Parallel condition - Centrifugal pump
Parallel condition - Centrifugal pump
(OP)
Hi everybody!
Here I have a pump that will operate in a parallel condition in its discharge, but I don't know how add their respective curves B-C and B-D, please see attached file. The pump will operate with flow 100 m3/h, but 25 m3/h in B-C and 75 m3/h in B-D.
Who can help me?
I've already done the calculation for suction and for A-B.
If you need any additional information please let me know!
Tks a lot!
Here I have a pump that will operate in a parallel condition in its discharge, but I don't know how add their respective curves B-C and B-D, please see attached file. The pump will operate with flow 100 m3/h, but 25 m3/h in B-C and 75 m3/h in B-D.
Who can help me?
I've already done the calculation for suction and for A-B.
If you need any additional information please let me know!
Tks a lot!





RE: Parallel condition - Centrifugal pump
For information, each part has a control valve, i.e., a control valve in B-C and another control valve in B-D, if it'll be necessary change system curves to get parallel condition curve "B-C + B-D".
regards
RE: Parallel condition - Centrifugal pump
what does the pump curve look like?
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Parallel condition - Centrifugal pump
Plus a search in Eng-Tips and the internet will turn up more info than you can handle regarding parallel pumping. A bit of self education does wonders for learning.
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.)
RE: Parallel condition - Centrifugal pump
The 2 system curve are too flat and with different static head. You will not get any flow in B-C until the system curve for B-D is more than 26 meter.
You need to increase the losses in the B-D branch by throttling or add a RO.
1) Tabulate the pump QH curve at the discharge point A.
2) Tabulate the system curve losses between A-B.
3) Table 1- table 2 will give you the available head of the pump at point B.
To plot the over all system curve from A to C + D, you add the flow rates of the 2 curves at the same head.
It is not possible in you case.
Plot the curve from table 3 onto the curve sheet and the intersections will give you the flow rate through each branch.