Question

4. A centrifugal pump has the following pressure - capacity characteristics: 500 495 490 | 480465 455420 395 360 325285 Pressure (kPa) 75 100125150175200 225250 Сарасity (m' , 25 50 It is planned to use this for a process having the following system characteristic: 350 370 400 435 465 505545 595660 725 |800 Pressure (kPa) 75 100 125 150175200225250 Сарасiry (m? 1-1) 25 50 (a) Determine the operating point for this pump with this system. (b) The actual flowrate required by the process is 50 m3 h-1. If the overall efficiency of the pump at this flowrate is 70%, determine the power consumed when the liquid being pumped has a density of 1200 kg m3. (c) A second pump is available which has the following characteristics: 400395 390380370 360 345 320305280 255 Pressure (kPa) 75 100 125150175200225250 Сарасity (m' n) 25 50 For the same flowrate (50 m3 h-1), this pump has an overall efficiency of 80%. (i) Determine the power used by this pump at a flowrate of 50 m3 h-1 Would it be a better choice? Give reasons for your answer. (ii) e a final choice si (iii) What other factors should be made?

Answer 1

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