spray bar question

[prospectordamon]

need to know how many holes and what size holes need to be in my spray bar application for my highbanker build. I am using 1.5" pipe. motor/pump specs are as follows:

9060 gallons per hour (151gpm)
Total head lift: 97.5 ft.
Suction head lift: 26 ft.

I want to run 2 rows of holes on each spray bar and of course have them jet across and make a "V" where the material will be dumped into the hopper. Any ideas or useful links with calculations on figuring this out? It sounds too simple to have calculations for but I want to be sure its right the first time! Thanks

[russau]

1.5 in. pipe is to big. you only need 3/4 or 1 inch at the most. id put the holes (3/16) about every 3/4 of a inch apart. you can always add more where needed if you need to.and dont forget to make the end caps of these tubes removable to clean out the sand that WILL biuld up.

[prospectordamon]

1.5 in. pipe is to big. you only need 3/4 or 1 inch at the most. id put the holes (3/16) about every 3/4 of a inch apart. you can always add more where needed if you need to.and dont forget to make the end caps of these tubes removable to clean out the sand that WILL biuld up.

thank you so much for you input, I will pick up some 1 inch pvc tomorrow, thanks for the end cap advise as I have already purchased everything in 1.5" (I will take back for refund) and didn't add that to my parts list, just simply a cap. good advise! Running that much psi wont pose a problem running piping 1/2 the size of my hose will it? thanks in advance!

[Klondikeike]

Klondike here...

When I design a placer wash plant... and considering the spray bars....I use really basic Algebra formula to match up the size and number of holes to the size of the delivery pipe of the spray bar...

TTRsquared.... is the formula... Try this... same thing written differently .."PIE times Radius squared".... PIE is a constant 3.14

EXAMPLE....
With a 2 inch diameter pipe... the formula would result in a number of R (Radius or 1/2 half the diameter) squared (or times itself) is
1 X 1 = 1 times 3.14 = 3.14 ....Total inches of holes sizes to equal the total surface area of the inside of a 2 inches pipe...

If you uses 1/8 inch holes... you could drill approximately 25 holes.... how much pressure and volume capacity of the pump will determine how much pressure will be present at each hole... fewer holes greater pressure... and how closely yo match the exact size of the pipe with the number and size of the holes may not have as much pressure present... So, in this example... I'd probably drill about 18 to 20 ...1/8 inch holes...Every commercial plant I have planned and built I have used this simple formula and it has worked each time...

If you used 1/4 inch holes in this example.. then you'd have to drill around 12 to 13 holes... or 3/16 inch holes would be about 16 to 17 holes...

Remember..and you can play around with the formula to prove it... that as you double the size of a pipe.. you quadruple the surface area...

A 4 inch pipe will deliver 4 times more water than a 2 inch pipe... and so on...

There are many different formulas you can use for his application that will take into account the pump size and volume size and so forth... however I have found this simple formula works really well and is very easy to calculate...

If you have a high volume pump... you can ad about 30% more holes than what this simple formula states you can use due the additional volume and pressure...but start out with the the number of holes stated by the formula...

In the picture below... I had a 6 inch, high volume and high pressure pipe...powered by a 40 hp 3 phase electric motor of which I divided the 6 inch discharge pipe into 3... 3 inch deliver pipes... 2 feeding the the wet vibrating feeder and one supplying water to the trommel...

Hope this helps...


Klondike...

[russau]

good advice!!!! but for small streams where he maybe pulling water, the turbidity stires up the small sands and will eventually plug his spraybar holes. thats why i said use 3/16 inch holes, and they will eventually get sand plugging these holes aswell but itll take longer.1/8 inch holes will plug to quickly!

[Klondikeike]

The 1/8 inch was for illustration only.. just to show a principle.... and you are right.. without the proper screen on the foot valve.. 1/8 would be too small in many cases... but not always...

3/16 is probably a good size depending on many factors as discussed in my original post...

Klondike...

[Hefty1]

Thanks for the info K.
I just did my spray bar for my highbanker using 7hp 2 " pump.
Used 1 1/2 " pipe = .75 x 3.14 = 2.355 x 1/4 = 9.42 holes.
Great pressure but not enough volume in the sluice.
Sluice is 16"wide x 5ft long, with 3/4" riffles.
Added 4 more holes= 13 holes, still not enough volume, but better.
I am going to wait till i get it out to the feild, cause i have to add 50ft or so, of 2" hose.
Now after that should i increase the size of the hole or add more holes?
Not real sure what speed i have to run the pump at yet

Any info will help

Hefty

[prospectordamon]

thanks Klondike! glad this thread is helping others! excellent info here!