booster pump

[krolley]

Hi all,

Maybe this is a stupid question...but help me anyway..

I have a pump with NPSHr approx 5 meter. The NPSHa is only 2 meter. It was a design mistake. Anyways, this pump capacity is 1500 m3/hr at about 10 bar.

To rectify this, I was thinking to install a booster pump upstream of this pump. Do I need to find a pump that also matches a 1500 m3/hr capacity (with lower head; proabably 5 bar)? or could i live with a lower capacity pump? Medium is water.


Thanks

 

[BigInch]

Get a pump with a BEP flow at the same capacity. If you try a smaller pump, you'll not be pumping at best efficiency at the 1500 m3/h flowrate, if it can do a 1500 m3/h flowrate.

What would you be doing, if you knew that you could not fail?

 

[Pumpsonly]

The booster pump must be of similar capacity and the the NPSHR must be lest than 2 meter at 1500m3/hr . The discharge head of the booster pump must be sufficient to over come the losses of the piping between the discharge and the main pump suction and provide the NPSHR to the main pump.
If you choose the booster to have 5 bar DP you will have total pump DP of 15 bar in the system.
and you will get more that 1500m3/hr if you do not throttle the discharge.

 

[poli60]

Just for brainstorming...
Anything to do to improve the existing system?
- increase NPSHA in the suction system
- modify pump to obtain a lower NPSHR
- put another pump in parallel
The installation of a booster pump will lead to shutoff troubles in the discharge system and will increase the operating costs.
An analysis of CAPEX/OPEX should be done to compare alternative solutions.