A centrifugal pump has the following pressure - capacitycharacteristics:
| Pressure (KPa) | 500 | 495 | 490 | 480 | 465 | 455 | 420 | 395 | 360 | 325 | 285 |
| Capacity (m3h-1) | 0 | 25 | 50 | 75 | 100 | 125 | 150 | 175 | 200 | 225 | 250 |
It is planned to use this for a process having the followingsystem characteristic:
| Pressure (KPa) | 350 | 370 | 400 | 435 | 465 | 505 | 545 | 595 | 660 | 725 | 800 |
| Capacity (m3h-1) | 0 | 25 | 50 | 75 | 100 | 125 | 150 | 175 | 200 | 225 | 250 |
(a) Determine the operating point for this pump with thissystem.
(b) The actual flowrate required by the process is 75m3h –1 . If the overall efficiency of thepump at this flowrate is 70%, determine the power consumed when theliquid being pumped has a density of 1250 kgm–3 .
(c) A second pump is available which has the followingcharacteristics:
| Pressure (KPa) | 400 | 395 | 390 | 380 | 370 | 360 | 345 | 320 | 305 | 280 | 255 |
| Capacity (m3h-1) | 0 | 25 | 50 | 75 | 100 | 125 | 150 | 175 | 200 | 225 | 250 |
For the same flowrate (75 m3h –1 ), thispump has an overall efficiency of 75%.
(i) Determine the power used by this pump at a flowrate of 75m3h –1 .
(ii) Would it be a better choice? Give reasons for youranswer.
(iii) What other factors should be considered before a finalchoice is made?
Please can you write clearly as sometime i struggle to read whathas been put and please can you be very detailed (put why youcancel something out, where a figure came from that wasnt providedetc) as i have seen a similar question answered with 5 differentanswers and none of them are the answers from an equation that theygive.
