wondering where all these different charts with different data are coming from?

The one I use is from Steve Childs of Cornel University and is the data sheets from his research.

On this chart you will be down to 4 CFM at 3000 feet to as much as 3200' depending on the size of the source pump.

At 800' it is rounded to 8 cfm across the chart for all pumps.

Also the numbers for CFM I am using are from a Surge Maintance Manual and based on the Babson Flow Meter, my Dad was a Surge Dealer and have the bock in hand.

I still have our farms BB2 pump which was the predecessor of the SP-11. The BB is for Babson Brothers and the 2 was for 2 milker pump. Since it takes not less than 4 CFM to run a single bucket milker at 15" of vac you need at least 8 to be produced from a 2 bucket milker. .55 would give you one milker and take the average farmer of 18-25 cows 4-5 hours to milk his cows; while with 2 milkers our farm milked 25 with the bb2 in under 2 hours. When my grandfather bought the BB$ from my Dad milking time dropped to about an hour. This unit ran 4 milkers for us and could handle a fifth unit if you were milking a dump cow(one that just had a calf or treated cow)...the milk had to be dumped for the calves to drink, hogs, or just dumped on the ground.

There is a .55 in reference to the motor capacity of the pump; if you glance at the book it looks like 5.5 due to an ink drip from the press plate or simply an error of an extra decimal point.

If you have this book it is on page 4-63 - B-3.

So back to the question since you are only producing 9-10 cfm depending on setup rpm then one 1" line will supply all the CFM you have to the releaser.

Think of it like this: You have a 15 cfm pump. If you put 3 lines out to the 800 foot releaser will you then be supplying 24 cfm to the releaser?

From the pump that could only make 15 CFMs...No you only had 15 to start with and since the one line can supply 8 you would only benefit from a second line and not to the equal amount that the first one supplied.

Guy just dropped of the BB2 and it is in descent shape. Delaval CFM Flow meter reads 8 cfm at 15", 4 cfm at 20.5" and 2 cfm at 23". The unit maxed out at 26" of vac on a closed system. After the holidays I will be cleaning the unit and adjusting the timing as it sounds a little off.

I will hook up a 1000' roll of tubing to see how many cfm at that distance after Christmas.

Ben

GeneralStark
12-23-2014, 06:59 PM
I think you are assuming that because Steve Childs' charts only show only show line loss down to 15 cfm below that there will be no line loss from friction, but that is not the case. There is always friction...

I don't know anything about these pumps and not sure if the bb2 is an sp-11 or whatever, and it seems there is disagreement over the cfm ratings. But, say the bb2 you are referring to is 800' from a releaser. At 20.5" and 4 cfm, you may not have as dramatic a line loss proportionally as you would with a larger pump as shown by the chart I posted earlier, but you will not still have 4 cfm at the releaser.

unc23win
12-23-2014, 09:29 PM
I am wondering where all these different charts with different data are coming from? Ben

I wasn't using a chart I was going by what I learned from producers on here who more than likely error on the side of caution by using larger line than needed and larger pumps than needed. I like those who I have learned from want to know for sure I have enough cfm and large enough pipe. If I were Maplewalnut and I had 3000' feet of 1 inch line I would for sure run two lines using a manifold of some sort.

I respect your allegiance to Steve Childs and his book however I think the book could be laid out better its easy to get confused. Having said that there is no need for you to be condescending.

BreezyHill
12-23-2014, 11:48 PM
I respect your allegiance to Steve Childs and his book however I think the book could be laid out better its easy to get confused. Having said that there is no need for you to be condescending.

If you think the book is confusing you should see the data sheets that he sent to me. It is easy to be confused with literally thousands of number and charts with this much information to digest. The more you study the charts the more you will learn of vacuum. I am a person that deals with numbers every day and have new study results nearly every month to read to keep on the cutting edge of the industry of Agriculture. In my world everything has to balance or an animal can get sick, not preform as desired or not produce as needed for a farmer or animal owner to make a profit and feed their family. When we have to put 45 grams per ton of feed 48 doesn't cut it nor does 43.

Not sure why my confusion, on different numbers is conceived as condescending...not meant that way; but I have seen on many occasions that people read information and don't understand what is being said. I had to email Steve on two points that I did not understand until it was explained by Steve. Our industry is super lucky to have Steve, Tim, and others doing studies that will help all producers design tubing systems to get the most production while maintaining the health of our bushes and checking accounts.


All things in motion have friction working upon them. it is just that there will be less frictional affect on a smaller amount of volume passing thru a pipe than on the maximum amount flowing thru a pipe.

To truly visualize frictional loses all you have to do is watch a sap ladder work...the slippage is your frictional loss. The bubble travels thru the center of the tubing with a tiny amount of sap being left on the tubing wall the larger the tubing the more the frictional area, but the larger the center column that transfers is.

While I support the theory of over sizing or over building for many things like roofs, floors, etc. If a person is going to expand in the future then by all means build it big the first time, but if it is a terminal system, then size it and build to specs and spend the saved money on other needed items and the saved time on the next project on the to do list.

Personally, I am not the type of person that looks down on any one. We all started somewhere, most at the bottom, but if we don't help each other out, our industry will suffer. Knowledge is useless until it is shared.

Ben