load loss in the pipe

[mir]

I have a 60.3x1.5 tube in which they pass 27 mc/h of water to 25°c. the pipe is 70 m long.

considering the only straight tube that load losses I have to wait for?

Thank you.
♪

 

[radio]

qui You should find everything you need to calculate your load loss.

Bye.

 

[mir]

Yes... just that I wanted a verification from someone who has a little eye... I turn out 10 m. of load loss on 70 meters of pipe.... possible?

 

[riccardot5765]

You have two possibilities.
the first is to apply the principle of bernoulli to the tube section, the second apply an explicit equation for load losses.

If you are with 5*10^3<re<10^8 and 10^(-6)<e/d<10^(-2) you can apply directly

(d^5*lv/l)/q^2=0.203/(log(e/3.7*d)+5.74/re^(0.9)

with an error of less than 1%

 

[maxopus]

without particular calculations the pipe seems undersized.
an old rule says that the water should circulate at 1 m/s.
in this case we are almost 3 m/s.

 

[mir]

Thank you... I know that the plant is under pressure because of the tube too small but we say that we are about a bar (for just 10 meters that I estimated load losses).

I was just looking for someone who could verify this load loss at "eye".

 

[riccardot5765]

I find myself a speed of about 2.62m/s and a lv of 66.5(m/s)^2

ot: wouldn't it be possible to place a formula editor in the forum?

 

[mir]

What do you mean?

 

[MBT]

the program that we use tells me:
q= 27 m3/h
density = 998.2 kg/m3
roughness = 0.06

v= 2.908 m/s (which for me is altina... )
pressure drop = 1.106 bar
which in fact are about 10m of water column

 

[mir]

Many thanks ... now I ask a question .... according to you if 2 pumps in series the capacities are added? or instead of a pump from 27 mc/h with 20 m. of prevalence can I mount 2 pumps from 27 mc/h with 10 m. of prevalence?

Thank you.
♪

 

[MBT]

hum... you should connect them in series, so the power pressure of the second would be 1 bar...
I think it is better to contact the manufacturer, even because if the first gives you less water than the second risk of cavitation and other problems. . .

However... any pump from about 3kw should give you 30 m3/h with 2-3 pressure bar. . .

I don't understand why looking for trouble with double pumps

 

[mir]

in fact I studied ... it makes much more sense to put them in parallel to double the courses than in series to increase the prevalence!

 

[MBT]

in fact I studied ... it makes much more sense to put them in parallel to double the courses than in series to increase the prevalence!

but it also makes more sense to have only one that gives you the required flow and prevalence and an emergency "in parking". . .
unless you have special needs. . .

 

[MarcoBi]

in fact I studied ... it makes much more sense to put them in parallel to double the courses than in series to increase the prevalence!

Yes, as mtb says, you can put them in parallel and (if necessary) keep one in "stand-by".
but you can put them (if needed) even in series: in this case the first pump (called booster) feeds the second. is a solution adopted especially when it takes great prevalences for which, to stay on commercial pumps, the path is "off" relaunching the product even more times precisely using booster pumps.

 

[riccardot5765]

What do you mean?

are load losses

 

[Ern]

Of course, if you put a second pump identical to the first and in series, double the prevalence to equal capacity. It may not be true, however, in the case of three pumps.