pumps and frequency inverters.

[userxyz]

Can I say...

I assume that I have to deal with centrifugal Pumps... They are 22kW each and are used to spray liquid on products.



So, when I lower from 50 to 40Hz, then we lower 20%.

51,2% Input Power needed if I calculate it with the formulas I've seen in previous posts ((40/50)³). The flow and pressure remains pretty good If i look in these curves.

Is this all right ?

 

[leitmotif]

Seems to me you have two overriding needs to install pump and or fluid control before even considering power savings.
1. Save on cost of oversprayed material - VFD speed control can do this
2. Save on cost of material sprayed when no parts. This may be better done with solenoid valves (maybe with bypass to tank) on pump discharge - may possibly be done with VFD.

You really need to determine what kind of pumps you are using. Send photo of pump.
When you know what you have then:
Get a pump curve from factory. The ones you have shown are a good description of the affinity laws. But are they for YOUR pumps you have installed?
Install pressure gages on pumps.
Install flow meters on pumps - get a Dwyer catalog.

At 22 Kw per pump and 14 pumps this is no small project for sure. What is the material you are coating parts with and I really wonder how big the product is -
what are you doing painting a ship in a one shot process (humor)
Dan Bentler

 

[DickDV]

No pump curves until you tell what kind of pumps these are! It matters a lot!

 

[leitmotif]

No pump curves until you tell what kind of pumps these are! It matters a lot!

Dick DV
Thank you for saying it for me.

I am not wasting my time using centrifugal pump rules when the pumps installed really turn out to be gear pumps.

Dan Bentler

 

[userxyz]

Centrifugal

Centrifugal Pumps, that's for sure. The maintenance departement gave me this info and will give me the details soon.

No pump curves until you tell what kind of pumps these are! It matters a lot!