Can inline double suction pump mount two inducers at the front of each impeller

[Steven_Wu]

Hi All

As we know, inducer normally be used in end-suction pump for extremely low NPShr application.

But can a double suction pump add inducers? This is only my ideal for big flow capacity and low NPSHr application. However, few pump manufactories I've know have this kind of pumps. Maybe there are some assembling problem or structure limitation when performing in the reality?

Has anybody ever seen this kind pump? and I will appreciate if one could provide some drawings to show.

thanks!

 

[Artisi]

Probably not.

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.)

 

[1gibson]

Try a VS6 pump instead

 

[LittleInch]

Fundamentally unsuited for an inducer. Inducers only work for end suction full face flow entry. Double suction the flow has to do a 90 degree turn.

Try lowering the pump speed / increase impellor diameter to get better NPSHR for same duty

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

 

[TenPenny]

If you look at a cross section of a double suction pump, you'll see that it would be almost impossible to put an inducer on the inlet of the impeller.

 

[MohdYaseen2010]

Regardless the possibility of achieving such setup.

Where inducer is devoted for reducing pump NPSHR by increasing static head upstream pump impeller; I am doubt about continuity of the hydraulic thrust balance that characterizing the double suction pump in case of utilizing inducer.

Moreover, if it's achievable, this will added more cost to the principally highly expensive double suction type. so for achieving more flow without going for such complications may you utilize another pump set in parallel.

Mohd Yaseen

 

[Steven_Wu]

Hi All

Thanks for all your replies and feed back.

Hi 1gibson

Consider the space limitation in vessel, I doubt VS6, i.e. multistage pump is a good solution.

Hi MohdYaseen2010
if mounting two inducer at both side, axial thrust can be counterbalanced. But as most you mentioned ,maybe the biggest challenge is the complex of hydraulic layout and pump casing structure.

 

[Artisi]

Why would axial thrust be eliminated? It's moot point anyway as it can't be done?

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.)

 

[Steven_Wu]

Hi Artisi
Mounting two inducer back to back can theoretically counterbalance the axial thrust generated by inducers. Beside, double suction impeller is also regarded as a "non axial thrust" rotor in theory. but due to manufacture deviation, maybe a little rest thrust exists.

Therefore, the axial force on shaft only contains weight of rotating parts, and suction pressure on shaft end.

 

[Artisi]

You have answered your own question, double suction pumps are already counterbalanced plus manufacturing deviations apply irrespective of impeller design.

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.)