Centrifugal Pump - Unusual Noise

[oswald88]

Hi All
We have a Centrifugal pump for circulating water to wash our products in the conveyor. The pump is producing unusual and heavy noise. There is no leak anywhere from the pump. What could be the reasons for this? details of pump as below

Make: Merser
Model: E 50.1.402
RPM: 2800

 

[EmmanuelTop]

The pump could be cavitating. Have you observed any other phenomena - erratic flow delivered by the pump, and/or erratic discharge pressure, etc.?

Dejan IVANOVIC
Process Engineer, MSChE

 

[oswald88]

discharge pressure gauge fluctuates some times, but shows 3 bar.

 

[Artisi]

A new problem or always been noisy?

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.)

 

[oswald88]

@Artisi: it is new problem, noisy from past one week.

 

[Artisi]

The obvious things to check:
1. Has any foreign material got into the pump.
2. Is the pump inlet chocked in anyway- possible cavitation as already pointed out.
3. Is the impeller loose, or other mechanical problem developing.
4. A better description of the noise would help.

Try throttling the delivery of the pump, ie. increase the discharge head by closing down a valve on the pump discharge - if cavitating the noise might reduce or even dissappear.

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.)

 

[LittleInch]

possible reasons?

Not enough flow coming into the pump (low level in the tank feeding it)
Air getting into the supply line (low level and vortexing of inlet pipe
Blocked inlet and cavitation
Bearings worn and not being lubricated properly
Water temperature too high
Coupling between ump and motor misaligned
Motor bearings failing
Debris / dirt / in the fluid.
All those issues artisi raised

You need to examine the pump properly and also note how it is in operation ( flow, amps, pressure and temperature at inlet and outlet, level in feed tank ( if relevant). Comparison with pump data sheet will help identify where it is being operated out of spec.

A fluctuating outlet pressure sounds like the pump is being starved of water or getting air in the system, but there could be lots of other problems.


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