2 replies to this topic

[mcgill.engineer]

Hi,

This seems like a simple problem, but for some reason I'm stuck. I believe it can be solved using Bernoulli's but I'm not sure.

I have a minimum flow header connecting a centrifugal pump to two tanks. Both tanks are identical but one is closer to the pump than the other. How do I calculate the level needed in each tank to maintain an equi-flow distribution for the two tanks?
Basically, the flow in my header is 1000 m3/hr. Lets assume Tank A is 1000 m away from the pump, while Tank B is 2000 m away. I need to calculate the level of liquid (gasoline) in each tank that will allow me to fill both at a rate of 500 m3/hr.


Thank you!

[mcgill.engineer]

OK nevermind. I managed to solve it.

Z1-ZA + P1-PA/rho.g + [〖Va〗^2 – 〖VA〗^2]/2g = f(LA/D) [V^2]/2g+ f(L/D) [〖Va〗^2]/2g
Z1-ZB + P1-PB/rho.g + [〖Vb〗^2 – 〖VB〗^2]/2g = f(LB/D) [V^2]/2g+ f(L/D) [〖Vb〗^2]/2g

[sheiko]

Hi,

This seems like a simple problem, but for some reason I'm stuck. I believe it can be solved using Bernoulli's but I'm not sure.

I have a minimum flow header connecting a centrifugal pump to two tanks. Both tanks are identical but one is closer to the pump than the other. How do I calculate the level needed in each tank to maintain an equi-flow distribution for the two tanks?
Basically, the flow in my header is 1000 m3/hr. Lets assume Tank A is 1000 m away from the pump, while Tank B is 2000 m away. I need to calculate the level of liquid (gasoline) in each tank that will allow me to fill both at a rate of 500 m3/hr.


Thank you!

It's difficult to give you a precise answer as you did not provide us a simplified sketch of the system. However, the flowrate in each branch (after the split) will depend on the total pressure drop in the branch. So if you want equal flowrate manage to provide same pressure at the destination (= tank liquid inlet nozzle) of each branch (given that the pressure at the split is equal for each branch). You will have to consider internal diameter, rugosity, length, elevation ... in each branch and liquid level in each tank for that purpose.

Edited by sheiko, 07 June 2010 - 01:40 PM.