impeller

[CH5OH]

I am looking into the possibility to build a vacuumunit
out of a submersible pump and an ejector.As it is suppose to be a hobby project, ejector,volute chamber and impeller would be casted out of fiber/epoxy.As a centrifugal pump builds up velocity in its impeller and convert velocity into pressure into its volute chamber, the ejector will then convert velocity of its driving fluid (water) into vacuum.

Q1.Since both impeller and ejector works on the velocity of the fluidum,is there any need for a diverging type of volute chamber?

Q2.How can you estimate a good working impeller design, starting from known rpm and kW eg getting all available kW of motor into creating vacuum?

 

[Artisi]

Doesn't sound like anything new, there are many "Jetpump" units on the market that do exactly what you are suggesting. Google jetpump - plenty of hits.

 

[CH5OH]

well to buy a unit would nullifie the hobby aspect of the project.I was looking more to some info on surface area and quantity of vanes and also inlet diameter/outlet diameter impeller in respect to drive power/rpm

 

[TenPenny]

Sounds like you could use Centrifugal Pumps Design and Application by Lobanoff and Ross (IBN 0-87201-200-x)...it has a good section on impeller and volute design.

 

[MartinSr00]

Q1 - I think you can get away with the divergent (downstream part) of the venturi (ejector). It's characteristics may change some, however.

Q2 - I vote for Stepanoff's Centrifugal and Axial Flow pumps. You can still buy it new. It should be in the library of any pump designer.

 

[CH5OH]

thanks,
Stepanoff and Lobanoff,
i'll look into it...