5 replies to this topic

[Reeda]

Hi

im working on the calculation of pressure drop in a pipeline from a pump to a tank.

The liquid pumped is sprayed in the tank through a spray nozzle. 

What is the criteria of calculating pressure drop in the liquid when it passes through the nozzle.

Also how can we calculate the pressure drop through bends?

Is Darcy equation the best to use to do these calculations or Bernoulli equation?

What is the criteria for pressure drop calculation when the pipe gets vertical?

Please do if anybody can help. I will be grateful

Thank you

[latexman]

Consult the vendor documentation on the model and size of spray nozzle you have.  These are usually well documented.  Google it.

 

Consult your favorite fluid flow textbook on the pressure drop of a bend.  I have used Crane Technical Paper 410 for years!  You can buy it on-line.  Again, google it.

 

I recommend Darcy.

 

Pressure drop is an economical balance, including vertical pipe.  If dP is too low, pipe may be too big and expensive.  If dP is too high, you pay for too much energy to run pumps and velocity is too high and you have erosion and other issues.  My personal rule of thumb is roughly 1 psi/100 feet.  It can be higher or lower depending on many things.

[samayaraj]

Is Darcy equation the best to use to do these calculations or Bernoulli equation?

What is the criteria for pressure drop calculation when the pipe gets vertical?

Please do if anybody can help. I will be grateful

Thank you

 

Darcy equation is used to find pressure drop in order to balance bernoulli equation.

 

For vertical pipe, if its completely filled with liquid, you can assume its a normal length pipe to calculate pressure drop.

 

#Samayaraj

[Reeda]

Thank you both of u for your help. 

[Reeda]

 

Is Darcy equation the best to use to do these calculations or Bernoulli equation?

What is the criteria for pressure drop calculation when the pipe gets vertical?

Please do if anybody can help. I will be grateful

Thank you

 

Darcy equation is used to find pressure drop in order to balance bernoulli equation.

 

For vertical pipe, if its completely filled with liquid, you can assume its a normal length pipe to calculate pressure drop.

 

#Samayaraj

 

Can you please give me some reference that i can quote for calculating the pressure drop of a vertical pipe like a normal (horizontal?) pipe??

[erj]

Hi

im working on the calculation of pressure drop in a pipeline from a pump to a tank.

The liquid pumped is sprayed in the tank through a spray nozzle. 

What is the criteria of calculating pressure drop in the liquid when it passes through the nozzle.

Also how can we calculate the pressure drop through bends?

Is Darcy equation the best to use to do these calculations or Bernoulli equation?

What is the criteria for pressure drop calculation when the pipe gets vertical?

Please do if anybody can help. I will be grateful

Thank you

 

Hello Reeda,

 

As much I understand you are having a pipe (or pipe network)  from pump to tank connected through a spray nozzle.

 

There are steps involved in pressure drop calculations from the system.

 

First calculate Frictional losses (using Darcy Weisbach, as suggested by everyone here) for the connecting pipes, and losses for bends and other fittings, Then using Mass conservation  and Energy conservation  (Bernoulli's equation) calculate mass flow rate at each node and pressure drops in pipes. At last calculate pressure drop for Nozzle.

 

This document might be helpful to you-

 

http://ir.library.or...32F1?sequence=1

 

Or you can use some of the pipe network analysis software applications to get results in fraction of seconds. 

 

Regards,

-

erjainrachit