1 reply to this topic

[deltaChe]

I found an article discuess about the centerfugal pump with recycle flow.
But I don't quite understand that, and also attached the paragrah of the article
that I don't understand in this thread.
When we included the recycle flow in the pump head curve,
the pump curve and pipe system curve will rotate clockwise (on fig 1-4 in the attached file)

But the rate flow drop from 120 to about 70, and it doesn't make any sense to me
because seems the rate flow should increase after we counted the recycle flow in.

Could any one help me out in this case?

Thank you very much.

Attached Files

•  recycle flow question.doc   86KB   50 downloads

[Qalander (Chem)]

I found an article discuess about the centerfugal pump with recycle flow.
But I don't quite understand that, and also attached the paragrah of the article
that I don't understand in this thread.
When we included the recycle flow in the pump head curve,
the pump curve and pipe system curve will rotate clockwise (on fig 1-4 in the attached file)

But the rate flow drop from 120 to about 70, and it doesn't make any sense to me
because seems the rate flow should increase after we counted the recycle flow in.

Could any one help me out in this case?

Thank you very much.

Dear hswang2 Hello/Good Evening,

Normally for Energy Efficient Operation of any Centrifugal pump the recycling is not a desirable option,but it might be

• process need or
• the downstream pipeline system need

Further in the query, referred attached image;it is clearly evident that

• while recycling a large %ge of possible flow rate gets back into suction/elsewhere with almost Negligible pressure in the stream. (A highly in-efficient operation)
• Normally such pumps are preferred to be operated at or closed to their
• "B.E.P." (or Best Efficiency Point) to be a feasible operation.

Accordingly such huge recycle has to be most usually avoided,except for temporary instances of short duration in any process scheme.

Hope this proves somewhat useful and helping to make you understand centrifugal pump's operation.