5 replies to this topic

[GMU]

Hi.

 

In a pumping station I have  the problema that this cavitation, can not increase the height of the tank that feeds to pumps because it involves increasing the concrete base and is not feasible, nor can lower the pump to increase the pressure head.

If someone tried reduces cavitation by placing a pipe of small diameter discharge side of the pump to the suction side in order to inject a small flow pressurized fluid in the suction.

 

I appreciate your comment.

 

 

[Bobby Strain]

Talk to your pump manufacturer. They might have a suggestion for you. And, you could run more pumps. Or raise the liquid level in the tank. If none of these works, then you should look to install a vertical can pump. Or, let the pump cavitate, repair as needed.

 

Bobby

[fallah]

GMU,

 

Investigate possibility of using an INDUCER at the pump suction; then contact the relevant vendor for such possibility...

[breizh]

Hi ,

What about piping arrangement in the suction lines ? With a sketch ideas may come on top of advices giving by others + Pump curve .

 

Hope this helps

 

Breizh

Edited by breizh, 27 September 2015 - 03:00 AM.

[Chemitofreak]

As a Process Engineer one can tackle pump cavitation problem by following methods:

1. Increasing the static height of the suction vessel

2. Increasing the LLLL in the suction vessel (LLLL is considered for calculating conservative value of NPSHa)

3. Increasing the system pressure

4. Decreasing the fluid temperature (i.e. decreasing the vapour pressure)

5. Increasing the suction piping diameter

6. Decreasing the suction piping length

 

Generally point 3 and 4 are difficult as those are generally fixed as per process requirement.

 

Cavitation can also be avoided by the following methods

A. Providing inducers (An Inducer is an axial flow impeller with blades that wrap in a helix around a central hub. An Inducer serves as a small booster pump for the main impeller. Usually inducers have between 2 and 4 vanes, although there may be more. The inducer imparts sufficient head to the liquid so that the NPSH requirement of the adjacent main impeller is satisfied)

B. Increasing the eye of the impeller

 

There can be more alternatives than A and B, but for that you need to contact the pump vendor, he is the right person to solve the issue

[GMU]

Gentlemen.

Thank you very much for your comments.
 

Will review the facility to see what improvements can be made and I will contact the manufacturer to see if you can place an inductor.