Pump noise level 1

[SlawomirK]

I have some considerations about pumps noise. There are some applications where noise is very unwanted and we need to find possible noiseless solution. For the choicing noiseless pump I consider as important:

1) motor size, efficiency, motor speed
2) pump efficiency, duty point
3) pump design (type)

Could you advise which type of pumps would have less noise in general and opposite way - which pumps are much more noisy than others?

Do you have some experiences how to reduce the noise by using special accesories?

Best Regards,
Slawomir

 

[LittleInch]

If you mean external noise then the motor and it's associated fan that is the source of most of a "pump" noise. Choose a low noise fan, get the rotational speed down as far as you can (4 pole or 6 pole motor, make sure it doesn't cavitate and away you go.

Cantrifugal pumps are smooth and often the pump itself is low noise. Piston pumps are not good, but screw pumps are often quite quiet also. Pumps are easier to jacket as so long as there is flow they don't really need cooling.

After that you need acoustic housings - I've fitted them and they are a complete pain, but if you need them to satisfy someone they work. You still need some air flow.

Otherwise go for a water cooled jacked pump and motor and take the nosie of the cooling fan somewhere else, or use a constant supply of cool water from somewhere either directly or via a HX.



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

 

[1gibson]

Unidirectional fans are typically quieter than bidirectional fans, so that's an easy one to consider but you'll still be around 75-80 dBa in most cases.

 

[Artisi]

Telling us why you need quiet pumps,where you intend running them, the flowrate / head etc. is essential information if you need meaningful answers, not an open-ended meaningless question such as you have asked.

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.)

 

[georgeverghese]

A lot of noise can also be generated through recycle lines when high flow / high dp is incurred across the recycle device. So one way to cut down on this noise is to use a VFD on the pump driver that will match the pumping duty to the actual demand by speed control.

 

[georgeverghese]

Believe the turndown on speed for a VFD is about 50%, below which motor winding cooling becomes a problem. If you want to go down to as low 10% of full speed or less, use an aux motor cooling fan which is operated by an independant fixed speed motor.

 

[georgeverghese]

For a centrifugal pump, turn down to less than 50% may not be required, since the developed pump head at at less than 50% speed may be next to nothing.