Vertical Turbine Submergence

[GaTechTheron]

A quick question:

-Assuming a constant speed vertical turbine in an open pit without a strainer: Does Submergence vary with pump flow?

-With a strainer, can you assume that no fluid level is required to avoid vorticity? Or rather, does a strainer surpress vorticity 100%?

Thanks!

 

[Kailee]

A quick answer.
- Yes
- No

Cheers!

 

[dabluffrat]

Required submergence does vary with flow. Required pump submergence is a function of both suction bell area and fluid velocity. As flow increases, velocity increases. Typically pump mfg will show one submergence value required on their curve. This is usually either for BEP flow, or max flow.

A strainer will increase the NPSH required slightly (which is a function of submergence in a vertical pump) but I believe the affects on vortex are negligible as the suction bell area remains the same. Some mfg will use what's called a suction umbrella to increase the suction bell dia in applications where available submergence is limited.

Did you know that 76.4% of all statistics are made up...

 

[rmw]

Your pump mfg will specify a minimum submergence for your particular pump.

1. locate it
2. believe it
3. exceed it if at all possible.

Also find out about pit sizing requirements from your pump mfg.

rmw