Thrust Loads in Vertical Multistage Centrifugal Pump Housing 1

[PatrickNZ]

Hi All

I am examining the nozzle loads on a pump tank. The pump is vertical centrifugal type, mounted on this nozzle.

The design thrust load for this assembly is approximately 2kN. My question is relating to how these loads are transferred to the pump housing and subsequently, the vessel nozzle.

My understanding- correct me if am missing something- is that the thrust load is generally dominated by the fluid momentum change and gravity forces. The thrust bearing will see such loading. However, as the fluid is accelerated and transported upward and out of the pump assembly, it turns through a 90° elbow. The resulting reaction at this elbow (which is rigidly contained within the pump housing assembly) would be equal and opposite to the downward thrust imposed on the shaft; resulting in a net zero load on the pump housing as a whole from this component of the thrust force. Is this thinking correct, i.e. the net thrust load acting on the pump is almost entirely gravity?

Appreciate everyone's thoughts.

 

[Rputvin]

You're looking at a Vertical Turbine Pump. While it's somewhat the same thing, the arrangement is quite different.

Here's some reading to get you started, and discuss with the pump supplier's methods for internally reducing thrust loads.

https://www.pumpsandsystems.com/sit...VerticalTurbinePumpThrustLoads-WhitePaper.pdf

 

[LittleInch]

I think that's right. Essentially all the forces are within the casing so there is no net thrust load onto the nozzle other than an element of the horizontal fluid force.

But weight of the pump and forces from the pipe are more important.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[PatrickNZ]

Thank you LittleInch, appreciate the confirmation of my thinking.

Since this is the case, do you then happen to know the reason why pump thrust loads are listed on supplier datasheets? Is this for sizing replacement thrust bearings, etc.?

 

[Artisi]

What thrust loads are listed?
There will be a hydraulic thrust load that will be carried by the bearings in the motor.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)